518
FXUS21 KWNC 011843
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EST March 01 2026

SYNOPSIS: Multiple model ensembles depict low pressure at mid-levels and the
surface over the central Contiguous U.S. (CONUS) at the outset of week-2, along
with strong high pressure at the surface and mid-levels over both coasts. This
setup is favored to bring potentially heavy precipitation for much of the
Mississippi, Tennessee, and Ohio Valleys, as well as portions of the Great
Lakes and Northeast U.S. along with high winds across much of the eastern
CONUS. Flooding is also possible for portions of the Southern Plains,
Mississippi, Tennessee, and Ohio Valleys as a result of this heavy
precipitation potential. Surface low pressure over the Gulf of Alaska is
favored to bring  Pacific moisture into the northwestern CONUS favoring the
potential for heavy snow for portions of the Cascades, and the Northern and
Central Rockies.

HAZARDS

Moderate risk of heavy precipitation for portions of the Central and Southern
Plains, lower Great Lakes region, and the Middle and Lower Mississippi,
Tennessee, and Ohio Valleys, Mon-Thu, Mar 9-12.

Slight risk of heavy precipitation for portions of the Central and Southern
Plains, Middle and Lower Mississippi, Tennessee, and Ohio Valleys, lower Great
Lakes, Mid-Atlantic, Northeast, and Southeast U.S., Mon-Thu, Mar 9-12.

Slight risk of heavy snow for much of the Northern Rockies, Mon-Wed, Mar 9-11.

Slight risk of high winds for much of the central and eastern CONUS, Mon-Thu,
Mar 9-12.

Slight risk of high winds for much of the Pacific Northwest, Great Basin, and
Rocky Mountains, Mon-Thu, Mar 9-12.

Slight risk of high winds for much of the southern and southeastern coast of
Alaska, Mon-Thu, Mar 9-12.

Slight risk of much below normal temperatures for much of southwestern Mainland
Alaska, Mon-Thu, Mar 9-12.

Flooding possible for portions of the Southern Plains, Middle and Lower
Mississippi, Ohio, and Tennessee Valleys and the lower Great Lakes region.

DETAILED SUMMARY

FOR WEDNESDAY MARCH 04 - SUNDAY MARCH 08:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR MONDAY MARCH 09 - SUNDAY MARCH 15: Multiple model ensemble solutions for
500-hPa height anomalies over North America depict an amplified synoptic
pattern at the outset of week-2, with a full latitude trough over the Great
Plains bookended with amplified ridges situated over both coasts. This setup
strongly favors cyclogenesis in the lee of the Rockies as well as enhanced
baroclinicity across the East, bringing the potential for heavy precipitation
from the Southern Plains across to the Northeast U.S. Model ensemble daily MSLP
forecasts indicate one such round of cyclogenesis during the week-1 period,
followed by a second surface low forming over the Central Plains around the
start of week-2. Uncalibrated probabilities from the GEFS and ECENS both
indicate at least a 40% chance of 3-day precipitation accumulations to exceed 1
inch for a large swath from East Texas across to portions of the Southeast
U.S., and up the Mississippi, Tennessee, and Ohio Valleys. The ECENS continues
to be more bullish, indicating probabilities exceeding 30% for 3-day
precipitation accumulation to exceed 2 inches for much of the Tennessee Valley.
Todays solutions also indicate the potential for heavy precipitation to extend
further into week-2. A moderate risk of heavy precipitation is maintained for
portions of the Central and Southern Plains, lower Great Lakes region, and the
Middle and Lower Mississippi, Tennessee, and Ohio Valleys valid for Mar 9-12,
and a slight risk of heavy precipitation extending out from these two hazards
to include much of central Texas, eastward to include the Appalachians, and
northward to include portions of the Great Lakes and Northeast U.S., also valid
for Mar 9-12. Combined precipitation accumulations from the week-1 and week-2
systems over 6 inches are likely in many locations. This quantity of water is
not easily accommodated by river systems, and river, stream, and urban flash
flooding are all possible as a result. A large area is highlighted for flooding
possible during the week-2 period portions of the Southern Plains, Middle and
Lower Mississippi, Ohio, and Tennessee Valleys and the lower Great Lakes
region, as well as northeastern Texas. Flooding and flash flooding are also
possible beyond these regions, particularly in low-lying areas.



Model solutions depict strong surface low pressure development and sharp
pressure gradients with these cyclogenesis events, resulting in the potential
for high winds for much of the eastern CONUS. Ensemble mean wind speeds from
the ECENS and GEFS both exceed 20mph across much of the Central and Southern
Plains and across the East as surface low pressure tracks eastward during the
first half of week-2, warranting a broad area highlighted for a slight risk of
high winds across much of the central and southern CONUS for Mar 9-12.



Model ensembles maintain surface low pressure over the Gulf of Alaska and moist
onshore flow over western North America, although strong surface high pressure
over the North Pacific generally limits the southern extent of this moist
inflow near the U.S.-Canadian border. Despite this, uncalibrated probabilities
from the GEFS and ECENS show a strong signal for 3-day snow accumulations to
exceed 6 inches for the northern Cascades early in week-2, and the bullish
ENECS indicates a 20% chance of accumulations to exceed a foot. With strong
cyclogenesis likely over the Great Plains models favor good penetration of the
moisture further into the West. Both the ECENS and GEFS indicate at least 20%
chance of 3-day snow accumulations to exceed 6 inches across the Northern
Rockies, and once again with the ECENS indicating higher chances than the GEFS.
These signals are somewhat weak with respect to hazard thresholds in this
region, but pattern recognition of the synoptic pattern overall indicates
enhanced snowfall potential across the West, particularly early in week-2. A
slight risk of heavy snow is posted for the Northern Rockies valid Mar 9-11. No
hazard for heavy snow is indicated for the Cascades, although locally heavy
accumulations remain possible. High winds are also possible across the West
associated with this pattern. Ensemble mean wind speeds over 20mph are
widespread across the Pacific Northwest and Interior West through the middle of
week-2, and 20-40% chances of wind speeds exceeding 30mph are noted near the
Wyoming I-80 corridor. Therefore, a slight risk of high winds is posted for
much of the CONUS west of and including the Rocky Mountains except for most of
California, valid Mar 9-12.



Surface low pressure over the Gulf of Alaska is also favored to enhance winds
along the southern and southeastern coast of Alaska, as well as maintain cold
easterly flow over the Interior. This pattern is favored to bring extremely
cold temperatures into much of the state during week-1. Todays model solutions
are slower to reduce this easterly flow, prolonging the potential for hazardous
cold remains for portions of southwestern Alaska into the middle of the
forecast period. Based on best model agreement, a slight risk of much
below-normal temperatures remains posted for much of the southwestern Mainland
of Alaska, valid Mar 9-12. The Probabilistic Extremes Tools (PETs) for minimum
temperatures from the GEFS and ECENS both indicate at least a 20% chance of
minimum temperatures to fall below the 15th climatological percentile along the
western coast of the state throughout week-2. The GEFS shows a weaker signal
but still indicates a 40% chance of minimum temperatures to fall below the 15th
percentile early in week-2, while the ECENS initially depicts probabilities
exceeding 80% on day-8 before dropping below 60% by day-12. Despite this
increase in signal, no moderate risk of much-below normal temperatures is
issued at this time, though the situation will be monitored in the coming days.
The PETs for maximum wind speeds depict a similar picture, with the GEFS
maintaining a 20% chance of maximum wind speeds to exceed the 85th percentile
through the middle of the forecast period, while the ECENS depicts 40% chances
of exceeding the 85th percentile for this region initially, weakening to a 20%
chance by the end of week-2. A slight risk of high winds is maintained for much
of the southern Alaskan coast and Southeast Alaska for Mar 9-12.

FORECASTER: Danny Barandiaran

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