Area Forecast Discussion
Issued by NWS Des Moines, IA

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KDMX 021733
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1233 PM CDT THU JUL 2 2015

.SHORT TERM /TODAY/...
ISSUED AT 308 AM CDT THU JUL 2 2015

WEAK UPPER LEVEL WAVE DROPPING SOUTHEASTWARD THROUGH THE WESTERN
DAKOTAS...TO SLIDE THROUGH SOUTHWESTERN IOWA THIS AFTERNOON IN
NORTHWEST FLOW PATTERN ALOFT. CURRENTLY AN AREA OF THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE DEVELOPED ACROSS THE CENTRAL
DAKOTAS...WITH ADDITIONAL ACTIVITY EXPECTED TO DEVELOP ACROSS
SOUTHEAST SD AND WESTERN IOWA THROUGH THE DAY AS THE WAVE PUSHES
THROUGH THE STATE. AREA ALSO UNDER THE INFLUENCE OF A LARGE AREA OF
HIGH PRESSURE CENTERED OVER WI/ERN MN/NE IA. HIGH RES MODELS CONFINE
THE MAJORITY OF THE CONVECTIVE ACTIVITY TO THE WEST OF THE CWA
ACROSS ERN NE AND FAR WESTERN IOWA. THIS LOOKS LIKE A FAIRLY DECENT
SOLUTION GIVEN THE TRAJECTORY OF THE UPPER WAVE AND DEALING WITH THE
INFLUENCE OF THE LARGE AREA OF HIGH PRESSURE AS WELL. THEREFORE HAVE
TRIMMED POPS SOME ACROSS THE CENTRAL/NORTHERN PORTIONS OF THE CWA
FOR TODAY...AND CONFINED THE POPS TO THE FAR WESTERN/SOUTHWESTERN
PORTIONS OF THE CWA. CLOUD COVER TO BE FAIRLY EXTENSIVE ACROSS THE
CWA TODAY WITH THAT UPPER WAVE MOVING THROUGH...BUT SHOULD STILL SEE
SOME PEEKS OF SUN ACROSS THE NORTHEAST. THEREFORE HAVE THE WARMEST
TEMPS IN THAT AREA...WITH SLIGHTLY COOLER HIGHS WHERE CLOUD COVER IS
GREATER AND CHANCES OF PRECIP AS WELL.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 308 AM CDT THU JUL 2 2015

LITTLE CHANGE TO THE GOING FORECAST AS THE OVERALL PATTERN AND
MODEL TRENDS REMAIN SIMILAR. A SHORTWAVE WILL DROP SOUTH/SOUTHEAST
ACROSS THE STATE THIS EVENING MAINLY AFFECTING FAR WESTERN AND
SOUTHERN IOWA. HOWEVER WITH WEAK INSTABILITY AND ANY DEEPER SHEAR
REMAINING TO THE WEST OF IOWA OR AT LEAST CENTRAL IOWA...WE WILL
MAINLY GET BRUSHED ACROSS THE WEST/SOUTHWEST THIS EVENING WITH
SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM. SEVERE WEATHER
POTENTIAL IS SLIM TO NONE FOR TONIGHT INTO FRIDAY.

THE MAIN SHOW CONTINUES TO BE THE STRONGER SHORTWAVE AND FRONTAL
PASSAGE FOR MONDAY. MODELS HAVE SLOWED THE FROPA DOWN AND NOW
SUNDAY AND SUNDAY EVENING LOOK MAINLY DRY. ONE THING OF NOTE...THE
MODELS BRING INCREASING INSTABILITY INTO IOWA SATURDAY INTO SUNDAY
AHEAD OF THE BOUNDARY. HOWEVER WITH LACK OF APPRECIABLE SHEAR AND
FORCING REMAINING WEST OF THE FORECAST AREA THROUGH SUNDAY EVENING
IT STILL LOOKS MAINLY DRY FOR THE WEEKEND HOWEVER AN ISOLATED
SHOWER OR STORM CANNOT BE RULED OUT. IT IS JUST TOO HIT AND MISS
TO INCLUDE A SLIGHT CHANCE ANYWHERE IN THE FORECAST AREA. SO WHILE
THE FORECAST REMAINS DRY THE INCREASING INSTABILITY MAY BE ENOUGH
FOR AN ISOLATED SHOWER OR STORM. THE MAIN EVENT REMAINS MONDAY
WITH THE FRONTAL PASSAGE EXPECTED DURING PEAK HEATING AND WARM
CLOUD DEPTHS SUFFICIENT FOR HEAVY RAINFALL WE WILL BE RETURNING TO
MENTIONING SEVERE CHANCES AND HEAVY RAINFALL WITH STORMS.

HIGH PRESSURE WILL QUICKLY BUILD IN BEHIND THE FRONTAL PASSAGE
LATE MONDAY NIGHT AND TUESDAY. LINGERING PRECIP WOULD BE CONFINED
TO SOUTHEAST IOWA MONDAY EVENING AND TUESDAY AT THIS POINT LOOKS
DRY. THE NEXT BEST CHANCE FOR PRECIP LOOKS TO BE FROM LATE IN THE
EXTENDED AND BEYOND WITH A LOW AND WARM FRONT SETTING UP SOMEWHERE
IN/NEAR IOWA. MODELS ARE NOT IN ANY SORT OF AGREEMENT AS TO TIMING
AND PLACEMENT WITH THE EURO THINKING THE LOW WILL BE IN NW IA AND
A FRONTAL BOUNDARY DRAPED ACROSS THE HIGHWAY 20 CORRIDOR AND THE
GFS KEEPING THE LOW ACROSS OMAHA AND THE FRONT MUCH FURTHER SOUTH.
THE EURO KEEPS THE STORM/SEVERE CHANCES FURTHER NORTH WHILE THE
GFS SUGGEST MORE WIDESPREAD THUNDERSTORM CHANCES.

&&

.AVIATION...02/18Z
ISSUED AT 1229 PM CDT THU JUL 2 2015

CONDITIONS WILL BE VFR THROUGH PERIOD. SHRA MAY AFFECT WESTERN
SITES KFOD/KDSM EARLY IN PERIOD...BUT HAVE NOT INCLUDED MENTION
ATTM WITH SYSTEM PUSHING SOUTH. WINDS WILL BECOME SOUTHERLY LATE
IN PERIOD...BECOMING LIGHT AFTER 00Z...AND INCREASING AGAIN BEYOND
12Z.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...BEERENDS
LONG TERM...FAB
AVIATION...AWB


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.