Area Forecast Discussion

    
                        

345

FXUS63 KSGF 202305

AFDSGF



Area Forecast Discussion

National Weather Service Springfield MO

605 PM CDT Tue May 20 2025



.KEY MESSAGES...



- Marginal (1 of 5) Risk for severe thunderstorms east of

  Highway 65 before 5 PM today. Hail up to half dollars and wind

  gust up to 60 mph will be the main hazards, but a brief

  window for a tornado cannot be ruled out.



- Marginal (1 of 5) Risk for severe thunderstorms south of

  Highway 60 on Wednesday. Primary hazard will be hail up to

  the size of half dollars.



- Cooler and relatively drier for the rest of this week, though

  a few isolated showers and thunderstorms possible Wednesday

  night (30-40% chance).



- The pattern is starting to look a bit soggy for Memorial Day

  Weekend with daily 40-70% rain chances and increasing model

  agreement for widespread rainfall accumulation.



&&



.SHORT TERM /THROUGH TONIGHT/...

Issued at 1253 PM CDT Tue May 20 2025



Synoptic analysis shows a negatively tilted upper level trough

extending from the northern Plains with the axis through the region,

and a 100+kt upper level jet streak over the Ozarks. An associated

surface low over Iowa is dragging a cold front south through

the forecast area, which is progged to push east out of the area

by the evening.



The Storm Prediction Center has areas east of Highway 65 in a

Marginal (1 of 5) risk for the potential of thunderstorm development

along the front as it continues to push east. This threat looks

fairly conditional, with latest model runs decreasing confidence in

this occuring within our CWA. The 12Z observed sounding shows a

fairly decent capping inversion, with a convective temperature of 83

degrees. Much of the area is expected to remain below that (highs in

the low to mid 70s), with the exception of Shannon/Ozark counties

which are expected to reach the low 80s as daytime heating

continues. By early afternoon, RAP guidance shows MLCAPE between

1000-1500 J/kg and 50-60kt 0-6km bulk shear as that jet streak

pushes overhead. With any storm development, there will be the

potential for them to become strong to severe, with the main hazards

being large hail up to half dollars and damaging wind gusts up to 60

mph. We can`t completely rule out an isolated tornado across the

eastern Ozarks, however this would be the less likely scenario as

SRH and low level shear decreases. By this evening around 5PM, the

severe threat will move out of the area as that front pushes east.



Behind the frontal passage, cooler temperatures will filter into the

region, with overnight lows in the upper 40s and low 50s.



&&



.LONG TERM /WEDNESDAY THROUGH TUESDAY/...

Issued at 1253 PM CDT Tue May 20 2025



Cooler air will continue to filter into the region heading towards

the end of the week, with afternoon highs in the low to mid 70s

(potentially reaching 80 towards the MO/AR border) on Wednesday, and

the upper 60s to low 70s Thursday and Friday. Overnight temperatures

are expected to drop down into the low to mid 40s (eastern Ozarks)

and into the upper 40s (far SW MO/SE KS) by Thursday night. Once we

head into the weekend, confidence in temperatures significantly

decreases, as the NBM 25th and 75th percentiles show a 10-15 degree

spread in both the afternoon highs and overnight lows both Saturday

and Sunday. Current NBM output is sticking towards the lower end of

that range, with highs in the upper 60s/low 70s. However if we

can get more warm air advection behind a warm front that`s

progged to stay south of the area, temperatures could be warmer.



Much of the area should remain dry Wednesday and Thursday, however

there is a 30-40% chance of showers and thunderstorms primarily

south of Highway 60 Wednesday evening as a low level jet over

eastern OK strengthens the isentropic ascent. This would be more of

a conditional scenario, and would depend on enough moisture return

to feed convective potential. Some CAMs hint at this possibility,

however others limit the moisture over the region, which would keep

things dry. If this does come to fruition, elevated instability of

at least 500 J/kg could develop over our area, with RAP guidance

showing deep layer shear between 50-70kts. Therefore, isolated

elevated supercells could pose a large hail threat. But again, this

is a conditional scenario, with low confidence in any convection.

The Storm Prediction Center has introduced a Marginal (1 of 5) risk

south of Highway 60 to account for this potential.



As we head into Memorial Day weekend, an upper level ridging pattern

will continue to slowly build over the Plains, with a frontal

boundary setting up to our south. Lee cyclogenesis developing over

the Rockies will allow for the amplification of a nocturnal low

level jet, which is progged to push overtop the warm front. This

pattern, coupled with upper level energy, will allow for daily

chances (50-60%) of showers and thunderstorms, bringing a wet

Memorial Day weekend. The current NBM probabilities of 72-hour QPF

is as follows:



>0.50": 65-85%

>1.00": 50-65%

>2.00": 25-45%

>4.00": 10-20%



The Weather Prediction Center has highlighted portions of the area

in a Marginal (1 of 4) risk on Friday and the entire area in a

Slight (2 of 4) risk for excessive rainfall on Saturday. We`ll

continue to hone in on specific details as we get closer to this

timeframe, however confidence is medium to high that it will be

a wet holiday weekend. Make sure to keep up with the forecast,

especially if you`re planning on participating in any outdoor

activities, especially along rivers and creeks.



&&



.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...

Issued at 603 PM CDT Tue May 20 2025



For the 00z TAFS, scattered Cumulus should continue to dissipate

early this evening with VFR conditions expected through the

period. Gusty west winds up to 25 kts at the onset of the TAFS

should quickly diminish and become light at less than 8 kts out

of the northwest overnight.



&&



.SGF WATCHES/WARNINGS/ADVISORIES...

KS...None.

MO...None.



&&



$$



SHORT TERM...Melto

LONG TERM...Melto

AVIATION...Lindenberg