Area Forecast Discussion
Issued by NWS Des Moines, IA

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000
FXUS63 KDMX 301729
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1229 PM CDT MON MAR 30 2015

.SHORT TERM /TODAY/...
ISSUED AT 338 AM CDT MON MAR 30 2015

SURFACE RIDGE SLIDING TO THE SOUTH OF IOWA CURRENTLY WITH WINDS
BECOMING SOUTHWEST ACROSS THE STATE.  WARM ADVECTION WILL INTENSIFY
THROUGH THE MORNING ALONG WITH SURFACE WINDS AS PRESSURE GRADIENT
TIGHTENS.  VERY GOOD SETUP FOR WARMING TEMPERATURES TODAY WITH
STRONG SOUTHWEST WINDS...DRY AIRMASS AND GENERALLY A GOOD AMOUNT OF
SUNSHINE.  THERMAL RIDGE WILL BUILD INTO THE STATE BY 00Z AND EXPECT
READINGS TO CLIMB INTO THE 70S FOR MOST LOCATIONS WITH 60S HOLDING
ON IN THE FAR NORTHEAST PORTIONS OF THE CWA.  GIVEN THE DEEP
MIXING...BLENDED MODEL DEWPOINTS WERE TOO HIGH AND LOWERED VALUES
ACCORDINGLY.  SURFACE LOW DROPPING SOUTH THROUGH THE UPPER MIDWEST
WILL REMAIN NORTHEAST OF THE STATE ALONG WITH ANY THREAT OF
PRECIPITATION.

.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 338 AM CDT MON MAR 30 2015

THE LONG TERM ISSUES CONTINUE TO REMAIN ON TRACK. WE START WITH
TONIGHT THROUGH TUESDAY AS BEING A GENERALLY WARM AND QUIET
PERIOD WITH A BUILDING RIDGE ACROSS THE ROCKIES THAT TRANSLATES
INTO THE UPPER MIDWEST. HIGHS THROUGH MIDWEEK WILL BE WARM WITH
READINGS IN THE LOW TO MID 70S. WEDNESDAY WILL BE THE WARMEST DAY
WITH HIGHS IN THE UPPER 70S.

WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT A STRONG SHORTWAVE WILL
MOVE ACROSS THE NORTHERN PLAINS BREAKING DOWN THE RIDGE WHILE AT
THE SURFACE A COLD FRONT WILL SWEEP ACROSS THE REGION. PRECIP WILL
BE TIES TO THE FRONTAL PASSAGE WHICH IS SLOWER AND THUS WILL NOT
COME THROUGH UNTIL VERY LATE AFTERNOON/EVENING. THERE IS A LOT OF
FORCING WITH THIS SYSTEM AND 0-6KM CAPE ON THE ORDER OF 1500 J/KG
SO EVEN THOUGH THE FRONT WONT BE COMING THROUGH DURING THE OPTIMAL
TIME IT IS CLOSE ENOUGH AND PLENTY UNSTABLE WITH AMPLE FORCING
GOOD SHEAR. STILL LOOKS LIKE THUNDERSTORMS WILL BE LIKELY AND A
FEW COULD BECOME SEVERE. SHEAR IS PRETTY UNIDIRECTIONAL SO THREATS
LOOK TO BE MORE HAIL/WIND AT THIS POINT. THE FRONT MOVES THROUGH
BY EARLY THURSDAY MORNING WITH SOME LINGERING SHOWERS POST FRONTAL
INTO EARLY AFTERNOON POSSIBLY. JUST KEPT TOKEN SLIGHT CHANCE POPS
SOUTHEAST IN THE AFTERNOON.

THE REST OF THE EXTENDED IS MARKED WITH SEVERAL SHORTWAVES
PUSHING ACROSS THE REGION BRINGING IN COOLER AIR LATE WEEK INTO
THE WEEKEND AND SOME PRECIP POTENTIAL ACROSS SOUTHERN IOWA LATE
THURSDAY NIGHT OR FRIDAY.

A FRONTAL BOUNDARY TRIES TO ESTABLISH ITSELF ACROSS IOWA IN THE
SUNDAY/MONDAY TIME FRAME BUT MODELS ARE STILL NOT HANDLING THE
DETAILS WELL. I HAVE SLIGHT CHANCE TO LOW CHANCE POPS ACROSS THE
AREA DURING THIS TIME. SOME INSTABILITY WORKS BACK INTO IOWA
MONDAY AND MONDAY NIGHT SO THUNDER WAS MENTIONED.

&&

.AVIATION...30/18Z
ISSUED AT 1227 PM CDT MON MAR 30 2015

VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD. EXPECT GUSTY
SOUTHWEST WINDS THROUGH THE AFTERNOON THEN DIMINISHING OVERNIGHT
AND BECOMING MORE NORTHWESTERLY.

&&

.FIRE WEATHER...
ISSUED AT 359 AM CDT MON MAR 30 2015

WILL SEE A MARGINAL FIRE WEATHER EVENT THIS AFTERNOON WITH RELATIVE
HUMIDITY VALUES DROPPING TO 15 TO 20 PERCENT AND SURFACE WINDS
APPROACHING 25 MPH DURING THE AFTERNOON. GFDI VALUES WILL BE IN
THE LOWER 50 /EXTREME CATEGORY/ IN PORTIONS OF WEST CENTRAL IOWA
AND AFTER COLLABORATION WITH SURROUNDING OFFICES...WILL GO WITH A
RED FLAG WARNING ACROSS ABOUT THE WESTERN HALF OF THE FORECAST
AREA FOR THE AFTERNOON.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR ADAIR-ADAMS-
AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-EMMET-
GREENE-GUTHRIE-HAMILTON-HUMBOLDT-KOSSUTH-MADISON-PALO ALTO-
POCAHONTAS-POLK-RINGGOLD-SAC-STORY-TAYLOR-UNION-WARREN-WEBSTER-
WRIGHT.

&&

$$

SHORT TERM...COGIL
LONG TERM...FAB
AVIATION...DONAVON
FIRE WEATHER...COGIL


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