Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
114 PM EDT Sat Sep 06 2025

Valid 00Z Sun Sep 07 2025 - 00Z Tue Sep 09 2025

...Stronger thunderstorms capable of severe and heavy rainfall
over parts of the Northeast to Mid-Atlantic today...

...There are Air Quality Alerts over parts of the Northwest and
Northern Rockies...

An unseasonably strong large scale upper-level closed low
dominates the Great Lakes again today, providing below average but
very pleasant temperatures across the area.  A few record low
temperatures or low maximum temperatures dot the area today
through early Monday, but departures from normal will moderate
from 10 to 15 below average to 5 to 10 toward Monday.  This broad
closed low continues to press a cold front eastward through the
Appalachian Mountains today, slightly faster northward into the
Northeast.  Ahead of the front, increased moisture and higher
temperatures will result in unstable air and solid potential for
showers and thunderstorms this afternoon; with stronger winds
aloft further north, the potential for severe weather including a
few tornadoes exists across New England with small hail and severe
winds extending southward along the front into the Mid-Atlantic
and eastern upslope portions of the Carolinas.  The Storm
Prediction Center (SPC) has a narrow Slight Risk (level 2 of 5)
from SW Maine to Northeast Maryland, with a Marginal Risk (1 of 5)
into northern Georgia.  Coincidentally, enhanced moisture across
the Mid-Atlantic will increase heavy rainfall potential for some
of the thunderstorms as well.  The Weather Prediction Center (WPC)
has highlighted a similar area in a Marginal Risk of Excessive
Rainfall (1 of 4); with an embedded Slight Risk (2 of 4) from
Philadelphia across New York City into southwestern New England.

This front will continue to sag southward across the Southeast
tomorrow (Sunday) and intersect with a languishing area of
enhanced deep layer moisture around a few weak surface lows and an
old frontal boundary across the Florida Peninsula.  The
combination will maintain a risk of shower and scattered
thunderstorm activity trough to early next week; the front will
also stall across south central Texas.  As such, WPC has
maintained a Marginal Risk of Excessive Rainfall suggesting an
isolated incident of flash flooding is possible across southern
Texas and the Southern Florida Peninsula on Sunday with the risk
continuing on Monday for Florida. 

Further west, lingering enhanced moisture under a slowly weakening
upper-level ridge of high pressure will continue to suggest
monsoon thunderstorms across portions of the Southwest.  Some
upslope flow from the southern Plains will help to further
concentrate moisture and therefore, thunderstorm activity within
the larger Marginal Risk of Excessive Rainfall (across the Four
Corners to the adjacent terrain to the Snake River Valley into the
Blue Mountains of Oregon), a small Slight Risk of Excessive
Rainfall has been placed along the Sacramento and southern Sangre
de Cristo Ranges in New Mexico.  Local forecast offices have
placed flood watch across similar areas, particularly the burn
scars of those areas.   By Sunday, the ridge will continue to be
suppressed by a subtle shortwave trough out of the northern stream
dropping through southwest Canada.  This will help to press out a
weak frontal zone or support some weak Chinook downslope flow to
bring warmer temperatures through the American Rockies into the
High Plains and eventually Northern Plains by Monday. 
Temperatures into the 80s will near 90 which is about 5 to 10
degrees above normal.  Some widely scattered showers may come with
the weak front but should light.

West of the frontal zone in the far western part of the
upper-level ridge, weaker winds, lower moisture will maintain the
potential for fire weather conditions and low air quality due to
smoke from ongoing fires.  Red Flag Warnings are up for portions
of Oregon and Washington and SPC has delineated areas of Dry
Thunderstorm potential today into tomorrow for OR, WA and ID.  The
Air Quality Alerts are in affect for Eastern Washington, Northern
Idaho, Western Montana, Western Wyoming and northwest Colorado. 

Gallina


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php