Prognostic Meteorological Discussion
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FXUS21 KWNC 031901
PMDTHR
US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EST January 03 2026

SYNOPSIS: There is better agreement today among the various ensemble mean
models during week-2. The ECENS, GEFS, and CMCE, support mid-level high
pressure over the far eastern Pacific Ocean and western North America, and
mid-level low pressure over the eastern contiguous U.S. (CONUS). There is also
a weak area of lingering low pressure predicted over the Southwest. Early in
the week-2 forecast period, a storm system is forecast to move off the East
Coast, accompanied by high winds and areas of heavy snow in the Great Lakes
region and Northeast. In the West, persistent surface high pressure forecast
over the Great Basin favors gusty downslope winds for southern California. In
Alaska, the mid-level height pattern favors significantly wetter conditions
over the state, and milder conditions for Southeast Alaska.

HAZARDS

Slight risk of heavy snow from the Lower Great Lakes region across northern New
York state and northern New England, Sun-Mon, Jan 11-12.

Slight risk of high winds over much of the Great Lakes, Northeast, and Upper
Mid-Atlantic, Sun-Mon, Jan 11-12.

Slight risk of high winds over southern California and vicinity, Sun-Sat, Jan
11-17.

DETAILED SUMMARY

FOR TUESDAY JANUARY 06 - SATURDAY JANUARY 10:
https://www.wpc.ncep.noaa.gov/threats/threats.php

FOR SUNDAY JANUARY 11 - SATURDAY JANUARY 17: During the first few days of the
week-2 forecast period, a broad low pressure system is predicted to move
eastward across the East Coast states and western Atlantic. During and after
the passage of this low pressure system, there is an increased chance of heavy
snow to the lee of the Lower Great Lakes, northern New York, and northern New
England. This is supported by raw (uncalibrated) snow amounts from the ECENS
and GEFS ensemble mean models and from the AI-version of the ECENS.
Accordingly, a slight risk of heavy snow is posted for these areas, valid Jan
11-12. It is worth noting that Lake Erie surface water temperatures are in the
30s, and once the lake surface freezes, the underlying moisture source
underneath the ice will be cut off.



In addition to the heavy snow hazard, a slight risk of high winds is valid for
the same days across most of the Great Lakes region, Northeast, and Upper
Mid-Atlantic. A tightened pressure gradient predicted in the mean sea-level
pressure fields of the models is forecast to result in wind speeds greater than
the 85th historical percentile and 20 mph. This is also warranted by the
Probabilistic Extremes Tool (PET) for wind.



Over the southeastern quarter of the Lower 48 states, the broad area of favored
heavy precipitation the last few days has been removed due to two
considerations. One reason is that today`s model guidance (PETs and
uncalibrated output) predicts a much smaller area of precipitation amounts that
exceed hazardous thresholds, with most of the former area now favored to
receive 0.50 - 0.75-inch of rain. A second reason is that northerly (offshore)
low-level flow is better indicated by today`s model runs over the Gulf Coast
states and the adjacent northern Gulf. This is expected to prevent the return
flow of warm, moist Gulf air into the western Gulf region/eastern Southern
Plains for an extended period.



Over the West, a predicted mid-level ridge and positive 500-hPa height
anomalies favor the development of surface high pressure over the Great Basin
early in the period. The clockwise circulation of air around this surface high
pressure system supports Santa Ana-type downslope winds that flow across
southern California from the interior to the Pacific coast. A slight risk of
episodic high winds is posted for southern California from Jan 11-17.
Typically, this activity would elevate the risk of fire weather. However, the
precipitation received over southern California during the previous two-week
period (Dec 18-31, 2025) was about 4 times their climatology. This will help to
minimize the risk of wildfires.



No temperature hazards have been posted on today`s map. For the past several
days, there was concern of Arctic air originating from the North Polar region
to advect due southward across central Canada into the north-central CONUS, but
the agreement between the various models and tools did not provide confident
support for a slight risk area of much below-normal surface temperatures. With
today`s mid-level height forecasts in better agreement on an amplified West
Coast ridge and amplified eastern CONUS trough, the northerly flow in-between
leads to increased chances of colder weather for the north-central states.



There are no hazards posted for Alaska today. The state is predicted to be
sandwiched between a 500-hPa trough over the Bering Sea, and an amplified
500-hPa ridge centered near the West Coast of North America. This flow pattern
is very different from the one observed during the last few weeks. Instead of
an extended period of bitter cold temperatures, the flow pattern favors
increased onshore flow and much wetter conditions over the state, in addition
to favored above normal mean temperatures over Southeast Alaska.

FORECASTER: Anthony Artusa

$$