Jump to content

  • Member Statistics

    17,916
    Total Members
    7,904
    Most Online
    simbasad2
    Newest Member
    simbasad2
    Joined

Drought Buster From The Gulf?

dailylurker

By dailylurker,
in Mid Atlantic

 Share

Recommended Posts

yoda

yoda

Posted
Posted

Afternoon AFD from LWX makes it sound good 

The upper low will continue to slowly drift northeastward from
the Lower Mississippi Valley into the Tennessee Valley Monday
into Monday night. As this occurs, showers will gradually
overspread the area from southwest to northeast. As it stands
now, most guidance holds precipitation off in the DC Metro
until the late afternoon or early evening hours, with
precipitation not starting until after dark Monday night around
Baltimore. The rain may start to become steadier and moderate
to locally heavy at times by late Monday night, especially
across Central Virginia. By Monday night, model soundings show
deep, saturated profiles, with very limited instability and
precipitable water values closing in on 1.5 inches. The lack of
instability should limit rainfall rates somewhat, with most of
the rain falling as a steady, soaking rain as opposed to very
heavy downpours that you`d typically see with a summer
thunderstorm. Still, model guidance hints that rainfall totals
may reach around 1-2 inches across Central Virginia by daybreak
Tuesday, with more rain expected to fall Tuesday into at least
Wednesday (see long term discussion below).

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A highly amplified and blocky synoptic pattern sets up for a
majority of next week. The initial feature of interest is a slow
moving closed low which is currently spinning over the Deep South.
This deep and anomalous system is set to become more negatively-
tilted in time while crossing the Tennessee Valley on Tuesday.
Eventually this trough begins to evolve into more of an open wave as
it treks toward the Mid-Atlantic region by mid-week. The slow
forward motion of this particular system may not see the trough axis
pass by until Thursday morning. At this point, the associated
surface fronts exit into the coastal Atlantic as high pressure
briefly returns. Mid/upper heights begin to build in earnest by late
in the work week ahead of the next weather maker.

What is currently a strong upper trough off the West Coast will
undergo a complex evolution across the nation over the next several
days. As expected, a large array of spread is noted across the board
when evaluating all recent guidance. The overall pattern shift does
favor unsettled conditions on Friday into portions of next weekend.

Looking more closely at Tuesday into Wednesday, the mentioned closed
low will tap into anomalous Gulf moisture. Characterized by
anomalies around 1 to 1.5 standard deviations above normal, this
system will interact with strong dynamics with the upper low to
produce periods of moderate to heavy rainfall. Ensembles support
around 2 to 3 inches of rain during a 24 to 48 hour period.
Depending on how much of this falls at once, there will be some
flood threat that emerges. However, this will depend on location and
intensity of such showers.
  • Like 4
  • Thanks 1
Link to comment
Share on other sites
CAPE

CAPE

Posted
Posted
21 minutes ago, EastCoast NPZ said:

Can't wait to see how we get screwed again this time.

The last "event" was one of the biggest short term busts in recent memory. Forecast rainfall totals here before last minute adjustments as the event was unfolding: 1-1.5"

Total rainfall here: 0.05" :rolleyes:

Luckily prior events performed/overperformed and got my area out of the drought. Really need a solid inch of rain now though as it has gotten pretty dry again.

  • Like 2
Link to comment
Share on other sites
yoda

yoda

Posted
Posted

FFWs likely coming tomorrow  

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Monday will act as a day of transition ahead of a wet pattern
setting up through around mid-week. The mentioned upper low
swirling across the Deep South is part of a larger scale
blocking regime (Rex Block). As a deep upper trough swings into
the western U.S., this will help nudge the stalled downstream
upper low. As this feature gains latitude in time, so will its
immense moisture pool, strong jet forcing, and overall shift in
sensible weather. Its slow poleward movement will carry some
risk of flooding, particularly where upslope trajectories come
into play (i.e., the eastern slopes of the Blue Ridge
Mountains). Although the local area is in continued drought
conditions, forecast rainfall amounts are high enough to cause
some flooding concerns late Monday through at least Tuesday
night.

The latest forecast package calls for rain to arrive into the
Potomac Highlands and central Shenandoah Valley by Monday
morning. Amounts should initially be light, particularly in
light of initial dry boundary layer conditions which may cause
some evaporation to occur. However, eventual moistening of the
column is expected which will gradually increase overall
precipitation efficiency. The swath of showers is expected to
track northeastward in time before reaching the I-95 metros by
around the evening rush hour. Despite all of the increased cloud
cover, high temperatures should still reach the low/mid 70s,
with 60s more likely across the central Shenandoah Valley back
into the Alleghenies.

Conditions continue to deterioriate into the night with
southeasterly moist advection further increasing. This moisture
plume appears tied all the way down through the southern Gulf of
America into the western Caribbean. Characterized by
precipitable waters around 1.50 to 1.60 inches, this is easily
1.5 to 2 standard deviations above average for mid-May. Not
surprisingly, forecast rainfall amounts are quite high, but are
also variable due to uncertainies in the upper low track.

By Tuesday morning, the main upper low is expected to lift
across the Mid-South toward the southern Appalachians. The
surface reflection of this system weakens as the upper low
slowly begins to fill, but the quality of moisture remains
intact. Tuesday will offer plenty of rainfall with 6-hour totals
in the 0.25 to 0.50 inch range, locally higher toward the Blue
Ridge. Given how spread out this event occurs over, much of this
rain could prove to be beneficial in nature. However, this will
less likely be the case along and east of the Blue Ridge where
storm totals could be double the rest of the area. Current
forecast storm totals are around 1.50 to 2.00 inches, but with
2.50 to 4.00 inches in the mentioned mountainous locations.
While Flood Watches are not out yet, these will likely be
considered during subsequent shifts.
  • Like 2
Link to comment
Share on other sites
CAPE

CAPE

Posted
Posted
1 hour ago, yoda said:

FFWs likely coming tomorrow  

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Monday will act as a day of transition ahead of a wet pattern
setting up through around mid-week. The mentioned upper low
swirling across the Deep South is part of a larger scale
blocking regime (Rex Block). As a deep upper trough swings into
the western U.S., this will help nudge the stalled downstream
upper low. As this feature gains latitude in time, so will its
immense moisture pool, strong jet forcing, and overall shift in
sensible weather. Its slow poleward movement will carry some
risk of flooding, particularly where upslope trajectories come
into play (i.e., the eastern slopes of the Blue Ridge
Mountains). Although the local area is in continued drought
conditions, forecast rainfall amounts are high enough to cause
some flooding concerns late Monday through at least Tuesday
night.

The latest forecast package calls for rain to arrive into the
Potomac Highlands and central Shenandoah Valley by Monday
morning. Amounts should initially be light, particularly in
light of initial dry boundary layer conditions which may cause
some evaporation to occur. However, eventual moistening of the
column is expected which will gradually increase overall
precipitation efficiency. The swath of showers is expected to
track northeastward in time before reaching the I-95 metros by
around the evening rush hour. Despite all of the increased cloud
cover, high temperatures should still reach the low/mid 70s,
with 60s more likely across the central Shenandoah Valley back
into the Alleghenies.

Conditions continue to deterioriate into the night with
southeasterly moist advection further increasing. This moisture
plume appears tied all the way down through the southern Gulf of
America into the western Caribbean. Characterized by
precipitable waters around 1.50 to 1.60 inches, this is easily
1.5 to 2 standard deviations above average for mid-May. Not
surprisingly, forecast rainfall amounts are quite high, but are
also variable due to uncertainies in the upper low track.

By Tuesday morning, the main upper low is expected to lift
across the Mid-South toward the southern Appalachians. The
surface reflection of this system weakens as the upper low
slowly begins to fill, but the quality of moisture remains
intact. Tuesday will offer plenty of rainfall with 6-hour totals
in the 0.25 to 0.50 inch range, locally higher toward the Blue
Ridge. Given how spread out this event occurs over, much of this
rain could prove to be beneficial in nature. However, this will
less likely be the case along and east of the Blue Ridge where
storm totals could be double the rest of the area. Current
forecast storm totals are around 1.50 to 2.00 inches, but with
2.50 to 4.00 inches in the mentioned mountainous locations.
While Flood Watches are not out yet, these will likely be
considered during subsequent shifts.

Higher terrain to the west, esp upslope areas. Probably not in the metros.

12z Euro probably has the right idea.

LOL Gulf of America in a NWS AFD. Pathetic.

 

  • Like 6
Link to comment
Share on other sites
high risk

high risk

Posted
Posted
11 hours ago, CAPE said:

12z HRRR isn't bad and the globals depict areas to the east and NE getting some decent scraps beyond hour 60. All remains to be seen.

         Yeah, the CAMs this evening look more like the earlier globals with decent rains from the Bay to all points west.    Still not as good of a consistent signal for the Eastern Shore, but it does seem like even those areas should eventually do at least ok (later Tuesday into Wednesday??).

  • Like 2
Link to comment
Share on other sites
yoda

yoda

Posted
Posted
13 hours ago, CAPE said:

Higher terrain to the west, esp upslope areas. Probably not in the metros.

12z Euro probably has the right idea.

LOL Gulf of America in a NWS AFD. Pathetic.

 

Correct so far with your call re watches  

Flood Watch
National Weather Service Baltimore MD/Washington DC
310 AM EDT Mon May 12 2025

VAZ025>027-029-030-036>040-507-508-121515-
/O.NEW.KLWX.FA.A.0004.250513T0000Z-250514T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Augusta-Rockingham-Shenandoah-Page-Warren-Nelson-Albemarle-Greene-
Madison-Rappahannock-Northern Virginia Blue Ridge-Central
Virginia Blue Ridge-
310 AM EDT Mon May 12 2025

...FLOOD WATCH IN EFFECT FROM THIS EVENING THROUGH TUESDAY EVENING...

* WHAT...Flooding caused by excessive rainfall is possible.

* WHERE...Portions of central, northwest, and western Virginia,
  including the following areas, in central Virginia, Albemarle,
  Central Virginia Blue Ridge, Greene and Nelson. In northwest
  Virginia, Madison, Northern Virginia Blue Ridge, Page,
  Rappahannock, Shenandoah and Warren. In western Virginia, Augusta
  and Rockingham.

* WHEN...From this evening through Tuesday evening.

* IMPACTS...Excessive runoff may result in flooding of creeks,
  streams, and other low-lying and flood-prone locations. Low-water
  crossings may be flooded.

* ADDITIONAL DETAILS...
  - While showers will spread into the area today, a prolonged
    period of moderate to heavy rain with embedded thunderstorms
    is expected tonight into Tuesday. Rainfall amounts of 2 to 4
    inches are likely, with locally higher amounts possible along
    the eastern slopes of the Blue Ridge Mountains. This rainfall
    may lead to scattered instances of flooding.
  - Please visit www.weather.gov/safety/flood for flood safety
    and preparedness information.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood
Warnings. Those living in areas prone to flooding should be prepared
to take action should flooding develop.
 
  • Like 1
Link to comment
Share on other sites
aldie 22

aldie 22

Posted
Posted

My neighbor refuses to have his gutters cleaned even though we back up to woods. During the last rain event here the water was pouring over the gutters enough to cause a crater in his yard. If this next event comes in hot like it is looking I'd imagine a doomsday scenario for his pavers and foundation. GFS and Euro both have about 2.4" for MBY

  • Like 2
Link to comment
Share on other sites
Mrs.J

Mrs.J

Posted
Posted
58 minutes ago, aldie 22 said:

My neighbor refuses to have his gutters cleaned even though we back up to woods. During the last rain event here the water was pouring over the gutters enough to cause a crater in his yard. If this next event comes in hot like it is looking I'd imagine a doomsday scenario for his pavers and foundation. GFS and Euro both have about 2.4" for MBY

We got a cap system installed to help with backing up to a tree line. Although over the years I really think we should have gotten larger gutters than what the builder put on. In very heavy rains we still get run over due to the size of the gutter being too small. So I am going to pull my flower boxes out onto the deck so the dirt does not get pushed out of them. 

  • Like 1
Link to comment
Share on other sites
  • WxUSAF pinned this topic
yoda

yoda

Posted
Posted

Flood watch expanded northward and eastward 

Flood Watch
National Weather Service Baltimore MD/Washington DC
125 PM EDT Mon May 12 2025

MDZ501-502-510-VAZ028-031-050-051-053>056-501-502-505-506-526-527-
WVZ050>053-503-504-130130-
/O.EXB.KLWX.FA.A.0004.250513T1000Z-250514T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Extreme Western Allegany-Central and Eastern Allegany-Eastern
Garrett-Frederick VA-Clarke-Orange-Culpeper-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-Northern
Fauquier-Southern Fauquier-Western Loudoun-Eastern Loudoun-
Northwest Prince William-Central and Southeast Prince
William/Manassas/Manassas Park-Hampshire-Morgan-Berkeley-
Jefferson-Western Mineral-Eastern Mineral-
125 PM EDT Mon May 12 2025

...FLOOD WATCH IN EFFECT FROM TUESDAY MORNING THROUGH LATE TUESDAY
NIGHT...

* WHAT...Flooding caused by excessive rainfall continues to be
  possible.

* WHERE...Portions of western Maryland, including the following
  areas, Central and Eastern Allegany, Eastern Garrett and Extreme
  Western Allegany, Virginia, including the following areas,
  Arlington/Falls Church/Alexandria, Central and Southeast Prince
  William/Manassas/Manassas Park, Clarke, Culpeper, Eastern Loudoun,
  Fairfax, Frederick VA, Northern Fauquier, Northwest Prince
  William, Orange, Southern Fauquier, Spotsylvania, Stafford and
  Western Loudoun, and West Virginia, including the following areas,
  Berkeley, Eastern Mineral, Hampshire, Jefferson, Morgan and
  Western Mineral.

* WHEN...From Tuesday morning through late Tuesday night.

* IMPACTS...Excessive runoff may result in flooding of creeks,
  streams, and other low-lying and flood-prone locations. Low-water
  crossings may be flooded.


* ADDITIONAL DETAILS...
  - While showers will spread into the area today, a prolonged
    period of moderate to heavy rain with embedded thunderstorms
    is expected late tonight into Tuesday night. Rainfall amounts
    of 2 to 4 inches are likely, with locally higher amounts
    possible along the eastern slopes of the Blue Ridge Mountains
    and Alleghenies. This rainfall may lead to scattered
    instances of flooding.
  - Please visit www.weather.gov/safety/flood for flood safety
    and preparedness information

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood
Warnings. Those living in areas prone to flooding should be prepared
to take action should flooding develop.
 
  • Like 2
Link to comment
Share on other sites
arlwx12

arlwx12

Posted
Posted

The latest AFD from LWX: (bolding mine)
  

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
The aforementioned upper low will continue to drift
northeastward toward the area tomorrow, and will eventually
become centered overhead during the day on Wednesday. A steady
rain will continue through much of the morning tomorrow within
the zone of large scale ascent downstream of the approaching
upper low. As we work into the afternoon hours, a mid-level dry
slot may start to work in from the southwest, which may allow
for a few breaks of sun and some limited surface
heating/development of surface based instability. If this
occurs, thunderstorms may start to develop within the dry slot
and lift northward into the area during the late
afternoon/evening hours. These thunderstorms may be capable of
producing heavier rainfall rates, and may potentially lead to
some instances of flooding. The earlier issued Flood Watch was
expanded to include all of the WV Panhandle, most of Northern
Virginia, and Allegany County in Maryland. A general 2-4 inches
of rain is expected by late Tuesday night across the watch area,
with localized higher totals along the eastern facing slopes of
the Blue Ridge and Alleghenies, where upslope southeasterly flow
should enhance totals. Further north and east, rainfall totals
are expected to be slightly lower, but an instance or two of
flooding can`t be completely ruled out. The steadier rain should
come to an end from southwest to northeast during the second
half of the night, with the Flood Watch ending as well late
Tuesday night.
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...