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Everything posted by Windspeed

  1. 000 WTNT64 KNHC 041250 TCUAT4 Tropical Storm Isaias Tropical Cyclone Update NWS National Hurricane Center Miami FL AL092020 900 AM EDT Tue Aug 4 2020 ...900 AM EDT POSITION UPDATE... ...STRONG WINDS...HEAVY RAINFALL...AND TORNADOES OCCURRING OVER EASTERN MARYLAND AND THE DELMARVA PENINSULA WILL SPREAD NORTHWARD ALONG THE MID-ATLANTIC COAST TODAY... A NOAA NOS/COOPS weather station at York River East, Virginia, recently reported a sustained wind of 59 mph (94 km/h) and a gust to 94 mph (150 km/h). Another NOAA NOS/COOPS weather station at Rappahannock Shoal, Virginia, recently reported a sustained wind of 53 mph (85 km/h) and a gust to 85 mph (135 km/h). SUMMARY OF 900 AM EDT...1300 UTC...INFORMATION ----------------------------------------------- LOCATION...38.2N 76.6W ABOUT 5 MI...10 KM SSW OF WILDEWOOD MARYLAND ABOUT 50 MI...80 KM S OF ANNAPOLIS MARYLAND MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NNE OR 25 DEGREES AT 33 MPH...54 KM/H MINIMUM CENTRAL PRESSURE...993 MB...29.32 INCHES $$ Forecaster Stewart/Roberts
  2. Significant surge coming into Oak Island.
  3. DBZ increasing in the NE eyewall band where the strongest winds are occurring. This may mix down some of those strong winds just below 950 hPa as that feature moves over the coastline.
  4. Might be. ECMWF op still over does gusts at 10 meters, but even some logical reduction would still be strong enough to produce major tree damage, force widespread outages with some structural failures.
  5. This has some kind of baroclinic induced feature occurring. Crazy southerly jet on the eastern side. Unfortunately with strong convective cells with mesos, that is going to mix down in gusts up the NC coastline.
  6. We're probably within 7-9 hours from landfall at this rate of motion based on estimated center; though due to angle of coastline, the western eyewall will be over the shoreline a few hours prior to official landfall. That is unless it tightens/shrinks considerably in the next 3-4 hours:
  7. Short but nice article by NOAA about tropical cyclone scientist, Isaac Monroe: Isaac Monroe Cline: The Cyclone Pioneer
  8. Unless a sting jet develops, which is possible considering it will undergo transition with trough interaction and possible baroclinic forcing near there. Otherwise, yes, the ECMWF does overdo wind maps. Strong 850 hPa flow would need intense convection to mix down without the jet.
  9. I mentioned earlier that I didn't expect Isaias to reacquire hurricane intensity. I may have been premature on that call. lol... As has been the case with this TC, just when it looks like it's finally swinging one way or the other, it does the opposite. Last night for example when it attempted a nice core only for it to get squashed. Then this morning during a long period of looking horribly disorganized. It's difficult to make a call to begin with. That being said, the experts at the NHC remained confident it would get its act together. Atmospheric dynamics are improving. There is still dry air in the mid levels to its SW, but as Isaias is taking on a more NNE course heading, the ability for mid-level flow to advect stable Theta-E off the SECONUS becomes harder. Also upper level divergence is becoming established with ~200 hPA flow now increasing poleward, thanks to trough interaction, which should help to vent convection. Aside from shear, it's still there, just decreasing to ~12-15 kts, which is low enough to be mitigated by the TC's mid level vortex, decreasing any angle of tilt for a potential eyeband; therefore, if a core is going to consolidate and stack, the next 12 hours is going to be the best time to see this potential through.
  10. It's definitely an improved look versus even just a few hours ago.
  11. Both the GFS and ECMWF, including their ensembles are quiet the next 10 days for TCG across the Atlantic Basin. The Euro op does hint at MDR development next week but we appear to be entering a break in activity. Not necessarily unwarranted. July was a busy month despite no TC getting especially intense. A climatological sharp rise in activity begins around the 19th. Most signals are still strong for a very active CV stretch of the season beginning in a few weeks and likely remaining that way through October. While we still have landfall and ECONUS impacts by Isaias to deal within the next 24 hours, after everything settles, enjoy the break.
  12. With the complete breakdown of the core it was attempting to form last night and the broader nature of the circulation center now, I no longer expect a hurricane at landfall. I may certainly be wrong, however, but given that environmental factors are still not the greatest, even if improved, Isaias picked a bad time to broaden the base of its vortex. It's going to take some impressive focused multi-convective systems in the mid levels to tighten this mess up. Now it's more a matter of time. That all being said, this is still a formidable TS and with trough interaction and baroclinic forcing, will likely have significant downstream impacts such as power disruptions, uprooted trees and enhanced convergence for flooding rainfall amounts well up into the Mid-Atlantic and New England.
  13. LLC to MLC is still tilted to the upper right. It will continue to be until the lower steering column becomes more southerly. Granted, this is going to occur, but let's not jump the gun here. Strong convective banding is trying to wrap upshear, but we still do not have a "core" aligned vortex and will not until the steering column changes and or shear decreases.
  14. Well can't fault Isaias for a lack of trying. Continues to attempt to wrap strong mid level banding upshear. Note the LLC position versus the strong northern "eyeband" feature trying..
  15. The lines are isometric meaning they are demarcations of equal measurement. In this case in intervals of 5 units in knots. Green means more favorable. Yellow means marginal. Red is unfavorable/hostile. The reason shear is lower north of Isaias is because low level steering flow is more aligned with mid and upper flow.