000
FXUS63 KDVN 032004
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
304 PM CDT SUN OCT 3 2010
.SYNOPSIS...
SURFACE RIDGE IS BUILDING NICELY INTO THE FORECAST AREA TODAY...WITH
THE RIDGE AXIS AS OF 2PM EXTENDING FROM NEAR GREEN BAY
WISCONSIN...SOUTHEAST ACROSS THE NORTHWEST CORNER OF THE CWA AND
DOWN INTO NORTH CENTRAL MISSOURI. UNDER THE RIDGE DEWPOINTS ARE
DOWN INTO THE MID 30S. CUMULUS FIELD HAS BEEN RESTRICTED TO ABOUT
THE EASTERN QUARTER OF THE FORECAST AREA...MAINLY WHERE DEWPOINTS
ARE SLIGHTLY HIGHER AND THERE IS LESS SUBSIDENCE AWAY FROM THE MAIN
SURFACE RIDGE AXIS. AT UPPER LEVELS...THE 850MB RIDGE IS ALSO
CENTERED OVER THE MIDWEST...AND THE 850MB TEMPERATURE ON THIS
MORNINGS SOUNDING WAS -1C. AT 500MB THE CUT OFF UPPER LOW HAS NOW
SHIFTED EAST TO OVER OHIO. SIGNIFICANT RIDGE OVER THE ROCKIES...BUT
WITH ONLY WEAK RISES OVER THE MIDWEST TO BRING IT OUR DIRECTION.
..LE..
&&
.SHORT TERM...TONIGHT AND MONDAY...
TONIGHT THERE IS ANOTHER RISK OF FROST TONIGHT...WITH MOSTLY CLEAR
SKIES AND LIGHTER WINDS THAN LAST NIGHT. THE MODELS ARE TRYING TO
HINT AT ANOTHER BATCH OF ALTOSTRATUS AFFECTING ABOUT THE EAST HALF
OF THE FORECAST AREA OVERNIGHT...BUT AM NOT TOTALLY CONVINCED IT
WILL ACTUALLY MATERIALIZE. IT APPEARS TO FORM LIKE THE ALTOSTRATUS
LAST NIGHT DID...WITH THE AFTERNOON CUMULUS LIFTING UP INTO THE
ALTOSTRATUS DECK AROUND SUNSET. TONIGHTS SHOULD FORM OVER SOUTHEAST
WISCONSIN. HOWEVER...THE CLOUD COVER THERE TODAY HAS LESS COVERAGE
AND AREAL EXPANSE THAN WHAT HAPPENED YESTERDAY...AND LOOKS MUCH MORE
CELLULAR TODAY. HOWEVER...THIS CAN CHANGE AND WILL HAVE TO WATCH
HOW THIS DEVELOPS FOR THE REMAINDER OF THE AFTERNOON AND EVENING.
FOR NOW AM PLANNING ON IT CLEARING ENOUGH FOR GOOD RADIATIONAL
COOLING...AND HAVE GONE WITH TEMPERATURES SIMILAR TO OR SLIGHTLY
WARMER THAN LAST NIGHT. MID LEVELS DO BEGIN TO WARM OVERNIGHT
TONIGHT WHICH COULD ALSO ACT AS A BRAKE ON THE RADIATIONAL EFFECTS.
THIS MORNING WIDESPREAD FROST WITH TEMPERATURES NEAR 30 WERE
OBSERVED ALONG AND NORTH OF HIGHWAY 20 IN IOWA. IT IS WORTH IT TO
ISSUE ANOTHER FROST ADVISORY FOR THE ENTIRE CWA AGAIN TONIGHT
THOUGH...AS ONLY ONE OR TWO SITES DIPPED BELOW 32 AND HAD HEAVY
FROST. TEMPERATURES OF 36 AND BELOW ARE LIKELY THROUGH THE ENTIRE
CWA. IF ALTOSTRATUS LINGERS AGAIN TONIGHT AS IS QUITE POSSIBLE...WE
MAY ONLY BE LOOKING AT NEAR 40 AND NO FROST. LATER SHIFTS WILL NEED
TO MONITOR.
MONDAY ANOTHER QUIET DAY VERY SIMILAR TO TODAY WITH TEMPERATURES
GRADUALLY WARMING. MAX TEMPS TO ONLY RISE INTO THE LOW 60S WITH
ONLY SHALLOW MIXING WITH THE LIGHT WINDS AND STRONG RIDGING STILL
OVERHEAD. ..LE..
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY...
MODEL INITIALIZATION OF THE LOW LEVEL MOISTURE WAS POOR AND
CONSISTENT WITH YESTERDAYS DISCOVERY...TOO DRY WHERE H85 DEW POINTS
ARE POSITIVE AND TOO MOIST WHERE THEY ARE NEGATIVE.
THE OVERALL WX PATTERN WILL REMAIN BENIGN AS THE HEMISPHERIC FLOW
EVOLVES INTO A STABLE 3 WAVE PATTERN WITH THE NORTHERN JET DOMINATE
AND THE SOUTHERN JET WEAK TO NON-EXISTENT. SHORTWAVE ENERGY WILL
DEVELOP CUT OFF LOWS ON BOTH COASTS BY MID WEEK WITH A SHORTWAVE
RIDGE OVER THE CENTRAL CONUS. THE MODELS KICK OUT THE WEST COAST CUT
OFF LOW LATE IN THE WEEK BUT THERE ARE QUESTIONS REGARDING HOW SOON
IT WILL HAPPEN. MODEL TRENDS HAVE BEEN TO DELAY THIS AS IT APPEARS
MOST OF THE SHORTWAVE ENERGY THAT WOULD SUPPLY THE KICK REMAINS
NORTH OF THE CUT OFF.
THEREFORE...DRY CONDITIONS WILL CONTINUE AND SENSIBLE WX WILL BE
DRIVEN BY MESOSCALE PROCESSES. AS THE SFC RIDGE MOVES EAST MONDAY
NIGHT THROUGH WEDNESDAY A MODERATION OF TEMPERATURES WILL OCCUR WITH
SOME DIURNAL CLOUDS.
WED NIGHT/THURS THE MODELS BRING DOWN THE NEXT FRONT. INSTEAD OF
UNDERGOING FRONTOLYSIS AS DEPICTED YESTERDAY...IT WILL PERSIST AND
CONTINUE MOVING SOUTH. SPARSE MOISTURE SHOULD RESULT IN NOTHING MORE
THAN AN INCREASE IN CLOUDS AND A WIND SHIFT TO MARK ITS PASSAGE.
FRIDAY ON...TEMPERATURES ARE EXPECTED TO BE AT OR ABOVE SEASONAL
NORMALS. ..08..
&&
.AVIATION...
VFR CONDITIONS TO CONTINUE FOR THE REST OF TODAY...TONIGHT AND
MONDAY. A SCATTERED CUMULUS DECKS IS AFFECTING KDBQ AND KMLI. THESE
SHOULD DISSIPATE WITH SUNSET...LEAVING SKIES SKC FOR THE OVERNIGHT
HOURS. SOME RIVER VALLEY FOG POSSIBLE...BUT NO IMPACTS EXPECTED FOR
TERMINALS. CUMULUS TO FORM AGAIN TOMORROW...BUT ONLY SCT AND ABOVE
3KFT. NORTH-NORTHEAST WINDS 5-12 KTS TODAY SHOULD DROP OFF
TONIGHT...AND SWITCH AROUND TO THE SOUTHEAST...BUT REMAIN BELOW 10
KTS. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FROST ADVISORY FROM 3 AM TO 9 AM CDT MONDAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FROST ADVISORY FROM 3 AM TO 9 AM CDT MONDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FROST ADVISORY FROM 3 AM TO 9 AM CDT MONDAY FOR CLARK-SCOTLAND.
&&
$$
LE/08
