Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 020232
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
832 PM CST SUN FEB 1 2015

.UPDATE...
ISSUED AT 829 PM CST SUN FEB 1 2015

CONDITIONS IMPROVING WITH WINDS LOWER THAN EXPECTED IN THE
SOUTHEAST. WILL ALLOW WINTER STORM WARNING TO EXPIRE AT 03Z. ALSO
WILL ISSUE A WIND CHILL ADVISORY FROM KDNS-KALO AND NORTH FOR 09Z
TO 15Z. NO OTHER SIGNIFICANT CHANGES TO FORECAST.

&&

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CST SUN FEB 1 2015

CONCERNS REMAIN THROUGH EARLY EVENING...BUT STORM IS BEGINNING TO
DEPART THE REGION AND CONDITIONS WILL RAPIDLY IMPROVE AFTER 06Z.
STRONG UPPER LEVEL LOW STILL PROVIDING QG FORCING RIGHT OVER THE I80
CORRIDOR CURRENTLY...AND AS EXPECTED DEF AXIS EXTENDS BACK INTO THE
REGION NOW...AND SHOULD BE MOVING EAST THIS EVENING TAKING THE
REMAIN IN AREA OF SNOW ALONG WITH IT. OVERALL ANOTHER INCH OR SO OF
LIGHT SNOW BETWEEN NOW AND EARLY EVENING OVER CENTRAL WITH 1 TO 2
POSSIBLE ADDITIONAL INCHES IN THE SOUTHEAST NEAR OTTUMWA. MOST OF
THE DAY THE WESTERN FRINGES OF THE AREA HAVE BEEN AFFECTED BY THE
STRONG SFC GRADIENT AS WELL AS COLD AIR ADVECTION...MORE PRONOUNCED
THAN THE CENTRAL AND SOUTHEAST. THIS HAS RESULTED IN BETTER MIXING
AND STRONGER WIND GUSTS. VISIBILITY HAS ALSO BEEN VARIABLE BETWEEN
1/2 AND 1/4 MILES AT TIMES...WITH NEAR BLIZZARD CONDITIONS IN RURAL
AREAS. BUFR SOUNDINGS CONTINUE TO SHOW THAT BETWEEN 23Z AND ABOUT
02Z WIND GUSTS WILL INCREASE ACROSS CENTRAL AND SOUTHEAST SECTIONS
FOR A PERIOD OF 2 TO 3 HOURS...GUSTING TO NEAR 40 MPH WITH BLOWING
SNOW. ALONG WITH THAT...TREES REMAIN SNOW COVERED AND LIKELY NOW THE
SNOW HAS FROZEN TO THE TREES. THIS MAY LEAD TO AN ADDITIONAL PERIOD
OF TREE DAMAGE AND THE POTENTIAL AGAIN FOR POWER OUTAGES DURING THE
EVENING HOURS. THE SYSTEM WILL EXIT THE AREA FROM NORTHWEST TO
SOUTHEAST WITH CLEARING BEGINNING NORTHWEST AROUND 02Z AND
PROGRESSING TOWARD OTTUMWA BY 10Z.  NEXT CONCERN WILL BE
TEMPERATURES. QUITE COLD CONDITIONS UPSTREAM OVER THE DAKOTAS.
CURRENT SURFACE WIND TRAJECTORY IS PULLING AIR IN FROM THE EASTERN
GREAT LAKES BUT BY 08Z TO 12Z WINDS WILL BE MORE NORTHWEST. AS RIDGE
SETTLES INTO THE AREA TEMPERATURES WILL BE WELL BELOW ZERO OVER THE
WEST AND NORTHWEST WITH RIDGE AXIS APPROACHING THE AREA. READINGS
MOST AREAS WITH THE EXCEPTION OF THE SOUTHEAST WILL BE BELOW ZERO BY
EARLY MORNING.

.LONG TERM /MONDAY THROUGH SUNDAY/...
ISSUED AT 340 PM CST SUN FEB 1 2015

LONG TERM WILL REMAIN IN AN ACTIVE PATTERN WITH PERIODS OF COLD AND
SNOW FOLLOWED BY MODERATING TEMPS. WE START OUT MONDAY VERY COLD
WITH THE FRESH SNOWPACK AND WIND CHILLS BETWEEN 10 AND 20 BELOW.  WE
DO BRIEFLY ECLIPSE ADVISORY CRITERIA IN THE FAR NW FOR A FEW HOURS
MONDAY MORNING BUT FOR RIGHT NOW THE BIGGER HEADLINE REMAINS THE
WINTER STORM WARNING THROUGH 9 PM.  THE EVENING SHIFT CAN EVALUATE
AFTER THE WINTER STORM WARNING IS OVER.

A WEAK SHORTWAVE SLIDES ACROSS NORTHEAST IOWA LATE MONDAY THROUGH
MONDAY EVENING.  NOT MUCH MOISTURE BUT THERE IS SOME FORCING AND IN
THE COLD AIR IT WONT TAKE MUCH TO SQUEEZE OUT SOME MEASURABLE
SNOWFALL.  I AM LOOKING AT SNOWFALL AMOUNTS LESS THAN AN INCH MAINLY
NORTHEAST OF AN ALGONA TO OTTUMWA LINE.

WE REMAIN IN A PARADE OF SHORTWAVES THROUGH THE REMAINDER OF THE
WEEK AND TUESDAY STILL LOOKS INTERESTING.  AS I SUSPECTED...THE
MODELS HAVE COME IN COLDER TUESDAY...THAT IS TO SAY NOT AS WARM AS
THEY WERE YESTERDAY.  THEY STILL DEVELOP A WARM FRONT JUST SOUTH OF
IOWA AS A SHORTWAVE DRIFTS THROUGH.  THE SOUNDINGS SHOW PRETTY QUICK
SATURATION THROUGH A DEEP LAYER AND THERE IS DECENT FORCING AND I
HIT SNOWFALL A BIT HARDER TODAY WITH ONE TO TWO INCHES ACROSS ALL
BUT THE FAR SOUTHERN FORECAST AREA.

FOR WEDNESDAY A STRONG ARCTIC BOUNDARY WILL MOVE IN AND WHILE MODELS
VARY ON THE AMOUNT OF MOISTURE...ONCE AGAIN ANOTHER SHORT WAVE
SWINGS ACROSS THE AREA COINCIDENT WITH THE FRONTAL BOUNDARY SO WE
ARE LOOKING FOR ANOTHER INCH OR TWO ACROSS MAINLY THE SOUTHERN
SECTIONS OF THE FORECAST AREA.  WE WILL REMAIN UNDER THE INFLUENCE
OF THE ARCTIC HIGH THROUGH THE END OF THE WEEK SO TEMPS WILL BE
COLD.

THERE IS SOME HOPE OF MODERATION TOWARDS FRIDAY/SATURDAY AS THE HIGH
MOVES OFF AND RETURN FLOW ENTERS IOWA BUT WITH THE FRESH SNOW I DONT
THINK MODELS ARE HANDLING TEMPS WELL AT ALL.  I EXPECT TO SEE COOLER
TEMPS WITH FUTURE MODEL RUNS. ANOTHER WEAK SHORT WAVE IS PROGGED TO
MOVE ACROSS IOWA SATURDAY NIGHT/SUNDAY FOR ANOTHER SHOT OF SNOW.

&&

.AVIATION...02/00Z
ISSUED AT 518 PM CST SUN FEB 1 2015

LOW PRESSURE OVER IN IS PULLING AWAY AS HIGH PRESSURE OVER THE
DAKOTAS BUILDS INTO THE AREA. IMPROVING CONDITIONS FROM THE
NORTHWEST WITH VFR REACHING THE NORTHWEST SITES THIS EVENING AND
THE SOUTHEAST LATE TONIGHT. VFR WITH MID LEVEL CONDITIONS AND
LIGHT WINDS MONDAY.

OUTLOOK...FAST MOVING PATTERN WILL BRING A SERIES OF WEATHER
SYSTEMS THROUGH THE AREA ABOUT EVERY 24 HOURS BEGINNING MONDAY
NIGHT. EACH WILL BRING MVFR TO IFR CONDITIONS IN SNOW AND STRATUS
FOR A SEVERAL HOUR PERIOD.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR ADAIR-ADAMS-
APPANOOSE-AUDUBON-BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-
CASS-CERRO GORDO-CLARKE-CRAWFORD-DALLAS-DAVIS-DECATUR-EMMET-
FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-
JASPER-KOSSUTH-LUCAS-MADISON-MAHASKA-MARION-MARSHALL-MONROE-PALO
ALTO-POCAHONTAS-POLK-POWESHIEK-RINGGOLD-SAC-STORY-TAMA-TAYLOR-
UNION-WAPELLO-WARREN-WAYNE-WEBSTER-WINNEBAGO-WORTH-WRIGHT.

WIND CHILL ADVISORY FROM 3 AM TO 9 AM CST MONDAY FOR BLACK HAWK-
BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CERRO GORDO-CRAWFORD-EMMET-
FRANKLIN-GREENE-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-KOSSUTH-
PALO ALTO-POCAHONTAS-SAC-STORY-WEBSTER-WINNEBAGO-WORTH-WRIGHT.

&&

$$

UPDATE...MS FEB 15
SHORT TERM...REV
LONG TERM...FAB
AVIATION...MS FEB 15



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