ATTENTION: For more information on the addition of the experimental Rapid Onset Drought hazard type to the Climate Prediction Center's 8-14 Day Hazards Outlook (Contiguous U.S. and Alaska), please click HERE.
Valid Wednesday March 06, 2024 to Tuesday March 12, 2024
US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM
EST February 27 2024
Synopsis: Model ensembles depict an enhanced
flow of Gulf of Mexico moisture moving over much of the eastern Contiguous U.S.
(CONUS) at the outset of week-2, bringing the potential for heavy
precipitation. A stalled frontal system prolongs the risk for heavy
precipitation over the Southeast U.S.into the middle of the forecast period. A
passing mid-level disturbance brings the potential for heavy snow to higher
elevations in portions of the western CONUS. Models depict similar disturbances
moving over the Great Plains and Great Lakes regions during week-2, bringing
with them the potential for high winds.
risk for heavy precipitation for portions of the Tennessee and Lower
Mississippi Valleys, and Southeast U.S., Wed-Thu, Mar 6-7.
Slight risk for heavy precipitation for portions of the Tennessee, Ohio,
and Lower Mississippi Valleys, Southern Appalachians, Mid-Atlantic, and
Southeastern U.S., Wed-Sun, Mar 6-10.
Slight risk for heavy precipitation for portions of the Central
Appalachians, Mid-Atlantic, and Northeast U.S., Wed-Fri, Mar 6-8.
Slight risk for high winds for portions of the Great Plains, Middle and
Upper Mississippi Valley, and Great Lakes region, Wed-Sun, Mar 6-10.
Slight risk for heavy snow for the Klamath and Sierra Nevada mountains and
higher elevations of western Nevada, as well as higher elevations for much of
the Interior West, Wed-Fri, Mar 6-8.
For Wednesday March 06 - Tuesday
March 12: There are several areas of active weather depicted in today’s
model solutions at the outset of week-2, however there is significant model
spread particularly over the western CONUS, leading to increased uncertainty in
today’s week-2 hazards outlook. The most active weather depicted in today’s
solutions remains over the southeast CONUS, with ample moisture flowing into a
series of fast-moving surface low pressure systems moving off the Rockies and
triggering widespread enhanced precipitation with the potential for
thunderstorm activity over the Southeast , particularly at the outset of
week-2. The GEFS and ECMWF precipitation Probabilistic Extremes Tools (PETs)
both indicate at least a 20% chance of 3-day precipitation totals to exceed the
85th percentile and 1 inch for much of the Southeast, and Tennessee and Lower
Mississippi Valleys for March 6-10. The ECMWF is particularly bullish, with
probabilities exceeding 40% over portions of the southeastern CONUS, and even
exceeding 60% over portions of the Mid-Atlantic and Northeast U.S. Given these
high probabilities, a moderate risk for heavy precipitation is posted for March
6-7 where model agreement is greatest and where the highest precipitation
totals are highlighted. Additionally, a slight risk for heavy precipitation is
posted for much of the southeastern CONUS for March 6-10 as heavy precipitation
is favored to persist beyond the beginning of week-2 along a stalled frontal
system. A slight risk for heavy precipitation is posted for portions of the
Mid-Atlantic and Northeast U.S. for March 6-8 where, in spite of large model
spread, a strong signal exists in the ECMWF PET and the risk of heavy
precipitation cannot be discounted. Finally, both deterministic and ensemble
solutions from the GEFS and ECMWF depict tight pressure gradients forming over
the Great Plains and Great Lakes regions as these low pressure systems move off
the Rockies, resulting in the potential for high winds. This is also supported
by the ECMWF PET for high wind, indicating a 20% probability of wind speeds
exceeding the 85th percentile and at least 20 mph over these areas from March
6th through at least the 10th, therefore a slight risk for high winds is posted
over this part of the country through the middle of week-2..
The other major feature in today’s model solutions is a low pressure system
moving off the North Pacific and into the Intermountain West early in week-2.
This storm system is well-depicted in GEFS and ECMWF ensemble solutions, and
the GEFS PET for snow water equivalent (SWE) indicates at least a 20%
probability of 3-day SWE accumulation exceeding the 85th percentile and 1 inch
for the Sierra Nevada and Klamath ranges, higher elevations of western Nevada,
as well as most of the Rockies and higher elevations of the central Great
Basin. Therefore, a slight risk for heavy snow is posted for the areas listed
for March 6-8. While there are indications that this system, as well as a
second system later in week-2, have the potential to bring heavy precipitation
and high wind closer to the coast, there is too much uncertainty to justify
posting any corresponding hazards at this time.
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.