Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0204 PM CDT Thu Sep 01 2022
Valid 021200Z - 031200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTHERN
OREGON INTO EXTREME NORTHEASTERN CALIFORNIA AND EXTREME NORTHWESTERN
NEVADA...
Critical highlights have been added to portions of the southern
Cascades for tomorrow/Friday afternoon. Model guidance consensus,
including high-resolution ensemble guidance, depicts an increasing
chance for widespread 20+ mph sustained south-southwesterly surface
winds during the mid to late afternoon hours. While the surface wind
field is still relatively marginal for Critical standards, RH may
dip into the 10-15 percent range by afternoon peak heating, with
fuels reaching near-record levels of dryness in some spots. The
anticipated wind field may encourage sufficient spread of new
wildfires as well as potential significant growth of pre-existing
fires given very favorable fuels/RH, necessitating Critical
highlights. It is also possible that a brief thunderstorm could
develop and produce a couple of strikes to support new ignitions,
though the threat is too sparse to introduce highlights this
outlook.
Otherwise, the previous forecast (see below) remains on track for
portions of the Central Plains.
..Squitieri.. 09/01/2022
.PREV DISCUSSION... /ISSUED 0155 AM CDT Thu Sep 01 2022/
...Synopsis...
Fire weather concerns will return to the Pacific Northwest and
portions of the central Plains on Friday. A dominant Great Basin
ridge will largely remain in place over the next 48 hours, but will
deamplify slightly as a shortwave trough impinges on its
northwestern periphery, strengthening flow over the northern Sierra
Nevada in the process. To the east, a departing upper wave over the
Canadian Prairies will help push a weak cold front into the Plains.
Breezy post-frontal conditions will support fire weather
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1044 AM CDT Thu Sep 01 2022
Valid 011700Z - 021200Z
The previous forecast remains on track, with only minor changes made
to the ongoing highlights to account for the latest guidance
consensus. Please see the previous forecast below for more details.
..Squitieri.. 09/01/2022
.PREV DISCUSSION... /ISSUED 1256 AM CDT Thu Sep 01 2022/
...Synopsis...
Fire weather concerns are expected across the northern Rockies and
northern High Plains this afternoon as an upper wave translates
across the region. A pair of upper troughs, noted over the northern
Rockies and northwestern Canadian Prairies in morning water-vapor
imagery, are expected to phase as they crest a Great Basin upper
ridge. This phasing will enhance mid-level flow and shift a Canadian
surface low into the Plains through the day. The passage of an
associated cold front across the northern Plains, coupled with
strengthening flow, will support breezy conditions over a region
with receptive fuels and antecedent dry conditions.
...Montana...
Latest guidance has delayed the passage of the Canadian cold front
across northern/central MT until later in the afternoon/evening
compared to previous model runs. While strong surface winds may be
less expansive than anticipated, a deepening lee trough and
strengthening zonal flow off the Rockies will foster breezy
downslope winds. Temperatures in the 90s and RH minimums in the
teens to 20s remain likely and will maintain the potential for
elevated fire weather conditions. A wind shift to the
north/northwest associated with the frontal passage is still
expected later today, but may occur just after peak daytime heating
during the 00-03 UTC time frame.
...Snake River Plain and Wyoming...
00 UTC soundings from BOI and RIW sampled very dry boundary-layer
conditions across ID and WY. Recent surface observations
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1225 PM CDT Thu Sep 01 2022
Valid 021200Z - 031200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE UPPER
MIDWEST/GREAT LAKES INTO THE CENTRAL PLAINS...AND ACROSS PARTS OF
CENTRAL/SOUTHERN ARIZONA...
...SUMMARY...
Isolated strong to severe thunderstorms are possible Friday
afternoon and evening from portions of the central Plains to the
Upper Midwest, and also across central and southern Arizona. Strong
wind gusts and isolated hail will be the main hazards with these
storms.
...Upper Midwest into the central Great Plains...
A mid/upper-level trough is forecast to move eastward across Ontario
and Quebec on Friday, with the trailing part of this trough moving
across the upper Great Lakes region. A weaker midlevel trough will
persist to the southwest across the mid-MS Valley into the southern
Plains. A cold front will move across the upper Midwest and the
northern/central Plains.
Moderate to locally strong buoyancy is forecast to develop along and
ahead of the front by Friday afternoon. A tendency for the strongest
large-scale ascent to stay north of the international border renders
timing/coverage of storm initiation uncertain, but isolated
development appears possible from the upper Great Lakes into the
central Plains by late afternoon/early evening. Effective shear of
25-35 kt will support multicell clusters and perhaps a supercell or
two, with an attendant risk of large hail and damaging wind gusts.
Northerly midlevel flow may support one or more southward-moving
clusters across the Plains during the mid/late evening, though the
southwestward extent of any severe threat remains uncertain at this
time.
...Arizona...
An increase in low-level moisture is expected across parts of
Arizona on Friday, which will aid in moderate diurnal
destabilization from the Mogollon Rim into the l
Severe thunderstorm 40 mph winds gust with 0.50" hail and deadly lighting
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0155 AM CDT Mon Aug 15 2022
Valid 161200Z - 171200Z
...Synopsis...
Upper ridging should continue across the western CONUS as an
amplified northwesterly flow regime becomes established across the
Plains states. Similar to Day 2, locally dry and breezy conditions
over dry fuel beds in terrain-favoring areas may occur by afternoon
peak heating from the Pacific Northwest into the northern Rockies.
However, guidance consensus shows a modest plume of monsoonal
moisture meandering northwestward towards the southern Cascades
through the day, with some of the latest high-resolution data
depicting sparse thunderstorm development by early evening. While
the storms will be relatively slow moving, the latest guidance also
suggests that these storms should be mainly dry. Overall confidence
in thunderstorm development is relatively low given scant buoyancy.
However, isolated dry thunderstorm highlights have been introduced
given how dry fuels are across far northeastern California and
immediate surrounding areas.
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0226 AM CDT Mon Aug 15 2022
Valid 171200Z - 181200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST...
...SUMMARY...
Isolated strong to severe thunderstorms capable of producing mainly
wind damage may occur Wednesday across portions of the Southeast.
...Southeast...
An upper trough/low should remain centered over the Mid-Atlantic and
Northeast on Wednesday. At the surface, a front is forecast to move
slowly southward across much of the Southeast through the period.
This boundary will likely provide a focus for thunderstorms
Wednesday afternoon and evening, some of which could be strong to
severe.
Mid-level west-northwesterly winds are forecast to remain fairly
modest across the Southeast, as this region will be on the southern
periphery of the upper trough/low encompassing much of the eastern
CONUS. Even so, a narrow zone of 20-30 kt deep-layer shear should
encourage some updraft organization. Thunderstorms should develop
along/near the front as it shifts slowly southward through the day.
Moderate to locally strong instability is generally expected to
develop south of the front, as robust diurnal heating of a
seasonably moist low-level airmass occurs. Multiple multicell
clusters may ultimately consolidate and spread southward through
early Wednesday evening. Owing to the steepened low-level lapse
rates and a mainly linear mode forecast, this activity may pose an
isolated threat for damaging downdraft winds.
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1127 AM CDT Mon Aug 15 2022
Valid 151630Z - 161200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING ACROSS PARTS OF THE CAROLINAS...
...SUMMARY...
Isolated severe thunderstorms may occur today across parts of the
Carolinas. An isolated severe wind/hail threat may also develop
across parts of the central and northern Plains this afternoon and
evening.
...Central Carolinas this afternoon/evening...
Pockets of surface heating and boundary-layer dewpoints in the mid
60s will contribute to some destabilization this afternoon across
the Piedmont, with thunderstorm development expected to focus along
a weak surface front/trough. Midlevel lapse rates will remain poor
over this area, but the daytime heating will still boost MLCAPE to
near 1000 J/kg. Embedded speed maxima rotating around the southwest
periphery of a midlevel trough over the Northeast will combine with
weak low-level winds (veering with height) to result in sufficient
deep-layer vertical shear for organized/supercell storms. A few
damaging gusts appear to be the main threat with these storms later
this afternoon into this evening.
Scattered thunderstorms will along be possible farther west along
the wind shift across GA/AL, where vertical shear will be weaker.
Primarily multicell storms will be capable of producing isolated
wind damage in this corridor later this afternoon.
...Northern Plains later this afternoon/evening...
A surface cold front has been reinforced by outflow with morning
convection across ND, and surface heating will be slowed some by
lingering clouds along the boundary into early afternoon. Still,
pockets of stronger surface heating and steep midlevel lapse rates
noted in the 12z BIS sounding will support MLCAPE of 1500-2000 J/kg
by late afternoon along the front/outflow. Vertical shear will be
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1211 PM CDT Mon Aug 15 2022
Valid 161200Z - 171200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE OZARK
PLATEAU INTO THE LOWER MS VALLEY...
...SUMMARY...
Isolated strong to severe thunderstorms appear possible Tuesday
across parts of the Ozarks into the lower Mississippi Valley and
central Gulf Coast. Occasional damaging winds should be the main
threat, but some hail may also occur.
...Synopsis...
A corridor of modest northwesterly flow aloft is expected to be in
place from the northern Plains through the Mid-South on Tuesday
morning, situated between upper ridging from the southern Plains
into the Great Basin and upper troughing from the Northeast into FL.
This western ridge/eastern trough upper pattern is forecast to
persist throughout the period as a shortwave trough moves through
the corridor of northwesterly flow from the Lower MO Valley through
the TN Valley into the Carolinas.
Surface pattern early Tuesday morning will likely feature a low over
southeast KS, with a diffuse stationary boundary extending
southeastward from this low to another low near the southern GA/SC
border. Boundary over the Southeast is expected to remain largely in
place, while a cold front progresses southward through OK and the TX
Panhandle.
...Ozark Plateau into the Lower MS Valley...
Numerous showers and thunderstorms are forecast to be ongoing at the
beginning of the period over MO, within the warm-air advection to
the northeast of the surface low mentioned in the synopsis. This
early morning activity should persist into the early afternoon
before diminishing in tandem with weakening low to mid-level
westerly flow.
Addition storm development is anticipated during the afternoon in
the vicinity of the stationary front, where low-level convergence
will combine with ample low-level moisture and str
Mesoscale Discussion 1680
NWS Storm Prediction Center Norman OK
0128 PM CDT Mon Aug 15 2022
Areas affected...Parts of south-central Texas
Concerning...Severe potential...Watch unlikely
Valid 151828Z - 152015Z
CORRECTED FOR TYPOS
Probability of Watch Issuance...20 percent
SUMMARY...A brief tornado or two will be possible with the stronger
updrafts in south-central Texas this afternoon. A watch is not
expected.
DISCUSSION...As temperatures continue to warm into the upper 70s to
low 80s F, some deeper updrafts have become evident on visible
satellite in parts of south-central Texas. Occasionally stronger
rotation has also been noted on KEWX radar over the last 30 minutes.
With continued heating, a few more updrafts could intensify this
afternoon. The influence of the tropical low pressure system has
enhanced low-level easterly/southeasterly winds. Based on the KDFX
and KEWX VAD winds, the most favorable area for low-level rotation
will be near the I-35 and Texas State Highway 16 corridors. There,
low-level flow enhancement will coincide with stronger surface
heating along the eastern flank of the low pressure circulation. A
watch is not expected for this activity this afternoon.
Mesoscale Discussion 1632
NWS Storm Prediction Center Norman OK
0439 PM CDT Tue Aug 02 2022
Areas affected...Parts of the western Florida Peninsula
Concerning...Severe potential...Watch unlikely
Valid 022139Z - 022315Z
Probability of Watch Issuance...5 percent
SUMMARY...Sporadic marginal hail and locally damaging gusts will be
possible as convection continues spreading across the western
Florida Peninsula this afternoon. A watch is not needed.
DISCUSSION...Latest radar data from TBW/MFL shows diurnally-driven
convection spreading slowly westward across parts of the western
Florida Peninsula this afternoon. An upper-level low evident in
water vapor imagery north of the Bahamas is contributing to
seasonably steep midlevel lapse rates and enhanced anvil-level
northerly flow. These factors, coupled with deep tropospheric
moisture (PWs near 2.0 in) and steepened boundary-layer lapse rates
could support marginal hail and locally damaging wet downbursts with
the stronger pulsating updrafts for next couple hours. However,
minimal cloud-layer shear will limit overall convective organization
outside of local congealing of cold pools -- precluding the need for
a watch.
Cool footage of some lighting in Hernando county FL.
