Area Forecast Discussion

000
FXUS63 KSGF 310605
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
105 AM CDT Fri Mar 31 2023

Key Messages:

1. A few marginally severe storms into this evening. Hail up to
the size of quarters and lightning are the main potential hazards.

2. Scattered severe storms expected Friday afternoon, especially
east of the Highway 65 corridor. Hail to the size of golf balls,
damaging wind gusts, and a few tornadoes are the primary potential
hazards.

3. Non-thunderstorm wind gusts of 45-60 mph on Friday with the
strongest gusts occurring Friday afternoon along and west of the
Highway 49 corridor.

3. Critical fire weather conditions Friday afternoon and evening
across western Missouri and southeast Kansas. Fires in these
conditions will rapidly grow and spread.

4. Active weather pattern returns next week, including severe
thunderstorm and flooding potential on Tuesday.

.SHORT TERM...(This evening through Friday)
Issued at 326 PM CDT Thu Mar 30 2023

Synoptic Pattern and Current Conditions: Water vapor imagery
depicts a deep upper level trough across the western CONUS with
an upper level ridge axis extending from the Dakotas into the
Lower Mississippi Valley. This puts the Missouri Ozarks region in
an increasingly diffluent southwesterly flow aloft.

At the surface, low pressure is organizing across eastern
Colorado. A warm front extends east from this low along the KS/NE
border and into western IA. South of the front, surface dew
points are slowly increasing with a ribbon of middle to upper 40s
readings now surging north along the I-49 corridor. Dew points
across the eastern Ozarks remain in the 30s.

Potential for Thunderstorms into Tonight: That increasingly
diffluent flow aloft will continue to overspread the region with
a 60-65 knot low level jet also progged to strengthen over
western MO. The combination of isentropic upglide and deeper layer
ascent will result in the development of scattered showers and
thunderstorms from late this afternoon into this evening across
southwest MO and SE KS. This activity will then spread northeast
across the Ozarks throughout the evening. The threat for organized
storms will then likely shift east and northeast of the area
after 06Z as an elevated mixed layer (EML) begins to shift into
the region.

Thunderstorms late this afternoon and evening will tend to be
elevated in nature, thus the potential for damaging winds looks
very low, if not nil. There will be the potential for marginally
severe hail (up to quarter-size) with a few storms as MUCAPE
values increase throughout the evening. HREF mean values are
running in the 500-1000 J/kg range this evening.

Severe Thunderstorm Potential Friday: The upper level trough will
lift out of the Rockies and into the Plains Friday morning with the
main upper level low forecast by short term ensembles to reach
the the SD/NE/IA junction by 00Z Saturday. At the surface, low
pressure will rapidly deepen and lift northeast through NE and
into northeastern IA by 00Z Saturday.

A dry line will trail this low pressure center and quickly
progress east across the Ozarks Friday afternoon. This dry line
will be a critical player for multiple reasons across the
Missouri Ozarks. From a convective initiation standpoint,
convergence along this feature in addition to increasing synoptic
scale lift with the approaching trough will provide potential
triggers for surface-based convective initiation.

Short range models still show some variance in the timing of the
dry line. This feature will reach the I-49 corridor somewhere in
the 17-19Z time range and the Highway 65 corridor in the 19-21Z
time frame. We are leaning towards a slightly quicker arrival of
this feature given the 12Z HREF guidance.

We are becoming increasingly concerned that surface-based initiation
may struggle to develop west of the U.S. 65 corridor given the
strength of that EML (capping inversion). The potential for
initiation will tend to increase as the dry line gets east of
Highway 65 given that temperatures will likely be warming into the
lower 70s with surface dew points in the lower 60s. It should be
noted that a few CAMS do not develop deep convection until the dry
line gets east of Highway 63. Storms that are able to develop
will push east of the Missouri Ozarks around or shortly after 00Z
Saturday.

Scheduled soundings for 12Z and 18Z on Friday will be very
revealing regarding cap strength.

When and if storms do develop, they will initially tend to take a
more discrete and supercellular mode given limited coverage and
strong deep layer shear (0-6 km bulk shear of 70+ knots). For
this reason, we have bumped up the max hail size to golf balls in
our messaging. These storms will also have the potential to
produce damaging winds, especially if there is any upscale growth
into small line segments. There will also be the potential for a
few tornadoes with 0-1 km SRH values in the 150-250 m2/s2 range.

Synoptic Scale Winds: Southerly surface winds will continue to
increase tonight and Friday morning as that low pressure deepens
and ejects into the Plains. Of particular concern will be the
time period between dry line passage and sunset. Bufkit soundings
continue to reveal impressive mixing and momentum transfers across
southeastern Kansas and western Missouri. Forecast soundings
indicate the potential for mixing all of the way up to 700 mb (if
not slightly higher). Short range models have been consistent in
depicting 50-60 knot winds in the 850-700 mb layer.

While we may see a deck of shallow cumulus clouds immediately
behind the dry line, confidence is high that these clouds will
shift east and result in full mixing, especially near and west of
the I-49 corridor. We have therefore hoisted a High Wind Warning
for Friday afternoon and early evening across that area with the
expectation of 55-60 mph gusts. The warning may need to be
expanded east if the quicker dry line scenario materializes.
Otherwise, the remaining Wind Advisories look good with gusts of
45-55 mph expected.

The combination of the strong winds and rapidly falling humidities
behind that dry line will also lead to critical fire weather
conditions from Friday afternoon into Friday evening across
southeast KS and western MO. See the Fire Weather Discussion below
for more details.

.LONG TERM...(Friday Night through Thursday)
Issued at 326 PM CDT Thu Mar 30 2023

Quiet Weekend: A cold front associated with that low pressure
system will pass through the region late Friday night. This will
usher a cooler air mass into the area with rather brisk northwest
winds persisting into Saturday. Areas up towards Rolla will still
see gusts around 40 mph Saturday morning. The NBM shows good
clustering for temperatures with forecast highs in the middle to
upper 50s on Saturday.

Sunday then looks dry and much warmer as upper level ridging
builds back into the central U.S. NBM numbers look reasonable
with highs returning into the upper 60s and lower 70s with brisk
southerly winds developing across the area.

Next Strong System: The WPC Clusters continue to show good
consensus that another amplified trough will swing out of the
Rockies and into the northern and central Plains from late Monday
into Tuesday. Surface low is once again progged to deepen across
the central High Plains before tracking northeast towards the
western Great Lakes.

Moisture return ahead of this next system looks like it may be
slightly better. Thus, the potential for both severe storms and
flooding will need to be monitored. Ahead of this system, NBM
statistical data shows good clustering around highs ranging from
the middle 70s to lower 80s both Monday and Tuesday.

Cooler temperatures will then filter into the region behind this
system for later next week. For those looking to get an early
start on the growing season, there is low-end frost potential
later next week if winds become light and clouds clear out. We
will get a better feel for this in the coming days.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1252 AM CDT Fri Mar 31 2023

An area of surface low pressure is moving north across the central
Plains early this morning. Ahead of the low gusty southerly winds
will occur now into this evening. Winds will increase and be quite
gusty this afternoon.

Moisture is advecting north into the area ahead of the low. As
this occurs ceilings will lower into the MVFR this morning.

As the low moves east scattered storms will develop across the
area during the morning areas and quickly move off to the
northeast. A dry line/front will then sweep through the area
during the afternoon hours additional storms will develop along
this feature, which may be just east of the TAF sites and race off
to the east. IFR conditions will occur with the storms along with
the potential for severe weather with the storms this morning and
afternoon.

Behind the front a much drier air mass will move in with skies
clearing quickly. Mixing will allow for some gusty westerly winds
this afternoon. Gusty winds will occur into this evening and
tonight but will not be as strong as this afternoon.

Low level wind shear will be possible the rest of the early
morning hours and could be possible again late this evening into
tonight too.

&&

.FIRE WEATHER...
Issued at 326 PM CDT Thu Mar 30 2023

A strong low pressure system will track northeast across the
central Plains on Friday. A dry line trailing from the low will
quickly sweep east across southeast KS and the Missouri Ozarks
Friday afternoon. Strong and gusty south winds will become
southwesterly behind the dry line with gusts increasing into the
45-60 mph range. The highest gusts will be near and west of the
I-49 corridor Friday afternoon.

Additionally, humidity will rapidly fall behind the passing dry
line with values in the 18-28% range from mid-afternoon through
early evening near and west of the Highway 65 corridor. Even for
areas that receive light rainfall, the combination of the wind and
low humidity will rapidly dry finer fuels.

A Red Flag Warning has therefore been issued for Friday afternoon
and evening for southeast KS and much of western MO.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...Wind Advisory until 1 PM CDT this afternoon for MOZ066-067-077-
     078-088-089-093-094-101-102.

     High Wind Warning from 1 PM this afternoon to 7 PM CDT this
     evening for MOZ066-067-077-078-088-089-093-094-101-102.

     Red Flag Warning from 2 PM this afternoon to 10 PM CDT this
     evening for MOZ055-056-066>069-077>081-088>091-093>095-
     101>103.

     Wind Advisory from 1 PM this afternoon to 1 PM CDT Saturday for
     MOZ055>058-068>071-080-081.

     Wind Advisory until 7 PM CDT this evening for MOZ079-090-095-103-
     104.

     Wind Advisory from 1 PM this afternoon to 1 AM CDT Saturday for
     MOZ082-083-091-092-096>098-105-106.

KS...Wind Advisory until 1 PM CDT this afternoon for KSZ073-097-101.

     High Wind Warning from 1 PM this afternoon to 7 PM CDT this
     evening for KSZ073-097-101.

     Red Flag Warning from 2 PM this afternoon to 10 PM CDT this
     evening for KSZ073-097-101.

&&

$$

SHORT TERM...Schaumann
LONG TERM...Schaumann
AVIATION...Wise
FIRE WEATHER...Schaumann