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FNUS21 KWNS 131649

FWDDY1



Day 1 Fire Weather Outlook  

NWS Storm Prediction Center Norman OK

1148 AM CDT Tue Apr 13 2021



Valid 131700Z - 141200Z



...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN GREAT BASIN...

...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN ARIZONA AND SOUTHWEST

NEW MEXICO...



...Eastern Utah and western Colorado...

Morning satellite imagery shows widespread cloud cover across the

region consistent with previous model forecasts. Despite the ongoing

clouds, surface dewpoints in the teens to single digits are

significantly lower than previous guidance indicated. This suggests

even modest warming through the day will result in relative humidity

values of 15-25%. The presence of gusty winds of 20-25 mph in close

proximity to the dry air and anomalously dry low-elevation fuels

will support the potential for pockets of elevated/critical fire

weather conditions along the western slope through the afternoon.

Precipitation chances are expected to increase later in the day with

the arrival of lift from the upper low, but should remain infrequent

enough that some fire weather threat develops before more widespread

precipitation begins tonight. There also exists the low probability

for a few dry storms and lightning strikes given weak buoyancy from

the increasing mid-level moisture ahead of the upper low. The

elevated area has been expanded northward to account for these

threats. 



The rest of the forecast remains on track with only minor

adjustments. Portions of the Southeast will see dry but calm

conditions with locally elevated fire weather potential while

critical fire weather conditions are expected across the southern

Great Basin into the Southwest.



..Lyons.. 04/13/2021



.PREV DISCUSSION... /ISSUED 0148 AM CDT Tue Apr 13 2021/



...Synopsis...

A mid-level trough will amplify across the Interior West as a

surface low deepens across the lower Great Basin today. Dry

southwesterly flow will develop during the afternoon across the

southern Great Basin and Lower Colorado River Basin, promoting

conditions favorable for wildfire spread across the lower terrain,

where fuels are most receptive to fire spread.



...Southern Great Basin into the Lower Colorado River Basin...

The combination of diurnal heating, increased gradient wind speeds

with the intensifying surface low, and downslope flow will promote

widespread 15-25 mph sustained west-southwesterly surface winds

across much of the lower Great Basin into the Lower Colorado River

Basin, where 10-20% RH will be common. Latest guidance consensus

continues to depict portions of southern Nevada into northwest

Arizona and far southeast Arizona into western New Mexico as primary

regions for longer-term, overlapping Critical winds/RH. Still, at

least locally Critical conditions are possible across the remainder

of the Elevated area. 



...Portions of the Southeast...

Relatively dry surface air is expected to meander across portions of

the southeast this afternoon, from South Carolina into the Florida

Peninsula. While much of the Southeast has experienced 2+ inch

rainfall within the past week, a minimum in precipitation

accumulations is noted across eastern Georgia into central and

southern South Carolina, where RH may dip into the 25-35% range by

afternoon peak heating. Fire weather highlights are being withheld

since mainly light and variable winds are present. However,

localized fire-spread concerns exist where 30% or less surface RH

overlaps dry fuels.



...Please see www.spc.noaa.gov/fire for graphic product...



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