Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 111616
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1116 AM CDT FRI APR 11 2014

.UPDATE...
ISSUED AT 1115 AM CDT FRI APR 11 2014

NOW THAT THE SHALLOW INVERSION HAS MIXED OUT...TEMPERATURES ARE
NOW RISING RAPIDLY OVER THE AREA THIS MORNING. THE INCREASING
SOUTHWEST WINDS AHEAD OF A WEAK TROUGH OVER MN INTO N CENTRAL IA
IS EXPECTED TO DEEPEN. THE ASSOCIATED MIXING SHOWN ON FORECAST
SOUNDINGS EXCEEDING 800 MB WOULD RESULT IN WIDESPREAD UPPER 60S TO
LOWER 70S. HAVE UPDATED THE FORECAST FOR WARMER HIGHS AND LOWER DEWPOINTS/RH
VALUES SEEN IN GRIDDED/MATRIX PRODUCTS. FURTHER ELABORATION ON HOW
THIS AFFECTS THE FIRE DANGER IS ADDRESSED IN THE FIRE WEATHER
SEGMENT BELOW.

&&

.SYNOPSIS...
ISSUED AT 322 AM CDT FRI APR 11 2014

00Z UPPER AIR ANALYSIS HAD 85OMB COLD FRONT JUST EAST OF CWA
STRETCHING FROM CENTRAL MICHIGAN TO NEAR KPIA. LATEST WV IMAGERY
DEPICTED SEVERAL WEAK SHORTWAVES EMBEDDED IN THE WEST NORTHWEST
FLOW ALOFT TRACKING OVER IOWA...NEBRASKA...AND THE DAKOTAS. THESE
WAVES ARE RESPONSIBLE FOR THE OCCASIONAL BREAKS IN THE HIGH LEVEL
CLOUDS STREAMING ACROSS THE AREA. WHERE THIS CLEARING HAS TAKEN
PLACE IN COMBINATION WITH THE LIGHT AND VARIABLE WINDS...TEMPS HAVE
DROPPED SEVERAL DEGREES WITH SOME SITES ALREADY IN THE UPPER 30S
EARLY THIS MORNING. DEWPOINTS WERE IN THE UPPER 20S TO LOWER 30S
ACROSS THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CDT FRI APR 11 2014

TODAY...QUIET AND DRY CONDITIONS WILL BE SEEN. WINDS TO INCREASE
10 TO 20 MPH OUT OF THE SOUTHWEST AS WEAK HIGH PRESSURE DRIFTS
SOUTH AND EAST OF THE AREA. ALL MODELS TRACK SHORTWAVE OVER THE
DAKOTAS EAST SOUTHEAST THIS AFTERNOON INTO SOUTHERN MINNESOTA AND
WISCONSIN KEEPING PCPN CHANCES FURTHER NORTH OF THE AREA. CLOUDS
TO DIMINISH TODAY GIVING WAY TO MOSTLY SUNNY SKIES AND BREEZY
SOUTHWEST WINDS. LATEST 00Z MODEL SUITE WERE TOO HIGH IN SURFACE
DEWPOINTS THAN COMPARED TO REALITY AND HAVE LOWERED DEWPOINTS SOME
THROUGHOUT THE DAY. THIS COMBINED WITH BREEZY SOUTHWEST WINDS WILL
PUSH RELATIVE HUMIDITY VALUES BELOW 30 PERCENT RESULTING IN AN
ELEVATED RISK FOR GRASS FIRES. FORECAST SOUNDINGS TODAY ALL SHOW
DEEP MIXING TO AT LEAST 750MB WHICH COMBINED WITH THE APRIL SUN
AND THE DRY ATMOSPHERE WILL HELP BOOST TEMPERATURES INTO THE
UPPER 60S AND LOWER 70S BY THE AFTERNOON.

TONIGHT...STRONG WAA WILL COMMENCE AT THE SURFACE AND ALOFT AHEAD
OF ORGANIZING SYSTEM IN THE PLAINS. A WEAK FRONTAL BOUNDARY IS
PROGGED TO BE ACROSS THE NORTH SECTIONS OF THE CWA WITH INCREASING
CLOUDS. HOWEVER...TIME HEIGHT SECTIONS INDICATE A VERY DRY
ATMOSPHERE AND DO NOT EXPECT ANY PCPN IN THE FAR NW SECTIONS BEFORE
12Z SATURDAY. MIN TEMPS TO OCCUR EARLY SATURDAY MORNING AND
REMAIN ABOVE NORMAL...WITH READINGS IN THE MID TO UPPER 40S.


.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 322 AM CDT FRI APR 11 2014

VERY ACTIVE PERIOD IN STORE OVER THE WEEKEND INTO VERY EARLY NEXT
WEEK FEATURING POTENTIAL FOR SEVERE WEATHER SATURDAY PM FOLLOWED
BY INCREASING LIKELIHOOD OF MUCH NEEDED AND BENEFICIAL WIDESPREAD
MODERATE TO HEAVY RAINS FOLLOWED LASTLY BY INCREASING LIKELIHOOD
OF A WINTRY MIX OR CHANGEOVER TO SNOW SUNDAY NIGHT AND MONDAY AM.

SATURDAY AND SATURDAY NIGHT...SCATTERED SHOWERS AND FEW STORMS
LIKELY TO IMPACT AREAS MAINLY NORTH OF I-80 DURING THE DAY WITH
INTERACTION OF SFC WARM FRONT AND TAIL OF ASCENT ATTENDANT TO
UPPER LEVEL SHORTWAVE PASSING THROUGH THE UPPER MIDWEST. FORECAST
HAS WARM FRONT MAKING IT THROUGH ALL BUT FAR NORTH WITH AID OF
DEVELOPING SFC LOW VICINITY OF THE IA/MN BORDER IN RIGHT ENTRANCE
REGION OF H3 JET STREAK. AS RESULT... WILL HAVE WIDESPREAD HIGHS
IN THE 70S WITH POSSIBLY A COUPLE SITES SOUTH TOUCHING 80F WITH
ENOUGH SUNSHINE. HOWEVER... IF THE PCPN FESTERS ALL DAY THIS COULD
RETARD NORTHWARD PROGRESSION OF WARM FRONT AND NEGATIVELY IMPACT
TEMPS (COOLER BY 3-5+ DEGS). BY MID TO LATE SATURDAY AFTERNOON THE
AIRMASS IN WARM SECTOR TO BECOME MODERATELY UNSTABLE WITH MUCAPES
SHOWN TO BE AROUND 1500-2000 J/KG SOUTH OF THE WARM FRONT. ANTICIPATE
CONVECTION TO DEVELOP BY LATE DAY FOCUSING ALONG/N OF WARM FRONT
AND ALSO ALONG COLD FRONT TO OUR WEST. WBZ OF 8000-9000 FT AGL AND
MID LEVEL DRY AIR SHOULD FACILITATE LARGE HAIL AS MAIN THREAT WITH
STORMS WITH SECONDARY THREAT STRONG TO MARGINAL SEVERE WINDS... WITH
THREAT MAINLY 4-10 PM. CONVECTION LIKELY TO CONTINUE INCREASING IN
COVERAGE SATURDAY NIGHT...WITH POTENTIAL FOR UPSCALE GROWTH INTO
MCS AHEAD OF EJECTING WAVE FROM COLORADO. POTENTIAL FOR SWATH(S) OF
AN INCH OR MORE OF RAIN WITH EXCELLENT MOISTURE FEED/TRANSPORT AIDED
BY 30+ KT H85 LOW LEVEL JET.

SUNDAY-SUNDAY NIGHT...MAY SEE PCPN OCCURRING ALL DAY IN ZONE ALONG
OUTFLOW ENHANCED BOUNDARY WITH PERSISTENT ISENTROPIC LIFT...WITH
RENEWED UPTICK IN COVERAGE AND INTENSITY BY AFTERNOON THROUGH
SUNDAY NIGHT AS PHASING OF NORTHERN AND SOUTHERN STREAM ENERGY
OCCURS WITH RESULTANT DEEPENING CYCLONE ROLLING UP ALONG FRONTAL
BOUNDARY ACROSS THE AREA. WITH PW`S OF 1.25-1.4 INCHES THE
FOCUS WILL BE WITH HEAVY RAINS OF 1-2+ INCHES WITH TRAINING POSSIBLE
AS BOUNDARY SHOWN TO BE NEARLY PARALLEL TO WEAK MID LEVEL FLOW.
CANT RULE OUT SOME LOCALIZED HYDRO ISSUES MAINLY IN AREAS THAT
SEE TRAINING BUT OVERALL THESE RAINS WELCOMED AND BENEFICIAL WITH
MUCH OF THE CWA IN ABNORMALLY DRY TO MODERATE DROUGHT CONDITIONS.
COLDER AIR WRAPPING IN BACKSIDE OF DEPARTING LOW SUNDAY NIGHT TO
LIKELY RESULT IN MIX OF RAIN/SNOW OR CHANGE TO ALL SNOW AFTER MIDNIGHT
ALL BUT FAR EAST/SOUTHEAST.

MONDAY-MONDAY NIGHT...SNOW OR RAIN/SNOW MIX TO END BY MIDDAY MOST
AREAS. CAN/T RULE OUT SOME SNOW ACCUM ON ELEVATED SURFACES... BUT
A LOT OF UNCERTAINTY ON ACCUMS GIVEN WARM AND WET GROUND. DIURNAL
PROCESSES MONDAY COUPLED WITH END OF PCPN SHOULD BRING RAPID MELT OF
ANY SNOW THAT DOES ACCUMULATE DURING THE DAY. REST OF THE DAY MONDAY
BLUSTERY AND COOL WITH HIGHS IN THE 40S. LOWS MONDAY NIGHT IN THE
20S TO AROUND 30F WITH DECREASING CLOUDS AND WINDS.

TUESDAY-THURSDAY...UPPER TROUGH PASSAGE TUESDAY WITH COLD POCKET
FOR CHILLY DAY IN THE 40S ALONG WITH INSTABILITY RAIN/SNOW SHOWERS
ESPECIALLY NORTH/NORTHEAST CWA. MORE TRANQUIL CONDITIONS EXPECTED
FOR WEDNESDAY WITH HIGH PRESSURE AND MODERATING TEMPS INTO THURSDAY.
SMALL RISK OF SHOWERS THURSDAY WITH BOUNDARY IN/NEAR CWA.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 628 AM CDT FRI APR 11 2014

VFR CONDITIONS EXPECTED THROUGH ENTIRE TAF CYCLE AT ALL TERMINALS.
SOUTHWEST WINDS 10 TO 15 KTS WITH OCCASIONAL GUSTS ABV 20 KTS
WILL BE SEEN MAINLY IN THE AFTERNOON BEFORE DISSIPATING BELOW 10
KTS AROUND SUNSET. INCREASING HIGH CLOUDS WILL BE SEEN LATE IN THE
PERIOD AHEAD OF APPROACHING STORM SYSTEM DEVELOPING OUT IN THE
PLAINS.


&&

.FIRE WEATHER...
ISSUED AT 1115 AM CDT FRI APR 11 2014

DEEP MIXING INTO THE VERY DRY AIRMASS SHOULD AGAIN RESULT IN
DEWPOINTS LOWERING INTO THE 20S THIS AFTERNOON...AS WAS ALREADY
OCCURRING OVER EASTERN IA AT 11 AM. DEWPOINTS AS LOW AS THE LOWER
TO MID 20S WILL RESULT IN MINIMUM RH VALUES IN THE TEENS AND 20S
AS SEEN OVER THE PAST SEVERAL DAYS.

WHILE WINDS WILL NOT BE NEAR RED FLAG CRITERIA...THE VERY LOW RH
VALUES...WARM TEMPERATURES...DRY FUELS...AND GFDI VALUES NOW PEGGING
THE MID 20S TO AROUND 30 OR VERY HIGH RANGE...WILL CONTINUE TO
RESULT IN A VERY HIGH THREAT OF GRASS FIRES THIS AFTERNOON. THESE
VALUES WILL BE GREATEST OVER EAST CENTRAL IA INTO NW IL. SIMILAR
CONDITIONS ARE LIKELY FOR SATURDAY AFTERNOON OVER MUCH OF THE
FORECAST AREA.

WILL CONTINUE TO HANDLE THIS ELEVATED THREAT WITH SPECIAL WEATHER
STATEMENTS.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

UPDATE...11
SYNOPSIS...GROSS
SHORT TERM...GROSS
LONG TERM...05
AVIATION...GROSS
FIRE WEATHER...11






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