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FNUS21 KWNS 300624

FWDDY1



Day 1 Fire Weather Outlook  

NWS Storm Prediction Center Norman OK

0123 AM CDT Tue Mar 30 2021



Valid 301200Z - 311200Z



...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST NEW MEXICO AND SOUTHWEST

TEXAS...



...Synopsis...

The upper-level trough, currently noted in water-vapor imagery over

the northwestern CONUS, will shift east over the next 24 hours into

the central Plains with broad upper-level ridging expected over the

West Coast. The evolution of this upper-level pattern will favor

surface pressure falls across the far southern High Plains ahead of

a southeastward surging cold front as well as building surface high

pressure over the Great Basin. The resulting windy conditions will

introduce fire weather concerns for portions of the southern High

Plains, the central Plains, and portions of California.



...Southern High Plains...

Elevated to critical fire weather conditions appear likely again

this afternoon as winds increase to around 15-25 mph amid modest

surface pressure falls over the region. Strengthening southwesterly

mid and upper-level flow coupled with deep boundary-layer mixing by

late afternoon will support wind gusts up to 30-35 mph. A

considerable westerly wind component over the southern Rockies will

favor downslope warming/drying and foster RH values falling well

below 15% over the region. Recent fuel analyses continue to show

dry, receptive fuels (which were likely exacerbated by Monday's dry,

windy conditions). As such, critical fire weather conditions are

expected again today within a broader zone of elevated conditions. 



...Central Plains...

Morning observations show a very dry post-frontal air mass

(featuring dewpoints in the low single digits) upstream from the

broader NE region. Building surface high pressure over the Northwest

this afternoon will help maintain pressure gradient winds as the dry

air advects into the region. Clear skies will allow for sufficient

diurnal warming for RH values to fall into the 20-25% range.

Coincidentally, deep boundary-layer mixing and a uni-directional

wind profile will allow for efficient downward transfer of stronger

flow aloft, which could manifest at the surface as wind gusts up to

35-40 mph. Fine fuels across this region remain receptive after the

recent dry frontal passage on Monday afternoon. Elevated fire

weather conditions appear most likely over central NE, but may

extend into adjacent portions of SD and KS.



...California...

Building surface high pressure over the Northwest/northern Great

Basin will augment the offshore pressure gradient across coastal

southern CA as well as northerly flow through the Sacramento Valley.

For coastal southern CA, northeast winds are forecast to increase

through the morning and should peak this evening into early

Wednesday morning with sustained winds between 20-30 mph. Wind gusts

up to 35-55 mph are possible, especially in the more wind prone

locations along the coastal mountains and hills. Strong downslope

warming and drying will help RH values fall into the single digits

for some locations. Fuel analyses and reports continue to suggest

that fuels are generally not yet receptive across this region, but

pockets of drier fuels will support an elevated fire weather

concern. 



Further north across the Sacramento Valley, diurnal heating and

falling RH into the 15-20% range, coupled with breezy northerly

winds, will support areas of elevated fire weather conditions.

Despite somewhat weaker mid-level flow compared to locations further

south, wind gusts up to 20-25 mph will be possible during peak

daytime heating.



..Moore.. 03/30/2021



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



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