Jump to content

arlwx

Members
  • Content count

    590
  • Joined

  • Last visited

About arlwx

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. arlwx

    October Discobs Thread

    LWX now including that 4-letter word in their Saturday/Sunday forecast. (snip)Friday into Saturday, the upper level ridge to the north will start to break down as a upper level trough builds into the Tennessee River Valley and the Smokey Mountains. A broad upper level trough will be positioned over eastern Canada and northern Maine. The upper level trough over Tennessee and Kentucky is forecast to broaden and expand further southward into Mississippi and Alabama. This will lead to a tapping of the warm and moist air from the Gulf Mexico. The models are pointing to a low pressure system forming over the Gulf of Mexico on Thursday and moving east to northeastward toward Florida and Georgia early on Friday. This low pressure system is expected to get caught up on the east side of the upper level trough and move northward along the eastern sea board. Both the 00Z GFS and Euro agree that a coastal storm will form and move northward along the east coast. The GFS takes the upper level trough and kicks it eastward forcing the coastal storm further off the coast while the Euro keep the trough further inland over Arkansas and Tennessee. The Euro is wetter and faster than the GFS. The Euro brings the coastal storm northward and moves precipitation into our region by 18Z (2pm) on Friday. The GFS brings the outer bands of precipitation into the region around 6Z (2am) Saturday morning and remains further off the coast leading to lesser rain event. Both models agree that some semblances of precipitation will likely occur on Saturday with there being a chance for precipitation starting sometime late Friday afternoon into evening. The 1000 to 500mb thicknesses seem to indicate that this weather event should be mainly a rain event with some snow potential late Saturday into Sunday for the higher elevation areas. A slight warm up will occur Friday into Saturday as winds become more southerly. Sunday, the coastal storm will shift further northeastward out of our area. Some lingerings rain and snow showers over the higher elevations will be possible on Sunday. The GFS tries to bring a secondary cold front Sunday afternoon while the Euro tries to keep this boundary mainly dry.(snip)
  2. arlwx

    October Discobs Thread

    Update: IAD hit 31 at 3 am.
  3. arlwx

    October Discobs Thread

    More freeze warnings towards Richmond. URGENT - WEATHER MESSAGE National Weather Service Wakefield VA 813 PM EDT Sun Oct 21 2018 VAZ048-062-064-509>511-220815- /O.CON.KAKQ.FZ.W.0003.181022T0600Z-181022T1200Z/ Fluvanna-Goochland-Caroline-Western Louisa-Eastern Louisa- Western Hanover- Including the cities of Goochland, Louisa, Mineral, and Ashland 813 PM EDT Sun Oct 21 2018 ...FREEZE WARNING REMAINS IN EFFECT FROM 2 AM TO 8 AM EDT MONDAY... * AREAS AFFECTED: Parts of Central Virginia northwest of Richmond. * HAZARDS: Freezing Temperatures. * TEMPERATURES: Lower 30s. * TIMING: Early Monday morning. * IMPACTS: Crops and other sensitive vegetation may be killed if left exposed. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Freeze Warning means sub-freezing temperatures are imminent or highly likely. These conditions will kill crops and other sensitive vegetation.
  4. arlwx

    October Discobs Thread

    2 am temps: DCA 43 BWI 36 IAD 34 RIC 37
  5. arlwx

    2018 Mid-Atlantic First Freeze Contest

    LWX note about where yesterday's freeze was: PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1021 AM EDT FRI OCT 19 2018 ...GROWING SEASON ENDED FOR PORTIONS OF WESTERN MARYLAND, EASTERN WEST VIRGINIA, THE NORTHERN SHENANDOAH VALLEY AND NORTHWESTERN VIRGINIA... WIDESPREAD SUB-FREEZING TEMPERATURES WERE OBSERVED THIS MORNING ACROSS PORTIONS OF WESTERN MARYLAND, EASTERN WEST VIRGINIA, THE NORTHERN SHENANDOAH VALLEY AND NORTHWESTERN VIRGINIA. THEREFORE, THE GROWING SEASON HAS ENDED, AND FROST AND FREEZE HEADLINES WILL NO LONGER BE ISSUED THIS YEAR FOR THE FOLLOWING COUNTIES: EASTERN AND WESTERN ALLEGANY COUNTY MD CLARKE COUNTY VA EASTERN AND WESTERN HIGHLAND COUNTY VA FREDERICK COUNTY VA PAGE COUNTY VA ROCKINGHAM COUNTY VA SHENANDOAH COUNTY VA WARREN COUNTY VA BERKELEY COUNTY WV EASTERN AND WESTERN GRANT COUNTY WV EASTERN AND WESTERN MINERAL COUNTY WV EASTERN AND WESTERN PENDLETON COUNTY WV HAMPSHIRE COUNTY WV HARDY COUNTY WV JEFFERSON COUNTY WV MORGAN COUNTY WV $$
  6. arlwx

    Winter 2018-19 Is Coming

    For what it's worth, LWX is featuring a link to their winter weather page. Featuring a chance for flakes in the Monterey VA area through Sunday morning.
  7. arlwx

    October Discobs Thread

    2 am roundup: DCA 45 BWI 38 IAD 38 RIC 42
  8. arlwx

    2018 Atlantic Hurricane Season Tracking Thread

    SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...29.0N 86.3W ABOUT 90 MI...145 KM SW OF PANAMA CITY FLORIDA ABOUT 90 MI...145 KM WSW OF APALACHICOLA FLORIDA MAXIMUM SUSTAINED WINDS...145 MPH...230 KM/H PRESENT MOVEMENT...N OR 10 DEGREES AT 13 MPH...20 KM/H MINIMUM CENTRAL PRESSURE...933 MB...27.55 INCHES
  9. arlwx

    2018 Atlantic Hurricane Season Tracking Thread

    Now CAT 2 Hurricane Michael Intermediate Advisory Number 11A NWS National Hurricane Center Miami FL AL142018 700 AM CDT Tue Oct 09 2018 ...MICHAEL STRENGTHENING WHILE MOVING NORTH-NORTHWESTWARD OVER THE SOUTHEASTERN GULF OF MEXICO... ...LIFE-THREATENING STORM SURGE...HURRICANE FORCE WINDS...AND HEAVY RAINFALL EXPECTED ALONG THE NORTHEASTERN GULF COAST... SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...24.5N 86.1W ABOUT 395 MI...635 KM S OF PANAMA CITY FLORIDA ABOUT 365 MI...590 KM S OF APALACHICOLA FLORIDA MAXIMUM SUSTAINED WINDS...100 MPH...155 KM/H PRESENT MOVEMENT...NNW OR 345 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...968 MB...28.58 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Warning for the Cuban province of Pinar del Rio has been discontinued. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Okaloosa/Walton County Line Florida to Anclote River Florida A Storm Surge Watch is in effect for... * Anclote River Florida to Anna Maria Island Florida, including Tampa Bay * Alabama/Florida border to Okaloosa/Walton County Line Florida A Hurricane Warning is in effect for... * Alabama/Florida border to Suwannee River Florida A Hurricane Watch is in effect for... * Alabama/Florida border to the Mississippi/Alabama border A Tropical Storm Warning is in effect for... * Alabama/Florida border to the Mississippi/Alabama border * Suwanee River Florida to Chassahowitzka Florida A Tropical Storm Watch is in effect for... * Chassahowitzka to Anna Maria Island Florida, including Tampa Bay * Mississippi/Alabama border to the Mouth of the Pearl River * Fernandina Beach Florida to South Santee River South Carolina A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm- force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Interests elsewhere across the southeastern United States should monitor the progress of Michael. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. DISCUSSION AND OUTLOOK ---------------------- At 700 AM CDT (1200 UTC), the eye of Hurricane Michael was located near latitude 24.5 North, longitude 86.1 West. Michael is moving toward the north-northwest near 12 mph (19 km/h). A north- northwestward to northward motion is expected through tonight, followed by a northeastward motion on Wednesday and Thursday. On the forecast track, the center of Michael will move across the eastern Gulf of Mexico through tonight. The center of Michael is expected to move inland over the Florida Panhandle or Florida Big Bend area on Wednesday, and then move northeastward across the southeastern United States Wednesday night and Thursday. Data from a NOAA Hurricane Hunter aircraft indicate that the maximum sustained winds have increased to near 100 mph (155 km/h) with higher gusts. Additional strengthening is expected, and Michael is forecast to be a major hurricane at landfall in Florida. Weakening is expected after landfall as Michael moves through the southeastern United States. Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 195 miles (315 km). NOAA buoy 42003 recently reported 1-minute mean winds of 47 mph (76 km/h) and a wind gust of 54 mph (87 km/h). The latest minimum central pressure reported by the NOAA aircraft is 968 mb (28.58 inches). HAZARDS AFFECTING LAND ---------------------- STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water has the potential to reach the following heights above ground if peak surge occurs at the time of high tide... Indian Pass FL to Cedar Key FL...8-12 ft Cedar Key FL to Crystal River FL...6-8 ft Okaloosa/Walton County Line FL to Indian Pass FL...6-9 ft Crystal River FL to Anclote River FL...4-6 ft Anclote River to Anna Maria Island FL including Tampa Bay...2-4 ft Alabama/Florida border to Okaloosa/Walton County Line FL...2-4 ft WIND: Hurricane conditions are expected within the hurricane warning area along the U.S. Gulf Coast by Wednesday, with tropical storm conditions expected by tonight or early Wednesday. Hurricane conditions will also spread well inland across portions of the Florida Panhandle, southeastern Alabama and southwestern Georgia. Tropical storm conditions are expected in the tropical storm warning area by tonight or early Wednesday, and are possible within the tropical storm watch area by that time. Hurricane conditions are possible within the hurricane watch area by Wednesday. Tropical storm conditions are possible in the watch area along the southeast U.S. coast Wednesday night and Thursday. RAINFALL: Michael is expected to produce the following rainfall amounts through Friday... Western Cuba...4 to 8 inches, with isolated maximum amounts of 12 inches. This rainfall could lead to life-threatening flash floods and mudslides. Florida Panhandle and Big Bend, southeast Alabama, and southern Georgia...4 to 8 inches, with isolated maximum amounts of 12 inches. This rainfall could lead to life threatening flash floods. Eastern Georgia, the Carolinas, and southern Virginia...3 to 6 inches. This rainfall could lead to life-threatening flash floods. Florida Peninsula, eastern Mid Atlantic, southern New England coast...1-3 inches. SURF: Swells generated by Michael are beginning to affect the coasts of the eastern and northern Gulf of Mexico. These swells will spread to portions of the northwestern and western Gulf of Mexico coast during the next day or so. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. TORNADOES: The threat for tornadoes will increase late tonight into Wednesday over parts of the Florida Panhandle, the northern Florida Peninsula, and southern Georgia. NEXT ADVISORY ------------- Next complete advisory at 1000 AM CDT.
  10. arlwx

    2018 Atlantic Hurricane Season Tracking Thread

    As of 5 pm, the models appear to have diverged into two camps. Most of them take Michael out over the Virginia Capes around Thursday evening. A few want to hit Pax River and OC. But that is as close as stormlovers will get (in current models) to anything coming up towards DC.
  11. arlwx

    Hurricane Michael

    Tropical Storm Michael Discussion Number 7 NWS National Hurricane Center Miami FL AL142018 400 AM CDT Mon Oct 08 2018 Michael has become better organized this morning, with the deep convection migrating westward on top of the low-level center and upper-level outflow beginning to increase within the western semicircle. An Air Force Reserve Hurricane Hunter aircraft made several passes through the system during the past few hours, and somewhat surprisingly, found that the central pressure has fallen to about 983 mb and maximum winds have increased to near 60 kt. This increase in intensity indicates that despite the shear which has been affecting Michael, the system has, by definition, rapidly intensified during the past 24 hours. With the increase in the initial wind speeds, the official intensity forecast is higher than in the previous forecast. Decreasing vertical shear and very warm sea surface temperatures are expected to support continued strengthening, and due to the favorable conditions, the NHC intensity forecast follows a blend of the IVCN consensus and the HCCA model. This new official forecast brings the intensity to just below major hurricane strength in 48 hours, and since the storm will still be over water for a time between 48 and 72 hours, there is a real possibility that Michael will strengthen to a major hurricane before landfall. Weakening is expected after landfall, but the system will likely maintain tropical storm strength after day 4 when it moves off the east coast of the United States. Michael should then become an extratropical low by day 5. The reconnaissance fixes indicate that Michael's center is moving northward, or 360 degrees at 6 kt. A general northward motion with some increase in forward speed is expected during the next 48 hours as Michael enters the southerly flow between high pressure over the western Atlantic and a deep-layer trough over the western and central United States. After 48 hours, Michael is expected to turn northeastward toward and across the southeastern United States, exiting over the western Atlantic between days 4 and 5. Nearly all of the track models have shifted westward after 24 hours, which left the previous forecast near the eastern edge of the guidance envelope. Due to this shift, the new NHC track forecast has also been adjusted westward close to the consensus aids. Overall the track guidance is in fairly good agreement up until landfall along the Florida Panhandle or Florida Big Bend, which has yielded a fairly confident track forecast. Key Messages: 1. Hurricane conditions are expected over portions of western Cuba, where a hurricane warning is now in effect. Tropical storm conditions are expected over the northeastern Yucatan Peninsula and the Isle of Youth today. 2. Michael is expected to produce heavy rainfall and flash flooding over portions of western Cuba and the northeastern Yucatan Peninsula of Mexico during the next couple of days. 3. Michael is forecast to be a hurricane, and possibly a major hurricane, when it reaches the northeastern Gulf Coast by mid-week, and storm surge and hurricane watches are now in effect for portions of the area. Some areas along the Florida Gulf Coast are especially vulnerable to storm surge, regardless of the storm's exact track or intensity. Residents in the watch areas should monitor the progress of this system and follow any advice given by local officials. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 20.6N 85.5W 60 KT 70 MPH 12H 08/1800Z 21.7N 85.6W 70 KT 80 MPH 24H 09/0600Z 23.5N 86.1W 85 KT 100 MPH 36H 09/1800Z 25.2N 86.7W 90 KT 105 MPH 48H 10/0600Z 27.2N 86.7W 95 KT 110 MPH 72H 11/0600Z 31.2N 84.5W 55 KT 65 MPH...INLAND 96H 12/0600Z 35.5N 77.5W 50 KT 60 MPH...INLAND 120H 13/0600Z 40.5N 64.5W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Berg
  12. arlwx

    2018 Atlantic Hurricane Season Tracking Thread

    Tropical Storm Michael Discussion Number 7 NWS National Hurricane Center Miami FL AL142018 400 AM CDT Mon Oct 08 2018 Michael has become better organized this morning, with the deep convection migrating westward on top of the low-level center and upper-level outflow beginning to increase within the western semicircle. An Air Force Reserve Hurricane Hunter aircraft made several passes through the system during the past few hours, and somewhat surprisingly, found that the central pressure has fallen to about 983 mb and maximum winds have increased to near 60 kt. This increase in intensity indicates that despite the shear which has been affecting Michael, the system has, by definition, rapidly intensified during the past 24 hours. With the increase in the initial wind speeds, the official intensity forecast is higher than in the previous forecast. Decreasing vertical shear and very warm sea surface temperatures are expected to support continued strengthening, and due to the favorable conditions, the NHC intensity forecast follows a blend of the IVCN consensus and the HCCA model. This new official forecast brings the intensity to just below major hurricane strength in 48 hours, and since the storm will still be over water for a time between 48 and 72 hours, there is a real possibility that Michael will strengthen to a major hurricane before landfall. Weakening is expected after landfall, but the system will likely maintain tropical storm strength after day 4 when it moves off the east coast of the United States. Michael should then become an extratropical low by day 5. The reconnaissance fixes indicate that Michael's center is moving northward, or 360 degrees at 6 kt. A general northward motion with some increase in forward speed is expected during the next 48 hours as Michael enters the southerly flow between high pressure over the western Atlantic and a deep-layer trough over the western and central United States. After 48 hours, Michael is expected to turn northeastward toward and across the southeastern United States, exiting over the western Atlantic between days 4 and 5. Nearly all of the track models have shifted westward after 24 hours, which left the previous forecast near the eastern edge of the guidance envelope. Due to this shift, the new NHC track forecast has also been adjusted westward close to the consensus aids. Overall the track guidance is in fairly good agreement up until landfall along the Florida Panhandle or Florida Big Bend, which has yielded a fairly confident track forecast. Key Messages: 1. Hurricane conditions are expected over portions of western Cuba, where a hurricane warning is now in effect. Tropical storm conditions are expected over the northeastern Yucatan Peninsula and the Isle of Youth today. 2. Michael is expected to produce heavy rainfall and flash flooding over portions of western Cuba and the northeastern Yucatan Peninsula of Mexico during the next couple of days. 3. Michael is forecast to be a hurricane, and possibly a major hurricane, when it reaches the northeastern Gulf Coast by mid-week, and storm surge and hurricane watches are now in effect for portions of the area. Some areas along the Florida Gulf Coast are especially vulnerable to storm surge, regardless of the storm's exact track or intensity. Residents in the watch areas should monitor the progress of this system and follow any advice given by local officials. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 20.6N 85.5W 60 KT 70 MPH 12H 08/1800Z 21.7N 85.6W 70 KT 80 MPH 24H 09/0600Z 23.5N 86.1W 85 KT 100 MPH 36H 09/1800Z 25.2N 86.7W 90 KT 105 MPH 48H 10/0600Z 27.2N 86.7W 95 KT 110 MPH 72H 11/0600Z 31.2N 84.5W 55 KT 65 MPH...INLAND 96H 12/0600Z 35.5N 77.5W 50 KT 60 MPH...INLAND 120H 13/0600Z 40.5N 64.5W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Berg
  13. arlwx

    September Discobs Thread

    New flood warning: Flood Warning National Weather Service Baltimore MD/Washington DC 458 AM EDT FRI SEP 28 2018 VAC059-061-153-683-685-281300- /O.NEW.KLWX.FA.W.0390.180928T0858Z-180928T1300Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Fairfax VA-Fauquier VA-City of Manassas Park VA-Prince William VA- City of Manassas VA- 458 AM EDT FRI SEP 28 2018 The National Weather Service in Sterling Virginia has issued a * Flood Warning for... Central Fairfax County in northern Virginia... East central Fauquier County in northern Virginia... The City of Manassas Park in northern Virginia... Central Prince William County in northern Virginia... The City of Manassas in northern Virginia... * Until 900 AM EDT. * At 455 AM EDT, automated stream gauges were reporting flooding of streams and some low lying areas. One to two inches of heavy rain overnight is driving stream rises.
  14. arlwx

    September Discobs Thread

    New flood watch up, as well as the previous flood warnings: Flood Watch National Weather Service Baltimore MD/Washington DC 239 AM EDT Thu Sep 27 2018 DCZ001-MDZ005-503>506-VAZ036>039-050>055-502-506-508-271445- /O.NEW.KLWX.FA.A.0006.180927T2200Z-180928T0800Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ District of Columbia-Carroll-Northwest Montgomery- Central and Southeast Montgomery-Northwest Howard- Central and Southeast Howard-Nelson-Albemarle-Greene-Madison- Orange-Culpeper-Prince William/Manassas/Manassas Park-Fairfax- Arlington/Falls Church/Alexandria-Stafford-Southern Fauquier- Eastern Loudoun-Central Virginia Blue Ridge- Including the cities of Washington, Eldersburg, Westminster, Germantown, Damascus, Bethesda, Rockville, Gaithersburg, Silver Spring, Lisbon, Columbia, Ellicott City, Lovingston, Charlottesville, Stanardsville, Madison, Orange, Gordonsville, Culpeper, Dale City, Manassas, Woodbridge, Lake Ridge, Montclair, Reston, Herndon, Annandale, Centreville, Chantilly, McLean, Franconia, Arlington, Alexandria, Falls Church, Falmouth, Turnbull, Leesburg, Ashburn, Sterling, and Wintergreen 239 AM EDT Thu Sep 27 2018 ...FLOOD WATCH IN EFFECT FROM THIS EVENING THROUGH LATE TONIGHT... The National Weather Service in Sterling Virginia has issued a * Flood Watch for portions of Maryland, The District of Columbia, and Virginia, including the following areas, in Maryland, Carroll, Central and Southeast Howard, Central and Southeast Montgomery, Northwest Howard, and Northwest Montgomery. The District of Columbia. In Virginia, Albemarle, Arlington/Falls Church/Alexandria, Central Virginia Blue Ridge, Culpeper, Eastern Loudoun, Fairfax, Greene, Madison, Nelson, Orange, Prince William/Manassas/Manassas Park, Southern Fauquier, and Stafford. * From this evening through late tonight * A wave of low pressure will ride northeast along a stalled front later today and tonight. Several inches of rain is possible, and with the ground already saturated, flooding is possible.
  15. arlwx

    2018 Atlantic Hurricane Season Tracking Thread

    Hurricane Florence Advisory Number 52 NWS National Hurricane Center Miami FL AL062018 500 AM EDT Wed Sep 12 2018 ...DANGEROUS FLORENCE HEADING TOWARD THE U.S. EAST COAST... ...EXPECTED TO BRING LIFE-THREATENING STORM SURGE AND RAINFALL TO PORTIONS OF THE CAROLINAS AND MID-ATLANTIC STATES... SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...29.0N 70.1W ABOUT 575 MI...925 KM SE OF CAPE FEAR NORTH CAROLINA MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H PRESENT MOVEMENT...WNW OR 300 DEGREES AT 17 MPH...28 KM/H MINIMUM CENTRAL PRESSURE...946 MB...27.94 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Tropical Storm Warning has been issued from north of Duck North Carolina to the North Carolina-Virginia border. The Hurricane Watch for this area has been discontinued. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * South Santee River South Carolina to Duck North Carolina * Albemarle and Pamlico Sounds, including the Neuse and Pamlico Rivers A Storm Surge Watch is in effect for... * Edisto Beach South Carolina to South Santee River South Carolina * North of Duck North Carolina to the North Carolina/Virginia border A Hurricane Warning is in effect for... * South Santee River South Carolina to Duck North Carolina * Albemarle and Pamlico Sounds A Hurricane Watch is in effect for... * Edisto Beach South Carolina to South Santee River South Carolina A Tropical Storm Warning is in effect for... * North of Duck North Carolina to the North Carolina/Virginia border A Tropical Storm Watch is in effect for... * North of the North Carolina/Virginia border to Cape Charles Light Virginia * Chesapeake Bay south of New Point Comfort Interests elsewhere in the southeastern and mid-Atlantic states should monitor the progress of Florence. A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm- force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. DISCUSSION AND OUTLOOK ---------------------- At 500 AM EDT (0900 UTC), the center of Hurricane Florence was located near latitude 29.0 North, longitude 70.1 West. Florence is moving toward the west-northwest near 17 mph (28 km/h). A motion toward the west-northwest and northwest is expected through Thursday. Florence is expected to slow down considerably by late Thursday into Friday, and move through early Saturday. On the forecast track, the center of Florence will move over the southwestern Atlantic Ocean between Bermuda and the Bahamas today, and approach the coast of North Carolina or South Carolina in the hurricane warning area on Thursday and Friday. Maximum sustained winds are near 130 mph (215 km/h) with higher gusts. Florence is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Strengthening is forecast through tonight. While some weakening is expected on Thursday, Florence is forecast to be an extremely dangerous major hurricane when it nears the U.S. coast. Hurricane-force winds extend outward up to 70 miles (110 km) from the center and tropical-storm-force winds extend outward up to 175 miles (280 km). The estimated minimum central pressure is 946 mb (27.94 inches). HAZARDS AFFECTING LAND ---------------------- STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water has the potential to reach the following heights above ground if peak surge occurs at the time of high tide... Cape Fear to Cape Lookout, including the Neuse, Pamlico, Pungo, and Bay Rivers...9-13 ft North Myrtle Beach to Cape Fear...6-9 ft Cape Lookout to Ocracoke Inlet...6-9 ft South Santee River to North Myrtle Beach...4-6 ft Ocracoke Inlet to North Carolina/Virginia Border...4-6 ft Edisto Beach to South Santee River...2-4 ft The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and destructive waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office. RAINFALL: Florence is expected to produce heavy and excessive rainfall in the following areas... Coastal North Carolina...20 to 30 inches, isolated 40 inches South Carolina, western and northern North Carolina...5 to 10 inches, isolated 20 inches Elsewhere in the Appalachians and Mid-Atlantic states...3 to 6 inches, isolated 12 inches This rainfall would produce catastrophic flash flooding and significant river flooding. WIND: Hurricane conditions are expected to reach the coast within the hurricane warning area on Friday. Winds are expected to first reach tropical storm strength on Thursday, making outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. SURF: Swells generated by Florence are affecting Bermuda and portions of the U.S. East Coast. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 800 AM EDT. Next complete advisory at 1100 AM EDT. $$ Forecaster Brown Hurricane Florence Discussion Number 52 NWS National Hurricane Center Miami FL AL062018 500 AM EDT Wed Sep 12 2018 The eye of Florence remains very distinct in infrared satellite imagery this morning. There has been little change to the cloud top temperatures surrounding the eye overnight, however, the overall cloud shield and central dense overcast has become slightly more symmetric. An Air Force Reserve Hurricane Hunter aircraft that was in the hurricane until just after midnight measured a peak 700-mb flight-level wind of 130 kt, and a SFMR wind of 107 kt in the northeast eyewall. A blend of these data and recent subjective and objective satellite intensity estimates supports an initial wind speed of 115 kt. Florence will be moving over sea surface temperatures of around 29C and through an area of low vertical wind shear during the next day or so. These conditions favor some strengthening, but eyewall replacement cycles could cause some fluctuations in intensity during that time. After that time, an increase in southwesterly shear, upwelling, and interaction with land is likely to lead to some weakening, however, Florence is expected to remain a dangerous major hurricane as it approaches the coastline. The new NHC intensity forecast is near the higher statistical guidance through 48 hours, then follows the trend of the decay SHIPS model after that time. Florence is moving west-northwestward or 300 degrees at 15 kt. There has been no change to the track forecast or reasoning for the first 36-48 hours, as Florence will continue to be steered west-northwestward to northwestward around the southwestern portion of a mid-level ridge centered northeast of Bermuda. By late Thursday, a mid-level ridge is forecast to begin building over the east-central United States, which is expected to cause Florence to slow down significantly by 48 hours. The track guidance is in good agreement through the first couple of days of the forecast period, and the NHC track forecast again brings the center of the hurricane very close to the coasts of North and South Carolina within 48 hours. Later in the period, the dynamical model spread increases but most of the guidance has continued its southward shift, and now take Florence southwestward near the coast of South Carolina by day 4. The NHC track has been adjusted southward at days 4 and 5, and is a little north of the consensus out of respect for continuity, however, the GFS, ECMWF, and the ECMWF ensemble mean is south of the NHC track forecast, and additional southward adjustment may be warranted in future advisories. It is important for users to realize that significant impacts extend well away from the center of Florence, and serious hazards such as a dangerous storm surge and flooding rains will cover a large area regardless of exactly where the center moves. Key Messages: 1. A life-threatening storm surge is now highly likely along portions of the coastlines of South Carolina and North Carolina, and a Storm Surge Warning is in effect for a portion of this area. All interests from South Carolina into the mid-Atlantic region should complete preparations and follow any advice given by local officials. 2. Life-threatening, catastrophic flash flooding and significant river flooding is likely over portions of the Carolinas and Mid-Atlantic states from late this week into early next week, as Florence is expected to slow down as it approaches the coast and moves inland. 3. Damaging hurricane-force winds are likely along portions of the coasts of South Carolina and North Carolina, and a Hurricane Warning is in effect. Strong winds could also spread inland into portions of the Carolinas. 4. Large swells affecting Bermuda and portions of the U.S. East Coast will continue this week, resulting in life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 12/0900Z 29.0N 70.1W 115 KT 130 MPH 12H 12/1800Z 30.3N 72.1W 120 KT 140 MPH 24H 13/0600Z 32.0N 74.4W 125 KT 145 MPH 36H 13/1800Z 33.2N 76.1W 120 KT 140 MPH 48H 14/0600Z 33.8N 77.3W 105 KT 120 MPH...NEAR THE COAST 72H 15/0600Z 33.8N 78.2W 85 KT 100 MPH...NEAR THE COAST 96H 16/0600Z 33.6N 79.7W 45 KT 50 MPH...INLAND 120H 17/0600Z 34.2N 82.7W 25 KT 30 MPH...INLAND $$ Forecaster Brown
×