Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 312325
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
625 PM CDT TUE MAR 31 2015

.SYNOPSIS...
ISSUED AT 346 PM CDT TUE MAR 31 2015

TEMPS WELL ABOVE NORMAL AND MAINLY WELL IN THE 60S TO LOWER 70S AT 3PM
WITH DEEP MIXING...DRY GROUND AND ABUNDANT SUNSHINE. THE ONLY
EXCEPTION BEING PORTIONS OF FAR NORTHWEST IL COUNTIES WHICH ARE SEEING
MORE CUMULUS WHERE BETTER LOW LEVEL MOISTURE LINGERING IN WAKE OF
LAKE ENHANCED BOUNDARY LIMITING TEMPS TO UPPER 50S/NEAR 60 FEW SPOTS.

PASSAGE OF SURFACE AND UPPER LEVEL RIDGING SUPPORTS DRY AND MAINLY
CLEAR SKIES MUCH OF NEXT 24 HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 346 PM CDT TUE MAR 31 2015

SURFACE RIDGE AXIS WILL PASS THROUGH THE CWA THIS EVENING THEN SHIFT
INTO OHIO VALLEY OVERNIGHT. SKIES WILL BE MAINLY CLEAR WITH WINDS
BECOMING LIGHT THEN SHIFTING TO SOUTHEAST AND SOUTH OVERNIGHT.
COOLEST LOW TEMPS (MAINLY 30S) FAVORED NORTHEAST HALF OF CWA WITH
MILDER LOWS IN THE 40S FAR WEST AND SOUTHWEST CWA WHERE STRONGER
SOUTHERLY WINDS EXPECTED TO DEVELOP OVERNIGHT.

WEDNESDAY...MAIN ITEM IS FIRE WEATHER CONCERNS OTHERWISE... WINDY AND
WARM WITH HIGHS IN THE 70S AREAWIDE BENEATH MAINLY SUNNY SKIES.
THE GUSTY SOUTHERLY WINDS 15-30 MPH AND DRY VEGETATION COMBINED WITH
LOWERING RELATIVE HUMIDITY VALUES WILL POSE VERY HIGH TO EXTREME FIRE
DANGER POTENTIAL. SEE FIRE WEATHER SECTION BELOW.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 346 PM CDT TUE MAR 31 2015

FORECAST FOCUS ON THUNDERSTORMS WEDNESDAY NIGHT THEN A SNOW
POTENTIAL ON FRIDAY. CONVECTIVELY ACTIVE PATTERN NEXT WEEK.

WEDNESDAY NIGHT...MOST OPERATIONAL MODELS HAVE SLOWED THE SYSTEM
JUST ENOUGH TO KEEP THE FIRST HALF OF THE EVENING DRY. FORECAST
SOUNDINGS SHOW DRY LOW LEVELS. BELIEVE THE GFS IS A BIT TOO
AGGRESSIVE WITH BRINGING QPF EASTWARD. THIS SLOWER MOVEMENT ALSO
DIMINISHES THE POTENTIAL FOR STRONGER STORMS AND INDEED SPC HAS
SHIFTED THE MARGINAL SEVERE FARTHER TO THE WEST OF THE DVN CWA.
UPPER LEVEL TROUGH WILL PROVIDE LARGE SCALE ASCENT AND WITH
INCREASING MOISTURE SHOWERS AND THUNDERSTORMS WILL BE AT LEAST
LIKELY. RAINFALL AMOUNTS MAY POTENTIALLY BE UP TO AN INCH IN OUR
WESTERN CWA...WITH LESSER AMOUNTS FARTHER EAST.

THURSDAY...SHOWERS AND THUNDERSTORMS WILL GRADUALLY END FROM NW TO
SE AS A COLD FRONT PUSHES SLOWLY ACROSS THE CWA. TEMPERATURES WILL
BE COOLER WITH HIGHS IN THE LOWER TO MID 60S.

FRIDAY...INTERESTING SCENARIO AS COLDER AIR INVADES THE CWA AS A
SECONDARY COLD FRONT AND UPPER LEVEL TROUGH PUSH INTO THE REGION.
THE ECMWF/GFS ALLOWS FOR CYCLOGENESIS IN THE SOUTHERN PLAINS TO PUSH
NORTHEAST AND INTENSIFY AS IT TRACKS INTO THE OHIO VALLEY. 850 MB
TEMPERATURES LOWER TO -4 TO -6C WHICH WOULD SUGGEST RAIN TURNING TO
SNOW. HOWEVER...1000-500 MB THICKNESS VALUES DON`T COOL DOWN TO THE
TRADITIONAL 540 THICKNESS FOR SNOW UNTIL LATER IN THE AFTERNOON AND
BY THAT TIME THE DEEPER MOISTURE IS STARTING TO SHIFT TO OUR EAST.
OTHER FACTORS TO CONSIDER TO DOWNPLAY ANY ACCUMULATION IS THIS IS
OCCURRING DURING THE DAY AND THE GROUND WILL BE WARM. FOR NOW WILL
MENTION RAIN/SNOW MIX OR CHANGING TO SNOW IN THE AFTERNOON.
TEMPERATURES WILL ALSO BE FALLING DURING THE DAY INTO THE 30S.

SUNDAY THROUGH TUESDAY...ACTIVE CONVECTIVE PATTERN AS UPPER FLOW
BECOMES MORE SOUTHWESTERLY COMBINED WITH GULF MOISTURE TRANSPORT...
ALONG WITH SYNOPTIC BOUNDARIES PUSHING INTO THE MIDWEST. THIS
APPEARS TO BE A PERIOD OF ACTIVE THUNDERSTORMS ALONG WITH MILD TO
WARM TEMPERATURES.

HAASE

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 625 PM CDT TUE MAR 31 2015

CLEAR SKIES AND VFR CONDITIONS WILL CONTINUE OVERNIGHT INTO
WEDNESDAY AS HIGH PRESSURE MOVES EAST OF THE REGION. LIGHT AND
VARIABLE WINDS OVERNIGHT WILL INCREASE AND BECOME GUSTY FROM THE
SOUTH FROM 15 TO 25 KTS AT ALL SITES LATE WEDNESDAY MORNING.

&&

.FIRE WEATHER...
ISSUED AT 346 PM CDT TUE MAR 31 2015

SOUTHERLY WINDS WILL INCREASE ON WEDNESDAY INTO RANGE OF 15 TO 25 MPH
WITH GUSTS TO NEAR 35 MPH AT TIMES. THIS COUPLED WITH VERY DRY
VEGETATION WILL LEAD TO A VERY HIGH TO EXTREME RISK OF FIRE DANGER
ON WEDNESDAY. THERE IS SOME POTENTIAL FOR RED FLAG WARNING
CRITERIA BEING MET...ESPECIALLY PORTIONS OF EASTERN IOWA WHERE
CURRENTLY FORECASTING MIN RELATIVE HUMIDITY VALUES NEAR 25 PERCENT
AND WINDS NEAR 25 MPH SUSTAINED CRITERIA. GIVEN THE ABOVE HAVE
GONE WITH A FIRE WEATHER WATCH FOR PORTIONS OF EASTERN IOWA WHERE
THE RED FLAG WARNING CRITERIA CLOSEST TO BEING MET AND WHERE GFDI
VALUES ARE IN EXTREME CATEGORY. THE CONCERN IS THAT WITH DRY
GROUND AND SLIGHTLY BACKED SOUTHEAST WIND JUST OFF SURFACE PULLING
IN DRY AIR FROM DEPARTING HIGH THAT THE DEWPOINTS FORECAST IN THE
UPPER 30S TO LOWER 40S MAY BE A BIT TOO HIGH. WHEN MIXING DOWN
FROM FCST SOUNDINGS (875-850 MB) ACTUALLY YIELDS LOWER DEWPTS IN
MID/UPPER 30S FAIRLY WIDESPREAD. THUS...COULD SEE MORE OF AREA
CLOSER TO RED FLAG WARNING CRITERIA.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
     EVENING FOR BENTON-BUCHANAN-DELAWARE-HENRY IA-IOWA-
     JEFFERSON-JOHNSON-KEOKUK-LINN-VAN BUREN-WASHINGTON.

IL...NONE.
MO...NONE.
&&

$$

SYNOPSIS...05
SHORT TERM...05
LONG TERM...HAASE
AVIATION...SHEETS
FIRE WEATHER...05






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