000 FXUS63 KDVN 060804 AFDDVN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 305 AM CDT SUN JUL 6 2008 .SYNOPSIS... STRENGTHENING LOW LEVEL JET SHOULD KICK OFF SOME SCATTERED ELEVATED CONVECTION THIS MORNING. THEN WEAK COLD FRONT IN THE NORTHERN PLAINS WILL PUSH INTO IA TONIGHT. THIS WILL BE THE FOCUS FOR MORE ORGANIZED THUNDERSTORMS AS MOISTURE AND INSTABILITY INTERACT WITH THE FRONT. THE FRONT STALLS IN OUR AREA WHICH WILL THEN TRIGGER PERIODIC THUNDERSTORM COMPLEXES. A STRONGER COLD FRONT WILL SWEEP THROUGH THE REGION TUESDAY NIGHT RETURNING COOLER AND DRIER AIR FOR WEDNESDAY AND THURSDAY. WARMER TEMPERATURES AND HIGHER HUMIDITY WILL SPREAD BACK INTO THE REGION BY NEXT WEEKEND. && .SHORT TERM...TODAY AND TONIGHT... REGIONAL PROFILERS INDICATE SOUTHWESTERLY LOW LEVEL JET STRENGTHENING EARLY THIS MORNING. AN AREA OF PRESSURE FALLS WAS INDICATED FROM MN TO NEB AS WARM AIR ADVECTION KICKS IN AND THIS PRESSURE FALL AREA SHOULD ADVANCE EAST. SCATTERED ELEVATED THUNDERSTORMS SHOULD DEVELOP THIS MORNING IN THE ZONE OF LOW LEVEL THETA-E ADVECTION MAINLY ACROSS NORTHERN IA. BUT SOME STORMS MAY MANAGE TO SNEAK INTO THE NORTHWEST PORTION OF OUR CWA. TEMPERATURES TODAY WILL PUSH WELL INTO THE 80S AS 850 MB TEMPS RISE TO AT LEAST +20C. SURFACE DEWPOINTS WILL ALSO BE ON THE RISE AS THE DAY PROGRESSES. LAST EVENINGS UPPER AIR ANALYSIS SHOWED 18C DEWPOINT AT 850 MB AT SGF. AS THE NORTHERN PLAINS COLD FRONT ADVANCES TOWARDS THE REGION LATER THIS AFTERNOON THERE WILL BE ANOTHER CHANCE FOR STORMS IN OUR NORTHWEST CWA. THE MORE ORGANIZED STORMS WILL OCCUR THIS EVENING AND OVERNIGHT AS A VEERING LOW LEVEL JET IMPINGES ON THE SLOWING COLD FRONT. COPIOUS MOISTURE SHOULD BE AVAILABLE BY THEN WITH FORECAST SOUNDINGS INDICATING PRECIPITABLE WATER OVER 2 INCHES. THE STRONGER STORMS WILL PRODUCE HEAVY RAIN BUT WITH THE DRY ANTECEDENT CONDITIONS AM NOT CONCERNED WITH FLOODING YET. FFG NUMBERS ARE WELL ABOVE 2-3 INCHES AND SHOULD BE ABLE TO HANDLE THIS FIRST ROUND OF ORGANIZED STORMS TONIGHT. THEREFORE NO FLASH FLOOD WATCH ISSUED...BUT THIS SITUATION COULD CHANGE OVER THE NEXT COUPLE OF DAYS. WITH DEEP LAYER SHEAR OF AT LEAST 25 KNOTS AND CAPES OVER 3000 J/KG POTENTIAL EXISTS FOR DAMAGING WINDS AND LARGE HAIL. SPC HAS OUTLOOKED MOST OF OUR IA COUNTIES IN A SLIGHT RISK LATER TODAY AND TONIGHT. ..HAASE.. .LONG TERM...MONDAY THROUGH SATURDAY... MAIN FOCUS WILL BE ACTIVE WEATHER REGIME MONDAY THROUGH TUESDAY NIGHT. MODELS AGREE WITH STALLED FRONT WAVERING ACROSS NRN IA AND CNTRL WI MONDAY AND MONDAY NIGHT AS WEAK SURACE WAVES MOVE ALONG THE FRONT IN RESPONSE TO S/W ENERGY MOVING THROUGH THE NRN PLAIN AND NCNTRAL U.S. BEST THREAT OF PCPN WILL BE OVER THE NRN CWA CLOSER TO THE BOUNDARY SO KEPT HIGHER POPS ACROSS THE NRN HALF OF THE CWFA. CHANCE POPS LOOK REASONABLE OVER THE SRN CWA WHERE OUTFLOW BOUNDARIES PUSHING SOUTH INTO THE WEAKLY SHEARED...WARM AND UNSTABLE AIRMASS CWA WILL BE THE FOCUS FOR TSRA DEVELOPMENT. PW/S ARE PROGGED TO BE FROM 1.5 TO OVER 2 INCHES DURING THE PERIOD...SO LOCALLY HEAVY RAIN WILL BE POSSIBLE. WITH THE HIGH PW/S AND POTENTIAL FOR SLOW MOVING OR TRAINING STORMS THERE MAY BE A FLASH FLOOD THREAT...BUT THIS WILL LARGELY DEPEND ON THE LOCATION OF ANY HEAVY RAINS THAT MAY OCCUR TONIGHT. A SEVERE THREAT WILL ALSO EXIST OVER MUCH OF THE AREA MONDAY AFTERNOON AND EVENING CONSIDERING THE VERY UNSTABLE AIRMASS EXPECTED TO BE OVER THE AREA. THE SURFACE FRONT WILL BE PUSHED SOUTH OF THE CWFA TUESDAY AS A DEEPER S/W MOVES THROUGH THE UPPER MIDWEST AND AND NORTH CENTRAL U.S. THE COLD FRONT IS EXPECTED TO BE OVER THE LOWER OHIO VALLEY BY WEDNESDAY MORNING. THEREFORE HAVE KEPT THE HIGHER CHANCE POPS IN THE SOUTH FOR TUESDAY AND LIMITED ANY MENTION OF PCPN TO THE FAR SOUTH TUESDAY NIGHT. WITH THE FRONT SOUTH OF THE REGION WEDNESDAY SOMEWHAT COOLER AND DRIER AIR WILL MOVE BACK INTO THE REGION. THIS SHOULD BE A SHORT BREAK IN THE WARM HUMID WEATHER WITH THE RETURN FLOW EXPECTED TO SET UP OVER THE AREA THURSDAY. SOUTHERLY FLOW WILL CONTINUE THEN INTO FRIDAY. KEPT DRY FORECAST GOING FOR WEDNESDAY NIGHT AND THURSDAY WITHOUT ANY APPARENT FORCING TO TAKE ADVANTAGE OF THE INSTABILITY. NO CHANGES WERE MADE TO THE FORECAST BEYOND THURSDAY NIGHT. DLF && .AVIATION... EXPECT VFR CONDITIONS TODAY. THERE WILL BE A CHANCE OF THUNDERSTORMS AT KCID THIS MORNING...AND THEN AT KCID AND KDBQ LATER THIS AFTERNOON. A MORE ORGANIZED AREA OF THUNDERSTORMS SHOULD DEVELOP AHEAD OF A SLOW MOVING COLD FRONT ESPECIALLY TONIGHT WHICH WOULD AFFECT MOST OF THE TAF SITES. WITH THE AIRMASS VERY MOIST AND UNSTABLE TONIGHT VERY HEAVY RAIN...STRONG GUSTY WINDS AND POSSIBLE HAIL CAN BE EXPECTED IN THE STRONGER STORMS. IFR CONDITIONS WILL ALSO OCCUR IN THE THUNDERSTORMS. ..HAASE.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ HAASE/DLF