Remnants of Hurricane Isaias

[TSSN+]

Going to be an interesting Sunday evening for someone. 
 

 

[Eskimo Joe]

What does total rainfall look like.on the 12z euro? 

[yoda]

2 minutes ago, Eskimo Joe said:

What does total rainfall look like.on the 12z euro? 

 

[LeesburgWx]

Sunday’s going to be wet. Pretty much 1-2 inches region wide

[Eskimo Joe]

21 minutes ago, yoda said:

Thanks a nice bit of rain. Nothing too crazy. 

[yoda]

Afternoon AFD from LWX 

 

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
245 PM EDT Fri Oct 9 2026

.WHAT HAS CHANGED...

Added a mention of possible gale conditions over the lower
Chesapeake Bay on Sunday as a result of passing remnants of
Hurricane Isaias.

&&

.KEY MESSAGES...
- 1) Remnants of Hurricane Isaias to bring rain, breezy
  conditions Sunday into Sunday night.

- 2) No hazardous weather expected next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Remnants of Hurricane Isaias to bring rain,
breezy conditions Sunday into Sunday night.

The pattern remains quiet through the first half of the weekend
as surface high pressure strengthens over the northeastern U.S.
However, this lengthy period of tranquil weather will come to an
end as this ridge retreats northward ahead of Isaias. Until
then, a thick area of high cirrus should continue to track
poleward. Daily highs will be in the low/mid 70s, with 60s
across mountain locations.

The main weather impact to the region over the next week is going to
be from the remnants of what is now Hurricane Isaias (Cat 3
strength). Model guidance is in generally good agreement that
Hurricane Isaias` surface low weakens and broadens as the system
moves into the TN Valley Saturday night into Sunday. The mid-
level circulation amplifies and becomes a strong cutoff low over
KY/TN that moves slowly east across the Mid- Atlantic Sunday
into Monday. Periods of rain are likely across the area at times
Saturday evening through Sunday night. Rainfall amounts of 1-2
inches are expected across the area. Higher rain totals are
certainly possible, but will depend on a few other smaller scale
features.

Tropical moisture surges north into our area Saturday night into
Sunday, with the highest PWAT values at or above 2" (most likely
east of the Blue Ridge). While the main cutoff low associated with
the remnants of Isaias remain west of the Appalachians on Saturday,
expect light rain to move in from south to north in the evening.
Forcing for ascent increases Saturday night, and especially Sunday
morning into Sunday afternoon as mid-level heights fall with the
approach of the cutoff low. There is going to be enhanced low-level
convergence somewhere over the region as the surface high to the
east and cutoff low to the west interact. Easterly flow into the
Blue Ridge could also produce enhanced rain amounts due to
orographic effects. Additionally, an inverted trough or wave of low
pressure tries to develop in lee of the Appalachians Sunday as it
crosses Virginia to the Delmarva.

Uncertainty remains regarding the exact evolution and timing of
these features, which will ultimately determine where / if any
locally heavy rain occurs. Continue to monitor the forecast over the
next couple of days. No Flood Watches are planned at this time as we
are still over 48 hours from the main slug of rain.
Additionally, there is a non-zero risk of isolated tornadoes on
Sunday. These post-tropical environments can be tricky as low-
level spin ups do occur. For now, the Storm Prediction Center
has maintained a Day 3 Marginal Risk area.

It is going to be noticeably breezy, especially in the mountains
where winds begin to pick up Saturday evening. The strongest winds
are most likely on Sunday. The current forecast for peak wind gusts
is 30-40 mph in the Alleghenies and 20-30 mph elsewhere.

Conditions dry out Monday morning into Monday afternoon as the
remnants of Isaias push offshore. Looking at mostly mild
temperatures for most of next week. A series of cold fronts cross
the region during the middle to late part of next week as the
synoptic pattern becomes more active. Aside from mountain rain
showers, most of the area looks to remain dry. The strongest cold
front arrives late next week, possibly bringing rain and colder air
behind it.

[Weather Will]

I'm sure everyone will be relieved that the WB 18Z 3K NAM is now onboard and not quite done at the end of run.

[stormy]

The satellite imagery in motion sends a message.  Isaias is coming our way. 

Many details remain but the general movement looks good.

[Ephesians2]

53 minutes ago, stormy said:

The satellite imagery in motion sends a message.  Isaias is coming our way. 

Many details remain but the general movement looks good.

About 12 inches below normal precip YTD and still in D2 down here. 

Hopefully this knocks about 2 inches or so off the deficit. It is awfully dry in a lot of places. 

[Jebman]

Congrats on more rain! Dale City tallies shall challenge then surpass our meager amounts, 40.7 for the year.

Enjoy this autumn, winter and well on into late spring in 2027. Mid Atlantic is right in the Plume! So is Destin, FL, as they are most assuredly finding out right about now. Some Southeastern communities will eclipse 20 inches easy, especially with training tropical thunderstorms.

[Jebman]

Got some watches in Virginia already

 

Flood Watch
National Weather Service Blacksburg VA
143 PM EDT Fri Oct 9 2026

NCZ001>003-018-019-VAZ015>017-032-101000-
/O.NEW.KRNK.FA.A.0009.261010T1500Z-261012T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ashe-Alleghany NC-Surry-Watauga-Wilkes-Grayson-Carroll-Floyd-
Patrick-
Including the cities of Whitetop, Dobson, Galax, Troutdale, Stuart,
West Jefferson, Boone, Floyd, Wilkesboro, Sparta, Independence, and
Volney
143 PM EDT Fri Oct 9 2026

...FLOOD WATCH IN EFFECT FROM SATURDAY MORNING THROUGH SUNDAY
EVENING...

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

* WHERE...Portions of North Carolina, including the following areas,
  Alleghany NC, Ashe, Surry, Watauga and Wilkes and southwest
  Virginia, including the following areas, Carroll, Floyd, Grayson
  and Patrick.

* WHEN...From Saturday morning through Sunday evening.

* IMPACTS...Excessive runoff may result in flooding of rivers,
  creeks, streams, and other low-lying and flood-prone locations.
  Creeks and streams may rise out of their banks. Low-water crossings
  may be flooded. Storm drains and ditches may become clogged with
  debris. Extensive street flooding and flooding of creeks and rivers
  are possible.

* ADDITIONAL DETAILS...
  - Upslope rainfall from a rather strong southeasterly Low level jet
    from the remnants of Isaias will bring increased precipitation
    along the crest of the southern Blue Ridge from Floyd county
    extending southwestward towards Watauga county. Widespread
    rainfall totals of 2-4 inches with locally higher totals in the
    5-6 range will be possible, especially for areas like Meadows of
    Dan, Boone, and Blowing Rock. These higher totals may lead to
    isolated instances of landslides along slopes that have been
    modified by humans like embankments or cut slopes. These areas
    may also see increased rises on local streamflows that may lead
    to flooding across low-water crossings.
  - http://www.weather.gov/safety/flood

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.

&&

$$

EB

[MN Transplant]

3 hours ago, high risk said:

My initial reaction was that tornado potential would be confined to southeast VA and the Eastern Shore, because widespread rain over the DC metro area would limit instability.   Looking at CAMs, however, suggests that rain will likely end by early or mid afternoon for areas south and southeast of the warm front, and some decently high theta-e air will be available.    With the intense shear forecasted, it won't take much instability to make things very interesting.   The question, though, the track of the surface low.  My money is still on a track that keeps the warm sector south and east of DC, but there are solutions that track the low further to the northwest which would put our area into the game later Sunday.

A big factor is that TC tornadoes are strongly diurnal.  The CAMs all have the same idea with a broken (super?)cellular line, but it doesn't really rotate up here until after sundown.  If I were chasing, I think I'd head to Lynchburg and plan to follow the cells northeast.

[CAPE]

Latest blend- looks like an inch or so across the region. Probably a nice stratiform rain event. Beneficial.

[AnEndlessMaze]

6 hours ago, JenkinsJinkies said:

I think it stuck because it transitioned into a nor’easter while it was over us.

So did Sandy but that got retired lol

[TSSN+]

19 minutes ago, AnEndlessMaze said:

So did Sandy but that got retired lol

Big difference between sandy and 2020 Isaias. Sandy was deadly and caused way more damage. 

 

[AnEndlessMaze]

3 minutes ago, TSSN+ said:

Big difference between sandy and 2020 Isaias. Sandy was deadly and caused way more damage. 

 

My point was all that Sandy damage happened after its extratropical transition. If the only criteria is supposedly “damage that occurred while it was tropical” then it doesn’t count.

[pazzo83]

lol trying to compare Sandy with 2020 Isaias.  Come on folks.

[pazzo83]

2 hours ago, AnEndlessMaze said:

So did Sandy but that got retired lol

Sandy did not become a Nor'easter - it became extra-tropical but it plowed west-ward into NJ.

[Jebman]

This storm is moving pretty quickly - That may well be the saving grace for many areas with respect to rainfall tallies. The rain is already out of the coastal areas; this storm is now all about the inland regions. It's really truckin'! I think at 18 mph!

[WVclimo]

00Z GFS just upped the ante for west of I-95

[Jebman]

Plenty of rain coming for N VA and the DMV! Its truckin!

[Jebman]

This thing is moving its rain shield north so fast it is almost in south Virginia!

[dailylurker]

Trajectory looks good. I know it's tropical but I don't hate seeing these big slugs of moisture coming from the south with cold air around this fall. I want my cabin in NY under the snow by February. 

[yoda]

Morning AFD from LWX 

DISCUSSION...

KEY MESSAGE 1...Remnants of Hurricane Isaias to bring rain, breezy
to windy conditions, and the threat of tornadoes Sunday.

Hurricane Isaias is forecast to move north toward the TN Valley
today as it weakens and eventually loses all of its tropical
characteristics. The mid-level circulation strengthens and becomes a
large cutoff low later tonight. To the east, surface high pressure
over the Northeast today moves offshore off southern New England
tonight.

The interaction of Isaias` remnants to the west and surface high to
the east will create a large area of convergence / broad frontal
zone over the Mid-Atlantic. There is good model agreement that rain
steadily moves from south to north this evening into tonight as
forcing for ascent increases with some mid-level height falls in
response to the approaching cutoff low. It`ll take a bit of time for
the surface to truly saturate, so any rain late afternoon to this
evening in Central Virginia is going to be light. Eventually,
tropical moisture with PWATs at or above 2" surges in after
midnight.

It is worth mentioning again that conditions are favorable for a
widespread soaking rain, and 00Z models have responded with more QPF
across the region. Forcing for ascent increases tonight, and
especially Sunday morning into Sunday afternoon as mid-level heights
fall with the approach of the cutoff low. Enhanced low-level
convergence and moisture transport will peak Sunday morning into
early Sunday afternoon. Strengthening easterly flow into the Blue
Ridge could also produce enhanced rain amounts due to orographic
effects. As a result, forecast rain amounts have increased to 1.5-
2.5", with locally higher amounts of 3-4" possible. No Flood Watch
issued with this forecast update as the heaviest rain is forecast to
occur in areas that can handle it, but will continue to monitor the
latest guidance today.

Another noticeable trend in the 00Z guidance is the higher
probabilities for severe weather Sunday afternoon. The main
synoptically forced rain moves north of the area early Sunday
afternoon. Rapid height-falls and increasing low-level winds provide
a few hour window where some breaks in the clouds area possible,
leading to pockets of instability. A surface wave of low pressure
moves right through our area Sunday afternoon. Forecast soundings
indicate large, swooping hodographs, with ample shear in place  to
support organized severe convection. Clusters of thunderstorms
develop along the leading edge of the surface low pressure, with
tornadoes and damaging wind gusts as the main threats (looks mostly
to be east of the Blue Ridge). The NAM12, RRFS, and 06Z HRRR all
show this scenario. The big question still remains how much
instability actually develops. SPC has introduced a Slight Risk for
Sunday just to our south, with a Marginal Risk north to the MD/PA
border.

The strong mid-level circulation is going to bring windy conditions
to the Alleghenies and Blue Ridge, starting late tonight into Sunday
morning. Wind Advisories have been issued for downsloping easterly
winds in the Alleghenies (western Garrett, western Grant, and
western Pendleton Counties), and the Blue Ridge. The current
forecast for peak wind gusts is 40-50 mph in the Alleghenies/Blue
Ridge and 20-30 mph elsewhere.

The remnants of Isaias push offshore Monday, bringing an end to any
lingering showers. While conditions return humid and warm Monday,
there likely won`t be much in the way of shower activity due to
subsidence behind the departing trough.

[AnEndlessMaze]

8 hours ago, pazzo83 said:

lol trying to compare Sandy with 2020 Isaias.  Come on folks.

Last post I promise- I’ve already derailed the thread enough lol

I had nearly a foot of rain and half the homes in our development flooded from Isaias 2020 ( @BlizzardNole remembers this). There were three tornadoes in SOMD that all caused damage too- one was just a few miles north of our house (at the time).

I just get angry at the names that are retired or not retired (Gordon still being a name after what it did to Haiti in 1994 is another ridiculous one).

Anyway, I hope we get some rain from this. My recently planted grass seed needs it.