683
FXUS63 KDMX 140637
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
137 AM CDT THU MAY 14 2026
KEY MESSAGES
- SCATTERED LIGHT SHOWERS AND A FEW THUNDERSTORMS ACROSS THE
NORTHERN HALF OF IOWA THIS AFTERNOON AND EVENING. SEVERE
WEATHER IS UNLIKELY IN THAT AREA. ANOTHER ROUND OF SCATTERED
STORMS OVER FAR SOUTHERN AND SOUTHEASTERN IOWA AFTER SUNSET
TONIGHT, WHERE THERE IS A MARGINAL RISK OF LARGE HAIL AND
STRONG WIND GUSTS WITH ANY STORMS.
- STRONG SOUTHERLY BREEZES TODAY, WITH SPEEDS OF 15-25 MPH IN
MOST AREAS THIS AFTERNOON AND GUSTS TO NEAR 40 MPH IN OUR
NORTHWESTERN COUNTIES. COMBINED WITH CONTINUING DRY CONDITIONS
AS RELATIVE HUMIDITY FALLS BELOW 30% THIS AFTERNOON, THERE ARE
ELEVATED FIRE WEATHER CONCERNS IN PARTS OF NORTHERN AND
WESTERN IOWA.
- WARMER AND MORE ACTIVE AT TIMES FROM LATER FRIDAY INTO EARLY
NEXT WEEK. HIGHS GENERALLY IN THE 80S EACH DAY AND MAY TOUCH
90 IN SOME PLACES. SEVERAL ROUNDS OF THUNDERSTORMS FROM LATE
FRIDAY THROUGH MONDAY.
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 137 AM CDT THU MAY 14 2026
IT HAS ONCE AGAIN BEEN A DRY, QUIET, CLEAR, AND SEASONALLY COOL
NIGHT ACROSS THE REGION WITH TEMPERATURES FALLING INTO THE UPPER
40S TO MID-50S AS OF THIS WRITING. HOWEVER, CHANGES ARE ON THE
WAY IN THE FORM OF WARMER AND STORMIER WEATHER OVER THE NEXT
SEVERAL DAYS. A LARGE SURFACE HIGH PRESSURE AREA IS CURRENTLY
RETREATING EASTWARD FROM WISCONSIN AND ILLINOIS TOWARD THE GREAT
LAKES REGION, WITH SURFACE FLOW IN OUR SERVICE AREA TURNING
AROUND TO LIGHT SOUTHEAST AND COOL, DRY AIR FLOWING IN FROM THE
DEPARTING HIGH. MEANWHILE, AT 500 MB A THERMAL RIDGE IS MOVING
OVER THE HIGH PLAINS AND WILL CROSS IOWA DURING THE DAY TODAY.
HOT ON ITS HEELS, A 500 MB LOW IS MOVING FROM MONTANA UP INTO
FAR SOUTHERN CANADA, WHERE IT WILL TRANSLATE SLOWLY EAST
NORTHEASTWARD OVER THE NEXT COUPLE OF DAYS. THIS WILL PLACE IOWA
BENEATH RELATIVELY BRISK ZONAL TO SLIGHTLY CYCLONIC STEERING
FLOW FOR THE REMAINDER OF THE WEEK.
A 500 MB SHORTWAVE IMPULSE WILL ROUND THE BASE OF THE LOW MOVING
UP INTO SOUTHERN CANADA TODAY, EMERGING OVER THE UPPER MIDWEST
THIS AFTERNOON AND EVENING. IN ADVANCE OF THIS IMPULSE, A BROAD
SURFACE LOW PRESSURE TROUGH WILL DEVELOP ALONG THE LEE OF THE
ROCKIES TODAY. THE PRESSURE GRADIENT BETWEEN THIS TROUGH AND
THE DEPARTING RIDGE OVER THE GREAT LAKES WILL TIGHTEN UP OVER
IOWA TODAY, ESPECIALLY IN OUR WESTERN COUNTIES THIS AFTERNOON.
SURFACE WINDS WILL TURN TO SOUTH SOUTHEAST AND ACCELERATE IN
RESPONSE, RESULTING IN ANOTHER BREEZY DAY ACROSS IOWA. THE SOUTH
SOUTHEASTERLY FETCH ALONG WITH AFOREMENTIONED THERMAL RIDGING
ALOFT WILL GENERALLY SUPPORT WARMER WEATHER TODAY. HOWEVER, THE
BROAD FORCING FOR ASCENT ASSOCIATED WITH THE SHORTWAVE ALOFT
WILL RESULT IN INCREASING CLOUDS FROM WEST TO EAST DURING THE
DAY, WHICH WILL BLUNT THE WARMING A BIT. EVEN SO, HIGHS ARE
FORECAST IN THE UPPER 70S TO PERHAPS 80 ACROSS OUR AREA THIS
AFTERNOON. MEANWHILE, THE CURRENT FORECAST CALLS FOR SUSTAINED
WINDS OF 20-25 MPH ACROSS MUCH OF THE AREA BY THE AFTERNOON,
WITH GUSTS TO NEAR 40 MPH ESPECIALLY IN OUR NORTHWESTERN
COUNTIES. COMBINED WITH RH FALLING INTO THE 25-30% RANGE THIS
WILL SUPPORT ELEVATED FIRE WEATHER CONCERNS ACROSS NORTHERN AND
WESTERN IOWA, THOUGH MITIGATED BY THE GREENNESS OF MANY SURFACE
FUELS.
ASIDE FROM TEMPERATURE AND WIND EFFECTS, POPS ALSO RETURN TO THE
FORECAST TODAY AS THE SHORTWAVE APPROACHES. THE AFOREMENTIONED
BROAD LIFT SUPPORTS A POSSIBILITY OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON AND EVENING ACROSS ABOUT THE NORTHERN HALF OF
IOWA, AND MOST MODEL SOLUTIONS DEPICT LIGHT ECHOES/QPF
ACCORDINGLY. FORECAST SOUNDINGS TO ILLUSTRATE A RELATIVELY STOUT
SURFACE DRY LAYER THAT WILL NEED TO BE OVERCOME, HOWEVER, AT
LEAST SCATTERED LIGHT SHOWERS AND A FEW THUNDERSTORMS SHOULD
STILL OCCUR IN OUR NORTHERN COUNTIES WHERE 40% POPS ARE CARRIED.
IT REMAINS TO BE SEEN HOW FAR SOUTH THESE WILL BE ABLE TO
SPREAD TOWARD CENTRAL IOWA, AS MOST OF THE FORCING IS FOCUSED TO
OUR NORTH, AND THE SURFACE DRY LAYER IS A BIT DEEPER/STRONGER
THE FARTHER SOUTH ONE GOES. IN ANY EVENT, LIMITED INSTABILITY
AND SHEAR ARE NOT SUPPORTIVE OF SEVERE WEATHER DURING THIS TIME.
THE SAME IS UNFORTUNATELY NOT TRUE IN SOUTHERN IOWA TONIGHT,
WHERE ADDITIONAL SHOWERS AND THUNDERSTORMS MAY DEVELOP ALONG THE
NOSE OF A NOCTURNAL LOW- LEVEL JET. THIS JET WILL INITIALLY
PRESENT ITSELF OVER EASTERN KANSAS THIS EVENING, THEN INTENSIFY
AND SPREAD INTO NORTHERN MISSOURI AFTER DARK TONIGHT. WHILE
INSTABILITY WILL BE MINIMAL OVER MUCH OF OUR FORECAST AREA, IT
WILL PERK UP TOWARD THE MISSOURI BORDER WITH MUCAPE OF AROUND
1000-1500 J/KG IN OUR FAR SOUTHERN COUNTIES. WHILE STORMS ARE
LIKELY FROM EASTERN KANSAS ACROSS NORTHERN MISSOURI IN
ASSOCIATION WITH THE DEVELOPING LLJ, IT IS UNCERTAIN HOW FAR
NORTH OF THE BORDER ANY STORMS WILL BE ABLE TO PENETRATE. GIVEN
THE ORIENTATION OF THE LLJ, THE MOST LIKELY PORTION OF OUR AREA
TO BE IMPACTED IS IN THE SOUTHEAST, ROUGHLY SOUTH OF A LINE FROM
MOUNT AYR TO OSKY OR SO, AND 40-60% POPS ARE CARRIED IN THAT
AREA OVERNIGHT ACCORDINGLY. GIVEN THE AFOREMENTIONED INSTABILITY
AND DEEP-LAYER SHEAR OF AROUND 30-40 KT, ANY STORMS THAT DO
REACH OUR FORECAST AREA WILL CARRY AN ATTENDANT THREAT OF LARGE
HAIL OR STRONG WIND GUSTS, AS OUTLINED APPROPRIATELY IN SPC
OUTLOOKS.
ANY OVERNIGHT THUNDERSTORMS IN OUR AREA WILL MOVE OFF TO THE
EAST BY EARLY FRIDAY MORNING AS THE SHORTWAVE AND LLJ DEPART,
YIELDING QUIET WEATHER FOR MOST OF THE DAY. THE SURFACE TROUGH
DEVELOPING ALONG THE LEE OF THE ROCKIES TODAY WILL SHUNT
SOUTHWARD AS A LOW CENTERED NEAR THE TEXAS PANHANDLE ON FRIDAY,
WHILE A SURFACE HIGH PRESSURE AREA DEVELOPS FROM MONTANA ACROSS
THE DAKOTAS AND TOWARD NORTHWESTERN IOWA. THIS WILL SET UP A
WEAK EFFECTIVE WARM FRONT LIKELY ORIENTED FROM WEST SOUTHWEST TO
EAST NORTHEAST SOMEWHERE ACROSS IOWA BY FRIDAY AFTERNOON.
ANOTHER 500 MB IMPULSE WILL APPROACH FROM THE WEST LATE IN THE
DAY, AND WITH STRONG INSTABILITY POOLING INTO IOWA SOUTH OF THE
BOUNDARY, PRESENT AN INCREASING CHANCE OF THUNDERSTORMS AND
SEVERE WEATHER LATE IN THE DAY. FORECAST SOUNDINGS INDICATE A
CAPPING INVERSION THAT WILL NEED TO BE OVERCOME, AND THIS WILL
LIKELY NOT OCCUR UNTIL FRIDAY EVENING AND ESPECIALLY FRIDAY
NIGHT, AS DISCUSSED FURTHER BELOW. OTHERWISE, THE MOST SENSIBLE
WEATHER EFFECT ON FRIDAY WILL BE MUCH WARMER TEMPERATURES, AS
WARM AIR ADVECTION AND AMPLE SUNSHINE SEND HIGHS INTO THE UPPER
80S ACROSS THE AREA, WITH LOWER 90S EVEN POSSIBLE IN THE WESTERN
HALF OF THE STATE.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
ISSUED AT 255 PM CDT WED MAY 13 2026
CLOUDS AND STORM CHANCES RETURN LATE FRIDAY INTO EARLY SATURDAY
AS A FRONT MOVES INTO THE STATE. THESE STORMS WILL BE FIGHTING
A HIGH PRESSURE IN THE NORTH AND DRY AIR. MODELS STILL HAVE A
FAIR AMOUNT OF DISAGREEMENT IN THE SOUTH IN THE TIMING AND
LOCATION OF THE NEXT SLUG OF THETA-E ADVECTION AND THE LLJ IS
NOT FAVORABLY POSITIONED. THE DEEP MOISTURE OFF THE GULF IS ALSO
SHUNTED OFF TO THE EAST IN THE LOW TO MID LEVELS POTENTIALLY
PUSHING THE GREATEST STORM THREAT TO THE EAST AS CONDITIONS WERE
LOOKING THIS TIME YESTERDAY, THOUGH MODELS ARE ALSO FURTHER
NORTH THAN THEY WERE YESTERDAY WITH BALLOONING INSTABILITY AND
STILL SUFFICIENT SHEAR IN SOUTHERN IOWA. CERTAINLY CANNOT RULE
OUT SOME STRONG TO SEVERE STORMS, BUT THE MESOSCALE DETAILS
REMAIN A BIT TOO UNCERTAIN AT THIS POINT WITH REFINEMENTS
LIKELY. THE SPC DOES HAVE A MARGINAL RISK (LEVEL 1 OUT OF 5) FOR
A GOOD PORTION OF THE AREA AND A SLIGHT RISK (LEVEL 2 OUT OF 5)
IN THE FAR SOUTH/SOUTHEAST ON LATE FRIDAY INTO SATURDAY.
THE ACTIVE PATTERN REMAINS THROUGH THE WEEKEND WITH ADDITIONAL STORM
CHANCES LATER SATURDAY INTO SUNDAY, AND AGAIN LATER SUNDAY INTO
MONDAY, AND ON MONDAY. SPC HAS ALL 3 OF THESE PERIODS (SATURDAY,
SUNDAY, MONDAY) WITH A 15% RISK. IT IS LIKELY THAT WHAT HAPPENS THE
PREVIOUS DAY WILL SOMEWHAT DICTATE WHAT HAPPENS IN SUBSEQUENT DAYS.
WILL CONTINUE TO WATCH THESE PERIODS CLOSELY AND PROVIDE ADDITIONAL
DETAILS IN THE COMING DAYS. TEMPERATURES WILL REMAIN WARM AND AT
LEAST IN THE 80S THROUGH THE WEEKEND. THESE TEMPERATURES WERE HELD
DOWN A BIT FROM NBM WITH NBM ON THE HIGH END OF THE TEMPERATURE
DISTRIBUTION AND LIKELY AFFECTED BY STORMS AND CLOUD DEBRIS AT
TIMES.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1038 PM CDT WED MAY 13 2026
CLOUD COVER IS EXPECTED TO INCREASE THROUGH THE DAY, ESPECIALLY
AFTER 18Z AS MID-LEVEL CLOUDS GRADUALLY MOVE WEST TO EAST OVER
IOWA. VFR CONDITIONS ARE EXPECTED TO REMAIN THOUGH ACROSS THE
TERMINALS THROUGH THE DAY. WINDS OUT OF THE SOUTHEAST THIS
MORNING WILL SHIFT MORE SOUTHERLY THROUGH THE DAY, AND INCREASE
LATE MORNING THROUGH THE AFTERNOON AS GUSTS UP TO 20-30 KNOTS
ARE ANTICIPATED, ESPECIALLY OVER NORTHERN IOWA. THERE REMAINS A
LOW SIGNAL FOR SHOWER ACTIVITY ACROSS NORTHERN IOWA INTO THE
LATER AFTERNOON/EARLY EVENING, THOUGH HAVE LEFT OUT OF THIS
CURRENT TAF PERIOD GIVEN LOW CONFIDENCE DUE TO LOW LEVEL DRY
AIR. CHANCES THEN INCREASE ACROSS THE FAR SOUTH LATE IN THE
PERIOD, BUT REMAIN LOW ENOUGH IN PROBABILITIES TO LEAVE OUT OF
THIS FORECAST ISSUANCE AND WILL CONTINUE TO MONITOR.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...05
LONG TERM...05
AVIATION...BURY
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