EconCurrents

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Mon Sep 16 2024
Valid 12Z Mon Sep 16 2024 – 12Z Wed Sep 18 2024

…Potential Tropical Cyclone Eight will bring wind and heavy rain to the
Carolinas and Mid-Atlantic…

…A strong upper low will bring unsettled weather and well below normal
temperatures to the West with high elevation snow in the Sierra Nevada and
Intermountain West…

…Severe thunderstorms possible for the Northern and Central High Plains
Tuesday…

While Francine’s remnants have been dissipating over the Southeast,
Potential Tropical Cyclone Eight has been strengthening off the Southeast
Coast. This disturbance is forecast to bring gusty winds and heavy rain to
portions of the Carolinas and Mid-Atlantic and dangerous coastal and beach
conditions to much of the Southeast and Mid-Atlantic coasts. The forward
motion of Potential Tropical Cyclone Eight will be slowed down by strong
high pressure over the Northeast, which will increase the chance of heavy
rainfall totals in the Carolinas today. Flash flooding will be a concern,
especially in the eastern Carolinas where the highest rainfall totals are
forecast, and flooding could have locally significant impacts. This
disturbance is forecast to gradually move north across the Carolinas into
the Mid-Atlantic, bringing a threat of locally heavy rainfall to the
region mid-week.

In the West, a deep upper low will bring unsettled weather and well below
normal temperatures to the region this week. The upper low is accompanied
by a strong surface frontal system that will push east across the
Intermountain West today and into the Plains Tuesday afternoon. This
system will bring widespread precipitation chances and gusty winds to much
of the West. Precipitation will fall mainly in the form of showers and
thunderstorms, but temperatures will be cold enough for the high
elevations of the Sierra Nevada and Intermountain West to see some early
season snow. Winter Weather Advisories are in effect through this evening
for the Sierra Nevada above 8000 feet where up to 4 inches of snow may
fall, and Wind Advisories are in effect through this evening for portions
of the Southwest where wind gusts could exceed 45 mph.

The surface low pressure system is forecast to strengthen in the lee of
the Rockies over Wyoming and Montana, and will bring a threat of scattered
severe thunderstorms to the northern and central High Plains Tuesday
afternoon and evening. The Storm Prediction Center has highlighted these
areas with a Slight Risk of Severe Thunderstorms (level 2/5), and the main
storm hazards will be severe wind gusts and hail. Showers and
thunderstorms will push east across the Plains Tuesday night and move
towards the Mississippi Valley on Wednesday.

Temperatures will have a broad range across the United States over the
next few days. The deep upper low will result in well below normal
temperatures in the West through at least mid-week, with the coldest
anomalies over the Great Basin and California where high temperatures will
be as low as 15-25 degrees below normal. On the flip side, temperatures
will be well above normal in the Central U.S. and Northeast. High
temperatures will generally be in the 80s and 90s for these regions. Below
normal temperatures are also forecast for the Southeast and Mid-Atlantic
today and Tuesday due to expected precipitation and cloud cover, but
temperatures should return to near normal for these regions by Wednesday.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sun Sep 15 2024
Valid 12Z Sun Sep 15 2024 – 12Z Tue Sep 17 2024

…Heavy rain/flash flood threat continues today for portions of the Lower
Mississippi Valley and Southeast…

…A coastal storm will bring wind and rain to the Carolinas and
Mid-Atlantic over the next few days…

…A strong low pressure system will bring unsettled weather and well
below normal temperatures to the West with high-elevation snow in the
Sierra Nevada…

Francine’s remnants will linger over the southeastern U.S. early this week
as a nearly stationary frontal boundary sags south to the Gulf Coast.
Chances for locally heavy rain and isolated to scattered instances of
flash flooding will continue today for portions of the Lower Mississippi
Valley and Southeast. There is a Slight Risk of Excessive Rainfall (level
2/4) for parts of Mississippi, Alabama, and the Florida panhandle where
flooding will be most likely. Chances for showers and storms will persist
across this region over the next few days, but the risk of flooding will
gradually decrease, with only isolated flooding concerns expected Monday
and Tuesday.

Meanwhile, a separate area of low pressure will strengthen off the
Southeast Coast and gradually move north towards the Carolinas. This
system is likely to bring gusty winds, heavy rain, coastal flooding, and
dangerous beach conditions to the Carolinas and portions of the
Mid-Atlantic through mid-week. Strong high pressure over the Northeast
will slow the forward motion of this system, increasing the chance of
heavy rainfall totals and flash flooding. There is a Slight Risk of
Excessive Rainfall (level 2/4) for portions of the eastern Carolinas and
far southeastern Virginia with an embedded Moderate Risk (level 3/4) over
southeastern North Carolina where the risk of flash flooding will be
highest. The National Hurricane Center is also monitoring this system for
potential subtropical or tropical development, and has marked this area
with a 50% chance of tropical formation over the next 48 hours. There is
still quite a bit of uncertainty on the timing, intensity, and track of
this system, so regularly check for forecast updates over the next couple
of days.

In the West, an unsettled pattern is beginning to take root as upper level
troughing moves into the region. A deep upper low will move over the West
Coast today and Monday and push across the Intermountain West to the
Rockies on Tuesday. This will push a strong frontal system across the West
that will bring widespread precipitation chances and much cooler
temperatures to the region over the next few days. Precipitation will
mainly fall as rain, but temperatures will be cold enough in the high
elevations of the Sierra Nevada for some early season snow. A Winter
Weather Advisory is in effect for portions of the Sierra Nevada above 8000
feet where up to 4 inches of snow may fall tonight and Monday.
Precipitation chances will also increase across the Southwest/Four Corners
region today as tropical moisture streams north from Tropical Cyclone
Ileana, which will support monsoon-like showers and thunderstorms through
Tuesday.

Temperatures will have a large range across the United States over the
next few days. Forecast precipitation and cloud cover will keep
temperatures slightly below normal across the Southeast and Mid-Atlantic,
with highs from the mid 70s to the mid 80s. Well above average
temperatures are forecast for the Central U.S. and Northeast, with the
highest anomalies forecast to develop under high pressure in the Upper
Midwest/Great Lakes region. High temperatures will reach the 80s and 90s,
which will be 10-20 degrees above normal for some areas. Well below
average temperatures are forecast to spread across the West through
Tuesday under the deep upper low/trough, and high temperatures will be as
low as 15-25 degrees below normal. The coldest anomalies will be in
Oregon, Nevada, and California on Monday. Highs in the 50s will be common
in the Great Basin, and highs will likely only reach the 30s and 40s in
the Sierra Nevada.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sat Sep 14 2024
Valid 12Z Sat Sep 14 2024 – 12Z Mon Sep 16 2024

…Heavy rain and flash flood threat will continue for portions of the
Southeast this weekend, then the flash flood threat will shift to the
Carolinas/Mid-Atlantic early next week…

…A strong low pressure system will bring unsettled weather to the West
late this weekend/early next week, with wintry precipitation expected at
high elevations…

…Well above average temperatures for the Central U.S. and Northeast;
well below average temperatures for the West…

Though it is now post-tropical, Francine will continue to bring a threat
for heavy rain and flash flooding to portions of the Southeast through
Sunday. The central area of low pressure will gradually sink south towards
the Gulf Coast with a stationary boundary extending to the Southeast Coast
and a cold front extending back towards the Southern Plains. The
stationary boundary will be the main focus for convection this weekend,
and training showers and thunderstorms with locally heavy rainfall will
create a threat for scattered instances of flash flooding. There is a
Slight Risk of Excessive Rainfall (level 2/4) for portions of Arkansas,
Tennessee, Mississippi, Alabama, and Georgia today and Sunday. Flash Flood
Watches are in effect for much of this area, and urban/poor drainage areas
and areas that already received heavy rainfall over the past few days will
be most at risk for flash flooding.

A separate area of low pressure will strengthen along the stationary
boundary extending from the Southeast Coast, which will maintain shower
and thunderstorm chances from Florida to the Carolinas and southern
Mid-Atlantic through early next week. This low pressure system is forecast
to gradually track north along the East Coast early next week and will
bring a heavy rain and flash flood threat to portions of the Carolinas and
Mid-Atlantic. There is a Slight Risk of Excessive Rainfall (level 2/4) for
eastern North Carolina on Monday where scattered instances of flash
flooding will be possible.

In the West, an unsettled pattern is forecast to develop this weekend as a
strong upper low pushes a frontal system across the region. The system
will nudge into the Pacific Northwest today, then move across northern
California, the Great Basin, and the northern Rockies Sunday and Monday.
Widespread showers and thunderstorms will accompany this system, and there
is a broad Marginal Risk of Excessive Rainfall (level 1/4) in effect for
portions of the Northern Rockies and Great Basin on Monday. This system
will also usher in well below normal temperatures, which will allow for
wintry precipitation to fall at higher elevations. A Winter Weather
Advisory is already in effect for portions of the Sierra Nevada where up
to 4 inches of snow may fall Sunday night and Monday. Precipitation
chances will also increase across the Southwest/Four Corners region late
this weekend into early next week as tropical moisture streams north ahead
of Tropical Cyclone Ileana.

Temperatures this weekend will have a large range across the United States
with well above average temperatures in the Central U.S. and Northeast and
well below average temperatures under the strong upper low in the West.
High temperatures will be in the 80s and 90s for the Central U.S. and
Northeast through Monday, which is more than 15 degrees above average for
some areas in the Upper Midwest/Great Lakes. High temperatures in the West
will be near to slightly below average today, then drop to 15 to 25
degrees below average in Oregon, California, and Nevada by Monday. Highs
in the 50s will be common in the Great Basin, and highs will likely only
reach the 30s and 40s in the Sierra Nevada.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Fri Sep 13 2024
Valid 12Z Fri Sep 13 2024 – 12Z Sun Sep 15 2024

…Francine will continue to weaken while bringing a heavy rain and flash
flood threat to the Southeast over the next couple days…

…Above average temperatures will develop across the Central U.S. and
Northeast while below normal temperatures persist in the Southeast and
West…

Francine will continue to weaken today as its low pressure center meanders
east across northern Arkansas. A stationary boundary extending from the
occluded system will remain parked across the Southeast and provide a
focus for showers and thunderstorms through Saturday. The storm’s slow
motion will result in multiple days of heavy rain for the Southeast, which
will create a flash flooding risk. There is a Slight Risk of Excessive
Rainfall (level 2/4) today from western Tennessee through northern and
central Alabama to central/southern Georgia, with an embedded Moderate
Risk (level 3/4) for portions of northern and central Alabama. Flooding
will be most likely in urban and poor drainage areas and areas that
receive training/repeat convection, and locally considerable flash
flooding may be possible, especially where soils are already saturated
from previous rainfall. The flash flood threat will continue for these
areas on Saturday with another Slight Risk (level 2/4). Flood Watches are
in effect for much of the risk area. If you encounter flooding, turn
around, don’t drown. It is never safe to walk or drive into flood waters,
and most flood fatalities occur in vehicles. Isolated severe thunderstorms
will also be possible for parts of the Southeast today where the Storm
Prediction Center has issues a Marginal Risk of Severe Thunderstorms
(level 1/5). Severe storm hazards may include a few tornadoes or severe
wind gusts.

The flash flood and severe weather threats associated with Francine will
gradually decease through the weekend, and the remnants will begin moving
south Saturday night and stall along the Gulf Coast on Sunday. Another
area of low pressure is forecast to form along the stalled frontal
boundary off the Southeast Coast, which will create stormy weather from
Florida through the eastern Carolinas through this weekend into early next
week.

In the north, an occluded low pressure system north of Montana will push
further into Canada today and Saturday and will bring a weak cold front
across the northern and central Plains. Precipitation will linger on the
backside of the low in the northern Rockies and northern High Plains this
morning, and cold air will allow for snow and mixed wintry precipitation
at higher elevations. Shower and thunderstorm chances will accompany the
weak cold front through Saturday. Strong high pressure over the Northeast
will prevent the front from making significant eastward progress, and the
front will weaken and dissipate on Sunday.

In the West, a stronger Pacific frontal system will approach the coast
later today and move inland over the weekend. Precipitation chances will
begin in the Northwest late tonight/early Saturday and spread across the
Great Basin and northern California Sunday into Monday. Precipitation
chances will also increase across portions of the Southwest on Sunday as
tropical moisture from Ileana spreads north.

Temperatures will be on the rise this weekend across the Central U.S. and
Northeast, with high temperatures forecast to reach values as high as
10-15 degrees above normal for this time of year. Highs in the 80s and 90s
will be common for the Plains, Upper Midwest/Great Lakes, and Northeast.
Precipitation and cloud cover from Francine will keep temperatures below
average for much of the Southeast. Temperatures across much of the West
will be near to slightly below average through Saturday. On Sunday, the
Pacific frontal system will usher in cooler, unsettled weather, and
temperatures will drop to well below normal along the West Coast.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Thu Sep 12 2024
Valid 12Z Thu Sep 12 2024 – 12Z Sat Sep 14 2024

…Heavy rainfall from Francine will spread into the Mid-South, Tennessee
Valley, and Southeast today while the severe weather threat shifts east
into Alabama and the Florida Panhandle…

…A round of moderate to heavy rain and strong thunderstorms with move
across the northern High Plains with high-elevation snow in the northern
Rockies…

…Elevated to critical fire weather concerns extend across much of the
High Plains and into portions of the central Great Basin…

Tropical Storm Francine continues to weaken and lift north early this
morning into southern Mississippi at the same time spreading gusty winds
and heavy rain across the region. The system is forecast to lose remaining
tropical characteristics later today as it pushes northward into the
Mid-South and connects with nearby frontal boundaries, while still
producing areas of locally heavy rain and chances for severe
thunderstorms. Tornadoes will be the main severe weather hazard through
tonight, potentially impacting parts of Alabama and the Florida Panhandle
along a slow-moving warm front. The Storm Prediction Center has issued a
Slight Risk (level 2/5) of severe weather for this region. The greatest
threat for considerable flash flooding exists across parts of northern and
central Alabama, where a slow-moving line of showers and thunderstorms
capable of containing intense rainfall rates could linger for several
hours and produce localized totals up to 10 inches. Heavy rain is also
possible from northeast Arkansas through the Tennessee Valley and into the
Florida Panhandle today. Looking ahead to the start of the weekend,
showers and localized torrential downpours will remain possible throughout
much of the Southeast as lingering tropical moisture and stationary
frontal boundaries stay draped across the region. Residents are advised to
have multiple ways of receiving warnings and never drive across flooded
roadways.

A potent storm system is also impacting parts of the West and High Plains
as an area of low pressure organizes in eastern Montana today. Areas of
heavy rain and severe weather are possible across the state. Gusty winds
and large hail associated with thunderstorms are most likely to impact
eastern Montana and far western North Dakota through tonight, with heavy
rain a potential weather hazard in central/western Montana. Additionally,
cool temperatures in the high elevations of the northern Rockies could
lead to early-season mountain snowfall for western Montana and the greater
Yellowstone National Park area. The other aspect of this system will
correspond with strong southerly winds throughout the High Plains. Wind
gusts up to 50 mph are possible, which could result in a few power
outages. These strong winds will also increase the fire weather threat
across the region as dry vegetation and low relative humidity create a
ripe environment for erratic fire behavior. Red Flag Warnings and/or Wind
Advisories span from southern Utah to North Dakota.

Elsewhere, high pressure will keep much of the Great Lakes and Northeast
dry as high temperatures increased into the 80s through the beginning of
this weekend. Warm and dry weather will also be found throughout the
Desert Southwest and southern Plains, with high temperatures into the
mid-to-upper 90s. Conversely, below average temperatures in the wake of a
cold front will be felt across much of the West to end the week.