Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 05/06/12
AREA FORECAST DISCUSSION
NWS DENVER CO
1142 AM MDT FRI MAY 4 2012
.AVIATION...DELAYED THE SHIFT TO THE NORTHWEST AT APA AND DEN AS
ANTICYCLONE A BIT SLOW TO DEVELOP. STILL THINKING THIS WILL
OCCUR BASED ON CURRENT UPPER LEVEL WINDS AND POTENTIAL FLOW OFF
CHEYENNE RIDGE.
&&
.PREV DISCUSSION... /ISSUED 942 AM MDT FRI MAY 4 2012/
UPDATE...CURRENT FORECAST TRENDS STILL LOOKING ON TRACK. FOG OVER
NORTHEAST CORNER HAS DISSIPATED AND STRATUS EXITED THE AREA.
AIRMASS LOOKS DRY AND STABLE...SO NO SHOWERS OR STORMS EXPECTED. ONLY
CONCERN FOR THIS AFTERNOON AND EARLY EVENING IS THE RED FLAG
CONDITIONS FOR NORTH AND MIDDLE PARKS DUE TO GUSTY WINDS AND LOW
RH. LATEST MODEL DATA CONTINUES TO SUPPORTS CRITICAL CONDITIONS
THERE. WINDS ACROSS SOUTH PARK STILL LOOKING MARGINAL AND WILL
HOLD OFF ON ISSUING A RED FLAG HILITE THERE FOR NOW. A BIT OF A
HEADS UP FOR TOMORROW...CONDITIONS ACROSS NORTH AND MIDDLE PARKS
DON`T SEEM TO CHANGE MUCH SO ANOTHER RED FLAG HILITE MAY BE
NEEDED. SOUTH PARK MAY ALSO BE INCLUDED. BUT WILL ADDRESS THIS
ISSUE LATER WHEN MORE DATA POURS IN.
AVIATION...CURRENT TAF TRENDS LOOKING REASONABLE...WILL CONTINUE
FOR THE 18Z ISSUANCE. WEAK FRONT PASSING SOUTH ACROSS PLAINS
TONIGHT COULD BRUSH AREA AIRPORTS EARLY SATURDAY MORNING. HOWEVER
LATEST DATA SUGGESTS DRAINAGE WINDS PREVAILING WHICH SHOULD KEEP
FRONT NORTH AND EAST OF AREA.
PREV DISCUSSION... /ISSUED 420 AM MDT FRI MAY 4 2012/
SHORT TERM...DRY SOUTHWEST FLOW ALOFT WILL BE OVER THE AREA
THROUGH TONIGHT WITH NO CHANCE OF PCPN. SOME DENSE FOG WILL BE
POSSIBLE OVER THE FAR NE CORNER THRU MID MORNING AND HAVE ALREADY
ISSUED AN ADVISORY. MEANWHILE MAIN CONCERN FOR THIS AFTN WILL BE
FIRE DANGER OVER THE HIGHER VALLEYS. LATEST DATA WOULD SUPPORT A
RED FLAG WARNING FOR ZNS 211 AND 213. PARK COUNTY IS A BIT MORE
IFFY DUE TO WINDS SO WILL HOLD OFF FOR NOW. HIGHS THIS AFTN WILL
BE A FEW DEGREES WARMER THAN THU IN MOST AREAS WITH 80S OVER NERN
CO.
FOR TONIGHT A CDFNT WILL MOVE INTO THE FAR NERN CORNER AFTER
MIDNIGHT WITH SOME STRATUS DEVELOPING BY 12Z.
LONG TERM...DRY AND WARM CONDITIONS ARE EXPECTED TO CONTINUE ON
SATURDAY AS MODERATE SOUTHWEST FLOW ALOFT REMAINS OVER THE STATE.
CHANGES WILL BE ON THEIR WAY SATURDAY NIGHT AND SUNDAY AS AN UPPER
TROUGH MOVES IN FROM THE NORTHWEST AND A STRONG COLD FRONT ENTERS
THE STATE FROM THE NORTH. UPSLOPE FLOW BEHIND THE FRONT WILL BRING
MUCH COOLER TEMPERATURES AND A MOISTENING AIRMASS TO THE REGION.
SUNDAY MORNING WILL BE TOO STABLE FOR ANY THUNDERSTORMS...BUT
HEATING THROUGH THE DAY ON SUNDAY COULD ALLOW AFTERNOON ACTIVITY
TO DEVELOP. COOL AND MOIST CONDITIONS WILL LAST THROUGH MONDAY AND
INTO TUESDAY MORNING AS UPPER TROUGHINESS REMAINS OVER NORTHEAST
COLORADO. FROM TUESDAY THROUGH THE REST OF THE WEEK...THE GFS AND
ECMWF SHOW WEAK UPPER RIDGING OVER COLORADO AS A CUTOFF LOW
LINGERS OVER NORTHWESTERN MEXICO. DYNAMICS AND WINDS SHOULD BE
WEAK UNDER THIS PATTERN AS WELL AS DRY. THE ECMWF IS MUCH DRIER
THAN THE GFS WHICH KEEPS BRINGING SOME MOISTURE OVER SOUTHWESTERN
COLORADO. HAVE REMOVED POPS FROM MOST OF THE FORECAST AREA FOR THE
TUESDAY THROUGH THURSDAY TIME PERIOD. TEMPERATURES WILL ALSO BE
GRADUALLY WARMING THROUGH THE WEEK AS THE UPPER RIDGING REMAINS IN
PLACE. IN SUMMARY...SUNDAY AND MONDAY WILL BE THE BEST OPPORTUNITY
FOR PRECIPITATION ACROSS THE FORECAST AREA WITH TEMPERATURES
BRIEFLY DROPPING TO COOLER THAN NORMAL. BUT THE CHANGE IN WEATHER
WILL BE SHORT LIVED AS WE WARM BACK ABOVE NORMAL BY MID-WEEK.
AVIATION...VFR THRU TONIGHT. WINDS WILL BE SSW THRU 15Z HOWEVER
AFTER THAT LATEST RUC IS SHOWING A WEAK LONGMONT ANTICYCLONE DUE
TO WNW FLOW OVER THE CHEYENNE RIDGE. THUS WINDS BY LATE MORNING MAY
BECOME LIGHT NNE AND THEN MORE ENE THRU THE AFTN HOURS. LATEST HI RES
WRF KEEPS WINDS LIGHT ELY THRU THE EARLY EVENING HOURS AND THEN
SHIFTS THEM TO THE SSW BY 06Z.
HYDROLOGY...NO TSTMS TODAY OR TONIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ211-213.
&&
$$
SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER CO
942 AM MDT FRI MAY 4 2012
.UPDATE...CURRENT FORECAST TRENDS STILL LOOKING ON TRACK. FOG OVER
NORTHEAST CORNER HAS DISSIPATED AND STRATUS EXITED THE AREA.
AIRMASS LOOKS DRY AND STABLE...SO NO SHOWERS OR STORMS EXPECTED. ONLY
CONCERN FOR THIS AFTERNOON AND EARLY EVENING IS THE RED FLAG
CONDITIONS FOR NORTH AND MIDDLE PARKS DUE TO GUSTY WINDS AND LOW
RH. LATEST MODEL DATA CONTINUES TO SUPPORTS CRITICAL CONDITIONS
THERE. WINDS ACROSS SOUTH PARK STILL LOOKING MARGINAL AND WILL
HOLD OFF ON ISSUING A RED FLAG HILITE THERE FOR NOW. A BIT OF A
HEADS UP FOR TOMORROW...CONDITIONS ACROSS NORTH AND MIDDLE PARKS
DON`T SEEM TO CHANGE MUCH SO ANOTHER RED FLAG HILITE MAY BE
NEEDED. SOUTH PARK MAY ALSO BE INCLUDED. BUT WILL ADDRESS THIS
ISSUE LATER WHEN MORE DATA POURS IN.
&&
.AVIATION...CURRENT TAF TRENDS LOOKING REASONABLE...WILL CONTINUE
FOR THE 18Z ISSUANCE. WEAK FRONT PASSING SOUTH ACROSS PLAINS
TONIGHT COULD BRUSH AREA AIRPORTS EARLY SATURDAY MORNING. HOWEVER
LATEST DATA SUGGESTS DRAINAGE WINDS PREVAILING WHICH SHOULD KEEP
FRONT NORTH AND EAST OF AREA.
&&
.PREV DISCUSSION... /ISSUED 420 AM MDT FRI MAY 4 2012/
SHORT TERM...DRY SOUTHWEST FLOW ALOFT WILL BE OVER THE AREA
THROUGH TONIGHT WITH NO CHANCE OF PCPN. SOME DENSE FOG WILL BE
POSSIBLE OVER THE FAR NE CORNER THRU MID MORNING AND HAVE ALREADY
ISSUED AN ADVISORY. MEANWHILE MAIN CONCERN FOR THIS AFTN WILL BE
FIRE DANGER OVER THE HIGHER VALLEYS. LATEST DATA WOULD SUPPORT A
RED FLAG WARNING FOR ZNS 211 AND 213. PARK COUNTY IS A BIT MORE
IFFY DUE TO WINDS SO WILL HOLD OFF FOR NOW. HIGHS THIS AFTN WILL
BE A FEW DEGREES WARMER THAN THU IN MOST AREAS WITH 80S OVER NERN
CO.
FOR TONIGHT A CDFNT WILL MOVE INTO THE FAR NERN CORNER AFTER
MIDNIGHT WITH SOME STRATUS DEVELOPING BY 12Z.
LONG TERM...DRY AND WARM CONDITIONS ARE EXPECTED TO CONTINUE ON
SATURDAY AS MODERATE SOUTHWEST FLOW ALOFT REMAINS OVER THE STATE.
CHANGES WILL BE ON THEIR WAY SATURDAY NIGHT AND SUNDAY AS AN UPPER
TROUGH MOVES IN FROM THE NORTHWEST AND A STRONG COLD FRONT ENTERS
THE STATE FROM THE NORTH. UPSLOPE FLOW BEHIND THE FRONT WILL BRING
MUCH COOLER TEMPERATURES AND A MOISTENING AIRMASS TO THE REGION.
SUNDAY MORNING WILL BE TOO STABLE FOR ANY THUNDERSTORMS...BUT
HEATING THROUGH THE DAY ON SUNDAY COULD ALLOW AFTERNOON ACTIVITY
TO DEVELOP. COOL AND MOIST CONDITIONS WILL LAST THROUGH MONDAY AND
INTO TUESDAY MORNING AS UPPER TROUGHINESS REMAINS OVER NORTHEAST
COLORADO. FROM TUESDAY THROUGH THE REST OF THE WEEK...THE GFS AND
ECMWF SHOW WEAK UPPER RIDGING OVER COLORADO AS A CUTOFF LOW
LINGERS OVER NORTHWESTERN MEXICO. DYNAMICS AND WINDS SHOULD BE
WEAK UNDER THIS PATTERN AS WELL AS DRY. THE ECMWF IS MUCH DRIER
THAN THE GFS WHICH KEEPS BRINGING SOME MOISTURE OVER SOUTHWESTERN
COLORADO. HAVE REMOVED POPS FROM MOST OF THE FORECAST AREA FOR THE
TUESDAY THROUGH THURSDAY TIME PERIOD. TEMPERATURES WILL ALSO BE
GRADUALLY WARMING THROUGH THE WEEK AS THE UPPER RIDGING REMAINS IN
PLACE. IN SUMMARY...SUNDAY AND MONDAY WILL BE THE BEST OPPORTUNITY
FOR PRECIPITATION ACROSS THE FORECAST AREA WITH TEMPERATURES
BRIEFLY DROPPING TO COOLER THAN NORMAL. BUT THE CHANGE IN WEATHER
WILL BE SHORT LIVED AS WE WARM BACK ABOVE NORMAL BY MID-WEEK.
AVIATION...VFR THRU TONIGHT. WINDS WILL BE SSW THRU 15Z HOWEVER
AFTER THAT LATEST RUC IS SHOWING A WEAK LONGMONT ANTICYCLONE DUE
TO WNW FLOW OVER THE CHEYENNE RIDGE. THUS WINDS BY LATE MORNING MAY
BECOME LIGHT NNE AND THEN MORE ENE THRU THE AFTN HOURS. LATEST HI RES
WRF KEEPS WINDS LIGHT ELY THRU THE EARLY EVENING HOURS AND THEN
SHIFTS THEM TO THE SSW BY 06Z.
HYDROLOGY...NO TSTMS TODAY OR TONIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ211-213.
&&
$$
SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER CO
420 AM MDT FRI MAY 4 2012
.SHORT TERM...DRY SOUTHWEST FLOW ALOFT WILL BE OVER THE AREA
THROUGH TONIGHT WITH NO CHANCE OF PCPN. SOME DENSE FOG WILL BE
POSSIBLE OVER THE FAR NE CORNER THRU MID MORNING AND HAVE ALREADY
ISSUED AN ADVISORY. MEANWHILE MAIN CONCERN FOR THIS AFTN WILL BE
FIRE DANGER OVER THE HIGHER VALLEYS. LATEST DATA WOULD SUPPORT A
RED FLAG WARNING FOR ZNS 211 AND 213. PARK COUNTY IS A BIT MORE
IFFY DUE TO WINDS SO WILL HOLD OFF FOR NOW. HIGHS THIS AFTN WILL
BE A FEW DEGREES WARMER THAN THU IN MOST AREAS WITH 80S OVER NERN
CO.
FOR TONIGHT A CDFNT WILL MOVE INTO THE FAR NERN CORNER AFTER
MIDNIGHT WITH SOME STRATUS DEVELOPING BY 12Z.
.LONG TERM...DRY AND WARM CONDITIONS ARE EXPECTED TO CONTINUE ON
SATURDAY AS MODERATE SOUTHWEST FLOW ALOFT REMAINS OVER THE STATE.
CHANGES WILL BE ON THEIR WAY SATURDAY NIGHT AND SUNDAY AS AN UPPER
TROUGH MOVES IN FROM THE NORTHWEST AND A STRONG COLD FRONT ENTERS
THE STATE FROM THE NORTH. UPSLOPE FLOW BEHIND THE FRONT WILL BRING
MUCH COOLER TEMPERATURES AND A MOISTENING AIRMASS TO THE REGION.
SUNDAY MORNING WILL BE TOO STABLE FOR ANY THUNDERSTORMS...BUT
HEATING THROUGH THE DAY ON SUNDAY COULD ALLOW AFTERNOON ACTIVITY
TO DEVELOP. COOL AND MOIST CONDITIONS WILL LAST THROUGH MONDAY AND
INTO TUESDAY MORNING AS UPPER TROUGHINESS REMAINS OVER NORTHEAST
COLORADO. FROM TUESDAY THROUGH THE REST OF THE WEEK...THE GFS AND
ECMWF SHOW WEAK UPPER RIDGING OVER COLORADO AS A CUTOFF LOW
LINGERS OVER NORTHWESTERN MEXICO. DYNAMICS AND WINDS SHOULD BE
WEAK UNDER THIS PATTERN AS WELL AS DRY. THE ECMWF IS MUCH DRIER
THAN THE GFS WHICH KEEPS BRINGING SOME MOISTURE OVER SOUTHWESTERN
COLORADO. HAVE REMOVED POPS FROM MOST OF THE FORECAST AREA FOR THE
TUESDAY THROUGH THURSDAY TIME PERIOD. TEMPERATURES WILL ALSO BE
GRADUALLY WARMING THROUGH THE WEEK AS THE UPPER RIDGING REMAINS IN
PLACE. IN SUMMARY...SUNDAY AND MONDAY WILL BE THE BEST OPPORTUNITY
FOR PRECIPITATION ACROSS THE FORECAST AREA WITH TEMPERATURES
BRIEFLY DROPPING TO COOLER THAN NORMAL. BUT THE CHANGE IN WEATHER
WILL BE SHORT LIVED AS WE WARM BACK ABOVE NORMAL BY MID-WEEK.
&&
.AVIATION...VFR THRU TONIGHT. WINDS WILL BE SSW THRU 15Z HOWEVER
AFTER THAT LATEST RUC IS SHOWING A WEAK LONGMONT ANTICYCLONE DUE
TO WNW FLOW OVER THE CHEYENNE RIDGE. THUS WINDS BY LATE MORNING MAY
BECOME LIGHT NNE AND THEN MORE ENE THRU THE AFTN HOURS. LATEST HI RES
WRF KEEPS WINDS LIGHT ELY THRU THE EARLY EVENING HOURS AND THEN
SHIFTS THEM TO THE SSW BY 06Z.
&&
.HYDROLOGY...NO TSTMS TODAY OR TONIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM MDT THIS MORNING FOR COZ050-051.
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
COZ211-213.
&&
$$
SHORT TERM...RPK
LONG TERM....DANKERS
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
305 PM CDT FRI MAY 4 2012
.DISCUSSION...
259 PM CDT
THE MAIN CONCERNS OVER THE COMING DAYS WILL BE THE LOW CHANCES
THUNDERSTORMS ACROSS THE SOUTHWESTERN PORTION OF THE CWA
TONIGHT...AND THEN THE CHANCES FOR THUNDERSTORMS SUNDAY AFTERNOON.
FOR TONIGHT...
THE LATEST SURFACE AND OBSERVED TRENDS SHOW THAT A COOL FRONT LAY
DRAPED ACROSS MUCH OF THE CWA. AS OF THE EARLY AFTERNOON HOURS THE
BOUNDARY STRETCHES FROM KVPZ TO JUST NORTH OF KJOT....THROUGH
NORTHERN DEKALB COUNTY AND INTO WESTERN WINNEBAGO COUNTY. BEHIND
THIS FEATURE WINDS BECAME NORTHERLY TO NORTHEASTERLY...PULLING IN
THE COLD MARINE AIRMASS INTO THE LAND. TEMPS ACROSS CHICAGO PEAKED
THIS MORNING AND HAVE SINCE FALLEN THROUGH THE DAY. TO THROW
INSULT TO INJURY FOR COASTAL LOCATIONS THIS MORNING...THE CHILLY
AIRMASS COLLIDED WITH THE WARM AND HUMID AIRMASS THIS
MORNING...ALLOWING FOG...SOMETIMES THICK AT TIMES TO DEVELOP AND
MEANDER INLAND. GENERALLY SKIES HAVE CLEARED AS OF THIS
AFTERNOON...BUT SOME PATCHY AREAS PERSIST THIS AFTERNOON.
THE SURFACE BOUNDARY IS CLEARLY DENOTED ON VISIBLE IMAGERY THIS
AFTERNOON...AS SURFACE CONVERGENCE IS ALLOWING SOME CU TO POP.
DESPITE THE WARM TEMPERATURES AND HIGH DEWPOINTS PERSISTING...THE
OVERALL ATMOSPHERE IS RATHER WORKED OVER FROM LAST NIGHT AND
OBJECTIVE SPC RAP ANALYSIS CONTINUES TO HIGHLIGHT PERSISTENT CIN
IN PLACE. THE HIGHEST AXIS OF INSTABILITY IS WELL TO THE SOUTH AND
WEST THIS AFTERNOON...AND THAT IS WHERE THE HIGHEST LIKELIHOOD OF
THUNDERSTORM ACTIVITY WILL REMAIN. MODIFIED SOUNDINGS FROM
DAVENPORT SHOW THAT THERE IS MODERATE ELEVATED CAPE /ON THE ORDER
OF 1000 TO 1500 J-KG/. COUPLED WITH THE CONTINUED HIGH PWAT
AIRMASS AND SOME WEAK SURFACE CONVERGENCE ALONG THE
BOUNDARY...WOULDNT BE SURPRISED AT SEEING SOME SHOWERS DEVELOP AND
PERHAPS A CLAP OF THUNDER LATER THIS AFTERNOON AND INTO THE
EVENING HOURS. ONE BIG LACKING INGREDIENT THIS AFTERNOON IS SHEAR
ACROSS OUR AREA. THE BETTER OF THE SHEAR IS WELL TO OUR SOUTH AS A
THE REMNANTS OF A SH/WV IS SHOOTING ACROSS SOUTHERN ILLINOIS AND
SHOWERS AND SOME STRONG STORMS ARE SHOOTING EAST OF ST LOUIS TO
EFFINGHAM. THE SECOND WAVE IS LIFTING THROUGH THE DAKOTAS...AND
WILL MOVE INTO MINNESOTA AND EVENTUALLY NORTHERN
WISCONSIN...LEAVING OUR AREA IN THE VOID OF ANY ORGANIZED
CONVECTION SUPPORTING SHEAR. SO...WHATEVER DOES DECIDE TO POP THIS
AFTERNOON SHOULD GO UP AND COME DOWN IN A QUICK FASHION. WITH THE
HIGH PWATS /ON THE ORDER OF 1.3 TO 1.6 INCHES/ THROUGH THE
COLUMN...ANY OF THESE SHOWERS WILL QUICKLY DROP A GOOD AMOUNT OF
RAIN...BUT OVER A CONFINED AREA. HIGH RESOLUTION GUIDANCE IS
PRETTY CONSISTENT WITH KEEPING THE ACTIVITY FOR OUR AREA GENERALLY
FROM A ROCKFORD TO MENDOTA TO KANKAKEE CORRIDOR. THOUGH THE RAP IS
OVERDONE ACROSS THE SOUTHERN COUNTIES AS OF 20Z...AND THE HRRR IS
TRYING TO SHOW SOME ACTIVITY BEGINNING TO BUBBLE AROUND 02Z.
PRESENT CU FIELD LOOKS ANEMIC...AND GENERALLY THE REST OF THE
AFTERNOON SHOULD REMAIN CALM.
HIGH TEMPERATURES WILL RANGE GREATLY FROM NORTHEAST TO SOUTHWEST
THIS WEEKEND. THE FRONTAL BOUNDARY IS NOT EXPECTED TO MOVE MUCH FROM
ITS PRESENT LOCATION...RATHER MEANDER SLIGHTLY AND WASH OUT. AREAS
NORTH OF THIS WILL REMAIN COLDER WITH A COOL NORTHEAST COMPONENT TO
THE WINDS...WHILE AREAS SOUTH WILL GENERALLY STAY WARMER. AN UPPER
LEVEL RIDGE WILL THEN SWING ACROSS THE AREA AND GUIDANCE STILL
INDICATES A NICE LITTLE RIDGE ROLLER MOVING THROUGH AND BRINGING THE
BETTER CHANCES SHOWERS AND THUNDERSTORMS TO THE REGION OVERNIGHT ON
SUNDAY. PWATS WILL STILL BE FLIRTING WITH THE HIGH SIDE THROUGH
THIS TIME...AND THE CHANCES FOR HEAVY RAINFALL WILL PERSIST
THROUGH THAT EVENT. AS THE RIDGE SLIDES EAST AND A TROUGH MOVES
THROUGH...THE AREA WILL GENERALLY FALL BACK INTO A COOLER
NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS CLOSER TO SEASONAL
WITH OFF AND ON CHANCES FOR SHOWERS THROUGH THE WEEK.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NORTHEAST WINDS THROUGH THIS AFTERNOON.
* IFR CIGS LIKELY RETURNING LATE TONIGHT.
* POSSIBLY LOWERING VISBYS TONIGHT...ESPECIALLY IF STRATUS
DOES NOT MATERIALIZE.
* SMALL CHANCE FOR SHRA/TSRA WELL WEST AND SOUTH OF THE AIRFIELD
THIS AFTERNOON...THEN A CHANCE AT THE AIRFIELD OVERNIGHT INTO
SATURDAY MORNING.
//DISCUSSION...UPDATED 18Z...
A COOL FRONT HAD PUSHED THROUGH THE CHICAGO AREA TERMINALS EARLY
THIS MORNING...TURNING WINDS OFF OF LAKE MICHIGAN. THESE WILL
CONTINUE THROUGH TONIGHT...OFFERING THE POTENTIAL FOR THE MARINE
LAYER TO CONTINUE TO HAVE INFLUENCE. WHILE CURRENT IFR CIGS AT ORD
WILL VERY LIKELY SCATTER THIS AFTERNOON...THE RETURN OF MVFR/IFR
CIGS AND POTENTIALLY VISBYS IS CERTAINLY WITHIN REASON FOR
TONIGHT. THE NORTHERN TERMINALS OF ORD...DPA...AND RFD ARE MOST
FAVORED TO SEE THE LOWEST CONDITIONS BASED ON MORE OF A TRAJECTORY
FROM ACROSS THE LAKE.
ISOLATED SHRA/TSRA MAY DEVELOP THROUGH 23Z TO THE WEST AND SOUTH
OF THE AIRFIELD ALONG THE OLD FRONTAL BOUNDARY. LATER TONIGHT INTO
SATURDAY MORNING...SCATTERED SHOWERS ARE POSSIBLE ACROSS NORTHERN
ILLINOIS AS AN UPPER LEVEL DISTURBANCE MOVES EAST ACROSS MN AND
WI. THE CONFIDENCE IN THIS REACHING AS FAR SOUTH AS NORTHERN IL IS
LOW AT THIS TIME.
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN NORTHEAST WINDS THIS AFTERNOON...THOUGH THEY
WILL LIKELY VARY AT TIMES BETWEEN 010 AND 080. MEDIUM CONFIDENCE
THAT THESE WILL AT LEAST BE 10 KT FOR THE BETTER PART OF THE
AFTERNOON.
* MEDIUM CONFIDENCE ON AT LEAST 1500 FT AND LOWER CIGS RETURNING
TONIGHT. LOW CONFIDENCE ON DURATION AND MAGNITUDE OF THE
CIGS/VISBYS TONIGHT.
* HIGH CONFIDENCE THAT ANY SHRA/TSRA THE REST OF THIS AFTERNOON
WILL REMAIN WEST AND SOUTH OF THE AIRFIELD. LOW CONFIDENCE ON
ANY SHOWERS LATE TONIGHT.
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT THROUGH THURSDAY...GENERALLY VFR BUT PERIODIC
CHANCES FOR SHRA/TSRA. THE BEST CHANCE APPEARS TO BE SUNDAY NIGHT
AND MONDAY. DRY WEATHER IS POSSIBLE THURSDAY.
MTF
&&
.MARINE...
229 PM CDT
A COLD FRONT HAS MOVED ACROSS LAKE MICHIGAN TODAY WITH NORTHERLY
WINDS SETTING UP BEHIND THE FRONT. THE FRONTAL BOUNDARY IS FORECAST
TO STALL ACROSS CENTRAL ILLINOIS THIS EVENING WHILE HIGH PRESSURE
BUILDS ACROSS ONTARIO...THEN EVENTUALLY EAST INTO QUEBEC LATE
SATURDAY INTO SUNDAY. NORTHERLY WINDS WILL GRADUALLY VEER TO THE
NORTHEAST AND EAST AS THE HIGH TRANSLATES EAST. ON SUNDAY...THE
FRONTAL BOUNDARY WILL WAVE NORTHWARD WITH WINDS BECOMING
SOUTHEASTERLY...THEN A COLD FRONT SWEEPS ACROSS THE LAKE ON MONDAY
ALLOWING NORTHWEST/NORTH WINDS TO OVERSPREAD THE LAKE. ALL IN
ALL...NOT LOOKING AT ANY HIGH IMPACT WIND SITUATIONS THROUGH THE
FIRST HALF OF NEXT WEEK...WITH THE STRONGEST WINDS EXPECTED OVER THE
NEXT 48 HRS OR SO IN THE 15 TO 25 KT RANGE.
ANOTHER CONCERN FOR TODAY IS THE FOG OVER THE OPEN WATERS. LATEST
VISIBLE SATELLITE IMAGERY STILL PARTLY BLOCKED BY HIGHER
CLOUDS...BUT LOOKING THROUGH THE GAPS IT DOES APPEAR THAT THERE IS
STILL AN EXPANSIVE AREA OF FOG OVER SOUTHERN LAKE MICHIGAN. DRIER
AIR WILL CONTINUE TO ERODE THIS AREA FROM THE NORTH...BUT IN THE
MEANTIME WILL EXTEND THE DENSE FOG ADVISORY THROUGH THIS EVENING.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
233 AM CDT FRI MAY 4 2012
.MESOSCALE DISCUSSION...
815 PM CDT
MAIN CONCERN FOR THE REST OF THE NIGHT IS FLASH FLOOD POTENTIAL.
TRAINING STORMS OVER NORTHEAST DUPAGE AND NORTHERN COOK COUNTY
CONTINUE TO REGENERATE. SOME ALSO PRODUCING SEVERE HAIL. OTHER
SLOW MOVING HEAVY RAIN PRODUCERS OVER BUREAU-LASALLE
COUNTIES...AND YET ANOTHER CLUSTER OF STORMS MOVING IN FROM
EASTERN IA.
SPC ANALYSIS INDICATES RIBBON OF PRECIPITABLE WATER IN EXCESS OF
1.5 FROM WEST CENTRAL TO NORTHEAST ILLINOIS. THIS IS ALSO AN AREA
OF HIGH 850 MOISTURE TRANSPORT. HRRR INDICATING HEAVIEST RAIN IN
THIS CORRIDOR AS WELL. WILL BE ISSUING A FLASH FLOOD WATCH FOR
OVERNIGHT FOR ALL BUT THE NORTH TIER OF COUNTIES.
ALLSOPP
&&
.DISCUSSION...
315 PM CDT
TONIGHT...
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO BE ONGOING
OVERNIGHT AND IT IS DIFFICULT TO ADD ANY SPECIFICS THIS AFTERNOON
AS TO WHEN THE HEAVIEST OF ACTIVITY WILL POP AND MOVE ACROSS...AS
GUIDANCE HAS BEEN STRUGGLING TO LATCH ONTO A SOLID SOLUTION. THE
HRRR AND RAP HAVE BEEN PRETTY CONSISTENT FROM RUN TO RUN IN
DEVELOPING CONVECTION ACROSS THE NORTHERN BORDER THIS AFTERNOON
AND EVENING...BUT AS THE MODELS HAVE BEEN UNDER PERFORMING THE LAST
FEW DAYS...NOT GOING TO COMPLETELY BITE OFF ON ANY ONE SOLUTION
HAPPENING THIS EVENING...LEADING TO A LOW CONFIDENCE OVERNIGHT
FORECAST. DO BELIEVE THAT THE ONGOING ACTIVITY FROM MKE TO ROUGHLY
MSN WILL TRY TO WORK SOUTH WHILE MOVING EAST...BUT WILL DEFER TO
SPECIFICS THAT FALL WITHIN THE MESO AFD ABOVE. FRONT WILL SLOWLY
BE SAGGING SOUTH ACROSS SOUTHERN WISCONSIN AND WORK INTO ILLINOIS
THROUGH THE OVERNIGHT HOURS. ACTIVITY WILL THEN BE ON THE WANE
AS WE GET CLOSER TO THE MORNING.
THE STRONG WARM AIR ADVECTION THAT SHOT TEMPERATURES INTO THE 80S
TODAY WILL SHIFT SOUTH. WITH THE FRONT DROPPING THROUGH AND ACROSS
CHICAGO...WINDS WILL FLIP AROUND TO THE NORTHEAST AND PULL A
COOLER MARINE AIRMASS ACROSS MUCH OF THE COASTLINE. MODELS CONTINUE
TO SLOW THIS TREND SLIGHTLY OVER PREVIOUS RUNS...BUT DOES CONTINUE TO
KEEP IT DRAPED ACROSS THE AREA. FORECAST SOUNDINGS AND RAW
NUMERICAL GUIDANCE HIGHLIGHTS GOOD INSTABILITY TO PERSIST SOUTH AND
WEST OF THIS FEATURE...THOUGH THE BEST INSTABILITY WILL BE WEST
ACROSS IOWA...AND OVERALL EFFECTIVE SHEAR WILL IS SUGGESTED TO BE AT
OR BELOW 30 KT INTO THE PEAK OF THE AFTERNOON. SPC HAS MOST OF THE
CWA IN A SLIGHT RISK FOR SEVERE STORMS TOMORROW...BUT IT DOES FOLLOW
THE OVERALL LOCATION OF THE FRONT...FAVORING AREAS WITH THE BEST
INSTABILITY. WITH NO REAL FORCING WIGGLING THROUGH THE FLOW
TOMORROW...THE OVERALL THREAT DOES NOT APPEAR TO BE HIGH...BUT
CANNOT RULE OUT THE POSSIBILITY OF SOME UNORGANIZED CELLS DEVELOPING
WITH MARGINAL SEVERE HAIL AND WIND GUSTS.
DID MAKE BIGGER CHANGES TO THE DAYTIME HIGHS ACROSS LAKE AND COOK
COUNTIES. WITH THE FRONT SAGGING SOUTH OF MOST THE METRO INTO THE
EARLY AFTERNOON...SHOULD SEE TEMPS HIT THEIR PEAK IN THE EARLY
AFTERNOON AND THEN FALL. STILL SOME CONSIDERABLE DIFFERENCES BETWEEN
THE MAV AND THE MET THIS AFTERNOON...WITH A 10+ DEGREE DIFFERENCE
BETWEEN THE TWO. THE THOUGHT IS THAT WITH THE FRONT TO THE
SOUTH...MOST COASTAL AREAS /INCLUDING THE CHICAGO METRO/ WILL SEE
HIGHS PEAKING IN THE UPPER 60S TO AROUND 70 BEFORE FALLING INTO THE
AFTERNOON...THOUGH IF MORE RAIN FALLS OVERNIGHT AND KEEPS CLOUDS
IN...MID 60S COULD BE PUSHING IT.
BY THE WEEKEND...UPPER LEVEL RIDGING ACROSS THE FOUR CORNERS REGION
WILL BEGIN TO SHIFT EAST AND OVERHEAD...BUT CONTINUED DISPARITY
BETWEEN LONG RANGE GUIDANCE IS LEADING TO FURTHER LOW END CONFIDENCE
ON PRECIP CHANCES INTO THE NEXT WEEK. TRENDS ARE INDICATING A
WEAK SHORTWAVE ROLLING ACROSS THE RIDGE LATE SUNDAY AND INTO
MONDAY WILL BRING THE NEXT BEST CHANCE FOR SHOWERS. AS THE RIDGE
SLIDES EAST AND A TROUGH MOVES THROUGH...WILL GENERALLY FALL BACK
INTO A COOLER NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS
CLOSE TO SEASONAL WITH OFF AND ON CHANCES THROUGH THE WEEK.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA/EMBEDDED TS TO CONTINUE FOR A FEW HOURS.
* WINDS BECOMING LIGHT TOWARD DAYBREAK THEN SHIFTING NORTHEAST OR
EAST-NORTHEAST BY MID-MORNING...A FEW GUSTS POSSIBLE AS SHIFT
OCCURS.
* MVFR VSBY POSSIBLE OVERNIGHT AS WINDS DIMINISH.
* MVFR CIGS EXPECTED FOR MUCH OF FRIDAY...WITH IFR POSSIBLE FRIDAY
MORNING.
MDB
//DISCUSSION...UPDATED 06Z...
TOUGH FORECAST THROUGH FRIDAY EVENING...ESPECIALLY IN TERMS OF
CIG/VSBY TRENDS. INITIAL CONCERN IS SHRA/TSRA CONTINUING FOR
ANOTHER FEW HOURS BEFORE SHIFTING OFF TO THE EAST AND SOUTH...WITH
A LONGER DURATION AT GYY. WIND DETAILS WILL BE A BIT TOUGH THROUGH
THE REST OF THE NIGHT WITH A PRIMARILY SOUTHWEST DIRECTION THE
NEXT FEW HOURS BEFORE BECOMING LIGHT AND VARIABLE AS A FRONTAL
BOUNDARY APPROACHES. THIS LIGHT WIND COMBINED WITH ABUNDANT LOW
LEVEL MOISTURE FROM THE RAIN WILL BRING A DECENT CHANCE FOR MVFR
VSBY LATE TONIGHT TOWARDS DAYBREAK. THE FRONT WILL SAG SOUTH OF
THE TERMINALS DURING THE EARLY/MID MORNING HOURS RESULTING IN A
SHIFT TO NORTHEAST OR EAST-NORTHEAST WINDS WHICH WILL CONTINUE
THROUGH THE DAY. WILL NEED TO WATCH POTENTIAL FOR SOME GUSTS TO
DEVELOP RIGHT BEHIND THE FRONT AS WELL.
THE NEXT BIG CONCERN IS CEILINGS. VFR CIGS WILL CONTINUE OVERNIGHT
WITH SOME MVFR BRIEFLY POSSIBLE IN THE HEAVIER PRECIP. ONCE WINDS
TURN NORTHEASTERLY WILL START TO SEE A BETTER POTENTIAL FOR
STRATUS DEVELOPMENT. MVFR LOOKS LIKELY WITH IFR POSSIBLE AS WELL.
ASSUMING MVFR/IFR DOES DEVELOP...THE NEXT CHALLENGE WILL BE CIG
TRENDS THROUGH THE DAY. LATEST GUIDANCE HAS BACKED OFF ON DURATION
OF LOWER CIGS BUT WITH FLOW OFF THE LAKE AM THINKING IMPROVEMENT
MAY BE TOUGH TO COME BY. WILL CONTINUE WITH MVFR CIGS AND HINT AT
IFR FRIDAY MORNING AND AFTERNOON...WITH FORECAST SOUNDINGS SHOWING
CIGS LOWERING AGAIN FRIDAY EVENING. WILL NEED TO KEEP EVALUATING
THIS BUT OVERALL CONFIDENCE IS QUITE LOW SO SOME OVERHAULING OF
THE TAF IS POSSIBLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN SHRA/EMBEDDED TS CONTINUING FOR A FEW HOURS.
* MEDIUM-HIGH CONFIDENCE IN WINDS DIMINISHING OVERNIGHT...HIGH
CONFIDENCE IN WINDS SHIFTING TO NORTH EAST OR EAST-NORTHEAST.
MEDIUM-HIGH CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE MVFR VSBY DEVELOPING OVERNIGHT.
* MEDIUM CONFIDENCE IN MVFR CIGS DEVELOPING FRIDAY MORNING BUT LOW
CONFIDENCE IN IF THEY WILL PERSIST OR IMPROVE DURING THE
AFTERNOON. LOW CONFIDENCE IN IFR POTENTIAL.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY THROUGH TUESDAY...GENERALLY PREVAILING VFR BUT WITH
PERIODIC CHANCES FOR SHRA/TSRA. BEST CHANCES FOR TSRA APPEAR TO BE
FRIDAY INTO THE WEEKEND.
WEDNESDAY...CHANCE SHRA. OTRW...VFR.
KJB
&&
.MARINE...
233 AM CDT
I HAVE DECIDED TO ISSUE A DENSE FOG ADVISORY FOR THE OPEN WATERS OF
SOUTHERN LAKE MICHIGAN THROUGH THIS MORNING. SEVERAL NEAR SHORE
OBSERVATIONS AND A SHIP OBSERVATION ACROSS THE NORTHERN SECTIONS OF
THE THE LAKE INDICATED AREAS OF DENSE FOG. I EXPECT THESE AREAS OF
FOG TO BE PUSHED TO THE SOUTHERN END OF LAKE MICHIGAN DURING THE
MORNING HORUS AS A COLD FRONT DROPS DOWN THE LAKE. WINDS BEHIND THIS
FRONT WILL QUICKLY BECOME NORTHERLY UP TO AROUND 20 KT. DRYER AIR
BUILDING IN BEHIND THIS FRONT SHOULD END THE THREAT OF FOG ACROSS
THE NORTHERN HALF OF THE LAKE QUICKLY THIS MORNING.
OTHERWISE...EXPECT WINDS TO BECOME EASTERLY LATER TONIGHT INTO
SATURDAY AS SURFACE HIGH PRESSURE MOVES ACROSS EASTERN ONTARIO.
THERE LOOKS TO BE A PERIOD OF EASTERLY WINDS UP TO AROUND 25 KT ON
SATURDAY AS THE PRESSURE GRADIENT STRENGTHENS OVER THE NORTHERN END
OF THE LAKE. A SURFACE TROUGH OF LOW PRESSURE WILL PUSH ACROSS THE
LAKE ON MONDAY...PRODUCING A WIND SHIFT FROM EAST SOUTHEASTERLY TO
NORTHERLY. THESE NORTHERLY WINDS LOOK TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032 UNTIL 7 AM FRIDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002 UNTIL 7 AM FRIDAY.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 10 AM
FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
114 AM CDT FRI MAY 4 2012
.MESOSCALE DISCUSSION...
815 PM CDT
MAIN CONCERN FOR THE REST OF THE NIGHT IS FLASH FLOOD POTENTIAL.
TRAINING STORMS OVER NORTHEAST DUPAGE AND NORTHERN COOK COUNTY
CONTINUE TO REGENERATE. SOME ALSO PRODUCING SEVERE HAIL. OTHER
SLOW MOVING HEAVY RAIN PRODUCERS OVER BUREAU-LASALLE
COUNTIES...AND YET ANOTHER CLUSTER OF STORMS MOVING IN FROM
EASTERN IA.
SPC ANALYSIS INDICATES RIBBON OF PRECIPITABLE WATER IN EXCESS OF
1.5 FROM WEST CENTRAL TO NORTHEAST ILLINOIS. THIS IS ALSO AN AREA
OF HIGH 850 MOISTURE TRANSPORT. HRRR INDICATING HEAVIEST RAIN IN
THIS CORRIDOR AS WELL. WILL BE ISSUING A FLASH FLOOD WATCH FOR
OVERNIGHT FOR ALL BUT THE NORTH TIER OF COUNTIES.
ALLSOPP
&&
.DISCUSSION...
315 PM CDT
TONIGHT...
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO BE ONGOING
OVERNIGHT AND IT IS DIFFICULT TO ADD ANY SPECIFICS THIS AFTERNOON
AS TO WHEN THE HEAVIEST OF ACTIVITY WILL POP AND MOVE ACROSS...AS
GUIDANCE HAS BEEN STRUGGLING TO LATCH ONTO A SOLID SOLUTION. THE
HRRR AND RAP HAVE BEEN PRETTY CONSISTENT FROM RUN TO RUN IN
DEVELOPING CONVECTION ACROSS THE NORTHERN BORDER THIS AFTERNOON
AND EVENING...BUT AS THE MODELS HAVE BEEN UNDER PERFORMING THE LAST
FEW DAYS...NOT GOING TO COMPLETELY BITE OFF ON ANY ONE SOLUTION
HAPPENING THIS EVENING...LEADING TO A LOW CONFIDENCE OVERNIGHT
FORECAST. DO BELIEVE THAT THE ONGOING ACTIVITY FROM MKE TO ROUGHLY
MSN WILL TRY TO WORK SOUTH WHILE MOVING EAST...BUT WILL DEFER TO
SPECIFICS THAT FALL WITHIN THE MESO AFD ABOVE. FRONT WILL SLOWLY
BE SAGGING SOUTH ACROSS SOUTHERN WISCONSIN AND WORK INTO ILLINOIS
THROUGH THE OVERNIGHT HOURS. ACTIVITY WILL THEN BE ON THE WANE
AS WE GET CLOSER TO THE MORNING.
THE STRONG WARM AIR ADVECTION THAT SHOT TEMPERATURES INTO THE 80S
TODAY WILL SHIFT SOUTH. WITH THE FRONT DROPPING THROUGH AND ACROSS
CHICAGO...WINDS WILL FLIP AROUND TO THE NORTHEAST AND PULL A
COOLER MARINE AIRMASS ACROSS MUCH OF THE COASTLINE. MODELS CONTINUE
TO SLOW THIS TREND SLIGHTLY OVER PREVIOUS RUNS...BUT DOES CONTINUE TO
KEEP IT DRAPED ACROSS THE AREA. FORECAST SOUNDINGS AND RAW
NUMERICAL GUIDANCE HIGHLIGHTS GOOD INSTABILITY TO PERSIST SOUTH AND
WEST OF THIS FEATURE...THOUGH THE BEST INSTABILITY WILL BE WEST
ACROSS IOWA...AND OVERALL EFFECTIVE SHEAR WILL IS SUGGESTED TO BE AT
OR BELOW 30 KT INTO THE PEAK OF THE AFTERNOON. SPC HAS MOST OF THE
CWA IN A SLIGHT RISK FOR SEVERE STORMS TOMORROW...BUT IT DOES FOLLOW
THE OVERALL LOCATION OF THE FRONT...FAVORING AREAS WITH THE BEST
INSTABILITY. WITH NO REAL FORCING WIGGLING THROUGH THE FLOW
TOMORROW...THE OVERALL THREAT DOES NOT APPEAR TO BE HIGH...BUT
CANNOT RULE OUT THE POSSIBILITY OF SOME UNORGANIZED CELLS DEVELOPING
WITH MARGINAL SEVERE HAIL AND WIND GUSTS.
DID MAKE BIGGER CHANGES TO THE DAYTIME HIGHS ACROSS LAKE AND COOK
COUNTIES. WITH THE FRONT SAGGING SOUTH OF MOST THE METRO INTO THE
EARLY AFTERNOON...SHOULD SEE TEMPS HIT THEIR PEAK IN THE EARLY
AFTERNOON AND THEN FALL. STILL SOME CONSIDERABLE DIFFERENCES BETWEEN
THE MAV AND THE MET THIS AFTERNOON...WITH A 10+ DEGREE DIFFERENCE
BETWEEN THE TWO. THE THOUGHT IS THAT WITH THE FRONT TO THE
SOUTH...MOST COASTAL AREAS /INCLUDING THE CHICAGO METRO/ WILL SEE
HIGHS PEAKING IN THE UPPER 60S TO AROUND 70 BEFORE FALLING INTO THE
AFTERNOON...THOUGH IF MORE RAIN FALLS OVERNIGHT AND KEEPS CLOUDS
IN...MID 60S COULD BE PUSHING IT.
BY THE WEEKEND...UPPER LEVEL RIDGING ACROSS THE FOUR CORNERS REGION
WILL BEGIN TO SHIFT EAST AND OVERHEAD...BUT CONTINUED DISPARITY
BETWEEN LONG RANGE GUIDANCE IS LEADING TO FURTHER LOW END CONFIDENCE
ON PRECIP CHANCES INTO THE NEXT WEEK. TRENDS ARE INDICATING A
WEAK SHORTWAVE ROLLING ACROSS THE RIDGE LATE SUNDAY AND INTO
MONDAY WILL BRING THE NEXT BEST CHANCE FOR SHOWERS. AS THE RIDGE
SLIDES EAST AND A TROUGH MOVES THROUGH...WILL GENERALLY FALL BACK
INTO A COOLER NORTHWESTERLY FLOW REGIME KEEPING DAYTIME HIGHS
CLOSE TO SEASONAL WITH OFF AND ON CHANCES THROUGH THE WEEK.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA/EMBEDDED TS TO CONTINUE FOR A FEW HOURS.
* WINDS BECOMING LIGHT TOWARD DAYBREAK THEN SHIFTING NORTHEAST OR
EAST-NORTHEAST BY MID-MORNING...A FEW GUSTS POSSIBLE AS SHIFT
OCCURS.
* MVFR VSBY POSSIBLE OVERNIGHT AS WINDS DIMINISH.
* MVFR CIGS EXPECTED FOR MUCH OF FRIDAY...WITH IFR POSSIBLE FRIDAY
MORNING.
MDB
//DISCUSSION...UPDATED 06Z...
TOUGH FORECAST THROUGH FRIDAY EVENING...ESPECIALLY IN TERMS OF
CIG/VSBY TRENDS. INITIAL CONCERN IS SHRA/TSRA CONTINUING FOR
ANOTHER FEW HOURS BEFORE SHIFTING OFF TO THE EAST AND SOUTH...WITH
A LONGER DURATION AT GYY. WIND DETAILS WILL BE A BIT TOUGH THROUGH
THE REST OF THE NIGHT WITH A PRIMARILY SOUTHWEST DIRECTION THE
NEXT FEW HOURS BEFORE BECOMING LIGHT AND VARIABLE AS A FRONTAL
BOUNDARY APPROACHES. THIS LIGHT WIND COMBINED WITH ABUNDANT LOW
LEVEL MOISTURE FROM THE RAIN WILL BRING A DECENT CHANCE FOR MVFR
VSBY LATE TONIGHT TOWARDS DAYBREAK. THE FRONT WILL SAG SOUTH OF
THE TERMINALS DURING THE EARLY/MID MORNING HOURS RESULTING IN A
SHIFT TO NORTHEAST OR EAST-NORTHEAST WINDS WHICH WILL CONTINUE
THROUGH THE DAY. WILL NEED TO WATCH POTENTIAL FOR SOME GUSTS TO
DEVELOP RIGHT BEHIND THE FRONT AS WELL.
THE NEXT BIG CONCERN IS CEILINGS. VFR CIGS WILL CONTINUE OVERNIGHT
WITH SOME MVFR BRIEFLY POSSIBLE IN THE HEAVIER PRECIP. ONCE WINDS
TURN NORTHEASTERLY WILL START TO SEE A BETTER POTENTIAL FOR
STRATUS DEVELOPMENT. MVFR LOOKS LIKELY WITH IFR POSSIBLE AS WELL.
ASSUMING MVFR/IFR DOES DEVELOP...THE NEXT CHALLENGE WILL BE CIG
TRENDS THROUGH THE DAY. LATEST GUIDANCE HAS BACKED OFF ON DURATION
OF LOWER CIGS BUT WITH FLOW OFF THE LAKE AM THINKING IMPROVEMENT
MAY BE TOUGH TO COME BY. WILL CONTINUE WITH MVFR CIGS AND HINT AT
IFR FRIDAY MORNING AND AFTERNOON...WITH FORECAST SOUNDINGS SHOWING
CIGS LOWERING AGAIN FRIDAY EVENING. WILL NEED TO KEEP EVALUATING
THIS BUT OVERALL CONFIDENCE IS QUITE LOW SO SOME OVERHAULING OF
THE TAF IS POSSIBLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN SHRA/EMBEDDED TS CONTINUING FOR A FEW HOURS.
* MEDIUM-HIGH CONFIDENCE IN WINDS DIMINISHING OVERNIGHT...HIGH
CONFIDENCE IN WINDS SHIFTING TO NORTH EAST OR EAST-NORTHEAST.
MEDIUM-HIGH CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE MVFR VSBY DEVELOPING OVERNIGHT.
* MEDIUM CONFIDENCE IN MVFR CIGS DEVELOPING FRIDAY MORNING BUT LOW
CONFIDENCE IN IF THEY WILL PERSIST OR IMPROVE DURING THE
AFTERNOON. LOW CONFIDENCE IN IFR POTENTIAL.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY THROUGH TUESDAY...GENERALLY PREVAILING VFR BUT WITH
PERIODIC CHANCES FOR SHRA/TSRA. BEST CHANCES FOR TSRA APPEAR TO BE
FRIDAY INTO THE WEEKEND.
WEDNESDAY...CHANCE SHRA. OTRW...VFR.
KJB
&&
.MARINE...
223 PM CDT
BROAD LOW PRESSURE WILL EVOLVE EAST ACROSS THE CENTRAL PORTION OF
LAKE MICHIGAN TONIGHT. IN ASSOCIATION WITH THIS FEATURE...CLUSTERS
OF THUNDERSTORMS WILL TRAVERSE ACROSS THE SOUTHERN TWO-THIRDS OF THE
LAKE...SOME OF THESE POTENTIALLY PRODUCING GUSTY WINDS IN EXCESS OF
35 KTS. GUSTY SOUTHWEST WINDS WILL CONTINUE INTO EARLY THIS EVENING
FROM CHICAGO EASTWARD ACROSS NEARSHORE AREAS...POTENTIALLY
CONTINUING INTO SMALL CRAFT ADVISORY CRITERIA THROUGH 8 OR 9 PM.
THE LOW WILL STEER A COLD FRONT SLOWLY SOUTHWARD ACROSS THE LAKE
TONIGHT INTO FRIDAY MORNING. THIS WILL REACH THE SOUTHERN PORTION OF
THE LAKE BY MIDDAY FRIDAY. NORTHEAST WINDS WILL TURN EAST THIS
WEEKEND AS LOW PRESSURE EVOLVES EASTWARD FROM THE CENTRAL
PLAINS...REACHING THE SOUTHERN GREAT LAKES TO MIDDLE OHIO VALLEY BY
SOMETIME EARLY NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032 UNTIL 7 AM FRIDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002 UNTIL 7 AM FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DES MOINES IA
1228 PM CDT FRI MAY 4 2012
.SHORT TERM.../TODAY/
WEAK SYNOPTIC SCALE FORCING ASSOCIATED WITH ELONGATED SHORT WAVE
FROM WRN GREAT LAKES INTO TX PANHANDLE CONTINUES TO COMBINE WITH
MOISTURE CONVERGENCE ALONG 305K ISENT SURFACE TO PRODUCE SCATTERED
THUNDERSTORMS ACROSS SRN IA. ORIGINALLY THOUGHT MO MCS WOULD
INTERCEPT INFLOW KEEPING CONVERGENCE TO OUR SOUTH...HOWEVER LARGER
SCALE FORCING HAS APPARENTLY ALLOWED MORE DEVELOPMENT FARTHER
NORTH. ELEVATED CAPES UP TO 2500 J/KG AND LITTLE CINH WITH ADEQUATE
EFFECTIVE SHEAR CONTINUE TO PRODUCE SUPERCELLS WITH HEAVY RAIN
POTENTIAL. EXPECT BOTH SEVERE AND HEAVY RAIN THREATS TO DIMINISH BY
SUNRISE HOWEVER AS 305K FLOW CONTINUES TO VEER AND WEAKEN...REDUCING
CONVERGENCE.
QUESTION THEN TURNS TO REDEVELOPMENT LATER IN THE DAY. NAM AND GFS
BOTH BUILD ANOTHER ROUND OF 2500-3000 J/KG MLCAPES AND LITTLE CINH
INTO THE HEART OF IA AS WARM FRONT GRADUALLY SURGES BACK NORTHWARD
INTO THE STATE...CONNECTING TO WEAK SURFACE WAVE OVER SRN SD.
CONVERGENCE WITH THIS FEATURE WILL BE WEAK BUT HRRR AND NMM WRF TRY
TO DEVELOP ISOLATED CONVECTION DURING PEAK HEATING. NOT COMFORTABLE
GOING DRY SO HAVE GONE WITH SLIGHT CHANCES DURING THE AFTERNOON.
BETTER SVR THREAT WOULD BE OVER NRN IA WHERE 0-6KM SHEAR IS THE
HIGHEST. IF ANY STORMS DO FORM THEY WOULD AGAIN BE SLOW MOVING WITH
WEAK H85/H3 WINDS AND B2K SUPERCELL MOTION. LIGHT WINDS...VERY
SEASONALLY HIGH PWS AND DEEP WARM CLOUD DEPTHS COULD ALSO PRODUCE
ISOLATED HEAVY RAINS IF ANYTHING DOES DEVELOP.
.LONG TERM.../TONIGHT THROUGH THURSDAY/
LONG TERM FORECAST IS A CHALLENGE ESPECIALLY EARLY IN THE PERIOD
UNTIL THE SYNOPTIC FRONT MOVES THROUGH SUNDAY NIGHT INTO MONDAY.
MESOSCALE FEATURES WILL BE A MAJOR FACTOR UNTIL THEN...SO WILL
HAVE TO GIVE DUE CONSIDERATION TO THEM IN ADDITION TO SYNOPTIC
FEATURES. IN ADDITION...SEVERE WEATHER AND HEAVY RAIN WILL REMAIN
A THREAT UNTIL THE SYNOPTIC FRONT MOVES THROUGH LATE THIS
WEEKEND.
FOR TONIGHT...ANY STORMS THAT DO DEVELOP WILL HAVE THE POTENTIAL
TO BE SEVERE. IN ADDITION...THEY WOULD BE EFFICIENT RAINFALL
PRODUCERS. FORECAST SOUNDINGS INDICATE PRECIPITABLE WATER VALUES
WILL BE AS HIGH AS THE 1.5 TO 1.75 RANGE TONIGHT...WHICH WOULD BE
BETWEEN THE 99TH PERCENTILE AND THE RECORD HIGH VALUES FOR THIS
TIME OF YEAR. IN ADDITION...COMPARISON OF MEAN STORM MOTION AND
CORFIDI VECTORS INDICATE THAT ANY STORMS WHICH DO DEVELOP WILL
EITHER BE SLOW MOVERS OR WILL TRAIN. THUS HAVE ADDED MENTION OF
HEAVY RAIN IN TONIGHT/S FORECAST. WILL LEAVE THE DECISION OF A
POTENTIAL FLASH FLOOD WATCH WITH THE DAY SHIFT.
THUNDERSTORM CHANCES WILL BE LOWER DURING THE DAY ON
SATURDAY...BUT WILL RETURN AGAIN SATURDAY NIGHT. ALTHOUGH
FORECAST SOUNDINGS INDICATE LOWER PRECIPITABLE WATER VALUES THAN
THOSE EXPECTED FOR TONIGHT...HEAVY RAIN WILL AGAIN BE A
POSSIBILITY IN ADDITION TO SEVERE WEATHER. OF COURSE...MESOSCALE
FEATURES MAY HELP ENHANCE ANY THUNDERSTORM ACTIVITY.
UPPER AIR PATTERN AND SENSIBLE WEATHER UNDERGO A SIGNIFICANT
SHIFT SUNDAY NIGHT INTO MONDAY...AS THE SYNOPTIC FRONT MOVES
THROUGH AND THEN AN UPPER LEVEL LOW SHIFTS SOUTHWARD FROM CANADA
TO THE NORTHERN CONUS. OVERALL...WEATHER WILL BECOME DRIER BUT
SOME PCPN IS POSSIBLE IN ASSOCIATION WITH THE UPPER LEVEL LOW. AT
THIS TIME THE BEST CHANCES FOR PCPN WOULD BE TO OUR NORTH.
&&
.AVIATION...04/18Z
MOIST SOUTHEASTERLY FLOW WILL CONTINUE THROUGH THE 24 HOUR TAF
PERIOD...BUT NOT A LOT OF STRONG FORCING FOR ORGANIZED INTENSE
THUNDERSTORMS. CONVECTION HAS DISRUPTED WARM FRONT LEAVING A
BOUNDARY IN NORTH IOWA AND NORTH MISSOURI. THUNDERSTORMS MOST LIKELY
TO WORK EAST ACROSS NORTHERN IOWA THIS EVENING...SO HAVE INCLUDED
THEM IN TAFS...FOR KDMX AND KOTM...CHANCES ARE TOO SMALL TO INCLUDE
AT THIS TIME. GIVEN HIGH MOISTURE EXPECT FOG AND/OR LOW STRATUS TO
DEVELOP AGAIN OVERNIGHT ACROSS STATE...AND THIS WILL TAKE SOME TIME
TO BURN OFF SATURDAY MORNING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...ZOGG
AVIATION...JUNGBLUTH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
734 AM CDT FRI MAY 4 2012
.SHORT TERM.../TODAY/
WEAK SYNOPTIC SCALE FORCING ASSOCIATED WITH ELONGATED SHORT WAVE
FROM WRN GREAT LAKES INTO TX PANHANDLE CONTINUES TO COMBINE WITH
MOISTURE CONVERGENCE ALONG 305K ISENT SURFACE TO PRODUCE SCATTERED
THUNDERSTORMS ACROSS SRN IA. ORIGINALLY THOUGHT MO MCS WOULD
INTERCEPT INFLOW KEEPING CONVERGENCE TO OUR SOUTH...HOWEVER LARGER
SCALE FORCING HAS APPARENTLY ALLOWED MORE DEVELOPMENT FARTHER
NORTH. ELEVATED CAPES UP TO 2500 J/KG AND LITTLE CINH WITH ADEQUATE
EFFECTIVE SHEAR CONTINUE TO PRODUCE SUPERCELLS WITH HEAVY RAIN
POTENTIAL. EXPECT BOTH SEVERE AND HEAVY RAIN THREATS TO DIMINISH BY
SUNRISE HOWEVER AS 305K FLOW CONTINUES TO VEER AND WEAKEN...REDUCING
CONVERGENCE.
QUESTION THEN TURNS TO REDEVELOPMENT LATER IN THE DAY. NAM AND GFS
BOTH BUILD ANOTHER ROUND OF 2500-3000 J/KG MLCAPES AND LITTLE CINH
INTO THE HEART OF IA AS WARM FRONT GRADUALLY SURGES BACK NORTHWARD
INTO THE STATE...CONNECTING TO WEAK SURFACE WAVE OVER SRN SD.
CONVERGENCE WITH THIS FEATURE WILL BE WEAK BUT HRRR AND NMM WRF TRY
TO DEVELOP ISOLATED CONVECTION DURING PEAK HEATING. NOT COMFORTABLE
GOING DRY SO HAVE GONE WITH SLIGHT CHANCES DURING THE AFTERNOON.
BETTER SVR THREAT WOULD BE OVER NRN IA WHERE 0-6KM SHEAR IS THE
HIGHEST. IF ANY STORMS DO FORM THEY WOULD AGAIN BE SLOW MOVING WITH
WEAK H85/H3 WINDS AND B2K SUPERCELL MOTION. LIGHT WINDS...VERY
SEASONALLY HIGH PWS AND DEEP WARM CLOUD DEPTHS COULD ALSO PRODUCE
ISOLATED HEAVY RAINS IF ANYTHING DOES DEVELOP.
.LONG TERM.../TONIGHT THROUGH THURSDAY/
LONG TERM FORECAST IS A CHALLENGE ESPECIALLY EARLY IN THE PERIOD
UNTIL THE SYNOPTIC FRONT MOVES THROUGH SUNDAY NIGHT INTO MONDAY.
MESOSCALE FEATURES WILL BE A MAJOR FACTOR UNTIL THEN...SO WILL
HAVE TO GIVE DUE CONSIDERATION TO THEM IN ADDITION TO SYNOPTIC
FEATURES. IN ADDITION...SEVERE WEATHER AND HEAVY RAIN WILL REMAIN
A THREAT UNTIL THE SYNOPTIC FRONT MOVES THROUGH LATE THIS
WEEKEND.
FOR TONIGHT...ANY STORMS THAT DO DEVELOP WILL HAVE THE POTENTIAL
TO BE SEVERE. IN ADDITION...THEY WOULD BE EFFICIENT RAINFALL
PRODUCERS. FORECAST SOUNDINGS INDICATE PRECIPITABLE WATER VALUES
WILL BE AS HIGH AS THE 1.5 TO 1.75 RANGE TONIGHT...WHICH WOULD BE
BETWEEN THE 99TH PERCENTILE AND THE RECORD HIGH VALUES FOR THIS
TIME OF YEAR. IN ADDITION...COMPARISON OF MEAN STORM MOTION AND
CORFIDI VECTORS INDICATE THAT ANY STORMS WHICH DO DEVELOP WILL
EITHER BE SLOW MOVERS OR WILL TRAIN. THUS HAVE ADDED MENTION OF
HEAVY RAIN IN TONIGHT/S FORECAST. WILL LEAVE THE DECISION OF A
POTENTIAL FLASH FLOOD WATCH WITH THE DAY SHIFT.
THUNDERSTORM CHANCES WILL BE LOWER DURING THE DAY ON
SATURDAY...BUT WILL RETURN AGAIN SATURDAY NIGHT. ALTHOUGH
FORECAST SOUNDINGS INDICATE LOWER PRECIPITABLE WATER VALUES THAN
THOSE EXPECTED FOR TONIGHT...HEAVY RAIN WILL AGAIN BE A
POSSIBILITY IN ADDITION TO SEVERE WEATHER. OF COURSE...MESOSCALE
FEATURES MAY HELP ENHANCE ANY THUNDERSTORM ACTIVITY.
UPPER AIR PATTERN AND SENSIBLE WEATHER UNDERGO A SIGNIFICANT
SHIFT SUNDAY NIGHT INTO MONDAY...AS THE SYNOPTIC FRONT MOVES
THROUGH AND THEN AN UPPER LEVEL LOW SHIFTS SOUTHWARD FROM CANADA
TO THE NORTHERN CONUS. OVERALL...WEATHER WILL BECOME DRIER BUT
SOME PCPN IS POSSIBLE IN ASSOCIATION WITH THE UPPER LEVEL LOW. AT
THIS TIME THE BEST CHANCES FOR PCPN WOULD BE TO OUR NORTH.
&&
.AVIATION...04/12Z
CLUSTER OF SCATTERED THUNDERSTORMS WILL CONTINUE TO AFFECT SERN IA
THIS MORNING WITH PATCHY MVFR/IFR CONDITIONS IN LOW CLOUDS...EVEN
DOWN TO LIFR IN SPOTS INCLUDING KDSM. CONDITIONS SHOULD GRADUALLY
IMPROVE LATER THIS MORNING AS CONVECTION EXITS. NEBULOUS FRONTAL
BOUNDARY ALONG IOWA MISSOURI BORDER WILL LIFT NORTHWARD BACK INTO IA
LATER TODAY AND MAY DEVELOP ADDITIONAL STORMS DURING PEAK HEATING.
CONFIDENCE IN TIMING AND LOCATION IS NOT GREAT ENOUGH TO INCLUDE AT
THE MOMENT...BUT LATE AFTERNOON AND THIS EVENING WOULD BE THE MOST
LIKELY TIMES. LATER TONIGHT SELY SURFACE FLOW BECOMES MORE ELY WITH
MODELS AND MOS GUIDANCE SUGGESTING SATURATED LOW LEVELS. THIS WILL
LIKELY LEAD TO REDUCED VISIBILITIES AND LOW CIGS WITH MOST FAVORABLE
LOCATIONS NERN HALF OF IA.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 AM CDT THIS MORNING FOR APPANOOSE-
DAVIS-MAHASKA-MONROE-WAPELLO.
&&
$$
SHORT TERM/AVIATION...SMALL
LONG TERM...ZOGG
AREA FORECAST DISCUSSION
NWS DES MOINES IA
336 AM CDT FRI MAY 4 2012
.SHORT TERM.../TODAY/
WEAK SYNOPTIC SCALE FORCING ASSOCIATED WITH ELONGATED SHORT WAVE
FROM WRN GREAT LAKES INTO TX PANHANDLE CONTINUES TO COMBINE WITH
MOISTURE CONVERGENCE ALONG 305K ISENT SURFACE TO PRODUCE SCATTERED
THUNDERSTORMS ACROSS SRN IA. ORIGINALLY THOUGHT MO MCS WOULD
INTERCEPT INFLOW KEEPING CONVERGENCE TO OUR SOUTH...HOWEVER LARGER
SCALE FORCING HAS APPARENTLY ALLOWED MORE DEVELOPMENT FARTHER
NORTH. ELEVATED CAPES UP TO 2500 J/KG AND LITTLE CINH WITH ADEQUATE
EFFECTIVE SHEAR CONTINUE TO PRODUCE SUPERCELLS WITH HEAVY RAIN
POTENTIAL. EXPECT BOTH SEVERE AND HEAVY RAIN THREATS TO DIMINISH BY
SUNRISE HOWEVER AS 305K FLOW CONTINUES TO VEER AND WEAKEN...REDUCING
CONVERGENCE.
QUESTION THEN TURNS TO REDEVELOPMENT LATER IN THE DAY. NAM AND GFS
BOTH BUILD ANOTHER ROUND OF 2500-3000 J/KG MLCAPES AND LITTLE CINH
INTO THE HEART OF IA AS WARM FRONT GRADUALLY SURGES BACK NORTHWARD
INTO THE STATE...CONNECTING TO WEAK SURFACE WAVE OVER SRN SD.
CONVERGENCE WITH THIS FEATURE WILL BE WEAK BUT HRRR AND NMM WRF TRY
TO DEVELOP ISOLATED CONVECTION DURING PEAK HEATING. NOT COMFORTABLE
GOING DRY SO HAVE GONE WITH SLIGHT CHANCES DURING THE AFTERNOON.
BETTER SVR THREAT WOULD BE OVER NRN IA WHERE 0-6KM SHEAR IS THE
HIGHEST. IF ANY STORMS DO FORM THEY WOULD AGAIN BE SLOW MOVING WITH
WEAK H85/H3 WINDS AND B2K SUPERCELL MOTION. LIGHT WINDS...VERY
SEASONALLY HIGH PWS AND DEEP WARM CLOUD DEPTHS COULD ALSO PRODUCE
ISOLATED HEAVY RAINS IF ANYTHING DOES DEVELOP.
.LONG TERM.../TONIGHT THROUGH THURSDAY/
LONG TERM FORECAST IS A CHALLENGE ESPECIALLY EARLY IN THE PERIOD
UNTIL THE SYNOPTIC FRONT MOVES THROUGH SUNDAY NIGHT INTO MONDAY.
MESOSCALE FEATURES WILL BE A MAJOR FACTOR UNTIL THEN...SO WILL
HAVE TO GIVE DUE CONSIDERATION TO THEM IN ADDITION TO SYNOPTIC
FEATURES. IN ADDITION...SEVERE WEATHER AND HEAVY RAIN WILL REMAIN
A THREAT UNTIL THE SYNOPTIC FRONT MOVES THROUGH LATE THIS
WEEKEND.
FOR TONIGHT...ANY STORMS THAT DO DEVELOP WILL HAVE THE POTENTIAL
TO BE SEVERE. IN ADDITION...THEY WOULD BE EFFICIENT RAINFALL
PRODUCERS. FORECAST SOUNDINGS INDICATE PRECIPITABLE WATER VALUES
WILL BE AS HIGH AS THE 1.5 TO 1.75 RANGE TONIGHT...WHICH WOULD BE
BETWEEN THE 99TH PERCENTILE AND THE RECORD HIGH VALUES FOR THIS
TIME OF YEAR. IN ADDITION...COMPARISON OF MEAN STORM MOTION AND
CORFIDI VECTORS INDICATE THAT ANY STORMS WHICH DO DEVELOP WILL
EITHER BE SLOW MOVERS OR WILL TRAIN. THUS HAVE ADDED MENTION OF
HEAVY RAIN IN TONIGHT/S FORECAST. WILL LEAVE THE DECISION OF A
POTENTIAL FLASH FLOOD WATCH WITH THE DAY SHIFT.
THUNDERSTORM CHANCES WILL BE LOWER DURING THE DAY ON
SATURDAY...BUT WILL RETURN AGAIN SATURDAY NIGHT. ALTHOUGH
FORECAST SOUNDINGS INDICATE LOWER PRECIPITABLE WATER VALUES THAN
THOSE EXPECTED FOR TONIGHT...HEAVY RAIN WILL AGAIN BE A
POSSIBILITY IN ADDITION TO SEVERE WEATHER. OF COURSE...MESOSCALE
FEATURES MAY HELP ENHANCE ANY THUNDERSTORM ACTIVITY.
UPPER AIR PATTERN AND SENSIBLE WEATHER UNDERGO A SIGNIFICANT
SHIFT SUNDAY NIGHT INTO MONDAY...AS THE SYNOPTIC FRONT MOVES
THROUGH AND THEN AN UPPER LEVEL LOW SHIFTS SOUTHWARD FROM CANADA
TO THE NORTHERN CONUS. OVERALL...WEATHER WILL BECOME DRIER BUT
SOME PCPN IS POSSIBLE IN ASSOCIATION WITH THE UPPER LEVEL LOW. AT
THIS TIME THE BEST CHANCES FOR PCPN WOULD BE TO OUR NORTH.
&&
.AVIATION...04/06Z
THUNDERSTORM CHANCES CONFINED TO MAINLY KOTM THROUGH THE NEXT 6 TO
10 HOURS...WITH SOME PATCHY LIGHT FOG POSSIBLE AT OTHER TAF SITES AS
SFC AND LOW LEVEL MOISTURE REMAINS HIGH WITH LIGHT WINDS. EXPECT
BREAK IN ANY SHRA/TSRA ACTIVITY AGAIN DURING THE BULK OF THE
DAYLIGHT HOURS...WITH THUNDERSTORM ACTIVITY EXPECTED TO DEVELOP
TOWARD THE EARLY EVENING/OVERNIGHT HOURS AGAIN FRIDAY. HAS BEEN
REALLY HARD TO NAIL PLACEMENT DOWN...SO HAVE STUCK WITH SOME VCSH
MENTIONS IN THE AREAS THAT SEEM MORE CONDUCIVE TO CONVECTIVE
DEVELOPMENT AT THIS TIME.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 AM CDT THIS MORNING FOR APPANOOSE-
DAVIS-MAHASKA-MONROE-WAPELLO.
&&
$$
SHORT TERM...SMALL
LONG TERM...ZOGG
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
346 PM CDT FRI MAY 4 2012
.DISCUSSION...
AN UPPER LEVEL TROUGH ACROSS THE WESTERN CONUS THIS AFTERNOON WILL
LIFT NORTHEAST INTO THE NORTHERN AND CENTRAL HIGH PLAINS BY SATURDAY
AFTERNOON. A DOWNSTREAM UPPER LEVEL RIDGE WILL AMPLIFY ACROSS THE
EASTERN CENTRAL AND SOUTHERN PLAINS TONIGHT THROUGH SATURDAY.
A WEAK SOUTHERN STREAM UPPER LEVEL TROUGH WAS LOCATED ACROSS CENTRAL
OK LATE THIS AFTERNOON AND WILL LIFT NORTHEAST INTO SOUTHWEST MO
THIS EVENING. THERE MAY BE ENOUGH ASCENT AHEAD OF THE WEAK H5 TROUGH
TO CAUSE ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP THIS
AFTERNOON ACROSS SOUTHEAST KS AND SOUTHWEST MO. FORECAST SOUNDINGS
ACROSS THE CWA SHOW A STRONG CAP...WHICH WILL PREVENT SFC BASED
PARCELS REACHING THEIR LFC...DUE TO AN EML AT 830 MB. THE 16Z RUN OF
THE HRRR IS THE ONLY NUMERICAL MODEL SHOWING ISOLATED THUNDERSTORMS
DEVELOPING ACROSS SOUTHEAST KS AND SOUTHWEST MO...SOUTH AND
SOUTHEAST OF THE CWA THIS AFTERNOON. I KEPT 14 POPS ACROSS THE
SOUTHEAST COUNTIES OF THE CWA THIS AFTERNOON AND TONIGHT...JUST IN
CASE THERE WAS ENOUGH ASCENT FOR PARCELS ABOVE THE CAPPING INVERSION
TO REACH THEIR LFC. IF THESE ELEVATED STORMS DEVELOP THEY WILL NOT
BE SEVERE ACROSS THE SOUTHEAST COUNTIES OF THE CWA.
TONIGHT...THERE MAY BE SOME WEAK ISENTROPIC LIFT AFTER 3Z FOR SCT TO
STRATUS TO DEVELOP BUT AFTER 10Z...850MB WINDS VEER MORE TO THE
SOUTHWEST...THUS ANY STRATUS MAY DISSIPATE AFTER 10Z SAT. OVERNIGHT
LOWS WILL ONLY DROP INTO THE UPPER 60S TO LOWER 70S.
SATURDAY...850MB WINDS WILL BACK TO THE SOUTH DURING THE MID AND
LATE MORNING HOURS. DEEP MOISTURE ADVECTION WILL CAUSE SFC DEWPOINTS
TO BE IN THE UPPER 60S TO LOWER 70S DURING THE AFTERNOON HOURS.
FORECAST SOUNDINGS CONTINUE TO SHOW THE EML KEEPING A MODERATELY
STRONG CAP IN PLACE ACROSS THE CWA. THE H5 TROUGH OVER THE WESTERN
CONUS WILL LIFT NORTHEAST INTO THE NORTHERN HIGH PLAINS DURING THE
LATE AFTERNOON HOURS. THE ONLY SFC CONVERGENCE AND ASCENT WILL BE
ALONG AND NORTH OF THE SFC BOUNDARY ACROSS NORTHERN AND WESTERN NE
DURING THE LATE AFTERNOON HOURS...WHERE SCATTERED THUNDERSTORMS WILL
DEVELOP. EXPECT A WARM AND HUMID DAY WITH HIGHS IN THE UPPER 80S TO
LOWER 90S...AND AFTERNOON HEAT INDICES IN MID TO UPPER 90S.
GARGAN
MODELS CONTINUE TO DIFFER ON FRONTAL POSITION/SPEED OF MOVEMENT
ACROSS THE CWA THROUGH SUNDAY. THE NAM CONTINUES TO BE THE FASTER
AMONG THE MODELS WITH THE SPEED OF THE FRONT...AND GFS THE SLOWER.
WENT WITH A COMPROMISE AMONG MODELS BRINGING THE FRONT INTO THE FAR
NORTHWEST CORNER SUNDAY MORNING AND EXITING THE SOUTHEAST CORNER
SUNDAY EVENING. STILL EXPECTED THE DEVELOPMENT OF THUNDERSTORM
COMPLEX WELL NORTH OF THE CWA SATURDAY EVENING...BUT APPEARS ONLY A
LOW END CHC/SCHC POPS WARRANTED ACROSS AREAS NORTH OF I 70 THROUGH
SUNRISE SUNDAY. THE REMAINDER OF THE CWA SHOULD BE DRY. AS THE FRONT
MOVES INTO AND ACROSS THE CWA SUNDAY/SUNDAY EVENING...THE CHANCE FOR
THUNDERSTORMS WILL INCREASE...MAINLY ACROSS AREAS ALONG AND EAST OF
HIGHWAY 99 FROM MID AFTERNOON INTO THE EVENING. ALTHOUGH SHEAR WILL
BE WEAK...MLCAPE WILL BE VERY HIGH TO EXTREME WITH VALUES IN
ACROSS THE SOUTHEAST 1/2 OF THE CWA COMMONLY IN THE RANGE OF
3500-4500 J/KG. THEREFORE...STILL A THREAT FOR LARGE HAIL AND
STRONG GUSTY WINDS ALONG AND AHEAD OF THE FRONT FROM MID AFTERNOON
INTO THE EARLY EVENING OVER THE NORTHEAST AND EAST CENTRAL
COUNTIES. THE FRONT WILL BEGIN TO BRING IN COOLER AND DRIER AIR
INTO THE NORTHWEST CWA SUNDAY WITH HIGHS IN THE MIDDLE 70S
NORTHWEST TO STILL THE MIDDLE 80S SOUTHEAST AHEAD OF THE FRONT AT
PEAK HEATING.
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL STEADILY DECREASE WEST TO
EAST ACROSS THE CWA SUNDAY EVENING...WITH DRY CONDITIONS ALL AREAS
LATER IN THE NIGHT. HAVE LOWERED LOWS INTO THE MIDDLE 50S TO NEAR 60.
THE EXTENDED FORECAST FROM MONDAY INTO THURSDAY STILL LOOKS TO BE
DOMINATED FROM COOLER HIGH PRESSURE WITH PLEASANT HIGHS IN THE 70S
AND LOWS IN THE UPPER 40S AND LOWER 50S EACH DAY. AS THE LARGE SFC
RIDGE SHIFTS FURTHER EAST BY LATE THURSDAY...MOISTURE WHICH WILL BE
POOLING TO THE SOUTH AND WEST OF THE AREA WILL GET ADVECTED
NORTHWARD INTO THE AREA FRIDAY. AS A SHORTWAVE TROUGH APPROACHES
FROM THE SOUTHWEST...THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
BE ON INCREASE AT THAT TIME. 63
&&
.AVIATION...
EXPECT VFR CONDITIONS FOR MUCH OF THE NEXT 24 HOURS. SCT TO AT
TIMES BKN CU WILL DEVELOP AT THE TAF SITES THIS AFTERNOON WITH
CU BASES OF 3,000 TO 4,000 FEET. THE CU SHOULD DISSIPATE AFTER
SUNSET. SCATTERED STRATUS WITH MVFR CEILINGS MAY DEVELOP AFTER 8Z SAT AND
MIX OUT AROUND 15Z SAT. THERE MAY BE BE SOME PERIODS OF BKN
STRATUS WITH MVFR CEILINGS BETWEEN 10Z AND 14Z SAT. WINDS WILL BE
SOUTH-SOUTHEAST UNDER 12 KTS THROUGH THE PERIOD.
GARGAN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
606 AM CDT FRI MAY 4 2012
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 202 AM CDT FRI MAY 4 2012
00Z 4 MAY 2012 250 HPA MAP ANALYSIS SHOWED A 115 KT JET EXTENDING FROM
NORTHERN CALIFORNIA AND ACROSS THE IDAHO TREASURE VALLEY. ANOTHER 115
KT JET WAS LOCATED ACROSS NORTHEASTERN ONTARIO. A WEAKER 75 KT SUBTROPICAL
JET WAS LOCATED ACROSS CHIHUAHUA AND ACROSS SOUTHWEST TEXAS. AT 500
HPA, SEVERAL SHORTWAVE TROUGHS WERE NOTED ACROSS THE CONUS. ONE OF THESE
WEAK IMPULSES TRIGGERED CONVECTION ACROSS SOUTHEASTERN COLORADO EARLIER
IN THE DAY. AT 700 HPA, VERY LITTLE CHANGE IN THE THERMODYNAMIC PROFILE
WAS NOTED ACROSS THE CENTRAL AND SOUTHERN PLAINS WITH VERY WARM TEMPERATURES
OF 10 TO 13 DEG C EXTENDING FROM THE TEXAS PANHANDLE AND ACROSS SOUTHWEST
KANSAS. A SIMILAR WARM PATTERN AT 850 HPA WITH TEMPERATURES IN THE 20
TO 29 DEG C PREVAILED ACROSS THE HIGH PLAINS. AT THE SURFACE, SIGNIFICANT
GULF OF MEXICO MOISTURE AS MARKED BY DEWPOINTS IN THE UPPER 60S TO LOWER
70S DEG F WAS OBSERVED EAST OF A DRYLINE FROM TEXAS TO KANSAS.
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 202 AM CDT FRI MAY 4 2012
THIS MORNING:
AROUND MIDNIGHT, CONVECTION ERUPTED ACROSS SOUTH CENTRAL KANSAS ON THE
NOSE OF A 50 KT 850 HPA JET. THE ONLY MODELS THAT CAPTURED THIS CORRECTLY
WAS THE GFS AND WRF-NMM. THIS CLUSTER HAS ALREADY MOVED OUT OF THE REGION
BUT DID MANAGE TO PUT DOWN SOME SEVERE HAIL.
THE NEXT MORNING CONCERN IS MOISTURE POOLING NORTH OF A SURFACE LOW.
THIS WILL CREATE SOME STRATUS FROM DODGE CITY TO HAYS THIS MORNING.
RELATIVE HUMIDITY PROGS AND OUTPUT FROM THE RAP SHOW THAT THE MOST LIKELY
AREA FOR LOWERED VISIBILITIES AND ENHANCED CLOUD COVER IS ACROSS THE
INTERSTATE 70 CORRIDOR. THE LOW LEVEL CLOUDS SHOULD START TO ERODE BY
MID MORNING.
TODAY:
TODAY WILL BE HOT WITH TEMPERATURES IN THE 90S DEG F. THIS IS A GOOD
20 DEGREES ABOVE NORMAL. FORECAST SOUNDINGS SHOW THE ATMOSPHERE BECOMING
DEEPLY MIXED TO ABOUT 500 HPA.FORECAST SOUNDINGS ARE ALSO FAIRLY DRY
SO EXPECTING FULL INSOLATION AFTER THE AFOREMENTIONED LOW CLOUDS DISSIPATE.
NO PRECIPITATION IS EXPECTED TODAY AS 500 HPA GEOPOTENTIAL HEIGHTS INCREASE
THROUGH THE DAY WITH SUBSIDENCE CONTINUING THROUGH THE ATMOSPHERIC COLUMN
IN RESPONSE TO MID AND LOW LEVEL RIDGING.
TONIGHT:
TRANQUIL WEATHER WILL CONTINUE THROUGH THE OVERNIGHT PERIOD. WEAK LEE
SURFACING TROUGHING ACROSS FAR EASTERN COLORADO WILL KEEP SOUTHERLY
WINDS IN THE FORECAST. SURFACE DEWPOINTS WILL MIX DOWN TO THE 30S DEG
F WEST TO AROUND 60 DEG F EAST THROUGH THE OVERNIGHT PERIOD. AS A RESULT,
OVERNIGHT LOWS WILL BE SLIGHTLY COOLER THAN COMPARED TO PREVIOUS NIGHTS
WITH 50S DEG F EXPECT ACROSS SW KANSAS AND LOW 60S DEG F EXPECTED ACROSS
SOUTH CENTRAL KANSAS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI MAY 4 2012
MODELS THIS MORNING REMAIN IN DECENT AGREEMENT WITH CONVECTION
DEVELOPING LATE SATURDAY NEAR THE RIGHT EXIT REGION OF AN UPPER
LEVEL JET THAT WILL BE LOCATED NEAR EASTERN WYOMING/NORTHEAST COLORADO.
THIS CONVECTION IS THEN FORECAST TO SPREAD EAST INTO NEBRASKA AND
PORTIONS OF NORTHERN KANSAS DURING THE OVERNIGHT PERIOD AS THIS
JET STREAK MOVES NORTHEAST INTO THE NORTHERN PLAINS. A COLD FRONT
WILL SURGE SOUTH ACROSS WESTERN KANSAS LATE SATURDAY NIGHT AND BY
EARLY SUNDAY MORNING THIS FRONT WILL EXTEND FROM SOUTH CENTRAL
KANSAS INTO THE PANHANDLE OF TEXAS. BEHIND THIS FRONT GUSTY NORTH
WINDS ARE STILL EXPECTED BASED ON THE TIGHT PRESSURE GRADIENT AND
925-850MB WINDS. GIVEN THE WINDS FORECAST IN THE BOUNDARY LEVEL
AND AT THE 850MB LEVEL SUNDAY WOULD NOT BE SURPRISED TO SEE WIND
SPEEDS REACHING WIND ADVISORY CRITERIA. AS A RESULT DID INCREASE
WINDS EARLY SUNDAY BEHIND THIS FRONT TO JUST BELOW 26KNOTS. 850MB
MIX DOWN TEMPERATURES FROM THE GFS AND ECMWF AT 18Z SUNDAY AND 00Z
MONDAY CONTINUE TO SUPPORT THE PREVIOUS TRENDS OF LOWERING
TEMPERATURES SUNDAY AFTERNOON. PRECIPITATION CHANCES WITH THE
FRONT STILL APPEARS SMALL WITH THE POSSIBLE EXCEPTION BEING
NORTHEAST/EAST OF DODGE CITY BASED ON LOW LEVEL MOISTURE AND
850-700MB FORCING BEING PRESENT EARLY SUNDAY.
SUNDAY NIGHT AND MONDAY A COOL DOME OF HIGH PRESSURE WILL SETTLE
INTO WESTERN KANSAS AS THIS COLD FRONT CONTINUES TO TRACK SOUTH
INTO CENTRAL/SOUTHERN TEXAS. 850MB TEMPERATURE TRENDS FROM BOTH
THE GFS AND ECMWF CONTINUES TO SUPPORT HIGHS ON MONDAY RANGING
FROM THE UPPER 60S TO LOWER 70S. THE CENTER OF THIS SURFACE HIGH
IS FORECAST TO CROSS WESTERN KANSAS MONDAY NIGHT, HOWEVER CLOUD
COVER WILL BE ON THE INCREASE AS ANOTHER UPPER LEVEL TROUGH BEGINS
TO APPROACH THE AREA AND MID LEVEL MOISTURE AND WARM AIR ADVECTION
DEVELOPS ACROSS EASTERN COLORADO/WESTERN KANSAS. IN ADDITION TO
INCREASING CLOUDS THERE MAY ALSO BE A CHANCE FOR SOME
PRECIPITATION LATE MONDAY THROUGH TUESDAY AHEAD OF THIS UPPER
TROUGH SO WILL KEEP A CHANCE OF PRECIPITATION GOING UNTIL THIS
NEXT SYSTEM FINALLY MOVES EAST OF WESTERN KANSAS. TEMPERATURES ARE
EXPECTED TO BE THE NEAR SEASONAL NORMALS THROUGH MID WEEK AS A
REINFORCEMENT OF COOLER AIR BRIEFLY RETURNS TO WESTERN KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 602 AM CDT FRI MAY 4 2012
WEAK UPSLOPE FLOW PERSISTS ACROSS NORTH CENTRAL AND MUCH OF
SOUTHWEST KANSAS EARLY THIS MORNING. HRRR EVEN SUGGESTS AREAS OF
DENSE FOG WILL STILL BE LIKELY FOR A FEW HOURS AT HAYS, HOWEVER
06Z NAM BUFR SOUNDINGS INDICATING ONLY A SHALLOW LAYER MOISTURE
WILL BE PRESENT IN THIS AREA THROUGH 14Z. GIVEN LATEST SATELLITE
TRENDS AND WEAK UPSLOPE FLOW WILL CONTINUE TO TREND TOWARDS A
BRIEF PERIOD OF IFR CONDITIONS AT HAYS WHILE ONLY MVFR VSBYS AT
DDC AND GCK UNTIL 14Z. AFTER 14Z VFR CONDITIONS CAN EXPECT AT ALL
TAF SITES. LIGHT WINDS WILL BECOME SOUTH/SOUTHWEST AND INCREASE TO
NEAR 10KTS BY MID DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 92 58 95 61 / 0 0 0 10
GCK 93 55 95 59 / 0 0 0 10
EHA 94 57 93 59 / 0 0 0 10
LBL 95 56 96 59 / 0 0 0 10
HYS 91 59 92 62 / 0 0 0 20
P28 95 63 96 66 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ030-031-
043>046.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
310 AM EDT FRI MAY 04 2012
.Short Term (Today through Saturday)...
Issued at 310 AM EDT May 4 2012
Upper air analysis is showing myriad little ripples in the flow
moving overhead throughout this short term period. The most
significant looking wave will pass overhead early Saturday, ending
up to our south by Saturday evening. At the surface, a weak
east-west cold front reaching from the central Plains into the Great
Lakes this morning will settle southward, landing somewhere in the
vicinity of the Ohio River/I-64 corridor by Saturday morning, and
then getting hung up there for the rest of the day.
Thunderstorm chances will gradually increase as the cold front
approaches, and will occasionally be enhanced by any weak upper
waves moving through. In the forecast we will slowly ramp
thunderstorm chances up from slight chance this morning to chance
this afternoon. Tonight looks like the best shot at rain, with
moisture pooling ahead of the front to the tune of 1.5 inch
precipitable waters, so will go with likelies north and central and
chance south. Over the course of the day on Saturday will push the
rain chances south as the day progresses, arriving at just a slight
chance of lingering showers or storms by Saturday evening.
With more clouds expected today than we have been seeing recently,
there is some question as to how unstable we will be able to get
this afternoon. Nevertheless, there could be enough surface based
instability and wind aloft to get a few strong to severe storms
going. Hail would be the primary threat, with gusty winds a
secondary possibility.
Severe weather looks less likely for Saturday, with much weaker wind
fields and less instability thanks to more widespread clouds and
precipitation in the morning. Also, if the timing of the Saturday
upper wave is correct, much of the region will be behind the wave by
evening.
Will stick with lower to middle 80s for highs today and Saturday
with clouds and chance of showers. We will still be ahead of the
cold front tonight so it should be another muggy, warm night with
lows again in the 60s.
.Long Term (Saturday night through Thursday)...
Issued at 310 AM EDT May 4 2012
The back-door front is still on track to slide southwest across the
forecast area and stall Saturday night and Sunday. As mentioned in
the previous forecast, the upper-level ridge axis will be directly
overhead Sunday, with indications of weak subsidence. This will act
to limit widespread convection, with only isolated thunderstorms
expected. Temperatures Sunday morning in the low to mid 60s will
give way to low and mid 80s for highs.
Latest guidance indicates flow aloft will become generally zonal
Monday and Tuesday with troughing becoming established across the
East Coast by Thursday as a strong shortwave moves through the Great
Lakes. At the surface, a weak surface low will move across the
Plains to the mid Mississippi River Valley by Monday morning and
continue progressing eastward, reaching the northeast CONUS by
Wednesday morning.
This pattern change will cause our stalled frontal boundary to
retreat northward as a warm front early Monday, with a short break
in precipitation until a cold front pushes through the region later
in the day Monday and Monday night. This will be the best chance to
experience numerous showers and thunderstorms. At this time, the
dynamics with this frontal passage do not appear too favorable for
organized severe weather, but some strong storms are still possible
as moderate instability will be present. Showers and a few lingering
storms will exit Tuesday morning as the cold front moves east. Highs
in the lower 80s Monday will give way to cooler temps Tuesday, with
highs generally in the mid 70s anticipated.
With a strong trough developing over the East Coast and surface high
pressure building across our region Tuesday night through Thursday,
will proceed with a generally dry forecast and cooler temperatures
as northerly flow will dominate. Could see some showers Wednesday
afternoon as models hint at a vort max tracking through the Ohio
Valley on the back side of the upper-level trough. Overall moisture
appears fairly limited, so will just carry a small chance of rain at
this time. Temperatures will continue to trend cooler with highs
Wednesday and Thursday ranging from the upper 60s to low 70s.
Overnight lows will have a similar trend, with lower 50s expected by
Wednesday night.
&&
.Aviation (06Z TAF Issuance)...
Updated at 120 AM EDT May 4 2012
A weak east-west cold front to our north will slowly settle
southward over the course of this TAF period, arriving somewhere in
the vicinity of the Ohio River by Saturday morning. As this front
approaches, thunderstorm chances will steadily increase. Rather
than have thunder in the TAFs for most of the forecast period, will
hold off for now and see how development progresses to our north.
The exception will be at SDF and LEX after 00Z tonight since the
front will be quite close by then and there is some semblance of
model agreement that thunderstorms will be in the area.
Another challenge is the possibility of sub-VFR ceilings by dawn
this morning, especially at BWG. Latest RR is showing a large area
of LIFR ceilings swelling northward from the Chattanooga area into
much of central Kentucky by 10Z. A look at current obs shows that
the RR actually has a very good handle on the ceilings in the
Chattanooga area at initialization, which creates some cause for
concern. For now will give a nod to the model and bring in a TEMPO
BKN MVFR ceiling at BWG for 10Z-14Z, and will continue to monitor to
see how things develop.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......13
Long Term........MJP
Aviation.........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
125 AM EDT FRI MAY 04 2012
.Short Term (Today through Friday)...
Issued at 300 PM EDT May 3 2012
Upper low over Tennessee has managed to sling a fairly extensive
cloud shield into Kentucky, but precip has had a tough time holding
together. The cloud cover has kept the environment from
destabilizing, and kept a lid on any convective development. However
it has warmed up enough along the river to generate a decent cu
field. With temps in the lower/mid 80s and another hour or two of
heating left, will hold on to the slight chance POP north of the
Parkways. Better chances will be found to the south with the
scattered showers that are ongoing.
Precip chances will end by sunset with the loss of daytime heating.
Will be another warm and muggy night, with lows generally in the mid
60s, but upper 60s in the urban heat island near Louisville.
Low-confidence forecast for Friday as we are hard pressed to pick
out the upper impulses that will ride over the top of the flat
ridge. Plenty of resulting uncertainty regarding when and where
these impulses will trigger convection. Therefore will ramp POPs up
to a high chance for the afternoon and evening, but cannot yet
refine it further. Atmosphere will be moderately unstable and
weakly/marginally sheared. GFS soundings show a bit more shear and
instability than the NAM, but also a decent cap around 750mb. Friday
night precip chances still ride on the ability for convection to
develop over Illinois in the afternoon, and then dive SE into the
Ohio Valley. SPC Day 2 outlook has a slight risk, with the main
threat looking like hail and wind in the late afternoon and evening.
.Long Term (Saturday through Thursday)...
Issued at 315 PM EDT May 3 2012
Weak northwest mid level flow will be over the area on Wednesday
with ridge axis dominating over the southern Plains. Ongoing
convection Saturday morning will likely be on the decrease as wave
rounding the periphery of the ridge slides southeast. Big question
will be how long convective debris hangs over the area and the
resultant impact on afternoon destabilization. Some model solutions
suggest another wave arriving in the afternoon evening, along with
chances that a weak back door cold front will approach from the
north toward the afternoon and evening. Overall, still going with
scattered showers and thunderstorms through the day on Saturday.
Still expect we could see a few strong pulse storms with small hail
and some gusty winds, however shear is too weak to anticipate any
more organized threat. Between Saturday morning convection and
afternoon/evening diurnal convection, most places should expect
rain, however the day should not be a washout. Highs are tricky and
will depend on convective cloud cover. This is evident in wide
spread in guidance. Have gone near the cooler guidance with highs in
the mid 80s.
Back door cool front will continue to slide southwest across the CWA
and stall out Saturday night and Sunday. Will keep Iso-Sct coverage
over the area during this time with the best shot west of I-65
Sunday. Ridge axis will be more over the area during this time and
weak subsidence inversion should limit coverage to a degree.
Anticipating low in the low to mid 60s Saturday night with highs
Sunday in the low to mid 80s.
As we move into the new work week mid level flow will flatten out in
response to a potent shortwave diving into the northern Plains. Weak
surface low will move across the Plains to the middle Mississippi
River valley by Monday morning. This will lift the stalled frontal
boundary back north as a warm front. Will leave iso-sct pops in the
forecast for Sunday evening as isentropic lift over the front could
spark some convection. Will likely be a lull between warm frontal
precip and the arrival of more widespread convection ahead of
surface low and associated cold front. Monday and Monday evening
look to be the best days to receive numerous showers and scattered
storms. At this point, warm sector does not appear to favor more
than a few strong storms as moderate instability combines with weak
shear. Showers and a few lingering storms will exit on Tuesday as
cold front moves east. Highs in the lower 80s Monday will cool off
to highs in the mid and upper 70s on Tuesday. Expect overnight lows
in the low to mid 60s.
Models generally agree on some degree of a strong trough developing
over the eastern CONUS from Tuesday night through the end of the
forecast period. Amount of low level moisture behind the front is in
question and therefore forecast remains mostly dry during this time.
However, temperatures will continue to trend cooler with highs on
Wednesday and Thursday down into the low to mid 70s. Lows by
Wednesday night should be down to the mid 50s.
&&
.Aviation (06Z TAF Issuance)...
Updated at 125 AM EDT May 4 2012
A weak east-west cold front to our north will slowly settle
southward over the course of this TAF period, arriving somewhere in
the vicinity of the Ohio River by Saturday morning. As this front
approaches, thunderstorm chances will steadily increase. Rather
than have thunder in the TAFs for most of the forecast period, will
hold off for now and see how development progresses to our north.
The exception will be at SDF and LEX after 00Z tonight since the
front will be quite close by then and there is some semblance of
model agreement that thunderstorms will be in the area.
Another challenge is the possibility of sub-VFR ceilings by dawn
this morning, especially at BWG. Latest RR is showing a large area
of LIFR ceilings swelling northward from the Chattanooga area into
much of central Kentucky by 10Z. A look at current obs shows that
the RR actually has a very good handle on the ceilings in the
Chattanooga area at initialization, which creates some cause for
concern. For now will give a nod to the model and bring in a TEMPO
BKN MVFR ceiling at BWG for 10Z-14Z, and will continue to monitor to
see how things develop.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......RAS
Long Term........BJS
Aviation.........13
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
657 PM EDT FRI MAY 4 2012
.SYNOPSIS...
A SOUTHWARD COLD FRONT WILL BRING THUNDERSTORMS TONIGHT. CANADIAN HIGH
PRESSURE WILL FOLLOW TO PROVIDE DRY, SEASONABLE CONDITIONS FOR THE
REST OF THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
BLEND OF RECENT RADAR DATA AND RAP/HRRR/MODEL OUTPUT SHOW
PREFRONTAL BANDS OF NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS
WILL MOVE SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY TONIGHT.
THE LAST OF THE SHOWERS SHOULD EXIT INTO CENTRAL WEST VIRGINIA
AROUND DAYBREAK SATURDAY. THE REST OF SATURDAY WILL BE DRY WITH
SOME SUNSHINE. FORECASTED TEMPERATURES TO BE NOT AS WARM AS THE
THURSDAY AND FRIDAY, BUT STILL MORE THAN 5 DEGREES WARMER THAN
NORMAL.
SOME THUNDERSTORMS EARLY TONIGHT CAN PRODUCE A BRIEF EPISODE OF
GUSTY WINDS, HAIL, AND HEAVY DOWNPOURS. REGARDING SEVERE
POTENTIAL, INSTABILITY APPEARS STRONG ENOUGH, BUT VERTICAL SHEAR
APPEARS RATHER WEAK. HENCE THAT IS WHY STORM CHARACTERISTICS WILL
BE MORE PULSE-LIKE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MODELS IN GENERAL AGREEMENT THAT RIDGE SURFACE AND ALOFT WILL
BRING MILD AND DRY CONDITIONS THROUGH SUNDAY. OPTED FOR SLOWER GFS
SOLUTION SUNDAY NIGHT AND MONDAY WITH RETURN NORTHWARD OF BOUNDARY
AND MOISTURE AHEAD OF A FAIRLY STRONG SURFACE LOW AND COLD FRONT
FOR MONDAY. THIS IS MORE IN LINE WITH 12Z ECMWF AND A BLEND OF
GFS/ECMWF USED.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
12Z GFS SHOWS A CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW TRACKING
NORTH OF THE GREAT LAKES EARLY IN THE WEEK AND REACHING SOUTHERN
QUEBEC LATE WEDNESDAY. OLD 00Z ECMWF TRACK DIGS THE UPPER LOW MUCH
FURTHER SOUTHWARD INTO THE APPALACHIANS BY THURSDAY. LEANED TOWARD
HPC PROGS WHICH ARE CLOSER TO GFS SOLUTION.
FORECAST LIKELY POPS FOR SHOWERS AND THUNDER MONDAY NIGHT INTO
TUESDAY WITH FRONTAL PASSAGE. TAPERED POPS TO SCATTERED COVERAGE
TUESDAY NIGHT INTO THURSDAY AS SYSTEM MAKES SLOW EASTWARD PROGRESS.
DRY CONDITIONS ARE FORECAST BY FRIDAY AS SURFACE HIGH BUILDS IN
FROM THE WEST.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
BLEND OF RECENT RADAR DATA AND HRRR MODEL OUTPUT SHOWS PREFRONTAL BANDS
OF MVFR SHOWERS AND SCATTERED IFR THUNDERSTORMS WILL MOVE
SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH ABOUT 08Z.
AREAS OF POST-FRONTAL POST-RAIN IFR FOG AND STRATUS CAN DEVELOP
LATE TONIGHT. HIGH PRESSURE SUBSIDENCE AND DRYING, PLUS DAYTIME
VERTICAL MIXING, WILL IMPROVE CONDITIONS TO VFR CUMULUS BY
SATURDAY AFTERNOON.
SURFACE WINDS WILL BECOME NORTHWEST 6-10 KTS LATE TONIGHT AND
SATURDAY. HIGHER GUSTS ARE POSSIBLE WITH THUNDERSTORMS TONIGHT.
.OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
HIGH PRESSURE WILL PROVIDE VFR CONDITIONS SATURDAY NIGHT THROUGH
EARLY MONDAY. THE NEXT LOW PRESSURE SYSTEM WILL MOVE ACROSS THE
LOWER GREAT LAKES AND INTO NEW ENGLAND BY WEDNESDAY. SCATTERED
SHOWERS AND STORMS WILL BRING THE POTENTIAL FOR RESTRICTIONS LATE
MONDAY THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
326 PM CDT FRI MAY 4 2012
.SHORT TERM...
CLOUDY AND WET CONDITIONS WILL PREVAIL THROUGH THE WEEKEND AS THE
WESTERN GREAT LAKES REGION REMAINS SITUATED BETWEEN CANADIAN HIGH
PRESSURE ANCHORED OVER HUDSON BAY AND AN APPROACHING LONG WAVE
TROUGH IN THE WEST. FOCUS FOR RAIN OVERNIGHT WILL BE ALONG A
CORRIDOR OF FGEN ON THE NOSE OF A REGION OF H85 WAA/THETA-E
ADVECTION. HOWEVER...TIMING THE RAIN AND PLACEMENT OF THE GREATEST
QPF TONIGHT/EARLY SAT IS DIFFICULT WITH MODELS SHOWING LARGE
DIFFERENCES IN MOISTURE PROFILES AND OMEGA FIELDS. ALTHOUGH EXPECT
ALL AREAS TO SEE AT LEAST SOME LIGHT RAIN...HAVE KEPT BROADBRUSH
50-60 POPS THROUGH THE NIGHT DUE TO UNCERTAINTY IN TIMING AND
LOCATION OF GREATEST RAINFALL.
THE RAIN WILL DIMINISH BRIEFLY ON SATURDAY...BEFORE A MORE ORGANIZED
AREA OF HEAVIER RAIN SPREADS NORTH AND EAST OVER THE REGION LATE
SATURDAY NIGHT. MODELS SHOWING BETTER AGREEMENT THAT THE LONG
WAVE TROUGH DEEPENS INTO A CUT OFF LOW OVER SASKATCHEWAN SAT
NIGHT...RESULTING IN A SRLY LOW LEVEL JET AND STRONG MOISTURE
TRANSPORT INTO THE NORTHERN PLAINS. AT THIS TIME...MODELS ARE
SUGGESTING WIDESPREAD RAINFALL AMOUNTS OF A HALF TO ONE INCH WILL
BE FOUND SAT NIGHT/SUNDAY.
EXTENDED...SUNDAY THROUGH FRIDAY...
UNSETTLED WEATHER PATTERN TO START THIS PERIOD AS MID LVL FLOW
DELIVERS INCREASING ASCENT. THIS OCCURS AS UPPER TROF ADVECTS EAST
FROM NRN PLAINS WITH ORGANIZED CONVERGENCE FOCUSING NEAR LOW LVL
FRONTAL BDRY. A WELL DEVELOPED DRY SLOT SHOULD CROSS THE REGION
MONDAY ALLOWING SUBSTANTIAL SFC WARMING. THIS WILL BE FOLLOWED BY
DEEPENING UPPER TROF MON NIGHT/TUESDAY. DEEP CYCLONIC CURVATURE
SFC/ALOFT SHOULD PROMOTE DEVELOPMENT OF A LARGE CANOPY OF LOW CLOUD
COVER WITH SCTD SHOWERS.MAY NEED TO TREND COVERAGE UPWARDS AS WE GET
CLOSER TO EVENT DUE TO ANOMALOUS NATURE OF MID LVL SYSTEM. WEDNESDAY
SHOULD FEATURE A DRYING TREND AND LATER UPDATES MAY BE ABLE TO
ACCELERATE THAT IDEA IF MID LVL TROF IS A BIT FASTER. DRY SPELL
LOOKS POSSIBLE FROM WED AFTN TO THURSDAY EVENING BEFORE NEXT FRONTAL
SYSTEM MOVES INTO REGION.
&&
.PREV DISCUSSION... /ISSUED 112 PM CDT FRI MAY 4 2012/
AVIATION...18Z TAF ISSUANCE...
LARGE CANOPY OF STRATUS COVERS ALL TERMINALS EXCEPT KHYR. EXPECT MVFR
CEILINGS TO CONTINUE AS BDRY LYR WARMING LIFTS BASES...EXCEPT AT KDLH
WHERE MOIST NE FLOW OFF LAKE SUPERIOR HAS LIMITED IMPROVEMENT SO
FAR. HOWEVER...DRIER AIR IS SPREADING DOWN LAKE ACCORDING TO
LATEST RUC13 ANALYSIS SO CL GS MAY CONTINUE TO LIFT THRU AFTN AT
KDLH. WIDESPREAD RAIN WILL SPREAD FROM WEST TO EAST LATER THIS
EVENING AND CONTINUE THROUGH TAF PERIOD. SATURATION/NOCTURNAL
COOLING SHOULD BRING IFR AND LOWER CLGS/VIS TO MOST AREAS
OVERNIGHT.
&&
.POINT TEMPS/POPS...
DLH 39 49 40 50 / 60 30 50 70
INL 41 57 41 54 / 50 20 50 60
BRD 45 62 46 61 / 60 30 70 50
HYR 44 61 43 60 / 60 40 40 70
ASX 40 48 41 55 / 60 40 30 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-142>148.
&&
$$
SHORT TERM...GRANING
LONG TERM....CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
112 PM CDT FRI MAY 4 2012
.AVIATION...18Z TAF ISSUANCE...
LARGE CANOPY OF STRATUS COVERS ALL TERMINALS EXCEPT KHYR. EXPECT MVFR
CEILINGS TO CONTINUE AS BDRY LYR WARMING LIFTS BASES...EXCEPT AT KDLH
WHERE MOIST NE FLOW OFF LAKE SUPERIOR HAS LIMITED IMPROVEMENT SO
FAR. HOWEVER...DRIER AIR IS SPREADING DOWN LAKE ACCORDING TO
LATEST RUC13 ANALYSIS SO CLGS MAY CONTINUE TO LIFT THRU AFTN AT
KDLH. WIDESPREAD RAIN WILL SPREAD FROM WEST TO EAST LATER THIS
EVENING AND CONTINUE THROUGH TAF PERIOD. SATURATION/NOCTURNAL
COOLING SHOULD BRING IFR AND LOWER CLGS/VIS TO MOST AREAS
OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 1040 AM CDT FRI MAY 4 2012/
UPDATE...
VISIBLE SAT IMAGERY SHOWS A SHARP CUT OFF IN THE CLOUD COVER OVER
WISCONSIN. HAVE UPDATED FORECAST TO REFLECT THE CLEAR SKIES OVER
PORTIONS OF THE CHEQUAMEGON NATIONAL FOREST. THE INCREASE IN SUN
TODAY IN THIS REGION WILL ALSO HELP TO RISE TEMPERATURES...SO HAVE
INCREASED MAX TEMPERATURES AND LOWERED MINIMUM RELATIVE HUMIDITIES
OVER WASHBURN/SAWYER/PRICE COUNTIES TODAY AS WELL.
ALSO ISSUED A DENSE FOG ADVISORY FOR NORTH SHORE OF LAKE SUPERIOR
WHERE COOL TEMPERATES AND AN ONSHORE FLOW WILL KEEP LOW CLOUDS
WITH FOG AND DRIZZLE THROUGH THE DAY.
PREV DISCUSSION... /ISSUED 655 AM CDT FRI MAY 4 2012/
AVIATION.../12Z TAF ISSUANCE/
LOW CLOUDS AND AREAS OF FOG WILL AFFECT MOST OF THE NORTHLAND THIS
MORNING. HOWEVER LATEST NAM12 GUIDANCE SUGGEST THE FOG SHOULD LIFT
AND CLOUD SHOULD SCTR OUT BY MIDDAY TODAY. AN UPPER LEVEL
SHORTWAVE WILL THEN TRACK ACROSS THE UPPER MIDWEST...BRINGING
AREAS OF LIGHT RAIN TO THE FCST AREA THIS AFTERNOON AND TONIGHT.
ISOLD STORMS ARE POSSIBLE...MAINLY ACROSS OUR SRN ZONES.
PREV DISCUSSION... /ISSUED 652 AM CDT FRI MAY 4 2012/
UPDATE...
INCREASED POPS THROUGH THIS MORNING BASED ON HOW QUICKLY RAIN IS
MOVING OUT OF EASTERN NORTH DAKOTA INTO NORTHWESTERN MINNESOTA.
ALSO CONTINUED PATCHY DRIZZLE THROUGH LATE THIS MORNING.
PREV DISCUSSION... /ISSUED 358 AM CDT FRI MAY 4 2012/
SHORT TERM [NOW - SATURDAY]...
TODAY...A VERY LOW OVERCAST STRATUS DECK THAT DEVELOPED NEAR LAKE
SUPERIOR EARLIER IN THE NIGHT WILL CONTINUE TO EXPAND WESTWARD
THIS MORNING...COVERING MUCH OF THE FA BY DAWN. THERE HAVE BEEN
SOME REPORTS OF FOG AND DRIZZLE CLOSER TO LAKE SUPERIOR EARLY THIS
MORNING. THE FOG COULD PERSIST INTO THE LATE MORNING. HIGH CLOUDS
WILL MOVE OVER THE FA THIS MORNING...TOO...SO THE FA SHOULD REMAIN
MOSTLY CLOUDY EVEN IF THE LOW STRATUS DECK BEGINS TO BREAK UP.
LIGHT TO BREEZY EASTERLY WINDS WILL DEVELOP THIS MORNING AS HIGH
PRESSURE DRIFTS OVER MANITOBA/ONTARIO AND LOW PRESSURE DEVELOPS IN
THE CENTRAL AND NORTHERN HIGH PLAINS. THE STRONGEST WINDS...WHICH
WILL BE AROUND 15 MPH WITH GUSTS UP TO 25 MPH...SHOULD BE FROM THE
TWIN PORTS TO BRAINERD AREA. THE LOW PRESSURE IN THE PLAINS COULD
BRING RAIN SHOWERS TO THE FA THIS MORNING AND
AFTERNOON AS THE TROUGH APPROACHES THE WESTERN FA AND A SHORTWAVE
MOVES THROUGH NORTH DAKOTA AND THEN NORTHERN MINNESOTA. THERE IS A
LACK OF AGREEMENT BETWEEN THE MODELS HOWEVER...WITH THE GEM
HOLDING OFF PCPN THROUGH THIS AFTERNOON...WHILE THE GFS BRINGS
PLENTY OF PCPN OVER THE FA. THEREFORE...HELD OFF ON INCREASING
POPS TO LIKELY...BUT MAY NEED TO MAKE SOME CHANGES TOWARDS THE END
OF THE SHIFT AFTER REVIEWING TRENDS. THE MODELS DO PROVIDE A
LITTLE SUPPORT FOR THUNDER THIS AFTERNOON...MAINLY ACROSS THE FAR
SOUTHWESTERN FA WHERE THERE MAY A LITTLE INSTABILITY...SLIGHTLY
NEGATIVE LIFTED INDICES...AND SLIGHTLY NEGATIVE SHOWALTER VALUES.
OTHERWISE...THINK MOST PCPN WILL BE FREE OF THUNDER. TEMPERATURES
WILL BE ON THE COOL SIDE ACROSS THE NORTHERN AND CENTRAL FA TODAY
DUE TO THE WINDS OFF THE LAKE...BUT THE SOUTHERN FA SHOULD CLIMB
INTO THE 60S.
TONIGHT...THE TROUGH MAY MOVE THROUGH THE FA TONIGHT...WITH THE
MODELS GIVING THE FA PCPN. HOWEVER...THERE IS STILL SOME MODEL
DISAGREEMENT...SO DID NOT INCREASE POPS TO LIKELY. THE MODELS
SUPPORT THE POSSIBILITY OF THUNDER ACROSS THE SOUTHERN FA.
SATURDAY...THE SHOWERS COULD LINGER INTO SATURDAY...BUT THE LATEST
GFS AND GEM INDICATE DRY WEATHER BY THE AFTERNOON...SO LOWERED
POPS. MAY NEED TO CONTINUE THIS TREND AND FORECAST DRY WEATHER
SATURDAY AFTERNOON IF THE ECMWF BACKS OFF ON ITS WETTER SOLUTION.
IT COMES DOWN TO A TROUGH THAT WILL BE LIFTING IN THE WESTERN
US...AND LOW PRESSURE ORGANIZING IN THE PLAINS. THE ECMWF IS
QUICKER AT THIS THAN THE GEM AND GFS. THE EASTERLY WINDS WILL
CONTINUE SATURDAY...RESULTING IN COOLER TEMPERATURES NEAR LAKE
SUPERIOR...BUT THE WESTERN AND SOUTHERN FA SHOULD SEE HIGH
TEMPERATURES NEAR 60 DEGREES.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
UNSETTLED CONDITIONS ARE EXPECTED FOR LATE THIS WEEKEND ACROSS THE
NORTHLAND WITH A COLD FRONT AND UPPER LEVEL SHORTWAVE EXPECTED
TO PROPAGATE EWD ACROSS THE UPPER MIDWEST. THE MODELS ARE IN
FAIRLY GOOD AGREEMENT IN SPREADING SHOWERS...AND POSSIBLY SOME
THUNDERSTORMS...FROM SOUTHWEST TO NORTHEAST ACROSS OUR CWA
SATURDAY NIGHT. THE PRECIPITATION WILL CONTINUE ACROSS OUR FCST
WITH THE FRONT OVER THE FCST AREA ON SUNDAY. HOWEVER THE PRECIP
COULD START TAPERING ACROSS OUR WRN ZONES AS EARLY AS SUNDAY
AFTERNOON. THE COLD FRONT AND SHORTWAVE SHOULD MOVE EAST OF THE
NORTHLAND SUNDAY NIGHT...WITH SCTD SHOWERS LINGERING ACROSS OUR
ERN AND NRN ZONES. THE MODELS THEN SHOW A FAIRLY STRONG UPPER
LEVEL LOW/TROUGH OVER SCNTL CANADA DIGGING SEWD ACROSS THE UPPER
MIDWEST MONDAY THROUGH TUESDAY. THE COLD AIR ALOFT ASSOCIATED WITH
THE TROUGH WILL COMBINE WITH MID-SPRING SFC TEMPS RESULTING IN A
CONTINUANCE OF SCATTERED SHOWERS AND STORMS. A RIDGE WILL BUILD
BACK OVER THE REGION WEDNESDAY AND THURSDAY...RESULTING IN A
RETURN TO MAINLY DRY CONDITIONS.
AVIATION...06Z TAF ISSUANCE...
EASTERLY SURFACE WINDS COMING OFF OF LAKE SUPERIOR HAS CREATED
FOGGY CONDITIONS AND A LOW STRATUS DECK THAT WILL AFFECT
KDLH/KHIB/KHYR AND BRING THEM INTO IFR CONDITIONS. FRIDAY
AFTERNOON WILL BE GUSTY AS HIGH PRESSURE FROM THE NORTHWEST PUSHES
SOUTHEAST TIGHTENING THE PRESSURE GRADIENT ACROSS THE AREA. LOWER
CLOUDS WILL MOVE IN TOMORROW MORNING AND RAIN INTO THE AREA FRIDAY
AFTERNOON AND EVENING. CONDITIONS ARE FORECAST TO BE VFR...BUT A
DEGRADATION OF CONDITIONS MAY BE POSSIBLE LATER.
&&
.POINT TEMPS/POPS...
DLH 38 50 40 52 / 50 30 50 60
INL 40 58 41 59 / 40 20 50 60
BRD 43 63 47 62 / 50 30 70 60
HYR 44 62 43 60 / 50 40 40 60
ASX 39 49 41 55 / 50 40 50 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 5 PM CDT THIS AFTERNOON FOR MNZ020-021.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-142>148.
&&
$$
AVIATION...CANNON
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
349 PM CDT Fri May 4 2012
.DISCUSSION...
ain concerns continue to be thunderstorm chances with a multitude
of outflow boundaries to be concerned about.
This Evening and Tonight:
The strongest outflow boundary and the one that seems to have the
best chance of initiating convection is still residing from near
Paola to south of Clinton, MO. There has been some deeper cloud
development in the vicinity of the boundary and given the extreme
instability, MUCAPE approaching 5,000 J/kg, if something could
develop it would likely become severe. But limited deep layer shear
would inhibit much organization so more multicell clusters would be
the most likely convective mode. Forecast soundings offer a mixed
scenario. The NAM maintains a fairly strong cap and inhibits
convection. The RUC weakens the cap to the point that mixed layer
parcel would be uninhibited and we`d be off to the races. Something
in between is probably the best scenario in which case a little
better forcing would be needed to break the cap. That said the
presence of the boundary within the extreme instability warrants at
least a small mention of thunderstorms. Forecast soundings in the
southern portions of the forecast area also show some mid level dry
air. All that said, should any storm get going they could easily
become severe with damaging winds and large hail possible. Also,
with ample amounts of moisture available any storm could drop
copious amounts of rainfall over a localized area.
During the overnight hours, storms may fire again in far northern MO
or southern IA and NE and move into northern MO. This area is not as
unstable as it is still recovering from morning convection but
3-4,000 J/kg could still be realized by late this afternoon. Shear
looks weak in this area so if any storms can get going and/or move
into northern MO they would likely be disorganized. There is still
ample moisture in this area and some areas received heavy rain so
any storm could easily produce additional flooding problems.
Saturday:
Hot and humid conditions will persist with heat indices in the mid
90s. This is very unseasonal and could pose problems for those who
are most sensitive to heat. Otherwise, it looks like the area should
be capped for most of the day inhibiting convective chances until
closer to sunset. By the evening and overnight hours we may see some
storms move into or develop in northern MO. Instability should be
around 3,000 J/kg but again shear looks marginal at best for storm
organization. So a more disorganized storm mode would be expected
with hail and damaging winds possible should storms impact the area.
Sunday:
Extreme instability is expected to build back into the forecast area
by Sunday afternoon and evening with potential 4-5,000 J/kg MUCAPE to
work with. Models differ a little with the timing of the frontal
boundary with the NAM bringing the boundary into NW MO late Sunday
morning. The GFS is little slower, holding it up until the evening
hours. Shear continues to looks rather weak in the warm sector of
the system which would limit storm organization. But with the
extreme instability and front to act as a trigger thunderstorms are
expected to develop during the afternoon hours and could easily
become severe. It looks like the biggest hazards with this system
will be large hail and damaging winds as well locally heavy rainfall
given the copious amounts of moisture available.
CDB
Medium Range (Monday through Friday)...
Medium range models are in very good agreement on the overall
pattern aloft which is marked by a dry airmass with seasonal
temperatures. Except for the possibility of some lingering post
frontal showers over the eastern CWA Monday morning as high pressure
builds in from the Rockies.
The first portion of this forecast period will be dominated by an
upper trough which will deepen as it digs southeast from south
central Canada through the Great Lakes and Upper MS Valley. The
ECMWF and GEM are in closer agreement on the depth of the system/
timing and thus get a slight nod over the more progressive GFS. This
allows a bit more cold air advection to work its way southward out
of southern Canada but temperatures through mid week will still be
near seasonal averages. Could see some light instability showers
sneak across the IA/MO border Tuesday afternoon but have low
confidence this far out.
By the end of the work week expect to see warm air advection move
back in as the surface high departs and an upper ridge builds into
the Northern Plains. GFS/ECMWF similarly address the issue of a closed
upper low over either northern Mexico or the far southwestern U.S.
opening up and being lifted northeast by the developing
southwesterly mid/upper level flow. Both models lift this feature
into the Central Plains by Friday and interact with an approaching
cold front to generate convection. Despite both models being on the
same page with this feature have limited confidence in them as they
both tend to have issues in handling closed upper lows this far out.
So, best option is to use a blend of models and await the next
couple of model runs.
MJ
&&
.AVIATION...
For the 18Z TAFs, confidence is fairly high that the terminals will
remain dry/convection free due to strong capping. However, scattered
to broken MVFR ceilings have developed along/north of a weakening
outflow boundary. These lower ceilings are expected to lift and
become predominately scattered by later this afternoon leaving VFR
conditions for the first 6-9 hours of the valid period. A stronger
outflow boundary was draped well south of the terminals and it`s
possible convection could develop in the vicinity of that boundary
but this would not impact the terminals. During the overnight hours,
there is some indication that MVFR to IFR ceilings may form.
Confidence is very low regarding this possibility as well as the
timing and duration of any lower ceilings. Given the rich low level
moisture and the preponderance of guidance suggesting the lower
clouds have added broken MVFR ceilings to the TAFs.
CDB
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
852 PM CDT SAT MAY 5 2012
.UPDATE...
STORMS HAVE BEEN SLOW TO DEVELOP THIS AFTN AND EVENING AS A STRONG
CAP HAS BEEN IN PLACE. THE CAP APPEARS TO HAVE WEAKENED SOME AFTER
SUNSET AND STORMS HAVE BEGUN TO FIRE ACROSS NCNTL NEB. THIS IS
CLOSE TO THE RUC13 SOLN WHICH WAS THE BASIS FOR A FCST UPDATE THIS
EVENING. WE ALSO SLOW THE DEPARTURE OF THE TSTMS OVERNIGHT AS THE
MODELS APPEAR TO BE TOO FAST AND CARRY LIKELY POPS ACROSS THE
NORTHEAST ZONES TIL MORNING.
HEAVY RAIN APPEARS TO BE THE OPERATIVE MODE IN ADDITION TO THE
SEVERE WEATHER THREAT. THE 310K MOISTURE TRANSPORT VECTORS IN THE
RUC13 ARE THROUGH THE ROOF AND PRECIPITABLE WATER IS FCST TO
APPROACH 1.5 INCHES. NESDIS HAS SENT TWO MESSAGES ALERTING NRN NEB
ABOUT THE POTENTIAL FOR HEAVY RAINFALL.
&&
.PREV DISCUSSION... /ISSUED 623 PM CDT SAT MAY 5 2012/
UPDATE...
AVIATION...
SCATTERED SEVERE THUNDERSTORMS MAY PERSIST UNTIL 12Z EAST OF
HIGHWAY 83. ISOLATED STRONG TO SEVERE THUNDESTORMS WEST OF HIGHWAY
83 SHOULD MOVE THROUGH BY 06Z. MVFR CIGS ARE EXPECTED WITH THE
PASSAGE OF A STRONG COLD FRONT CURRENTLY OVER NORTHEAST WYOMING.
VFR IS EXPECTED ALL AREAS BY 12Z. FLIGHT CONDITIONS WILL IMPROVE
FROM WEST TO EAST WITH THE PASSAGE OF THE COLD FRONT THIS EVENING
AND OVERNIGHT.
PREV DISCUSSION... /ISSUED 302 PM CDT SAT MAY 5 2012/
DISCUSSION...STRONG COLD FRONT PLOWS INTO WESTERN AND NORTH CENTRAL
NEB EARLY THIS EVENING...MOISTURE AND INSTABILITY POOLING JUST TO
THE NORTH OF A STATIONARY OUTFLOW BOUNDARY BISECTING THE
AREA...SHOULD ALLOW FOR TSTM DEVELOPMENT ALONG THE FRONT AS IT
MOVES SOUTHEAST. STORMS SHOULD MOVE SOUTHEAST OF THE AREA AFTER
MIDNIGHT AS NORTH WINDS INCREASE BEHIND THE FRONT.
IN THE WAKE OF THE STRONG COLD FRONTAL PASSAGE...MUCH COOLER AND
LESS HUMID CONDITIONS ARE EXPECTED FOR SUNDAY INTO MONDAY. BREEZY TO
WINDY CONDITIONS ARE ALSO EXPECTED SUNDAY MORNING IN THE WAKE OF THE
FRONT. STRONG COLD AIR ADVECTION...COUPLED WITH NAM MODEL FORECASTED
500 METER WINDS AROUND 30 KTS...COULD ALLOW FOR SOME SUSTAINED WINDS
AROUND 25 TO 30 MPH DURING THE MORNING. WINDS SHOULD DECREASE SOME
DURING THE AFTERNOON...AS THE PRESSURE GRADIENT RELAXES AND CAA
ADVECTION WEAKENS. A SECONDARY COLD FRONTAL SURGE IS EXPECTED
MONDAY...WITH NORTHWEST WINDS INCREASING AGAIN.
IN THE UPPER LEVELS...A STRONG UPPER LEVEL LOW...LOCATED ACROSS THE
NORTHERN PLAINS...WILL COMBINE WITH A DISTURBANCE DROPPING SOUTH
THROUGH THE NORTHERN ROCKIES...AND KEEP OUR AREA IN SOUTHWEST FLOW
ALOFT THOUGH MONDAY. WILL INCLUDE A SLIGHT CHANCE FOR SHOWERS ACROSS
FAR SOUTHWEST NEB AND INTO THE SOUTHERN NEB PANHANDLE AS THE
AFOREMENTIONED NORTHERN ROCKIES DISTURBANCE DIVES SOUTH. BEYOND
MONDAY...BOTH THE ECMWF AND GFS MODELS AGREE THAT THE NORTHERN
PLAINS UPPER LEVEL LOW WILL MOVE SOUTHEAST INTO THE GREAT LAKES
REGION. THIS TURNS THE UPPER FLOW TO NORTHWEST ALOFT TUESDAY AND
WEDNESDAY. WITH LIMITED LOW LEVEL MOISTURE...AND NO DISTINCT
SHORTWAVES NOTED WITHIN THE UPPER FLOW...EXPECTING MAINLY DRY
CONDITIONS. LATE IN THE WEEK...THE GREAT LAKES UPPER LEVEL LOW WILL
BE KICKED EAST AS A NEW NORTHERN STREAM ENERGY MOVES INTO SOUTHERN
CANADA. THIS SHOULD DRIVE ANOTHER COLD FRONT SOUTH INTO THE
AREA...ALONG WITH SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS. AT
THIS TIME IT APPEARS THAT LIMITED LOW LEVEL MOISTURE SHOULD KEEP ANY
PRECIPITATION ISOLATED.
TEMPERATURE WISE...MILD CONDITIONS ARE ANTICIPATED SUNDAY THROUGH
TUESDAY...WITH HIGHS IN THE 60S. LOOKING AT THE FROST POTENTIAL FOR
MONDAY MORNING...APPEARS WINS WILL STAY UP ENOUGH TO PRECLUDE MUCH
THREAT. TUESDAY MORNING COULD BE A DIFFERENT STORY...AS SFC HIGH
PRESSURE WILL BE LOCATED JUST WEST OF THE AREA. THIS MAY ALLOW WINDS
ACROSS THE PANHANDLE TO GO NEARLY CALM...AND SOME FROST LOOKS
POSSIBLE IN THAT AREA. TEMPERATURES SHOULD BEGIN TO MODIFY...WITH
HIGHS IN THE 70S WEDNESDAY AND THURSDAY...BEFORE A COOL DOWN BACK
INTO THE 60S FRIDAY AND SATURDAY.
AVAIATION...FOR KVTN AND KLBF...SHORT TERM MODEL GUIDANCE IS
STRUGGLING WITH A SOUTHWARD ADVANCING BOUNDARY GENERATED FROM EARLY
CONVECTION ACROSS CENTRAL SOUTH DAKOTA. SINCE THE SHORT TERM
SOLUTIONS ARE STRUGGLING...CONFIDENCE REMAINS LOW TO MODERATE FOR
THE REMAINING TAF CYCLE...ESPECIALLY IN REGARDS TO STORM COVERAGE
THIS AFTERNOON AND WIND SPEED/DIRECTION. A WARM FRONT WILL LIFT
NORTH ACROSS NORTH CENTRAL NEBRASKA THIS AFTERNOON AND SHOULD
PROVIDE A FOCUS FOR STORM DEVELOPMENT...SOME OF WHICH MAY BE
SEVERE. AS OF NOW THE HIGHEST CONVECTIVE POTENTIAL REMAINS ACROSS
NORTH CENTRAL NEBRASKA...POSSIBLE AFFECTING THE KANW AND KONL
TERMINALS. FURTHER SOUTH HOWEVER...MODELS INDICATE AN ADVANCING
DRYLINE WHICH MAY SUPPORT ADDITIONAL STORM DEVELOPMENT. DUE TO THE
SPORADIC NATURE OF CONVECTIVE STORMS...AND THE FACT THE MODELS ARE
NOT CORRECTLY ASSESSING WHERE CONVECTIVE BOUNDARIES EXIST...FELT IT
WAS BEST TO MENTION IN THIS DISCUSSION AND LEAVE STORM MENTION OUT OF
THE OFFICIAL TAF FORECAST FOR KLBF AND KVTN FOR NOW. HOWEVER NOTE
THAT A VERY UNSTABLE ATMOSPHERE IS EXPECTED LATE THIS AFTERNOON
ALONG AND SOUTH OF THE WARM FRONT. LARGE HAIL...STRONG ERRATIC
THUNDERSTORM WIND GUSTS...AND POSSIBLY TORNADOES WOULD BE POSSIBLE
LATE THIS AFTERNOON/EARLY EVENING WITHIN THIS ENVIRONMENT.
ATTENTION NOW TURNS TO THE WIND POTENTIAL TONIGHT AND LATE IN THE
TAF FORECAST PERIOD. AN UPPER LEVEL WAVE CROSSING THE NORTHERN HIGH
PLAINS WILL DRAG A COLD FRONT THROUGH AREA EARLY THIS EVENING
/00Z-03Z AT VTN...AFTER 03Z AT LBF/. STRONG COLD AIR ADVECTION AND
PRESSURE RISES WILL ALLOW FOR GUSTY NORTHWEST WIND OVERNIGHT...WITH
GUSTS POSSIBLY EXCEEDING 30KTS. EXPECT WIND SPEEDS TO RELAX SOME
LATE IN THE TAF PERIOD /AFTER 15Z/. OTHERWISE STRATUS IS EXPECTED
BEHIND THE FRONTAL PASSAGE...SO IFR WOULD BE EXPECTED AT ALL AREA
TERMINALS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1223 PM CDT FRI MAY 4 2012
.AVIATION...18Z TAF. QUIET CONDITIONS CURRENTLY FORECAST FOR THIS
TAF PERIOD...WITH CONCERNS LYING WITH PRECIPITATION CHANCES LATER
TODAY/TONIGHT THEN FOG EARLY SAT MORNING. NOT EXPECTING ANY
SIGNIFICANT CHANGES WITH WIND DIRECTION THROUGH THE
PERIOD...REMAINING GENERALLY SOUTHEASTERLY...COULD SEE A FEW GUSTS
THIS AFTERNOON AND WILL BE VARIABLE EARLY TOMORROW
MORNING...OTHERWISE SPEEDS SHOULD BE AROUND 10 KTS. AT THIS POINT
STILL AM NOT CONFIDENT ENOUGH IN THE TERMINAL SEEING ANY
THUNDERSTORMS LATER ON TO PUT IN THE TAF...BUT WILL NEED TO KEEP
AN EYE ON IT. WITH NO CHANGE IN THE AIR MASS IN PLACE THROUGH THE
TAF PERIOD...NOT SEEING WHY THE TERMINAL WOULDNT SEE ANOTHER ROUND
OF FOG EARLY SAT MORNING...AND INSERTED IFR VISIBILITIES.
UPCOMING FORECASTS WILL TWEAK UP/DOWN AS NECESSARY.
&&
PREV DISCUSSION... /ISSUED 356 AM CDT FRI MAY 4 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT. AREAS OF FOG DEVELOPED
EARLY THIS MORNING IN PRESENCE OF LLVL MOISTURE AND NEARLY CALM OR
LIGHT EASTERLY WINDS. RUC13 SEEMS TO BE HANDLING THE VSBYS THE BEST
AND SUGGESTS PRETTY MUCH OUR ENTIRE CWA MAY BE UNDER INFLUENCE OF
DENSE FOG BY MORNING AND HAVE ISSUED DENSE FOG ADV UNTIL 8 AM FOR
ALL BUT OUR FAR NORTHERN COUNTIES WHERE TEMP/DP SPREAD IS
CURRENTLY GREATER...AND OUR FAR EASTERN CWA WHERE HIGH CLOUD COVER
FM CONVECTION TO OUR SE MAY HOLD UP VSBYS. WILL CONTINUE TO
MONITOR TRENDS EARLY THIS MORNING AS TO WHETHER HEADLINE NEEDS TO
BE EXPANDED OR NOT.
LOOKING FOR FOG TO BURN OFF AFTER DAYBREAK WITH DAYTIME
HEATING...THEN MUCH OF THE DAY IS LOOKING DRY. PATTERN ALOFT
FEATURED SOUTHWESTERLY FLOW WITH MID/UPPER TROUGH ORIENTED FM
ALBERTA INTO THE NORTHERN ROCKIES. JET STREAK NOSES INTO THE NC
ROCKIES TODAY WHILE A SERIES OF SUBTLE SHORTWAVE LIFT FM BASE OF
TROUGH. AT THE SURFACE WARM FRONT LIFTS INTO NC NEB THIS AFTERNOON
AND CONVERGENCE ALONG FRONT AND ENERGY ASSOCIATED WITH WAVES IS
EXPECTED TO INITIATE CONVECTION IN VCNTY OF FRONT. SREF INDICATES
AN AXIS OF INSTABILITY MUCAPES OF 4000 J/KG ACROSS EASTERN NEB/KS
WITH EFFECTIVE SHEAR AROUND 30KTS IN OUR CWA....INCREASING TO NEAR
50 KTS NEAR THE FRONTAL BOUNDARY JUST TO OUR NORTH. INITIATION
LOOKS TO BE JUST TO OUR NORTH ALONG THE FRONT FOR MAIN FOCUS WITH
ACTIVITY POTENTIALLY REACHING OUR NORTHERN ZONES TONIGHT. SOME
QUESTION AS TO WHETHER ACTIVITY MAY FIRE TO THE WEST NEAR THE DRY
LINE OR PERHAPS A DIFFERENTIAL HEATING BOUNDARY AS OCCURRED
YESTERDAY. FOR NOW WILL MAINTAIN MAIN FOCUS ALONG THE WARM FRONT
FOR TONIGHT...WITH SEVERE STORMS POSSIBLE. ALSO FOR TONIGHT...LLVL
FLOW REMAINS FM A LIGHT EASTERLY DIRECTION AS BOUNDARY SAGS SOUTH.
LOOKING AT POTENTIAL FOR FOG DEVELOPMENT AGAIN OVERNIGHT.
ON SATURDAY...WARM FRONT LIFTS NORTH IN AFTERNOON THEN COOL FRONT
PUSHES SOUTH SATURDAY NIGHT. LOOKING AT FAIRLY DECENT CHCS FOR
CONVECTION SATURDAY NIGHT AS THE STRONGER FRONT MOVES THROUGH AS
UPPER TROUGH CROSSES THE DAKOTAS. SEVERE STORMS ARE PROBABLE AGAIN
IN PRESENCE OF HIGH INSTABILITY AHEAD OF APPROACHING BOUNDARY AND
INCREASING SHEAR AS FRONT APPROACHES. COLD FRONT REACHES ALL BUT OUR
FAR SOUTHEAST CWA BY SUNDAY MORNING...AND HAVE LINGERED SOME
THUNDER INTO SUNDAY IN THIS AREA...WITH JUST RAIN SHOWERS FARTHER
NORTH AS INSTABILITY DIMINISHES.
COOLER...BREEZY/WINDY CONDITIONS SETTLE IN ON SUNDAY BEHIND THE
BOUNDARY WITH PCPN CHCS DECREASING DURING THE DAY. DRY WEATHER IS
FORECAST SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH THURSDAY.
BY MONDAY...AN UPPER LEVEL RIDGE ACROSS THE EASTERN HALF OF THE
CONUS WILL BEGIN TO BREAK DOWN AS AN UPPER LEVEL TROUGH PUSHES
ACROSS THE CENTRAL CONUS. RIDGING WILL PUSH ACROSS THE NORTHWEST
COAST BEHIND THE TROUGH...WHILE A CLOSED UPPER LOW WILL PUSH ACROSS
THE SOUTHEAST ASSOCIATED WITH THE BASE OF THE TROUGH. AT THE SURFACE
LOW PRESSURE IS EXPECTED TO SHIFT ACROSS SOUTHERN CANADA WHILE HIGH
PRESSURE REMAINS CENTERED ACROSS THE ROCKIES.
THE UPPER LEVEL TROUGH IS EXPECTED TO DIVE SOUTHEAST ACROSS THE OHIO
RIVER VALLEY IN THE LONG TERM PERIOD. WITH THE SURFACE LOW FOLLOWING
SUIT...HIGH PRESSURE FROM CANADA WILL SLIDE SOUTHWARD INTO THE
CENTRAL PLAINS. COOLER 850 MB TEMPERATURES WILL ALSO SHIFT
SOUTHWARD...INDICATING COOLER HIGH TEMPERATURES IN THE LONG TERM
PERIOD. HOWEVER...850 MB TEMPERATURES STILL REMAIN NEAR 10 TO 13
DEGREES CELSIUS...SUGGESTING UPPER 60S TO LOWER 70S FOR HIGHS.
AT THIS TIME...THERE IS SOME DISCREPANCY AMONG MODELS REGARDING
PRECIPITATION CHANCES IN THE LONG TERM PERIOD. THE GFS REMAINS DRY
THROUGHOUT THE ENTIRE PERIOD...WHILE THE ECMWF TRIES TO GENERATE
SLIGHT POPS ACROSS THE PLAINS SPECIFICALLY TUESDAY. THE ECMWF TRIES
TO GENERATE A FEW SCATTERED POPS ACROSS THE FORECAST AREA...AS
COOLER AIR SLIDES SOUTH ALONG THE BACKSIDE OF THE TROUGH. ASSOCIATED
WITH THE LOCATION OF THE RIGHT ENTRANCE REGION OF UPPER LEVEL
JET...ENOUGH LIFT COULD BE POSSIBLE DURING THE AFTERNOON ON TUESDAY.
HOWEVER...BOTH MODELS SUGGEST DEWPOINTS IN THE 35 TO 40 DEGREE
RANGE. AT THIS POINT...DECIDED TO KEEP THE LONG TERM DRY UNTIL
MODELS CAN COME INTO BETTER AGREEMENT ON MOISTURE POTENTIAL AND
LOCATION OF THE UPPER LEVEL JET.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
816 AM CDT FRI MAY 4 2012
.UPDATE...EXTENDED THE DENSE FOG ADVISORY UNTIL 10 AM WITH THE
MAJORITY OF AUTOMATED STATIONS ACROSS THE CWA REMAINING AT/BELOW
ONE QUARTER OF A MILE. OTHERWISE ONLY MINOR TWEAKS MADE
&&
.PREV DISCUSSION... /ISSUED 356 AM CDT FRI MAY 4 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT. AREAS OF FOG DEVELOPED
EARLY THIS MORNING IN PRESENCE OF LLVL MOISTURE AND NEARLY CALM OR
LIGHT EASTERLY WINDS. RUC13 SEEMS TO BE HANDLING THE VSBYS THE BEST
AND SUGGESTS PRETTY MUCH OUR ENTIRE CWA MAY BE UNDER INFLUENCE OF
DENSE FOG BY MORNING AND HAVE ISSUED DENSE FOG ADV UNTIL 8 AM FOR
ALL BUT OUR FAR NORTHERN COUNTIES WHERE TEMP/DP SPREAD IS
CURRENTLY GREATER...AND OUR FAR EASTERN CWA WHERE HIGH CLOUD COVER
FM CONVECTION TO OUR SE MAY HOLD UP VSBYS. WILL CONTINUE TO
MONITOR TRENDS EARLY THIS MORNING AS TO WHETHER HEADLINE NEEDS TO
BE EXPANDED OR NOT.
LOOKING FOR FOG TO BURN OFF AFTER DAYBREAK WITH DAYTIME
HEATING...THEN MUCH OF THE DAY IS LOOKING DRY. PATTERN ALOFT
FEATURED SOUTHWESTERLY FLOW WITH MID/UPPER TROUGH ORIENTED FM
ALBERTA INTO THE NORTHERN ROCKIES. JET STREAK NOSES INTO THE NC
ROCKIES TODAY WHILE A SERIES OF SUBTLE SHORTWAVE LIFT FM BASE OF
TROUGH. AT THE SURFACE WARM FRONT LIFTS INTO NC NEB THIS AFTERNOON
AND CONVERGENCE ALONG FRONT AND ENERGY ASSOCIATED WITH WAVES IS
EXPECTED TO INITIATE CONVECTION IN VCNTY OF FRONT. SREF INDICATES
AN AXIS OF INSTABILITY MUCAPES OF 4000 J/KG ACROSS EASTERN NEB/KS
WITH EFFECTIVE SHEAR AROUND 30KTS IN OUR CWA....INCREASING TO NEAR
50 KTS NEAR THE FRONTAL BOUNDARY JUST TO OUR NORTH. INITIATION
LOOKS TO BE JUST TO OUR NORTH ALONG THE FRONT FOR MAIN FOCUS WITH
ACTIVITY POTENTIALLY REACHING OUR NORTHERN ZONES TONIGHT. SOME
QUESTION AS TO WHETHER ACTIVITY MAY FIRE TO THE WEST NEAR THE DRY
LINE OR PERHAPS A DIFFERENTIAL HEATING BOUNDARY AS OCCURRED
YESTERDAY. FOR NOW WILL MAINTAIN MAIN FOCUS ALONG THE WARM FRONT
FOR TONIGHT...WITH SEVERE STORMS POSSIBLE. ALSO FOR TONIGHT...LLVL
FLOW REMAINS FM A LIGHT EASTERLY DIRECTION AS BOUNDARY SAGS SOUTH.
LOOKING AT POTENTIAL FOR FOG DEVELOPMENT AGAIN OVERNIGHT.
ON SATURDAY...WARM FRONT LIFTS NORTH IN AFTERNOON THEN COOL FRONT
PUSHES SOUTH SATURDAY NIGHT. LOOKING AT FAIRLY DECENT CHCS FOR
CONVECTION SATURDAY NIGHT AS THE STRONGER FRONT MOVES THROUGH AS
UPPER TROUGH CROSSES THE DAKOTAS. SEVERE STORMS ARE PROBABLE AGAIN
IN PRESENCE OF HIGH INSTABILITY AHEAD OF APPROACHING BOUNDARY AND
INCREASING SHEAR AS FRONT APPROACHES. COLD FRONT REACHES ALL BUT OUR
FAR SOUTHEAST CWA BY SUNDAY MORNING...AND HAVE LINGERED SOME
THUNDER INTO SUNDAY IN THIS AREA...WITH JUST RAIN SHOWERS FARTHER
NORTH AS INSTABILITY DIMINISHES.
COOLER...BREEZY/WINDY CONDITIONS SETTLE IN ON SUNDAY BEHIND THE
BOUNDARY WITH PCPN CHCS DECREASING DURING THE DAY. DRY WEATHER IS
FORECAST SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH THURSDAY.
BY MONDAY...AN UPPER LEVEL RIDGE ACROSS THE EASTERN HALF OF THE
CONUS WILL BEGIN TO BREAK DOWN AS AN UPPER LEVEL TROUGH PUSHES
ACROSS THE CENTRAL CONUS. RIDGING WILL PUSH ACROSS THE NORTHWEST
COAST BEHIND THE TROUGH...WHILE A CLOSED UPPER LOW WILL PUSH ACROSS
THE SOUTHEAST ASSOCIATED WITH THE BASE OF THE TROUGH. AT THE SURFACE
LOW PRESSURE IS EXPECTED TO SHIFT ACROSS SOUTHERN CANADA WHILE HIGH
PRESSURE REMAINS CENTERED ACROSS THE ROCKIES.
THE UPPER LEVEL TROUGH IS EXPECTED TO DIVE SOUTHEAST ACROSS THE OHIO
RIVER VALLEY IN THE LONG TERM PERIOD. WITH THE SURFACE LOW FOLLOWING
SUIT...HIGH PRESSURE FROM CANADA WILL SLIDE SOUTHWARD INTO THE
CENTRAL PLAINS. COOLER 850 MB TEMPERATURES WILL ALSO SHIFT
SOUTHWARD...INDICATING COOLER HIGH TEMPERATURES IN THE LONG TERM
PERIOD. HOWEVER...850 MB TEMPERATURES STILL REMAIN NEAR 10 TO 13
DEGREES CELSIUS...SUGGESTING UPPER 60S TO LOWER 70S FOR HIGHS.
AT THIS TIME...THERE IS SOME DISCREPANCY AMONG MODELS REGARDING
PRECIPITATION CHANCES IN THE LONG TERM PERIOD. THE GFS REMAINS DRY
THROUGHOUT THE ENTIRE PERIOD...WHILE THE ECMWF TRIES TO GENERATE
SLIGHT POPS ACROSS THE PLAINS SPECIFICALLY TUESDAY. THE ECMWF TRIES
TO GENERATE A FEW SCATTERED POPS ACROSS THE FORECAST AREA...AS
COOLER AIR SLIDES SOUTH ALONG THE BACKSIDE OF THE TROUGH. ASSOCIATED
WITH THE LOCATION OF THE RIGHT ENTRANCE REGION OF UPPER LEVEL
JET...ENOUGH LIFT COULD BE POSSIBLE DURING THE AFTERNOON ON TUESDAY.
HOWEVER...BOTH MODELS SUGGEST DEWPOINTS IN THE 35 TO 40 DEGREE
RANGE. AT THIS POINT...DECIDED TO KEEP THE LONG TERM DRY UNTIL
MODELS CAN COME INTO BETTER AGREEMENT ON MOISTURE POTENTIAL AND
LOCATION OF THE UPPER LEVEL JET.
AVIATION...KGRI TAF UPDATE. FOG CONTINUES TO EXPAND ACROSS THE
FORECAST AREA. VISIBILITY RESTRICTIONS ARE EXPECTED TO FLUCTUATE
BETWEEN ONE QUARTER MILE AND 1 MILE AT TIMES. WITH LIGHT AND
VARIABLE WINDS AND AMPLE MOISTURE IN THE AREA...FOG MAY BE SLOW TO
DISSIPATE UNTIL SUNRISE THIS MORNING.
PREV DISCUSSION... /ISSUED 1241 AM CDT FRI MAY 4 2012/
AVIATION...06Z KGRI TAF. AS A SURFACE TROUGH PASSES THROUGH THE
REGION OVERNIGHT TONIGHT...WINDS WILL LIKELY REMAIN LIGHT AND
VARIABLE...TO EVEN CALM AT TIMES. AS A RESULT...COMBINED WITH
AMPLE MOISTURE IN THE REGION...FOG DEVELOPMENT WILL REMAIN
POSSIBLE ACROSS THE TAF SITE. FOG THAT DEVELOPS WILL LIKELY BE
PATCHY IN NATURE. NEIGHBORING SITES HAVE HAS EXPERIENCED
VISIBILITY REDUCTIONS FROM 5 SM TO EVEN A QUARTER OF A MILE IN
SOME AREAS. AT THIS TIME...DECIDED TO LEAVE MENTION OF AT LEAST
IFR VISIBILITIES AND CEILINGS IN THE TEMPO GROUP...AS MODEL
SOUNDINGS INDICATE FOG COULD EASILY REACH THE TAF SITE. BESIDES
FOG POTENTIAL THIS MORNING...CLOUD BASES SHOULD REMAIN FAIRLY HIGH
WITH THE POSSIBILITY FOR CUMULUS DEVELOPMENT THIS AFTERNOON AS
TEMPERATURES CLIMB WELL INTO THE 80S. THERE REMAINS THE
POSSIBILITY FOR THUNDERSTORMS DURING THE EVENING AND OVERNIGHT
HOURS TONIGHT...BUT EXPECT THEM TO BE SCATTERED IN NATURE SO WILL
LEAVE OUT OF THE TAF FOR NOW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR NEZ041-
046>049-060>064-072>077-082>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ005-006-
017-018.
&&
$$
UPDATE...ADO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
356 AM CDT FRI MAY 4 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT. AREAS OF FOG DEVELOPED
EARLY THIS MORNING IN PRESENCE OF LLVL MOISTURE AND NEARLY CALM OR
LIGHT EASTERLY WINDS. RUC13 SEEMS TO BE HANDLING THE VSBYS THE BEST
AND SUGGESTS PRETTY MUCH OUR ENTIRE CWA MAY BE UNDER INFLUENCE OF
DENSE FOG BY MORNING AND HAVE ISSUED DENSE FOG ADV UNTIL 8 AM FOR
ALL BUT OUR FAR NORTHERN COUNTIES WHERE TEMP/DP SPREAD IS
CURRENTLY GREATER...AND OUR FAR EASTERN CWA WHERE HIGH CLOUD COVER
FM CONVECTION TO OUR SE MAY HOLD UP VSBYS. WILL CONTINUE TO
MONITOR TRENDS EARLY THIS MORNING AS TO WHETHER HEADLINE NEEDS TO
BE EXPANDED OR NOT.
LOOKING FOR FOG TO BURN OFF AFTER DAYBREAK WITH DAYTIME
HEATING...THEN MUCH OF THE DAY IS LOOKING DRY. PATTERN ALOFT
FEATURED SOUTHWESTERLY FLOW WITH MID/UPPER TROUGH ORIENTED FM
ALBERTA INTO THE NORTHERN ROCKIES. JET STREAK NOSES INTO THE NC
ROCKIES TODAY WHILE A SERIES OF SUBTLE SHORTWAVE LIFT FM BASE OF
TROUGH. AT THE SURFACE WARM FRONT LIFTS INTO NC NEB THIS AFTERNOON
AND CONVERGENCE ALONG FRONT AND ENERGY ASSOCIATED WITH WAVES IS
EXPECTED TO INITIATE CONVECTION IN VCNTY OF FRONT. SREF INDICATES
AN AXIS OF INSTABILITY MUCAPES OF 4000 J/KG ACROSS EASTERN NEB/KS
WITH EFFECTIVE SHEAR AROUND 30KTS IN OUR CWA....INCREASING TO NEAR
50 KTS NEAR THE FRONTAL BOUNDARY JUST TO OUR NORTH. INITIATION
LOOKS TO BE JUST TO OUR NORTH ALONG THE FRONT FOR MAIN FOCUS WITH
ACTIVITY POTENTIALLY REACHING OUR NORTHERN ZONES TONIGHT. SOME
QUESTION AS TO WHETHER ACTIVITY MAY FIRE TO THE WEST NEAR THE DRY
LINE OR PERHAPS A DIFFERENTIAL HEATING BOUNDARY AS OCCURRED
YESTERDAY. FOR NOW WILL MAINTAIN MAIN FOCUS ALONG THE WARM FRONT
FOR TONIGHT...WITH SEVERE STORMS POSSIBLE. ALSO FOR TONIGHT...LLVL
FLOW REMAINS FM A LIGHT EASTERLY DIRECTION AS BOUNDARY SAGS SOUTH.
LOOKING AT POTENTIAL FOR FOG DEVELOPMENT AGAIN OVERNIGHT.
ON SATURDAY...WARM FRONT LIFTS NORTH IN AFTERNOON THEN COOL FRONT
PUSHES SOUTH SATURDAY NIGHT. LOOKING AT FAIRLY DECENT CHCS FOR
CONVECTION SATURDAY NIGHT AS THE STRONGER FRONT MOVES THROUGH AS
UPPER TROUGH CROSSES THE DAKOTAS. SEVERE STORMS ARE PROBABLE AGAIN
IN PRESENCE OF HIGH INSTABILITY AHEAD OF APPROACHING BOUNDARY AND
INCREASING SHEAR AS FRONT APPROACHES. COLD FRONT REACHES ALL BUT OUR
FAR SOUTHEAST CWA BY SUNDAY MORNING...AND HAVE LINGERED SOME
THUNDER INTO SUNDAY IN THIS AREA...WITH JUST RAIN SHOWERS FARTHER
NORTH AS INSTABILITY DIMINISHES.
COOLER...BREEZY/WINDY CONDITIONS SETTLE IN ON SUNDAY BEHIND THE
BOUNDARY WITH PCPN CHCS DECREASING DURING THE DAY. DRY WEATHER IS
FORECAST SUNDAY NIGHT.
.LONG TERM...MONDAY THROUGH THURSDAY.
BY MONDAY...AN UPPER LEVEL RIDGE ACROSS THE EASTERN HALF OF THE
CONUS WILL BEGIN TO BREAK DOWN AS AN UPPER LEVEL TROUGH PUSHES
ACROSS THE CENTRAL CONUS. RIDGING WILL PUSH ACROSS THE NORTHWEST
COAST BEHIND THE TROUGH...WHILE A CLOSED UPPER LOW WILL PUSH ACROSS
THE SOUTHEAST ASSOCIATED WITH THE BASE OF THE TROUGH. AT THE SURFACE
LOW PRESSURE IS EXPECTED TO SHIFT ACROSS SOUTHERN CANADA WHILE HIGH
PRESSURE REMAINS CENTERED ACROSS THE ROCKIES.
THE UPPER LEVEL TROUGH IS EXPECTED TO DIVE SOUTHEAST ACROSS THE OHIO
RIVER VALLEY IN THE LONG TERM PERIOD. WITH THE SURFACE LOW FOLLOWING
SUIT...HIGH PRESSURE FROM CANADA WILL SLIDE SOUTHWARD INTO THE
CENTRAL PLAINS. COOLER 850 MB TEMPERATURES WILL ALSO SHIFT
SOUTHWARD...INDICATING COOLER HIGH TEMPERATURES IN THE LONG TERM
PERIOD. HOWEVER...850 MB TEMPERATURES STILL REMAIN NEAR 10 TO 13
DEGREES CELSIUS...SUGGESTING UPPER 60S TO LOWER 70S FOR HIGHS.
AT THIS TIME...THERE IS SOME DISCREPANCY AMONG MODELS REGARDING
PRECIPITATION CHANCES IN THE LONG TERM PERIOD. THE GFS REMAINS DRY
THROUGHOUT THE ENTIRE PERIOD...WHILE THE ECMWF TRIES TO GENERATE
SLIGHT POPS ACROSS THE PLAINS SPECIFICALLY TUESDAY. THE ECMWF TRIES
TO GENERATE A FEW SCATTERED POPS ACROSS THE FORECAST AREA...AS
COOLER AIR SLIDES SOUTH ALONG THE BACKSIDE OF THE TROUGH. ASSOCIATED
WITH THE LOCATION OF THE RIGHT ENTRANCE REGION OF UPPER LEVEL
JET...ENOUGH LIFT COULD BE POSSIBLE DURING THE AFTERNOON ON TUESDAY.
HOWEVER...BOTH MODELS SUGGEST DEWPOINTS IN THE 35 TO 40 DEGREE
RANGE. AT THIS POINT...DECIDED TO KEEP THE LONG TERM DRY UNTIL
MODELS CAN COME INTO BETTER AGREEMENT ON MOISTURE POTENTIAL AND
LOCATION OF THE UPPER LEVEL JET.
&&
.AVIATION...KGRI TAF UPDATE. FOG CONTINUES TO EXPAND ACROSS THE
FORECAST AREA. VISIBILITY RESTRICTIONS ARE EXPECTED TO FLUCTUATE
BETWEEN ONE QUARTER MILE AND 1 MILE AT TIMES. WITH LIGHT AND
VARIABLE WINDS AND AMPLE MOISTURE IN THE AREA...FOG MAY BE SLOW TO
DISSIPATE UNTIL SUNRISE THIS MORNING.
PREV DISCUSSION... /ISSUED 1241 AM CDT FRI MAY 4 2012/
AVIATION...06Z KGRI TAF. AS A SURFACE TROUGH PASSES THROUGH THE
REGION OVERNIGHT TONIGHT...WINDS WILL LIKELY REMAIN LIGHT AND
VARIABLE...TO EVEN CALM AT TIMES. AS A RESULT...COMBINED WITH
AMPLE MOISTURE IN THE REGION...FOG DEVELOPMENT WILL REMAIN
POSSIBLE ACROSS THE TAF SITE. FOG THAT DEVELOPS WILL LIKELY BE
PATCHY IN NATURE. NEIGHBORING SITES HAVE HAS EXPERIENCED
VISIBILITY REDUCTIONS FROM 5 SM TO EVEN A QUARTER OF A MILE IN
SOME AREAS. AT THIS TIME...DECIDED TO LEAVE MENTION OF AT LEAST
IFR VISIBILITIES AND CEILINGS IN THE TEMPO GROUP...AS MODEL
SOUNDINGS INDICATE FOG COULD EASILY REACH THE TAF SITE. BESIDES
FOG POTENTIAL THIS MORNING...CLOUD BASES SHOULD REMAIN FAIRLY HIGH
WITH THE POSSIBILITY FOR CUMULUS DEVELOPMENT THIS AFTERNOON AS
TEMPERATURES CLIMB WELL INTO THE 80S. THERE REMAINS THE
POSSIBILITY FOR THUNDERSTORMS DURING THE EVENING AND OVERNIGHT
HOURS TONIGHT...BUT EXPECT THEM TO BE SCATTERED IN NATURE SO WILL
LEAVE OUT OF THE TAF FOR NOW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR NEZ041-
046>049-060>064-072>077-082>087.
KS...DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR KSZ005-006-
017-018.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
105 AM EDT FRI MAY 4 2012
.SYNOPSIS...
WARM BUT UNSETTLED WEATHER WILL CONTINUE THROUGH TONIGHT AND INTO
FRIDAY. HIGH PRESSURE WILL THEN BUILD INTO THE REGION FOR THE
WEEKEND...BRINGING A RETURN TO FAIR WEATHER AND MORE SEASONABLE
TEMPERATURES.
&&
.NEAR TERM /THROUGH TODAY/...
THROUGH THE EARLY MORNING HOURS...AN ORGANIZED LINE OF SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO PUSH EAST OF THE CWA. THE HRRR HAS
NOT PERFORMED WELL WITH THIS...BUT THE 00Z NAM/RGEM TO APPEAR TO
SHOW SOME SKILL IN CAPTURING THIS. BLENDING THIS WITH SATELLITE
AND RADAR TRENDS...ONLY SEE A CHANCE OF ADDITIONAL SHOWERS IN MOST
LOCATIONS OUTSIDE OF THIS EXITING LINE. THE EXCEPTION TO THIS IS
IN FAR WESTERN LOCATIONS...WHERE BOTH NAM/RGEM DO BRING IN MORE
QPF LATER TONIGHT. THIS IS SUPPORTED BY RADAR TRENDS...WHICH SHOWS
SHOWERS ACROSS SOUTHERN ONTARIO...POISED TO TRACK INTO THE NIAGARA
FRONTIER THROUGH DAYBREAK.
ON FRIDAY...ANY LINGERING NOCTURNAL CONVECTION SHOULD EXIT THE AREA
FAIRLY QUICKLY DURING THE EARLY MORNING HOURS. ONCE THIS IS
GONE...ANY LINGERING CHANCES WILL BE DRIVEN BY THE PASSAGE OF THE
LOW AND ITS TRAILING COLD FRONT...WHICH NOW APPEARS AS IF IT WILL
MOVE THROUGH THE AREA MORE QUICKLY THAN BEFORE. COUPLING THIS
QUICKER MOVEMENT WITH WHAT SHOULD BE A GREATER DEGREE OF CLOUD COVER
AND SIGNIFICANTLY LOWER AMOUNTS OF INSTABILITY COMPARED TO
TODAY...FEEL THAT CONVECTIVE CHANCES WILL BE LOWER OVERALL...ALONG
WITH A MUCH REDUCED SEVERE THREAT COMPARED TO HOW THINGS LOOKED JUST
A FEW DAYS AGO. FOR THESE REASONS...HAVE TRIMMED POPS BACK TO THE
CHANCE CATEGORY AFTER THE FIRST FEW HOURS OF TOMORROW MORNING...WITH
THESE THEN DIMINISHING FROM NORTHWEST TO SOUTHEAST IN THE AFTERNOON
FOLLOWING THE PASSAGE OF THE MAIN COLD FRONT.
TEMPERATURE-WISE...EXPECT A WARM AND SOMEWHAT HUMID NIGHT WITH THE
AREA REMAINING IN THE WARM SECTOR TONIGHT...WITH OVERNIGHT LOWS
GENERALLY IN THE LOWER TO MID 60S. DAYTIME HIGHS ON FRIDAY WILL THEN
GENERALLY RANGE THROUGH THE 70S...A LITTLE COOLER THAN TODAY GIVEN
THE INCREASED CLOUD COVER AND SLIGHTLY COOLER AIR WORKING IN BEHIND
THE COLD FRONT.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
MODELS HAVE COME INTO SOLID AGREEMENT ON THE POSITION/TIMING OF A
COOL FRONT THAT WILL DROP SOUTH ACROSS LAKE ONTARIO AND INTO
WESTERN/CENTRAL NEW YORK STARTING FRIDAY NIGHT. AS THIS COOL AND
STABLE AIRMASS SURGES SOUTHWARDS EXPECT ANY LINGERING CONVECTION TO
DISSIPATE AND/OR SLIDE SOUTH INTO PENNSYLVANIA WITH THE FRONTAL
BOUNDARY. ALTHOUGH THE AIRMASS MOVING IN WILL DRY OVER
TIME...LINGERING LOW LEVEL MOISTURE COMBINED WITH UPSLOPE NORTHERLY
FLOW WILL LIKELY KEEP LOW CLOUDS LOCKED IN ACROSS THE FORECAST AREA
THROUGH THE NIGHT AND AT LEAST THROUGH THE FIRST HALF OF
SATURDAY...LEADING TO WHAT SHOULD BE A RATHER DREARY...DRIZZLY
MORNING ON SATURDAY. EARLY MORNING LOWS IN THE LOW TO MID 50S SHOULD
STRUGGLE INTO THE LOW TO MID 60S THE AFTERNOON...PROVIDED THE DRY
AIR MIXES ALL THE WAY TO THE SURFACE AND CLOUD COVER GRADUALLY
BREAKS UP AS PROGGED.
THE CLEARING TREND SHOULD CONTINUE THROUGH SATURDAY NIGHT AS A COOL
AND DRY DOME OF HIGH PRESSURE BUILDS ACROSS THE REGION OUT OF CANADA
AHEAD OF A BROAD UPPER LEVEL RIDGE OVER THE GREAT LAKES. EXPECT A
COOL NIGHT SATURDAY NIGHT WITH TEMPERATURES COOLING INTO THE LOWER
40S UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. THE FAIR WEATHER WILL
CONTINUE THROUGH THE BALANCE OF THE WEEKEND UNDERNEATH THE HIGH WITH
TEMPERATURES RUNNING RIGHT AROUND NORMAL...IN THE LOW TO MID
60S...WHICH WILL SEEM DOWNRIGHT CHILLY COMPARED TO THE CURRENT BALMY
WEATHER.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE FIRST HALF OF NEXT WEEK WILL FEATURE A TRANSITION BACK INTO A
MORE UNSETTLED PATTERN FOR WESTERN AND CENTRAL NEW YORK. THE RIDGE
OF HIGH PRESSURE EXTENDING OVER THE REGION FROM CANADA WILL START TO
SLIDE EAST ON MONDAY AS A VIGOROUS UPPER LEVEL LOW/TROUGH DIGS INTO
THE UPPER MIDWEST. THIS UPPER TROUGH WILL AID IN SURFACE
CYCLOGENESIS OVER THE NATION/S MID-SECTION SUNDAY. AS THIS SURFACE
LOW MOVES INTO THE OHIO VALLEY MONDAY...EXPECT WIDESPREAD WARM
ADVECTION AHEAD OF THIS LOW TO WORK ITS WAY INTO THE FORECAST
AREA...ALLOWING FOR TEMPERATURES TO WARM BACK INTO THE UPPER 60S
MONDAY. ACCOMPANYING THIS WARM ADVECTION WILL BE AN INCREASE WITH
POPS AS A WARM FRONTAL BOUNDARY AND ASSOCIATED ISENTROPIC UPLIFT
APPROACHES THE AREA. THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
MODEL RUNS REGARDING THE LOCATION OF THE BOUNDARY WITH THE 12Z GFS
RUN KEEPING THE BOUNDARY...AND ASSOCIATED PRECIP...JUST TO OUR SOUTH
WHILE THE ECMWF/GEM MODELS BOTH BRING WARMER AIR AND WIDESPREAD
PRECIP UP INTO THE AREA. FOR NOW WILL STICK WITH BROADBRUSH CHANCE
POPS TO REFLECT THE GENERAL TREND TOWARDS UNSETTLED WEATHER WITH
MORE REFINEMENT AS THE TIMING/LOCATION OF THE FRONTAL BOUNDARY
BECOMES CLEARER.
IN SPITE OF DIFFERENCES IN THE DETAILS...MODELS ALL AGREE ON THE
DEVELOPMENT OF A FULL LATITUDE UPPER LEVEL TROUGH OVER THE EASTERN
UNITED STATES ON TUESDAY AS THE AFOREMENTIONED UPPER LOW OVER THE
UPPER MIDWEST MOVES EAST AND PHASES WITH THE CUTOFF LOW OVER QUEBEC.
THIS LARGE TROUGH WILL BE SITUATED ACROSS THE FORECAST AREA BY THE
MIDDLE OF NEXT WEEK...RESULTING IN WIDELY SCATTERED SHOWER ACTIVITY
AND A COOLING TREND BACK TO NEAR SEASONAL NORMALS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
THE MAIN AREA OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO EXIT
TO THE EAST THROUGH 12Z. THERE IS A SECONDARY AREA OF SHOWERS WITH
EMBEDDED THUNDERSTORMS...WHICH APPEARS MUCH LESS ACTIVE THAN THE
FIRST LINE. HOWEVER...THIS MAY BRING ANOTHER TSTM TO BUF/IAG
DURING THE EARLY MORNING HOURS...WITH AN OUTSIDE CHANCE FOR TSTMS
AT OTHER TAF LOCATIONS. CHANCES FOR SHOWERS WILL DIMINISH FROM
NORTH TO SOUTH ON FRIDAY.
OUTSIDE OF SHOWERS CONDITIONS SHOULD MAINLY BE VFR. HOWEVER...ANY
CLEARING WIND SHIFT TO A PERSISTENT ONSHORE FLOW WOULD HAVE THE
POTENTIAL TO LOWER CIGS/VSBY GIVEN THE MOIST BOUNDARY LAYER.
OUTLOOK...
FRIDAY NIGHT...MVFR/VFR WITH LINGERING SHOWERS ENDING.
SATURDAY THROUGH MONDAY...VFR.
TUESDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
ADDED SOME FOG OVER LAKE ONTARIO FOR THIS EVENING WITH THE
COMBINATION OF WARM/MOIST AIR OVER A COLD LAKE PRODUCING SOME
REDUCTION IN VISIBILITY PER THE VISIBLE SATELLITE IMAGERY AND
WEBCAMS.
GENERALLY LIGHT TO MODEST WINDS WILL CONTINUE ACROSS THE LOWER LAKES
REGION OVER THE NEXT FEW DAYS...WITH NO WIND HEADLINES ANTICIPATED
THROUGH THE WEEKEND. THE ABOVE SAID...THERE WILL BE THE POSSIBILITY
OF SOME THUNDERSTORMS TONIGHT AND FRIDAY AS A LOW PRESSURE SYSTEM
EASES SOUTHEAST ACROSS THE REGION...SOME OF WHICH COULD PRODUCE
LOCALLY HIGHER WINDS AND WAVES.
AFTER FRIDAY...HIGH PRESSURE WILL BUILD BACK ACROSS THE REGION AND
BRING A RETURN TO FAIR WEATHER.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...APFFEL/HITCHCOCK/JJR
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...APFFEL
MARINE...HITCHCOCK/JJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1139 PM EDT SAT MAY 5 2012
.SYNOPSIS...
A COLD FRONT DROPPING SOUTH ACROSS THE AREA COULD BRING STRONG TO
SEVERE THUNDERSTORMS THIS EVENING. A FEW SHOWERS WILL LINGER INTO
SUNDAY...WITH COOLER DAYTIME TEMPERATURES BOTH SUNDAY AND MONDAY AS
HIGH PRESSURE BUILDS FROM THE NORTH. WARMING WILL FOLLOW INTO MID
WEEK...AS HIGH PRESSURE MOVES OFFSHORE AND A COLD FRONT APPROACHES
FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 PM SATURDAY...THE THUNDERSTORMS FINALLY DID ORGANIZE INTO
A LONG SQUALL LINE EXTENDING FROM THE PAMLICO SOUND CLEAR DOWN INTO
THE CHARLESTON SC AREA...ALMOST EXACTLY AS THE HRRR MODEL HAD BEEN
SHOWING. THE HRRR`S TIMING WAS OFF BY 1-2 HOURS BUT THE RADAR
APPEARANCE WAS VERY GOOD. SOME REDEVELOPMENT OF ELEVATED SHOWERS AND
ISOLATED THUNDERSTORMS HAS OCCURRED IN THE PAST HOUR ACROSS THE SC
MIDLANDS AND ALSO UP IN THE RALEIGH/DURHAM AREA. THE SC CONVECTION
WILL PROBABLY AFFECT THE SOUTHERN HALF OF OUR PEE DEE FORECAST AREA
IN THE NEXT SEVERAL HOURS...MAINLY SOUTH OF FLORENCE AND ALONG THE
SANTEE RIVER. THE SHALLOW CONVECTION IN THE RALEIGH AREA MAY NOT
MAKE IT THIS FAR SOUTH AS RADAR DEPICTIONS ARE WEAKENING. THE ACTUAL
SURFACE COLD FRONT IS VERY DIFFICULT TO FIND AT THIS HOUR WITH THE
THERMAL GRADIENT LARGELY WIPED OUT BY EARLIER CONVECTION...BUT
MODELS SHOW AN INCREASING NORTH WIND SHOULD DEVELOP SUNDAY MORNING.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...DAYBREAK SUNDAY INCREASING NE WINDS WILL
BE OVERSPREADING THE REGION...AS A SURFACE LOW DEPARTING OFFSHORE
OF CAPE FEAR INTERACTS WITH HIGH PRESSURE BUILDING FROM THE NORTH.
HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS SUNDAY SINCE POST-FRONT
MOISTURE WILL REMAIN ADEQUATE AND A FEW IMPULSES ALOFT DROP SOUTH
OVER THE AREA IN THE EARLY AND MID AFTERNOON. IT DOES APPEAR THAT
DRYING WILL WIN OUT OVER NC BY MID AFTERNOON AND OVER OUR SOUTHERN
ZONES BY THE EARLY EVENING.
DAYTIME TEMPERATURES WILL BE 10-15 COOLER ACROSS THE FORECAST AREA
BOTH SUNDAY AND MONDAY COMPARED TO TODAY DUE TO CLOUDS AND AIR OF
COOLER ORIGIN BEHIND THE FRONT. BECAUSE OF SUSTAINED WINDS
OVERNIGHT OUR MINIMUMS WILL REMAIN SOMEWHAT ELEVATED BOTH MON/TUE
MORNING WITH READINGS AROUND 60 DEG...MILDEST COASTAL ZONES AND
COOLEST OVER THE INTERIOR WHERE LESS WIND INFLUENCE WILL BE SEEN.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 230 PM SATURDAY...HIGH PRESSURE OFFSHORE TUESDAY CREATES WARM
SOUTHERLY RETURN FLOW ACROSS THE CAROLINAS. WITH GUIDANCE NOW
SHOWING A SLOWER FROPA...TUESDAY WILL END UP BEING MOSTLY SUNNY WITH
TEMPS AT OR SLIGHTLY ABOVE 80. CANNOT RULE OUT AN ISOLATED TSTM IN
THE AFTN...BUT DRY AIR IN THE MID LEVELS WILL PRECLUDE MUCH IN THE
WAY OF COVERAGE. CONTINUED WARM SOUTHERLY FLOW AND INCREASING CLOUD
COVER WILL KEEP MINS TUESDAY NIGHT ONLY IN THE MID 60S.
WEDNESDAY STILL LOOKS TO BE AN ACTIVE DAY WITH POTENTIALLY
WIDESPREAD CONVECTION ALONG AND AHEAD OF A POTENT COLD FRONT. RETURN
FLOW PUSHES PWATS UP TO 1.75 INCHES AND ALLOWS FOR ADVECTION OF THE
THETA-E RIDGE INTO THE EASTERN CAROLINAS. WHILE THIS HAPPENS...S/W
TROUGH SPAWNS A SURFACE LOW ACROSS THE OHIO VALLEY WHICH DRAGS A
COLD FRONT THROUGH THIS AREA WEDNESDAY AFTN. ATTM IT APPEARS THIS
COULD COINCIDE WITH PEAK HEATING...AND INSTABILITY PARAMETERS AS
WELL AS UPPER SUPPORT LOOK DECENT...SO CONFIDENCE IS INCREASING IN
TSTM DEVELOPMENT DURING THE AFTN. HOWEVER...SOUNDINGS NO LONGER SHOW
FULL AND DEEP SATURATION WHICH COULD SERVE AS A LIMITING FACTOR TO
RAINFALL...UNFORTUNATELY. NOTE AS WELL THAT THE GFS CONTINUES TO
SHOW AN AREA OF CONVECTION NEAR FLORIDA EARLY WED WHICH TRIES TO
WORK UP THE COAST. THIS COULD ENHANCE RAINFALL ALONG THE COAST...BUT
IN THIS SETUP FREQUENTLY ACTS TO SQUELCH RAINFALL SINCE IT CUTS OFF
THE DEEP MOIST FLOW. WE WILL HAVE TO WAIT AND SEE...BUT FOR NOW WILL
CARRY HIGH CHC POP FOR WEDNESDAY...WITH HIGHEST POP ACROSS THE
NORTH. STILL BELIEVE MEX NUMBERS ARE TOO HIGH WEDNESDAY...BUT HIGHS
A DEGREE OR TWO ABOVE 80 SEEM REASONABLE.
COOL HIGH PRESSURE BUILDS IN BEHIND THE FRONT EARLY THURSDAY...AND
THE END OF THE WEEK THROUGH SATURDAY WILL SEE TEMPS RETURN TO JUST
BELOW CLIMO WITH AMPLE SUNSHINE. EXPECT MAX TEMPS IN THE UPPER 70S
TO AROUND 80...WITH MINS AT NIGHT IN THE MID AND UPPER 50S.
&&
.AVIATION /00Z SATURDAY THROUGH THURSDAY/...
AS OF 00Z...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS HAVE FIRED IN
ADVANCE OF A COLD FRONT WITH AN MCS AFFECTING POINTS JUST NORTH OF
THE FORECAST AREA. MODEL GUIDANCE CONTINUES TO SHOW THAT SHOWERS
AND STORMS WILL CONTINUE TO EXPAND IN COVERAGE ACROSS OUR AREA FOR
THE NEXT HOUR OR TWO. HAVE INCLUDED TEMPO GROUPS AT ALL TAF SITES
FOR 3 TO 4 HOURS BEGINNING BETWEEN 00Z AND 02Z. THERE HAVE BEEN
FAIRLY GUSTY WINDS WITH STORMS TO THE NORTH AND WEST SO GUSTS UP TO
35 KT HAVE BEEN INCLUDED IN THE TAFS. AFTER THE STORMS END...MOIST
LOW-LEVELS AND WEAK CAA SHOULD SET THE STAGE FOR POST-FRONTAL
SCATTERED TO BROKEN IFR CEILINGS TO DEVELOP AND SPREAD SOUTH. THESE
CEILINGS SHOULD LIFT TO MVFR BY MID-LATE MORNING AND VFR AROUND
NOON. WINDS BY SUNDAY MORNING WILL BE NORTH TO NORTHEAST AT AROUND
10 KNOTS.
EXTENDED OUTLOOK...LOW CONFIDENCE EARLY MORNING FOG/IFR MONDAY AND
TUESDAY. CHANCE SHOWERS AND THUNDERSTORMS TUESDAY NIGHT INTO
WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 PM SATURDAY...HIGH PRESSURE CENTERED FROM FLORIDA ACROSS
THE NORTHERN BAHAMAS WILL BECOME SUPPRESSED TO THE SOUTH AS A COLD
FRONT SLIDES SOUTH ALONG THE CAROLINA COAST TONIGHT. STRONG TO
SEVERE THUNDERSTORMS ACROSS THE EASTERN CAROLINAS HAVE SLID OFF THE
COAST AND ARE PUSHING THROUGH THE OFFSHORE WATERS CURRENTLY. WIND
GUSTS WERE MEASURED UP TO 45 KNOTS EARLIER AT A COUPLE LOCATIONS
NEAR THE BEACHES. THE WEATHER SHOULD QUIETEN DOWN CONSIDERABLY
OVERNIGHT AS THE STORMS PUSH INTO THE GULF STREAM...AND A
COOLER WEST TO NORTHWEST FLOW DEVELOPS AS A COLD FRONT SLIPS IN FROM
THE NORTH.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...PRIMARY THREAT WILL BE TSTMS OFFSHORE
EARLY ON SUNDAY AND THE POTENTIAL FOR LOCALLY STRONG WINDS AND
CLOUD TO WATER LIGHTNING STRIKES ASSOCIATED WITH A SURFACE LOW
OFFSHORE. INCREASING NE WINDS WILL REQUIRE A CAUTIONARY HEADLINE
IN THE CWF MAINLY FOR SUNDAY AFTN...POSSIBLY INTO EVENING AS HIGH
PRESSURE BUILDS FROM THE NORTH. THE TREND IN WINDS IS TO WEAKEN
AND VEER MONDAY AND TUESDAY...BECOMING SSE MONDAY NIGHT AND SSW
BY TUESDAY AS HIGH PRESSURE MOVES OFFSHORE...AND A WEAK COLD FRONT
APPROACHES FROM THE NORTH. S-SE WAVE ENERGY WILL BECOME ENE SUNDAY
IN A BUMPY 3-5 FEET OVER THE 0-20NM WATERS...HIGHEST SEAS NORTH OF
FRYING PAN SHOALS AND WELL OFFSHORE. THE GULF STREAM WILL BE A BIT
HAZARDOUS SUNDAY AS NE WINDS CLASH WITH THE ROBUST CURRENTS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 230 PM SATURDAY...HIGH PRESSURE OFFSHORE DRIFTS FURTHER FROM
THE COAST THROUGH WEDNESDAY AHEAD OF AN ADVANCING COLD FRONT. THIS
CREATES A TIGHTENING PRESSURE GRADIENT...AND WINDS VEERING SLOWLY
FROM SE TUESDAY...TO SW WEDNESDAY...AT 10-15 KTS. SEVERAL DIFFERENT
WAVES WILL BE EVIDENT WITHIN THE SPECTRUM DURING THIS TIME...A SE
SWELL OF 2FT/10 SEC...AND A SE WIND WAVE...BECOMING SW WEDNESDAY.
FORTUNATELY...THESE WILL ALL BE AT RATHER LOW AMPLITUDES...SO TOTAL
SEAS WILL BE ONLY IN THE 2-4 FT RANGE. LATE WED NIGHT COLD FRONT
OCCURS ACROSS THE WATERS TURNING WINDS TO THE NORTH...THEN NE BY
THURSDAY EVE. THERE WILL BE A PERIOD OF ENHANCED NORTH WINDS BEHIND
THE FRONT...UP TO 15-20 KTS...BEFORE EASING LATE TO 5-10 KTS.
ALTHOUGH WAVE HEIGHTS WILL REMAIN AROUND 2-4 FT THROUGH
THURSDAY...WAVE STEEPNESS WILL INCREASE BEHIND FROPA FOR SEVERAL
HOURS AS N/NE WIND WAVES BECOME PREDOMINANT WITHIN THE WAVE
SPECTRUM.
&&
.TIDES/COASTAL FLOODING...
AS OF 230 PM SATURDAY...A FULL MOON TONIGHT WILL BRING UNUSUALLY
HIGH WATER LEVELS FOR THE NEXT FEW DAYS DURING THE EVENING HIGH
TIDE...THE HIGHEST OF THE TWO HIGH TIDES. TONIGHT...MINOR FLOODING
SHOULD BE CONFINED TO PORTIONS OF THE CAPE FEAR RIVER IN DOWNTOWN
WILMINGTON WHERE WATER LEVELS ARE EXPECTED TO REACH JUST OVER 5.5
FT DURING THE EVE. THIS WILL BE ENOUGH TO ISSUE A COASTAL FLOOD
ADVISORY FOR A PORTION OF NEW HANOVER COUNTY. NORTHEAST WINDS MAY
DRIVE TIDES EVEN HIGHER SUN NIGHT...AND ACROSS A BROADER AREA TO
INCLUDE THE BEACHES. HIGH TIDE THIS EVENING IS AROUND 8 PM AT THE
COAST AND 10 PM ALONG THE CAPE FEAR IN DOWNTOWN WILMINGTON. HIGH
TIDE SUNDAY NIGHT IS AROUND 830 PM ALONG THE BEACHES. THERE IS
ABOUT A TWO HOUR LAG TIME IN DOWNTOWN WILMINGTON.
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT
EDT TONIGHT FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...8
NEAR TERM...TRA
SHORT TERM...COLBY
LONG TERM...JDW
AVIATION...RAN
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
910 PM EDT SAT MAY 5 2012
.SYNOPSIS...
A COLD FRONT DROPPING SOUTH ACROSS THE AREA COULD BRING STRONG TO
SEVERE THUNDERSTORMS THIS EVENING. A FEW SHOWERS WILL LINGER INTO
SUNDAY...WITH COOLER DAYTIME TEMPERATURES BOTH SUNDAY AND MONDAY AS
HIGH PRESSURE BUILDS FROM THE NORTH. WARMING WILL FOLLOW INTO MID
WEEK...AS HIGH PRESSURE MOVES OFFSHORE AND A COLD FRONT APPROACHES
FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 900 PM SATURDAY...JUST A QUICK UPDATE TO THE FORECAST TO
ADJUST POPS FOR RECENT RADAR TRENDS. DESPITE A COOLING AND
STABILIZING BOUNDARY LAYER STORMS CONTINUE TO STRENGTHEN AS THEY
APPROACH THE COAST WITHIN AN ENVIRONMENT OF ELEVATED CAPE 1000-1500
J/KG. THE STRONGEST 0-6KM BULK SHEAR IS PROBABLY OCCURRING NOW AND
SHOULD DECREASE AS THE MID-LEVEL SPEED MAX PUSHES EAST-SOUTHEAST AND
OFFSHORE. PREVIOUS DISCUSSION FROM 630 PM FOLLOWS...
THE LATEST HRRR AND NAM RUNS SHOW FAIRLY WIDESPREAD CONVECTION
DEVELOPING WITHIN THE NEXT 60-90 MINUTES ACROSS NORTHERN SOUTH
CAROLINA...CONSOLIDATING INTO A SQUALL LINE WITH THE ACTIVITY OVER
EAST-CENTRAL NORTH CAROLINA...AND MOVING SOUTHEAST AND OFF THE COAST
THIS EVENING. WHILE THERE IS OBVIOUSLY SUFFICIENT AREAL COVERAGE OF
CONVECTION IN THE RALEIGH/SANFORD VICINITY TO GENERATE A SIGNIFICANT
SURFACE COLD POOL AND STRONG LEADING-EDGE WINDS...OUR FORECAST FOR
50-60 PERCENT COVERAGE OF STORMS ACROSS NORTHEAST SOUTH CAROLINA IS
HEAVILY CONTINGENT ON MUCH MORE STORM ORGANIZATION DEVELOPING SOUTH
OF FAYETTEVILLE THAN IS CURRENTLY OBSERVED ON RADAR. SURFACE-BASED
CAPE IN THE 1500-2000 J/KG RANGE...LIFTED INDICIES TO -5...AND 0-6
KM BULK SHEAR VALUES AROUND 30 KT ARE SUPPORTIVE OF STORM
ORGANIZATION THIS EVENING. COMPARED TO THE PREVIOUS FORECAST WE HAVE
ONLY MADE SMALL DOWNWARD EDITS TO PREDICTED COVERAGE OF STORMS IN
SOUTH CAROLINA. THE BEST POTENTIAL OF CONVECTION IN OUR FORECAST
AREA REMAINS ACROSS SOUTHEASTERN NORTH CAROLINA NORTH OF CAPE FEAR
WHERE THE RALEIGH/SANFORD SQUALL LINE MAY DRAG THROUGH IN THE NEXT
FEW HOURS. DAMAGING WINDS ARE THE PRIMARY EXPECTED SEVERE WEATHER
MODE... ALTHOUGH SOME MARGINALLY SEVERE HAIL CANNOT BE RULED OUT.
THE SYNOPTIC SETTING HAS AN EAST-WEST COLD FRONT SAGGING SOUTHWARD
ACROSS CENTRAL NORTH CAROLINA EARLY THIS EVENING...WITH HIGH
PRESSURE ACROSS FLORIDA AND THE NORTHERN BAHAMAS RETREATING TO THE
SOUTH. THE PASSAGE OF A PACKET OF STRONG MID-LEVEL WINDS THIS
EVENING WILL HELP ENHANCE STORM ORGANIZATION FROM NOW UNTIL 10-11 PM
OR SO...AT WHICH POINT THE BULK OF THE SIGNIFICANT CONVECTION SHOULD
BE PUSHING EAST AND OFFSHORE. NW AND N WINDS WILL OVERSPREAD THE
AREA AFTER MIDNIGHT BEHIND THE FRONT...BUT WITH LITTLE REAL COLD
ADVECTION UNTIL SUNDAY. NO CHANGES HAVE BEEN MADE TO LOW
TEMPERATURES...WITH MID TO UPPER 60S EXPECTED FOR MOST AREAS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...DAYBREAK SUNDAY INCREASING NE WINDS WILL
BE OVERSPREADING THE REGION...AS A SURFACE LOW DEPARTING OFFSHORE
OF CAPE FEAR INTERACTS WITH HIGH PRESSURE BUILDING FROM THE NORTH.
HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS SUNDAY SINCE POST-FRONT
MOISTURE WILL REMAIN ADEQUATE AND A FEW IMPULSES ALOFT DROP SOUTH
OVER THE AREA IN THE EARLY AND MID AFTERNOON. IT DOES APPEAR THAT
DRYING WILL WIN OUT OVER NC BY MID AFTERNOON AND OVER OUR SOUTHERN
ZONES BY THE EARLY EVENING.
DAYTIME TEMPERATURES WILL BE 10-15 COOLER ACROSS THE FORECAST AREA
BOTH SUNDAY AND MONDAY COMPARED TO TODAY DUE TO CLOUDS AND AIR OF
COOLER ORIGIN BEHIND THE FRONT. BECAUSE OF SUSTAINED WINDS
OVERNIGHT OUR MINIMUMS WILL REMAIN SOMEWHAT ELEVATED BOTH MON/TUE
MORNING WITH READINGS AROUND 60 DEG...MILDEST COASTAL ZONES AND
COOLEST OVER THE INTERIOR WHERE LESS WIND INFLUENCE WILL BE SEEN.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 230 PM SATURDAY...HIGH PRESSURE OFFSHORE TUESDAY CREATES WARM
SOUTHERLY RETURN FLOW ACROSS THE CAROLINAS. WITH GUIDANCE NOW
SHOWING A SLOWER FROPA...TUESDAY WILL END UP BEING MOSTLY SUNNY WITH
TEMPS AT OR SLIGHTLY ABOVE 80. CANNOT RULE OUT AN ISOLATED TSTM IN
THE AFTN...BUT DRY AIR IN THE MID LEVELS WILL PRECLUDE MUCH IN THE
WAY OF COVERAGE. CONTINUED WARM SOUTHERLY FLOW AND INCREASING CLOUD
COVER WILL KEEP MINS TUESDAY NIGHT ONLY IN THE MID 60S.
WEDNESDAY STILL LOOKS TO BE AN ACTIVE DAY WITH POTENTIALLY
WIDESPREAD CONVECTION ALONG AND AHEAD OF A POTENT COLD FRONT. RETURN
FLOW PUSHES PWATS UP TO 1.75 INCHES AND ALLOWS FOR ADVECTION OF THE
THETA-E RIDGE INTO THE EASTERN CAROLINAS. WHILE THIS HAPPENS...S/W
TROUGH SPAWNS A SURFACE LOW ACROSS THE OHIO VALLEY WHICH DRAGS A
COLD FRONT THROUGH THIS AREA WEDNESDAY AFTN. ATTM IT APPEARS THIS
COULD COINCIDE WITH PEAK HEATING...AND INSTABILITY PARAMETERS AS
WELL AS UPPER SUPPORT LOOK DECENT...SO CONFIDENCE IS INCREASING IN
TSTM DEVELOPMENT DURING THE AFTN. HOWEVER...SOUNDINGS NO LONGER SHOW
FULL AND DEEP SATURATION WHICH COULD SERVE AS A LIMITING FACTOR TO
RAINFALL...UNFORTUNATELY. NOTE AS WELL THAT THE GFS CONTINUES TO
SHOW AN AREA OF CONVECTION NEAR FLORIDA EARLY WED WHICH TRIES TO
WORK UP THE COAST. THIS COULD ENHANCE RAINFALL ALONG THE COAST...BUT
IN THIS SETUP FREQUENTLY ACTS TO SQUELCH RAINFALL SINCE IT CUTS OFF
THE DEEP MOIST FLOW. WE WILL HAVE TO WAIT AND SEE...BUT FOR NOW WILL
CARRY HIGH CHC POP FOR WEDNESDAY...WITH HIGHEST POP ACROSS THE
NORTH. STILL BELIEVE MEX NUMBERS ARE TOO HIGH WEDNESDAY...BUT HIGHS
A DEGREE OR TWO ABOVE 80 SEEM REASONABLE.
COOL HIGH PRESSURE BUILDS IN BEHIND THE FRONT EARLY THURSDAY...AND
THE END OF THE WEEK THROUGH SATURDAY WILL SEE TEMPS RETURN TO JUST
BELOW CLIMO WITH AMPLE SUNSHINE. EXPECT MAX TEMPS IN THE UPPER 70S
TO AROUND 80...WITH MINS AT NIGHT IN THE MID AND UPPER 50S.
&&
.AVIATION /00Z SATURDAY THROUGH THURSDAY/...
AS OF 00Z...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS HAVE FIRED IN
ADVANCE OF A COLD FRONT WITH AN MCS AFFECTING POINTS JUST NORTH OF
THE FORECAST AREA. MODEL GUIDANCE CONTINUES TO SHOW THAT SHOWERS
AND STORMS WILL CONTINUE TO EXPAND IN COVERAGE ACROSS OUR AREA FOR
THE NEXT HOUR OR TWO. HAVE INCLUDED TEMPO GROUPS AT ALL TAF SITES
FOR 3 TO 4 HOURS BEGINNING BETWEEN 00Z AND 02Z. THERE HAVE BEEN
FAIRLY GUSTY WINDS WITH STORMS TO THE NORTH AND WEST SO GUSTS UP TO
35 KT HAVE BEEN INCLUDED IN THE TAFS. AFTER THE STORMS END...MOIST
LOW-LEVELS AND WEAK CAA SHOULD SET THE STAGE FOR POST-FRONTAL
SCATTERED TO BROKEN IFR CEILINGS TO DEVELOP AND SPREAD SOUTH. THESE
CEILINGS SHOULD LIFT TO MVFR BY MID-LATE MORNING AND VFR AROUND
NOON. WINDS BY SUNDAY MORNING WILL BE NORTH TO NORTHEAST AT AROUND
10 KNOTS.
EXTENDED OUTLOOK...LOW CONFIDENCE EARLY MORNING FOG/IFR MONDAY AND
TUESDAY. CHANCE SHOWERS AND THUNDERSTORMS TUESDAY NIGHT INTO
WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 900 PM SATURDAY...NO CHANGES TO THE PRIOR FORECAST THINKING.
LINE OF STRONG TO SEVERE T-STORMS WILL APPROACH THE COAST WITHIN THE
NEXT HOUR WITH STRONG WINDS AND SOME HAIL EXPECTED. PREVIOUS
DISCUSSION FROM 630 PM FOLLOWS...
HIGH PRESSURE CENTERED FROM FLORIDA ACROSS THE NORTHERN BAHAMAS WILL
BECOME SUPPRESSED TO THE SOUTH AS A COLD FRONT SLIDES SOUTH ALONG
THE CAROLINA COAST TONIGHT. OF IMMEDIATE CONCERN WITH THIS FRONT IS
THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS TO DEVELOP IN THE
NEXT 1-2 HOURS. LATEST SHORT-TERM MODEL GUIDANCE SHOWS A BROKEN
SQUALL LINE POSSIBLY DEVELOPING ACROSS THE EASTERN CAROLINAS AND
PUSHING OUT ACROSS THE WATERS BEFORE MIDNIGHT. STRONG WINDS ALONG
THE LEADING EDGE OF THE SQUALL LINE ARE THE PRIMARY THREAT AND COULD
RESULT IN SPECIAL MARINE WARNINGS LATER THIS EVENING.
OTHERWISE...SYNOPTIC SOUTHWEST WINDS 10-15 KT HAVE INCREASED TO
15-18 KT NEAR THE BEACHES WITH THE SEABREEZE. THESE SYNOPTIC WINDS
WILL SHIFT TO THE W AND NW AFTER MIDNIGHT AS THE COLD FRONT SINKS
INTO THE AREA...THEN TO THE N SUNDAY MORNING. SEAS AVERAGE 3 FT WITH
SOME 2-FOOTERS NEAR THE SC COAST.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...PRIMARY THREAT WILL BE TSTMS OFFSHORE
EARLY ON SUNDAY AND THE POTENTIAL FOR LOCALLY STRONG WINDS AND
CLOUD TO WATER LIGHTNING STRIKES ASSOCIATED WITH A SURFACE LOW
OFFSHORE. INCREASING NE WINDS WILL REQUIRE A CAUTIONARY HEADLINE
IN THE CWF MAINLY FOR SUNDAY AFTN...POSSIBLY INTO EVENING AS HIGH
PRESSURE BUILDS FROM THE NORTH. THE TREND IN WINDS IS TO WEAKEN
AND VEER MONDAY AND TUESDAY...BECOMING SSE MONDAY NIGHT AND SSW
BY TUESDAY AS HIGH PRESSURE MOVES OFFSHORE...AND A WEAK COLD FRONT
APPROACHES FROM THE NORTH. S-SE WAVE ENERGY WILL BECOME ENE SUNDAY
IN A BUMPY 3-5 FEET OVER THE 0-20NM WATERS...HIGHEST SEAS NORTH OF
FRYING PAN SHOALS AND WELL OFFSHORE. THE GULF STREAM WILL BE A BIT
HAZARDOUS SUNDAY AS NE WINDS CLASH WITH THE ROBUST CURRENTS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 230 PM SATURDAY...HIGH PRESSURE OFFSHORE DRIFTS FURTHER FROM
THE COAST THROUGH WEDNESDAY AHEAD OF AN ADVANCING COLD FRONT. THIS
CREATES A TIGHTENING PRESSURE GRADIENT...AND WINDS VEERING SLOWLY
FROM SE TUESDAY...TO SW WEDNESDAY...AT 10-15 KTS. SEVERAL DIFFERENT
WAVES WILL BE EVIDENT WITHIN THE SPECTRUM DURING THIS TIME...A SE
SWELL OF 2FT/10 SEC...AND A SE WIND WAVE...BECOMING SW WEDNESDAY.
FORTUNATELY...THESE WILL ALL BE AT RATHER LOW AMPLITUDES...SO TOTAL
SEAS WILL BE ONLY IN THE 2-4 FT RANGE. LATE WED NIGHT COLD FRONT
OCCURS ACROSS THE WATERS TURNING WINDS TO THE NORTH...THEN NE BY
THURSDAY EVE. THERE WILL BE A PERIOD OF ENHANCED NORTH WINDS BEHIND
THE FRONT...UP TO 15-20 KTS...BEFORE EASING LATE TO 5-10 KTS.
ALTHOUGH WAVE HEIGHTS WILL REMAIN AROUND 2-4 FT THROUGH
THURSDAY...WAVE STEEPNESS WILL INCREASE BEHIND FROPA FOR SEVERAL
HOURS AS N/NE WIND WAVES BECOME PREDOMINANT WITHIN THE WAVE
SPECTRUM.
&&
.TIDES/COASTAL FLOODING...
AS OF 230 PM SATURDAY...A FULL MOON TONIGHT WILL BRING UNUSUALLY
HIGH WATER LEVELS FOR THE NEXT FEW DAYS DURING THE EVENING HIGH
TIDE...THE HIGHEST OF THE TWO HIGH TIDES. TONIGHT...MINOR FLOODING
SHOULD BE CONFINED TO PORTIONS OF THE CAPE FEAR RIVER IN DOWNTOWN
WILMINGTON WHERE WATER LEVELS ARE EXPECTED TO REACH JUST OVER 5.5
FT DURING THE EVE. THIS WILL BE ENOUGH TO ISSUE A COASTAL FLOOD
ADVISORY FOR A PORTION OF NEW HANOVER COUNTY. NORTHEAST WINDS MAY
DRIVE TIDES EVEN HIGHER SUN NIGHT...AND ACROSS A BROADER AREA TO
INCLUDE THE BEACHES. HIGH TIDE THIS EVENING IS AROUND 8 PM AT THE
COAST AND 10 PM ALONG THE CAPE FEAR IN DOWNTOWN WILMINGTON. HIGH
TIDE SUNDAY NIGHT IS AROUND 830 PM ALONG THE BEACHES. THERE IS
ABOUT A TWO HOUR LAG TIME IN DOWNTOWN WILMINGTON.
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT
EDT TONIGHT FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...8
NEAR TERM...TRA
SHORT TERM...COLBY
LONG TERM...JDW
AVIATION...RAN
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
730 PM EDT SAT MAY 5 2012
.SYNOPSIS...
A COLD FRONT DROPPING SOUTH ACROSS THE AREA COULD BRING STRONG TO
SEVERE THUNDERSTORMS THIS EVENING. A FEW SHOWERS WILL LINGER INTO
SUNDAY...WITH COOLER DAYTIME TEMPERATURES BOTH SUNDAY AND MONDAY AS
HIGH PRESSURE BUILDS FROM THE NORTH. WARMING WILL FOLLOW INTO MID
WEEK...AS HIGH PRESSURE MOVES OFFSHORE AND A COLD FRONT APPROACHES
FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM SATURDAY...THE LATEST HRRR AND NAM RUNS SHOW FAIRLY
WIDESPREAD CONVECTION DEVELOPING WITHIN THE NEXT 60-90 MINUTES
ACROSS NORTHERN SOUTH CAROLINA...CONSOLIDATING INTO A SQUALL LINE
WITH THE ACTIVITY OVER EAST-CENTRAL NORTH CAROLINA...AND MOVING
SOUTHEAST AND OFF THE COAST THIS EVENING. WHILE THERE IS OBVIOUSLY
SUFFICIENT AREAL COVERAGE OF CONVECTION IN THE RALEIGH/SANFORD
VICINITY TO GENERATE A SIGNIFICANT SURFACE COLD POOL AND STRONG
LEADING-EDGE WINDS...OUR FORECAST FOR 50-60 PERCENT COVERAGE OF
STORMS ACROSS NORTHEAST SOUTH CAROLINA IS HEAVILY CONTINGENT ON MUCH
MORE STORM ORGANIZATION DEVELOPING SOUTH OF FAYETTEVILLE THAN IS
CURRENTLY OBSERVED ON RADAR. SURFACE-BASED CAPE IN THE 1500-2000
J/KG RANGE...LIFTED INDICIES TO -5...AND 0-6 KM BULK SHEAR VALUES
AROUND 30 KT ARE SUPPORTIVE OF STORM ORGANIZATION THIS EVENING.
COMPARED TO THE PREVIOUS FORECAST WE HAVE ONLY MADE SMALL DOWNWARD
EDITS TO PREDICTED COVERAGE OF STORMS IN SOUTH CAROLINA. THE BEST
POTENTIAL OF CONVECTION IN OUR FORECAST AREA REMAINS ACROSS
SOUTHEASTERN NORTH CAROLINA NORTH OF CAPE FEAR WHERE THE
RALEIGH/SANFORD SQUALL LINE MAY DRAG THROUGH IN THE NEXT FEW HOURS.
DAMAGING WINDS ARE THE PRIMARY EXPECTED SEVERE WEATHER MODE...
ALTHOUGH SOME MARGINALLY SEVERE HAIL CANNOT BE RULED OUT.
THE SYNOPTIC SETTING HAS AN EAST-WEST COLD FRONT SAGGING SOUTHWARD
ACROSS CENTRAL NORTH CAROLINA EARLY THIS EVENING...WITH HIGH
PRESSURE ACROSS FLORIDA AND THE NORTHERN BAHAMAS RETREATING TO THE
SOUTH. THE PASSAGE OF A PACKET OF STRONG MID-LEVEL WINDS THIS
EVENING WILL HELP ENHANCE STORM ORGANIZATION FROM NOW UNTIL 10-11 PM
OR SO...AT WHICH POINT THE BULK OF THE SIGNIFICANT CONVECTION SHOULD
BE PUSHING EAST AND OFFSHORE. NW AND N WINDS WILL OVERSPREAD THE
AREA AFTER MIDNIGHT BEHIND THE FRONT...BUT WITH LITTLE REAL COLD
ADVECTION UNTIL SUNDAY. NO CHANGES HAVE BEEN MADE TO LOW
TEMPERATURES...WITH MID TO UPPER 60S EXPECTED FOR MOST AREAS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...DAYBREAK SUNDAY INCREASING NE WINDS WILL
BE OVERSPREADING THE REGION...AS A SURFACE LOW DEPARTING OFFSHORE
OF CAPE FEAR INTERACTS WITH HIGH PRESSURE BUILDING FROM THE NORTH.
HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS SUNDAY SINCE POST-FRONT
MOISTURE WILL REMAIN ADEQUATE AND A FEW IMPULSES ALOFT DROP SOUTH
OVER THE AREA IN THE EARLY AND MID AFTERNOON. IT DOES APPEAR THAT
DRYING WILL WIN OUT OVER NC BY MID AFTERNOON AND OVER OUR SOUTHERN
ZONES BY THE EARLY EVENING.
DAYTIME TEMPERATURES WILL BE 10-15 COOLER ACROSS THE FORECAST AREA
BOTH SUNDAY AND MONDAY COMPARED TO TODAY DUE TO CLOUDS AND AIR OF
COOLER ORIGIN BEHIND THE FRONT. BECAUSE OF SUSTAINED WINDS
OVERNIGHT OUR MINIMUMS WILL REMAIN SOMEWHAT ELEVATED BOTH MON/TUE
MORNING WITH READINGS AROUND 60 DEG...MILDEST COASTAL ZONES AND
COOLEST OVER THE INTERIOR WHERE LESS WIND INFLUENCE WILL BE SEEN.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 230 PM SATURDAY...HIGH PRESSURE OFFSHORE TUESDAY CREATES WARM
SOUTHERLY RETURN FLOW ACROSS THE CAROLINAS. WITH GUIDANCE NOW
SHOWING A SLOWER FROPA...TUESDAY WILL END UP BEING MOSTLY SUNNY WITH
TEMPS AT OR SLIGHTLY ABOVE 80. CANNOT RULE OUT AN ISOLATED TSTM IN
THE AFTN...BUT DRY AIR IN THE MID LEVELS WILL PRECLUDE MUCH IN THE
WAY OF COVERAGE. CONTINUED WARM SOUTHERLY FLOW AND INCREASING CLOUD
COVER WILL KEEP MINS TUESDAY NIGHT ONLY IN THE MID 60S.
WEDNESDAY STILL LOOKS TO BE AN ACTIVE DAY WITH POTENTIALLY
WIDESPREAD CONVECTION ALONG AND AHEAD OF A POTENT COLD FRONT. RETURN
FLOW PUSHES PWATS UP TO 1.75 INCHES AND ALLOWS FOR ADVECTION OF THE
THETA-E RIDGE INTO THE EASTERN CAROLINAS. WHILE THIS HAPPENS...S/W
TROUGH SPAWNS A SURFACE LOW ACROSS THE OHIO VALLEY WHICH DRAGS A
COLD FRONT THROUGH THIS AREA WEDNESDAY AFTN. ATTM IT APPEARS THIS
COULD COINCIDE WITH PEAK HEATING...AND INSTABILITY PARAMETERS AS
WELL AS UPPER SUPPORT LOOK DECENT...SO CONFIDENCE IS INCREASING IN
TSTM DEVELOPMENT DURING THE AFTN. HOWEVER...SOUNDINGS NO LONGER SHOW
FULL AND DEEP SATURATION WHICH COULD SERVE AS A LIMITING FACTOR TO
RAINFALL...UNFORTUNATELY. NOTE AS WELL THAT THE GFS CONTINUES TO
SHOW AN AREA OF CONVECTION NEAR FLORIDA EARLY WED WHICH TRIES TO
WORK UP THE COAST. THIS COULD ENHANCE RAINFALL ALONG THE COAST...BUT
IN THIS SETUP FREQUENTLY ACTS TO SQUELCH RAINFALL SINCE IT CUTS OFF
THE DEEP MOIST FLOW. WE WILL HAVE TO WAIT AND SEE...BUT FOR NOW WILL
CARRY HIGH CHC POP FOR WEDNESDAY...WITH HIGHEST POP ACROSS THE
NORTH. STILL BELIEVE MEX NUMBERS ARE TOO HIGH WEDNESDAY...BUT HIGHS
A DEGREE OR TWO ABOVE 80 SEEM REASONABLE.
COOL HIGH PRESSURE BUILDS IN BEHIND THE FRONT EARLY THURSDAY...AND
THE END OF THE WEEK THROUGH SATURDAY WILL SEE TEMPS RETURN TO JUST
BELOW CLIMO WITH AMPLE SUNSHINE. EXPECT MAX TEMPS IN THE UPPER 70S
TO AROUND 80...WITH MINS AT NIGHT IN THE MID AND UPPER 50S.
&&
.AVIATION /00Z SATURDAY THROUGH THURSDAY/...
AS OF 00Z...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS HAVE FIRED IN
ADVANCE OF A COLD FRONT WITH AN MCS AFFECTING POINTS JUST NORTH OF
THE FORECAST AREA. MODEL GUIDANCE CONTINUES TO SHOW THAT SHOWERS
AND STORMS WILL CONTINUE TO EXPAND IN COVERAGE ACROSS OUR AREA FOR
THE NEXT HOUR OR TWO. HAVE INCLUDED TEMPO GROUPS AT ALL TAF SITES
FOR 3 TO 4 HOURS BEGINNING BETWEEN 00Z AND 02Z. THERE HAVE BEEN
FAIRLY GUSTY WINDS WITH STORMS TO THE NORTH AND WEST SO GUSTS UP TO
35 KT HAVE BEEN INCLUDED IN THE TAFS. AFTER THE STORMS END...MOIST
LOW-LEVELS AND WEAK CAA SHOULD SET THE STAGE FOR POST-FRONTAL
SCATTERED TO BROKEN IFR CEILINGS TO DEVELOP AND SPREAD SOUTH. THESE
CEILINGS SHOULD LIFT TO MVFR BY MID-LATE MORNING AND VFR AROUND
NOON. WINDS BY SUNDAY MORNING WILL BE NORTH TO NORTHEAST AT AROUND
10 KNOTS.
EXTENDED OUTLOOK...LOW CONFIDENCE EARLY MORNING FOG/IFR MONDAY AND
TUESDAY. CHANCE SHOWERS AND THUNDERSTORMS TUESDAY NIGHT INTO
WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM SATURDAY...HIGH PRESSURE CENTERED FROM FLORIDA ACROSS
THE NORTHERN BAHAMAS WILL BECOME SUPPRESSED TO THE SOUTH AS A COLD
FRONT SLIDES SOUTH ALONG THE CAROLINA COAST TONIGHT. OF IMMEDIATE
CONCERN WITH THIS FRONT IS THE POTENTIAL FOR STRONG TO SEVERE
THUNDERSTORMS TO DEVELOP IN THE NEXT 1-2 HOURS. LATEST SHORT-TERM
MODEL GUIDANCE SHOWS A BROKEN SQUALL LINE POSSIBLY DEVELOPING ACROSS
THE EASTERN CAROLINAS AND PUSHING OUT ACROSS THE WATERS BEFORE
MIDNIGHT. STRONG WINDS ALONG THE LEADING EDGE OF THE SQUALL LINE ARE
THE PRIMARY THREAT AND COULD RESULT IN SPECIAL MARINE WARNINGS LATER
THIS EVENING.
OTHERWISE...SYNOPTIC SOUTHWEST WINDS 10-15 KT HAVE INCREASED TO
15-18 KT NEAR THE BEACHES WITH THE SEABREEZE. THESE SYNOPTIC WINDS
WILL SHIFT TO THE W AND NW AFTER MIDNIGHT AS THE COLD FRONT SINKS
INTO THE AREA...THEN TO THE N SUNDAY MORNING. SEAS AVERAGE 3 FT WITH
SOME 2-FOOTERS NEAR THE SC COAST.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM SATURDAY...PRIMARY THREAT WILL BE TSTMS OFFSHORE
EARLY ON SUNDAY AND THE POTENTIAL FOR LOCALLY STRONG WINDS AND
CLOUD TO WATER LIGHTNING STRIKES ASSOCIATED WITH A SURFACE LOW
OFFSHORE. INCREASING NE WINDS WILL REQUIRE A CAUTIONARY HEADLINE
IN THE CWF MAINLY FOR SUNDAY AFTN...POSSIBLY INTO EVENING AS HIGH
PRESSURE BUILDS FROM THE NORTH. THE TREND IN WINDS IS TO WEAKEN
AND VEER MONDAY AND TUESDAY...BECOMING SSE MONDAY NIGHT AND SSW
BY TUESDAY AS HIGH PRESSURE MOVES OFFSHORE...AND A WEAK COLD FRONT
APPROACHES FROM THE NORTH. S-SE WAVE ENERGY WILL BECOME ENE SUNDAY
IN A BUMPY 3-5 FEET OVER THE 0-20NM WATERS...HIGHEST SEAS NORTH OF
FRYING PAN SHOALS AND WELL OFFSHORE. THE GULF STREAM WILL BE A BIT
HAZARDOUS SUNDAY AS NE WINDS CLASH WITH THE ROBUST CURRENTS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 230 PM SATURDAY...HIGH PRESSURE OFFSHORE DRIFTS FURTHER FROM
THE COAST THROUGH WEDNESDAY AHEAD OF AN ADVANCING COLD FRONT. THIS
CREATES A TIGHTENING PRESSURE GRADIENT...AND WINDS VEERING SLOWLY
FROM SE TUESDAY...TO SW WEDNESDAY...AT 10-15 KTS. SEVERAL DIFFERENT
WAVES WILL BE EVIDENT WITHIN THE SPECTRUM DURING THIS TIME...A SE
SWELL OF 2FT/10 SEC...AND A SE WIND WAVE...BECOMING SW WEDNESDAY.
FORTUNATELY...THESE WILL ALL BE AT RATHER LOW AMPLITUDES...SO TOTAL
SEAS WILL BE ONLY IN THE 2-4 FT RANGE. LATE WED NIGHT COLD FRONT
OCCURS ACROSS THE WATERS TURNING WINDS TO THE NORTH...THEN NE BY
THURSDAY EVE. THERE WILL BE A PERIOD OF ENHANCED NORTH WINDS BEHIND
THE FRONT...UP TO 15-20 KTS...BEFORE EASING LATE TO 5-10 KTS.
ALTHOUGH WAVE HEIGHTS WILL REMAIN AROUND 2-4 FT THROUGH
THURSDAY...WAVE STEEPNESS WILL INCREASE BEHIND FROPA FOR SEVERAL
HOURS AS N/NE WIND WAVES BECOME PREDOMINANT WITHIN THE WAVE
SPECTRUM.
&&
.TIDES/COASTAL FLOODING...
AS OF 230 PM SATURDAY...A FULL MOON TONIGHT WILL BRING UNUSUALLY
HIGH WATER LEVELS FOR THE NEXT FEW DAYS DURING THE EVENING HIGH
TIDE...THE HIGHEST OF THE TWO HIGH TIDES. TONIGHT...MINOR FLOODING
SHOULD BE CONFINED TO PORTIONS OF THE CAPE FEAR RIVER IN DOWNTOWN
WILMINGTON WHERE WATER LEVELS ARE EXPECTED TO REACH JUST OVER 5.5
FT DURING THE EVE. THIS WILL BE ENOUGH TO ISSUE A COASTAL FLOOD
ADVISORY FOR A PORTION OF NEW HANOVER COUNTY. NORTHEAST WINDS MAY
DRIVE TIDES EVEN HIGHER SUN NIGHT...AND ACROSS A BROADER AREA TO
INCLUDE THE BEACHES. HIGH TIDE THIS EVENING IS AROUND 8 PM AT THE
COAST AND 10 PM ALONG THE CAPE FEAR IN DOWNTOWN WILMINGTON. HIGH
TIDE SUNDAY NIGHT IS AROUND 830 PM ALONG THE BEACHES. THERE IS
ABOUT A TWO HOUR LAG TIME IN DOWNTOWN WILMINGTON.
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT
EDT TONIGHT FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...8
NEAR TERM...TRA
SHORT TERM...COLBY
LONG TERM...JDW
AVIATION...RAN
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
512 PM EDT FRI MAY 4 2012
.SYNOPSIS...
WEAK UPPER LEVEL DISTURBANCES WILL AFFECT THE AREA LATE THIS
AFTERNOON AND EVENING AND AGAIN SATURDAY AFTERNOON AND EVENING.
A BACKDOOR COLD FRONT WILL SINK SOUTH ACROSS THE AREA SATURDAY
NIGHT AND SUNDAY MORNING. A COLD FRONT WILL CROSS THE AREA FROM
THE WEST ON WEDNESDAY. COOL HIGH PRESSURE WILL FOLLOW FOR LATE
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 430 PM FRIDAY...THE LATEST SEVERAL HRRR RUNS SHOW ISOLATED TO
SCATTERED SHOWERS/T-STORMS WILL DEVELOP OVER THE EASTERN PIEDMONT IN
THE NEXT HOUR...ADVECTING SOUTHEAST TOWARD THE COAST BY SUNSET.
RADAR COMPOSITES SHOW SOME MODEST MID-LEVEL ECHOES ACROSS CENTRAL
NORTH AND SOUTH CAROLINA. AS THE CONVECTIVE CAP WEAKENS THROUGH NOW
AND 23Z/6PM THIS ACTIVITY COULD FURTHER DEVELOP TO VERIFY THE HRRR`S
PREDICTION. COVERAGE SHOULD AMOUNT TO NO MORE THAN 1/4 OF THE
AREA...SO WE WILL MAINTAIN THE CURRENTLY 20 POPS THROUGH THE EVENING
HOURS. NO SIGNIFICANT CHANGES HAVE BEEN MADE TO OTHER WEATHER
ELEMENTS. PREVIOUS DISCUSSION FROM 130 PM FOLLOWS...
PLENTY OF HIGH LEVEL CLOUDINESS EXPECTED TO PASS ACROSS THE REGION
THROUGH THE EVENING...WITH SOME DIURNAL CU IN AN AREA CURRENTLY
DEFINED BY LIMITED LOW-LEVEL MOISTURE. THE HIGH CLOUDS HAVE HAD AN
IMPACT ON TEMPERATURES...BUT AREAS RECEIVING BREAKS HAVE CREPT INTO
THE MID 80S EARLY THIS AFTERNOON. A WEAK IMPULSE WILL PASS OFF THE
COAST THIS EVENING...AND ANOTHER WILL APPROACH FROM THE NW LATE
TONIGHT. PROSPECTS FOR CONVECTION DO NOT APPEAR TO BE THAT PROMISING
WITH ONLY WIDELY SCATTERED CONVECTION POSSIBLE. BETTER CHANCES FOR
SHOWERS WILL FOLLOW IN THE SHORT TERM PERIOD. LOWS TONIGHT WILL
RANGE FROM THE MID 60S INLAND TO THE UPPER 60S ALONG THE COAST
(NORMAL LOWS ARE MID TO UPPER 50S).
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A MID-LEVEL SHORTWAVE ACROSS THE OHIO VALLEY...
EMBEDDED WITHIN NORTHWEST FLOW ALOFT...WILL MOVE ACROSS THE AREA
SAT AFTERNOON/EVE AS A BACKDOOR COLD FRONT NEARS THE AREA FROM THE
NORTH. AIRMASS WILL BE UNSTABLE WITH MIXED LAYER CAPE VALUES AROUND
2000 J/GK. MODEL SOUNDINGS SUPPORTIVE OF STRONG WINDS GUSTS AT THE
SURFACE GIVEN INVERTED-V PROFILES. HOWEVER...MID-LEVEL LAPSE RATES
ARE NOT PARTICULARLY CONDUCIVE FOR DEEP CONVECTION AND THIS SHOULD
SERVE TO LIMIT SEVERE WEATHER POTENTIAL. WILL BRING POPS UP TO GOOD
CHANCE...THUS KEEPING A SCATTERED COVERAGE. IF MODEL TRENDS
CONTINUE...COVERAGE MAY GET BUMPED UP TO NUMEROUS. COLD FRONT SHOULD
REACH THE NORTHERN ZONES DURING THE EVE AND THEN MOVE ACROSS THE
REMAINDER OF THE FORECAST AREA OVERNIGHT...SHIFTING WINDS TO THE NE.
AIRMASS SHOULD DRY OUT SUFFICIENTLY DURING SUN...ESPECIALLY BY
AFTERNOON. POPS WILL BE HELD TO SLIGHT CHANCE WITH SOUTHERNMOST
ZONES MORE INCLINED THAN NORTHERN AREAS FOR AN ISOLATED SHOWER.
HIGHS ON SAT WILL BE CONSIDERABLY ABOVE CLIMATOLOGY WITH MANY AREAS
AWAY FROM THE COAST GETTING TO NEAR 90. INLAND PROGRESSION OF
SEABREEZE...WHILE NOT PINNED TO THE COAST...SHOULD BE LIMITED
GIVEN SOUTHWEST FLOW. THIS WILL KEEP THE BEACH COMMUNITIES AND
NEARBY ENVIRONS...ESPECIALLY ACROSS BRUNSWICK AND SOUTHERN NEW
HANOVER COUNTIES...IN THE LOWER TO MID 80S. SUN WILL BE
CONSIDERABLY COOLER WITH NE WINDS SHAVING 5 TO 10 DEGREES OFF.
HIGHS WILL BE IN THE LOWER TO MID 80S WITH PERHAPS A FEW UPPER 70S
ACROSS THE CAPE FEAR REGION. COOLEST NIGHTTIME LOWS WILL OCCUR SUN
NIGHT...AROUND 60 TO NEAR 65.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...HIGH PRESSURE DRIFTS OFFSHORE DURING MONDAY
BRINGING RETURN FLOW BACK INTO THE CAROLINAS. MID LEVEL RIDGE LAGS
BEHIND HOWEVER...SO E/NE FLOW CONTINUES THROUGH THE MID PORTIONS
OF THE COLUMN ACTS AS A LIMITING FACTOR TO TEMPS...SO EXPECT A
NEAR CLIMO DAY.
SOUTHERLY FLOW PERSISTS TUESDAY...INCREASING COLUMN MOISTURE...AND
SETTING THE STAGE FOR A POTENTIALLY SIGNIFICANT QPF EVENT LATE
TUESDAY AND WEDNESDAY. DEEP SOUTHERLY FLOW HELPS RAISE PWATS TO
NEARLY 2 INCHES...OR 2 STANDARD DEVIATIONS ABOVE NORMAL. AT THE SAME
TIME...A VORT MAX EJECTS OUT OF THE MS VLY AND MOVES
OVERHEAD...WHILE A STRONGER NORTHERN STREAM S/W DRIVES A COLD FRONT
TOWARDS THE CAROLINAS...ALL OF THIS OCCURRING IN AN AIR MASS RICH IN
THETA-E. MOISTURE TRANSPORT VECTORS PEAK ACROSS THE EASTERN
CAROLINAS VERY EARLY WEDNESDAY...COINCIDENT WITH APPROACH OF UPPER
JET AND DEVELOPING SURFACE LOW NEAR OUR AREA...WHICH SUGGESTS AT
LEAST A PERIOD OF MDT/HVY CONVECTIVE RAIN. ATTM THE ECMWF IS SLOWER
AND STRONGER WITH THESE FEATURES...AND IS THE OUTLIER...BUT EVEN THE
GFS HAS AN EXTENDED PERIOD OF RAIN/TSTMS BEGINNING LATE TUESDAY AND
PERSISTING UNTIL FROPA LATE WED MORNING. CURRENT HPC QPF PROGS
SUGGEST A WIDESPREAD 1" RAINFALL EVENT...BUT IN PERSISTENT DROUGHT
HAVE DIFFICULTY BUYING SUCH A HIGH AMOUNT. WILL INCREASE POP TO HIGH
CHANCE WITH ENHANCED QPF...AND HOPE IT COMES TO FRUITION DUE TO
ONGOING RAINFALL DEFICITS. WILL UNDERCUT MEX NUMBERS DUE TO CLOUDS
AND RAIN...WITH HIGHS IN THE UPPER 70S TO LOW 80S.
COOL HIGH PRESSURE BUILDS IN BEHIND THE FRONT FOR THE END OF THE
WEEK WITH MAX AND MIN TEMPS BOTH SLIGHTLY BELOW CLIMO.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...VFR IS EXPECTED THROUGH THIS AFTERNOON. WINDS WILL BE
SOUTHWEST TO WEST AT FLO/LBT AND SSW 10-15 KT AT THE COASTAL
TERMINALS THIS AFTERNOON.
EXPECT MID TO UPPER LEVEL BKN/OVC CONVECTIVE DEBRIS CLOUDS FROM TSTM
ACTIVITY IN THE WESTERN CAROLINAS LATE THIS AFTERNOON THROUGH
TONIGHT. LOW CONFIDENCE BUT WILL INCLUDE VCTS FOR THE INLAND
TERMINALS ROUGHLY FROM 01Z-05Z DUE TO INCREASED VORTICITY/UVVS
ASSOCIATED WITH A DAMPENING UPPER S/W TROF PROGRESSING THRU THE
UPPER RIDGE. SUB-VFR CONDITIONS WILL BE POSSIBLE AT THE INLAND
TERMINALS SHOULD ANY OF THIS ACTIVITY ACTUALLY MOVE OVERHEAD. THIS
ACTIVITY SHOULD WEAKEN AS IT SPREADS TO THE COAST LATE EVENING/EARLY
MORNING.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND THUNDERSTORMS
SATURDAY...AND AT THE SOUTHERN TERMINALS SUNDAY. LOW CONFIDENCE
EARLY MORNING FOG/IFR MONDAY AND TUESDAY. CHANCE SHOWERS AND
THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 430 PM FRIDAY...A MODERATE SEABREEZE CIRCULATION IS ONGOING
ACROSS THE NEARSHORE WATERS CURRENTLY...WITH WINDS BACKED AROUND TO
THE SOUTH-SOUTHWEST AT AROUND 15 KNOTS. FARTHER OFFSHORE A SOUTHWEST
WIND 10-15 KT CONTINUES. THE ONLY MAJOR CHANGE TO THE FORECAST IS TO
LOWER SEA HEIGHTS SUBSTANTIALLY FOR THIS EVENING WHERE AREA BUOYS
ARE SHOWING AVERAGE SEA HEIGHTS ONLY AROUND 2 FEET CURRENTLY.
PREVIOUS DISCUSSION FROM 130 PM FOLLOWS...
A WEAK RIDGE AXIS LOCATED ACROSS THE OFFSHORE WATERS RESULTING FROM
THE DEVELOPMENT OF A WEAK LEE TROUGH TO THE WEST IS KEEPING W TO SW
FLOW ACROSS THE COASTAL WATERS. A RESULTANT SEA BREEZE WILL ALLOW
SOME BACKING OF THE FLOW AND INCREASE IN SPEEDS THAT WILL PERSIST
INTO THE EVENING. SEAS REMAIN 2 FT ACROSS MOST OF THE COASTAL WATERS
BUT WILL INCREASE ONCE THE SOUTHWESTERLY FLOW INCREASES THIS
AFTERNOON. CHOPPY CONDITIONS TONIGHT WILL IMPROVE OVERNIGHT AS
SPEEDS DIMINISH SOME AND BEGIN TO VEER BACK TO A WESTERLY DIRECTION.
COULD SEE SOME CONVECTION OVERNIGHT...BUT MOST OF THE ACTIVITY
SHOULD OCCUR OVER THE OFFSHORE WATERS WHERE THE INSTABILITY WILL BE
GREATEST.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...WILL INITIALIZE WITH SW WINDS SAT. WINDS WILL
SHIFT TO THE N AND THEN NE WITH THE PASSAGE OF A BACKDOOR COLD FRONT
SAT NIGHT...LASTLY ACROSS THE SOUTHERN WATERS. WINDS WILL THEN
REMAIN FROM THE NE THROUGH THE REMAINDER OF THE WEEKEND. STRONGEST
WINDS THIS PERIOD WILL BE DURING A NE SURGE SUN AFTERNOON AND EVE.
WINDS MAY REACH SMALL CRAFT ADVISORY LEVELS IN GUSTS DURING THIS
TIME. HIGHEST SEAS WILL OCCUR SUN NIGHT...BUILDING FROM 3 TO 4 FT
SAT TO AS HIGH AS 4 TO 6 FT LATE SUN AND SUN NIGHT. A MARGINAL SMALL
CRAFT ADVISORY MAY BE REQUIRED LATE IN THE WEEKEND.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...MODERATE NE WINDS START THE PERIOD AS HIGH
PRESSURE RIDGES DOWN THE EAST COAST. THESE WINDS...OF 10-15
KTS...WILL GRADUALLY VEER TO THE EAST...THEN SOUTH THROUGH THE
NIGHT AS HIGH DRIFTS OFFSHORE AND ALLOWS RETURN FLOW TO DEVELOP
ACROSS THE WATERS. BY TUESDAY...S/SE WINDS BEGIN TO INCREASE AS
PRESSURE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD
FRONT...BECOMING 10-20 KTS LATE TUESDAY NIGHT AND EARLY
WEDNESDAY...BEFORE EASING AND VEERING TO THE NW LATE WEDNESDAY
BEHIND COLD FRONT. THE SEA SPECTRUM WILL BE DOMINATED BY WIND
WAVES THROUGH THE PERIOD...NE WIND WAVES OF 4-5 FT MONDAY DROP TO
3-4 FT TUE/WED WITH A PREDOMINANT SOUTHERLY WIND WAVE. LATE
WEDNESDAY NIGHT A PERIOD OF CONFUSED SEAS WILL OCCUR BEFORE NW
WIND WAVES DEVELOP BEHIND THE FRONT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...JDW
AVIATION...MRR/SRP
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
314 PM CDT FRI MAY 4 2012
.SHORT TERM...
MAIN CHALLENGE WILL BE TRYING TO NARROW DOWN PCPN CHANCES OVER THE
NEXT THREE DAYS. MODELS NOT VERY CLOSE IN AGREEMENT SO WILL TRY
NOT TO STRAY TOO FAR FROM CONTINUITY FOR NOW.
TONIGHT...FA HAS REMAINED PRETTY CLOUDY AND COOL TODAY WITH STEADY
EAST WINDS. THESE DRIER EAST/NE WINDS HAVE REALLY PUT THE DAMPER
ON PCPN TODAY. THERE REALLY HAS NOT BEEN MUCH PCPN AT ALL ACROSS
THE FA THIS AFTERNOON. WHAT THERE IS HAS TAPERED OFF TO SPRINKLES
NOW. THE CLOUDS SHOULD CONTINUE TO HOLD OVER THE AREA TONIGHT AND
THESE CLOUDS WILL HELP TO HOLD UP TEMPS. SOME GUIDANCE PRODUCTS
ARE INDICATING THE POTENTIAL FOR SOME FOG TONIGHT. BETTER CHANCES
FOR FOG MAY BE ALONG AND WEST OF THE VALLEY FURTHER AWAY FROM THE
DRIER EASTERLY FLOW. WILL START OUT WITH FOG MENTIONED ACROSS THE
KDVL REGION AND LET LATER SHIFTS TAKE ANOTHER LOOK AT IT. AS FAR
AS PCPN CHANCES GO IT SEEMS THAT RIGHT NOW THE MAIN ACTION HAS
BEEN ACROSS SOUTHERN SD INTO SOUTHERN MN. REALLY NO LOW LEVEL JET
TO SPEAK OF TONIGHT BUT THE UPPER JET REMAINS OVER THE AREA WITH
SOME 850MB WARM ADVECTION. NOT REALLY INTENSE PARAMETERS BUT
ENOUGH TO KEEP SOME LOW CHANCES FOR PCPN OVER THE FA AND SLIGHTLY
BETTER ACROSS THE SOUTH.
SAT-MON...MOST OF SAT LOOKS DRY TOO. IF IT STAYS CLOUDY IT WILL
PROBABLY STAY COOL LIKE IT DID TODAY SO ENDED UP CUTTING BACK A
LITTLE ON TEMPS. IF THE AREA GETS MORE SUN THESE TEMPS WILL
PROBABLY BE A LITTLE TOO COOL. MODELS CONTINUE TO SHOW SAT NIGHT
BEING THE BEST CHANCE FOR MORE PCPN ACROSS THE AREA. BEST
INSTABILITY REMAINS SOUTH OF THE FA SO HIGHER PCPN AMOUNTS SHOULD
STAY SOUTH OF THE FA TOO. COULD BE ANOTHER EVENT LIKE TODAY WHERE
THERE IS MORE PCPN ACROSS THE SOUTH THAN THE NORTH...AND AMOUNTS
END UP BEING MUCH LESS THAN EXPECTED. EITHER WAY MODEL AGREEMENT
NOT THE BEST WITH THIS EVENT BUT THEY HAVE BEEN TRENDING SOUTH
WITH THE HEAVIEST PCPN OR ACROSS EASTERN SD INTO SOUTHERN MN. DRY
SLOT SHOULD START TO WORK INTO THE AREA ON SUN AND SUN NIGHT.
AGAIN MODELS ALL OVER THE PLACE IN REGARD TO PCPN PLACEMENT SO IT
COULD BE COMPLETELY DRY OR THERE COULD BE SOME LINGERING LIGHT
PCPN. BY MON THERE MAY BE SOME COLD POOL AFTERNOON SHOWERS WITH
BEST CHANCES ACROSS THE NORTH.
.LONG TERM (MON NIGHT THRU FRI)...
LARGE UPPER SYSTEM WILL BE MOVING ACROSS SOUTH CENTRAL CANADA AT THE
START OF THE EXTENDED PERIOD. CWFA WILL BE UNDER DEEP LAYERED
CYCLONIC FLOW AT THE START OF THE EXTENDED PERIOD WITH TEMPERATURES
JUST A BIT BELOW NORMAL. WITH THE CYCLONIC FLOW AND COLDER AIR ALOFT
COULD SEE SOME -SHRA. MODELS HAVE BEEN FLIP/FLAPPING ABOUT UPPER LOW
EARLY IN PERIOD IN REGARDS TO IT DROPPING SOUTH INTO MINNESOTA
TUESDAY. ECMWF HAS BEEN SLOWER AND DEEPER PAST 2 RUNS AND ABOUT 12
HOURS SLOWER THAN GFS/GEM/DGEX. AS LATEST RUNS IN GENERAL
AGREEMENT FEEL ALLBLENDS WILL HAVE A DECENT HANDLE INTO TUESDAY.
COULD BE PRETTY WINDY AT THE START OF THIS PERIOD WITH GOOD
DIRECTION HOOK-UP AND TIGHT GRADIENT INTO TUESDAY MORNING...
ESPECIALLY IF SLOWER ECMWF VERIFIES BETTER.
SURFACE HIGH BUILDS IN OVER THE AREA WEDNESDAY MORNING SO IT COULD
BE THE COOLEST OF THIS PERIOD...WITH LOWS WEDNESDAY MORNING IN THE
30S. AS HIGH DEPARTS UPPER RIDGE BUILDS AHEAD OF NEXT WAVE CRASHING
THE COAST. WITH PATTERN FLATTENING OUT THE SYSTEM APPEARS A BIT MORE
PROGRESSIVE THAN ONE EARLY THIS PERIOD. MODELS SUGGEST SUFFICIENT
RETURN FLOW DEVELOPS RESULTING IN WEAK INSTABILITY. 700 WAA AND LOW
LEVEL MOISTURE RETURN SHOULD BE SUFFICIENT TO GENERATE SOME TSRA
LATER ON THURSDAY. SOME LIGHT SHRA ANTICIPATED WITH FRONTAL PASSAGE
EARLY FRIDAY.
&&
.AVIATION...
EXPECT VFR THROUGH 03Z-06Z...THEN MVFR OR LOCAL IFR CIG POSSIBLE
AS BOUNDARY LAYER FORECAST TO SATURATE. HRRR DID A GOOD JOB OF
PREDICTING BREAKUP OF THIS MORNINGS IFR CIGS REDEVELOPS AREAS OF
MVFR/IFR CIGS AFT 05Z. RASH IN THE DVL AREA EXPECTED TO CONTINUE
THROUGH 00Z. RASH MOVG INTO FAR AND GFK AREAS AFT 01Z AND BJI /
TVF AFTER 06Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
GODON/EWENS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
755 PM EDT SAT MAY 5 2012
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL DECREASE THIS AFTERNOON AND EVENING
AS AN UPPER LEVEL DISTURBANCE DEPARTS. DRIER AIR WILL MOVE IN
TONIGHT THROUGH SUNDAY. A COLD FRONT APPROACHES MONDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
730 PM UPDATE...FORECAST GENERALLY IN GOOD SHAPE. DID EXTEND SLIGHT/LOW
CHANCE POPS JUST A COUPLE OF HOURS THROUGH ABOUT 03Z WITH THE HRRR AS
CONVECTION HAS BEEN STUBBORNLY HANGING ON ALONG SURFACE CONVERGENCE
BOUNDARY NEAR THE OHIO RIVER. SHOWERS AND SOME THUNDER SHOULD
DISSIPATE FAIRLY QUICKLY BY 03Z WITH THE LOSS OF DAYTIME HEATING.
PREVIOUS DISCUSSION...THE SHORTWAVE TROUGH CROSSING THE AREA HAS BEEN
BRINGING RATHER WET WEATHER TODAY. SHOWERS CONTINUE BRINGING HEAVY
RAIN AT TIMES WITH PERSISTENTLY LOW CLOUDS...BOTH OF WHICH SHOULD
IMPROVE THROUGH THE REMAINDER OF AFTERNOON AND EVENING. IN AREAS
TO THE NORTH WHERE BREAKS IN THE CLOUDS HAVE FORMED THEY HAVE BEEN
QUICKLY FILLED WITH NEW SHOWERS OR THUNDERSTORMS. THE UPPER TROUGH
WILL EXIT THE AREA TO THE EAST IN LATER THIS AFTERNOON. SOME
PARTIAL CLEARING WILL SPREAD FROM WEST TO EAST BUT AS LONG AS
SOLAR HEATING IS TRIGGERING NEW CONVECTION ANY SUNBREAKS WILL BE
RATHER SMALL AND BRIEF. AFTER SUNSET...CLEARING WILL OCCUR MUCH
MORE RAPIDLY MAKING FOG AND LOW STRATUS VERY LIKELY TONIGHT.
SUNDAY LOOKS LIKE A QUIETER DAY WITH PARTLY TO MOSTLY SUNNY
CONDITIONS FOLLOWING A SOMEWHAT SLOW CLEARING OF MORNING FOG AND LOW
CLOUDS. ISOLATED AFTERNOON THUNDERSTORMS ARE POSSIBLE BUT SHOULD
REMAIN CONFINED TO THE EASTERN MOUNTAINS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MAIN FEATURE IN SHORT TERM IS A SLOW MOVING COLD FRONT SLATED TO
ENTER SE OH ZONES EARLY TUESDAY MORNING...AND BRIEFLY STALL BEFORE
S/W TROF MOVES THROUGH KICKING IT THRU WV. MODELS SHOWING A LOT OF
DRY AIR IN BL ON MONDAY IN WARM SECTOR. THUS HAVE NIXED MUCH OF POPS
DURING THE DAY ON MONDAY...SAVE FOR SOME LOW CHC ACROSS THE
MOUNTAINS FOR SOME OROGRAPHIC ENHANCED LIFT ON S TO SE FLOW. HAVE
INCREASED SKY COVER CONSIDERABLY ACROSS EASTERN SLOPES SUNDAY NIGHT
INTO MONDAY WITH WEDGE TYPE EVENT ACROSS VA PIEDMONT ON E TO SE
FLOW. HAVE ALSO DECREASED SKY COVER MOST PLACES WEST OF MTNS WITH
THE DELAY IN MOISTURE ON MONDAY. WILL WATCH FOR POTENTIAL PREFRONTAL
BAND OF CONVECTION TO RACE OUT AHEAD OF FRONTAL BOUNDARY MONDAY
EVENING AND NIGHT...PROBABLY WEAKENING ONCE INTO WV. HAVE SOME
LKLY/CAT POPS WITH THIS ACROSS SE OH OH BEFORE DECREASING TO LKLY
ACROSS MTNS. ALSO CARRIED LKLY POPS ALONG AND JUST AHEAD OF FROPA.
SOME DRIER AIR MAY FILTER IN ACROSS SE OH LATE. WITH BOUNDARY TRYING
TO STALL IN EASTERN OH FOR A TIME MONDAY NIGHT INTO EARLY
TUESDAY...WILL HAVE TO WATCH FOR WATER PROBLEMS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS ARE COMING INTO BETTER AGREEMENT ON THE MAIN WEATHER SYSTEM
AFFECTING US EARLY IN THIS PERIOD. MODELS HAVE TRENDED FASTER WITH
THE COLD FRONT...WHICH ACTUALLY CROSSES OUR AREA TUESDAY NIGHT.
SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM MAY ACCOMPANY THE FRONT
ITSELF.
BEHIND THE FRONT...COOLER...MOIST...UNSTABLE AIR UNDER NORTHWEST
FLOW WILL BRING SCATTERED SHOWERS LATER TUESDAY NIGHT AND
WEDNESDAY...ESPECIALLY IN THE MOUNTAINS WITH THE AID OF UPSLOPE.
EXPECT TEMPERATURES TO RETURN TO NEAR NORMAL LEVELS...WHICH MAY FEEL
CHILLY COMPARED TO OUR RECENT WARM SPELL.
CANADIAN HIGH PRESSURE THEN ESTABLISHES CONTROL FOR THURSDAY INTO
THE EARLY WEEKEND WITH DRY AND NEAR SEASONABLE TEMPERATURES.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
CLOUDS HAVE GENERALLY BEGUN TO SCATTER ACROSS THE AREA WITH VFR
CONDITIONS. A FEW SHOWERS/THUNDERSTORMS CURRENTLY TO THE NORTH OF
PKB MIGHT IMPACT THIS TERMINAL IN THE NEXT HOUR OR SO...BUT MOVEMENT
IS VERY SLOW AT THIS POINT. LIFR/VLIFR CONDITIONS WITH FOG AND/OR
LOW STRATUS ARE EXPECTED TO FORM BY 09Z WITH ABUNDANT LOW LEVEL
MOISTURE IN PLACE. CONDITIONS ARE EXPECTED TO IMPROVE BY 14Z-15Z
SUN...WITH VFR CONDITIONS PREVAILING AFTER.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: TIMING OF OVERNIGHT FOG/LOW STRATUS FORMATION
AND MORNING DISSIPATION MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 05/06/12
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY M M M M M M L H M L L L
HTS CONSISTENCY M M M M M M M M M L L L
BKW CONSISTENCY L L L L L L L H H H H M
EKN CONSISTENCY L L M M M M L H H M M L
PKB CONSISTENCY M M M M M M L L L L L L
CKB CONSISTENCY M M M M M M M M L L L L
AFTER 00Z MONDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY NIGHT
INTO TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/JMV/JR
NEAR TERM...50/JR
SHORT TERM...30
LONG TERM...JMV
AVIATION...50
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
456 PM CDT FRI MAY 4 2012
.DISCUSSION...
SEE AVIATION DISCUSSION BELOW
&&
.AVIATION...
A SEVERE THUNDERSTORM WATCH IS IN AFFECT FOR THE ENTIRE AREA UNTIL
11PM CDT. A SHORT WAVE TROUGH CENTERED IN CENTRAL OKLAHOMA WITH AN
AXIS EXTENDING SOUTH SOUTHWEST THROUGH CROCKETT COUNTY IS MOVING
EAST SLOWLY. A LINE OF SHOWERS AND THUNDERSTORMS APPROXIMATELY
FIFTY TO SIXTY MILES WIDE IS CURRENTLY NORTH OF BLACKWELL TX
EXTENDS NORTHEAST TO NEAR ALBANY AND FORT GRIFFIN TX AND ABILENE...
IS ASSOCIATED WITH A WEAK DRY LINE. SOME STORMS ARE SEVERE OR WILL
BECOME SEVERE WITH GUSTY WINDS...HEAVY RAIN AND POSSIBLE HAIL.
ADDITIONAL SHOWERS ARE EXPECTED TO DEVELOP ALONG THIS LINE FARTHER
SOUTH THIS EVENING AS THE ENTIRE LINE ADVANCES EAST THROUGH THE
AREA THE NEXT 6 HOURS. NEAR THIS DEVELOPING LINE OF SHOWERS
AND THUNDERSTORMS EXPECT IFR CONDITIONS...LOCALLY HEAVY RAIN IN
THUNDERSTORMS...AND LOCALLY GUSTY SURFACE WINDS THAT MAY CAUSE
LOCAL AND BRIEF WINDY CONDITIONS AND CROSS WIND LANDING AND
TAKEOFF CONDITIONS THE NEXT 3 TO 6 HOURS. ELSEWHERE AWAY FROM THIS
SHOWER LINE MOSTLY VFR CONDITIONS WILL PREVAIL.MOSTLY VRF
CONDITIONS ARE EXPECTED TO PREVAIL ACROSS MOST OF THE AREA BY LATE
NIGHT AND INTO EARLY SATURDAY MORNING. VERY LOCALIZED PATCHY
GROUND FOG IS POSSIBLE BY EARLY MORNING IN THE VICINITY OF EVENING
RAIN AREAS.
&&
.PREV DISCUSSION... /ISSUED 354 PM CDT FRI MAY 4 2012/
SHORT TERM..
LATEST RUC SHOWING INITIATION OF CONVECTIVE ACTIVITY ASSOCIATED WITH
AN UPPER SHORT WAVE JUST WEST OF CROCKETT COUNTRY CONCOMITANT WITH
THE POSITION OF THE DRYLINE...WHERE LATEST RADAR LOOP IS ALSO
SHOWING SOME DEVELOPMENT. RUC ALSO SHOWING A DAMPENING OF THIS
FEATURE OVER THE NEXT SEVERAL HOURS. MORE PROMISING FOR LATER THIS
AFTERNOON INTO EARLY EVENING IS A DEEPENING UPPER SHORTWAVE IN THE
VICINITY OF A TIGHTENING DRYLINE OVER THE EASTERN BIG COUNTRY SOUTH
INTO THE HEARTLAND... WHERE THE BEST CHANCE OF CONVECTION WOULD
RESIDE. DRYLINE WILL RETREAT THROUGH THE LATE EVENING HOURS WITH
RAINFALL ENDING OVER THE CWA AFTER MIDNIGHT.
LOOKING FOR A WARMER DAY TOMORROW WITH 100 PLUS TEMPS OVER THE BIG
COUNTRY AND THE WESTERN CONCHO VALLEY. UPPER RIDGING OVER THE
FORECAST AREA TOMORROW WILL BE UNDERCUT BY A SHORTWAVE MOVING OVER
THE SOUTHERN CWA BY LATE TOMORROW AFTERNOON...WITH THE BEST CHANCE
OF CONVECTIVE ACTIVITY...PER THE LATEST NAM...OVER OUR SOUTHEASTERN
COUNTIES.
LONG TERM...
LOW CONFIDENCE FORECAST FOR MUCH OF THE EXTENDED PERIOD. DRYLINE
WILL RETREAT WESTWARD SATURDAY EVENING WITH A FEW STORMS POSSIBLE
DURING THE EVENING HOURS. ONE LAST DAY OF TEMPERATURES IN THE 90S
ON SUNDAY...AS COOLER TEMPERATURES ARE ON THE WAY FOR NEXT WEEK
WITH HIGHS MAINLY IN THE 80S MONDAY THROUGH FRIDAY. CONSIDERABLE
MODEL DIFFERENCES EXIST WITH THE SOUTHWARD PROGRESSION OF THE COLD
FRONT SUNDAY NIGHT INTO MONDAY. THE NAM IS THE FASTEST MODEL AND
BRINGS THE FRONT INTO THE NORTHERN BIG COUNTRY LATE SUNDAY AFTERNOON
WHILE THE GFS IS ABOUT 12 HOURS SLOWER. DECIDED TO SPLIT THE
DIFFERENCE BETWEEN THE TWO BUT LEAN A BIT MORE IN FAVOR WITH THE
NAM AND BRING THE FRONT ACROSS THE AREA DURING THE OVERNIGHT
HOURS. KEPT SLIGHT POPS GOING SUNDAY NIGHT AND AGAIN ON MONDAY
WITH THE PASSAGE OF THE FRONT.
THE FRONT IS EXPECTED TO STALL JUST SOUTH OF THE AREA THROUGH MID
WEEK BEFORE WASHING OUT. MEDIUM RANGE MODELS CONTINUE TO SHOW A
CLOSED UPPER LOW DEVELOPING OVER THE DESERT SOUTHWEST/BAHA REGION
EARLY NEXT WEEK...THEN TRACKING EAST TOWARDS WEST TEXAS BY MID
WEEK. GFS REMAINS VERY WET WITH THIS SCENARIO BUT CONFIDENCE
CONTINUES TO BE LOW CONCERNING PRECIPITATION CHANCES NEXT WEEK.
THE FORECAST WILL CONTINUE TO ADVERTISE SLIGHT PRECIPITATION CHANCES
FOR MUCH OF NEXT WEEK...PENDING HIGHER CONFIDENCE IN THE MODELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 97 72 100 71 93 / 20 20 10 10 10
SAN ANGELO 100 70 100 70 94 / 20 20 10 20 10
JUNCTION 95 71 97 70 93 / 10 20 10 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/99
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
354 PM CDT FRI MAY 4 2012
.SHORT TERM..
LATEST RUC SHOWING INITIATION OF CONVECTIVE ACTIVITY ASSOCIATED WITH
AN UPPER SHORT WAVE JUST WEST OF CROCKETT COUNTRY CONCOMITANT WITH
THE POSITION OF THE DRYLINE...WHERE LATEST RADAR LOOP IS ALSO
SHOWING SOME DEVELOPMENT. RUC ALSO SHOWING A DAMPENING OF THIS
FEATURE OVER THE NEXT SEVERAL HOURS. MORE PROMISING FOR LATER THIS
AFTERNOON INTO EARLY EVENING IS A DEEPENING UPPER SHORTWAVE IN THE
VICINITY OF A TIGHTENING DRYLINE OVER THE EASTERN BIG COUNTRY SOUTH
INTO THE HEARTLAND... WHERE THE BEST CHANCE OF CONVECTION WOULD
RESIDE. DRYLINE WILL RETREAT THROUGH THE LATE EVENING HOURS WITH
RAINFALL ENDING OVER THE CWA AFTER MIDNIGHT.
LOOKING FOR A WARMER DAY TOMORROW WITH 100 PLUS TEMPS OVER THE BIG
COUNTRY AND THE WESTERN CONCHO VALLEY. UPPER RIDGING OVER THE
FORECAST AREA TOMORROW WILL BE UNDERCUT BY A SHORTWAVE MOVING OVER
THE SOUTHERN CWA BY LATE TOMORROW AFTERNOON...WITH THE BEST CHANCE
OF CONVECTIVE ACTIVITY...PER THE LATEST NAM...OVER OUR SOUTHEASTERN
COUNTIES.
&&
.LONG TERM...
LOW CONFIDENCE FORECAST FOR MUCH OF THE EXTENDED PERIOD. DRYLINE
WILL RETREAT WESTWARD SATURDAY EVENING WITH A FEW STORMS POSSIBLE
DURING THE EVENING HOURS. ONE LAST DAY OF TEMPERATURES IN THE 90S
ON SUNDAY...AS COOLER TEMPERATURES ARE ON THE WAY FOR NEXT WEEK
WITH HIGHS MAINLY IN THE 80S MONDAY THROUGH FRIDAY. CONSIDERABLE
MODEL DIFFERENCES EXIST WITH THE SOUTHWARD PROGRESSION OF THE COLD
FRONT SUNDAY NIGHT INTO MONDAY. THE NAM IS THE FASTEST MODEL AND
BRINGS THE FRONT INTO THE NORTHERN BIG COUNTRY LATE SUNDAY AFTERNOON
WHILE THE GFS IS ABOUT 12 HOURS SLOWER. DECIDED TO SPLIT THE
DIFFERENCE BETWEEN THE TWO BUT LEAN A BIT MORE IN FAVOR WITH THE
NAM AND BRING THE FRONT ACROSS THE AREA DURING THE OVERNIGHT
HOURS. KEPT SLIGHT POPS GOING SUNDAY NIGHT AND AGAIN ON MONDAY
WITH THE PASSAGE OF THE FRONT.
THE FRONT IS EXPECTED TO STALL JUST SOUTH OF THE AREA THROUGH MID
WEEK BEFORE WASHING OUT. MEDIUM RANGE MODELS CONTINUE TO SHOW A
CLOSED UPPER LOW DEVELOPING OVER THE DESERT SOUTHWEST/BAHA REGION
EARLY NEXT WEEK...THEN TRACKING EAST TOWARDS WEST TEXAS BY MID
WEEK. GFS REMAINS VERY WET WITH THIS SCENARIO BUT CONFIDENCE
CONTINUES TO BE LOW CONCERNING PRECIPITATION CHANCES NEXT WEEK.
THE FORECAST WILL CONTINUE TO ADVERTISE SLIGHT PRECIPITATION CHANCES
FOR MUCH OF NEXT WEEK...PENDING HIGHER CONFIDENCE IN THE MODELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 97 72 100 71 93 / 20 20 10 20 10
SAN ANGELO 100 70 100 70 94 / 20 20 10 20 10
JUNCTION 95 71 97 70 93 / 10 20 10 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
15/24
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1041 PM CDT SAT MAY 5 2012
.UPDATE...
MCV READY TO PUSH OUT OVER LAKE MICHIGAN WITH SHOWERS ALL BUT
GONE. 02Z SURFACE ANALYSIS HAD A 2MB ONE-HOURLY PRESSURE FALL OVER
EASTERN OUTAGAMIE COUNTY...THAT IS NOW DOWN TO 1MB AROUND PORT WASHINGTON
ON 03Z ANALYSIS.
ATTENTION TURNS TO DEVELOPING MCS ON APEX OF INVERTED SURFACE
TROUGH ON THE SOUTH DAKOTA/MINNESOTA BORDER ON NOSE OF 40-50 KT
LOW-LEVEL JET. HRRR KEEPS BULK OF MCS TO THE WEST...WITH SOME WARM
ADVECTIN WING PRECIPITATION DEVELOPING OVER THE WESTERN CWA AFTER
08Z. CWASP CHECKLIST FOR BOTH THE 18Z GFS AND 00Z NAM KEEP HIGHER
PROBABILITY OF SEVERE BACK TO THE WEST THROUGH 12Z SUNDAY. 00Z NAM
STILL HOLDS OFF ON THUNDERSTORMS FOR THE CWA UNTIL SUNDAY
AFTERNOON IN THE WEST AND NEVER REALLY GETS HIGHER THAN 50 PCT IN
THE EAST AS WARM SECTOR ONLY MOVES INTO SOUTHWEST HALF OF CWA.
&&
.AVIATION/06Z TAFS/...
STRATUS IS EXPANDING UNDER REMNANT CIRRUS SHIELD FROM DEPARTING
MCV. OPEN AREA OVER NW CWA LOOKS TO BE FILLING BACK IN. WILL WATCH
MSN UP TO ISSUANCE TO DECIDE IF MVFR/IFR CIGS WILL BE THE RULE
OVERNIGHT...THOUGH LATEST NAM/RAPID UPDATE FORECAST SOUNDINGS SHOW IFR
INTO THE EARLY DAYLIGHT HOURS. WILL HOLD OFF ON THUNDER AT TAF
SITES UNTIL AFTERNOON...BUT AGAIN NEXT SHIFT WILL HAVE TO WATCH
OVERNIGHT MCS DEVELOPMENT/MOVEMENT CURRENTLY ON SOUTH
DAKOTA/MINNESOTA BORDER BACK INTO CENTRAL NEBRASKA FOR THE NEED
FOR AN EARLIER ARRIVAL OF SHOWERS/THUNDER ESPECIALLY AT KMSN.
&&
.PREV DISCUSSION... /ISSUED 708 PM CDT SAT MAY 5 2012/
AVIATION/00Z TAFS/...UPDATED.
LATEST RAPID UPDATE SOUNDINGS INDICATING CIGS WILL NOT IMPROVE AS
MUCH AS PREVIOUSLY THOUGHT AS COOL EAST-NORTHEASTERLY SURFACE FLOW
IS TOPPED BY INCREASINGLY MOIST AND WARM LAYER AT/ABOVE 925 MB
WITH WARM AIR ADVECTION OVERNIGHT. KEPT CIGS AT IFR IN THE EAST AND MVFR
AT KMSN THROUGH THE NIGHT...WITH IMPROVEMENT BY 13Z SUNDAY. ALSO
BACKED OFF ON TIMING OF CONVECTION CLOSER TO PASSAGE OF INVERTED
SURFACE TROUGH LATE SUNDAY AFTERNOON/EVENING...WITH THE CAVEAT
THAT AN MCS THAT IS EXPECTED TO DEVELOP IN EASTERN NEBRASKA LATER
THIS EVENING MAY REACH KMSN EARLY IN THE MORNING...THOUGH MOST
MODELS TAKE IT SOUTH THROUGH ILLINOIS BEFORE IT WOULD REACH ANY
TAF SITES.
PREV DISCUSSION... /ISSUED 359 PM CDT SAT MAY 5 2012/
TONIGHT AND SUNDAY - CONFIDENCE...MEDIUM
WATCHING YET ANOTHER COMPLEX HEAD FOR SOUTHERN WISCONSIN THIS
AFTERNOON. SOUTHERN TAIL OF THE LINE OF STORMS REMAINS
SEVERE...BUT MAY TURN FAR ENOUGH SOUTH ALONG THE CAPE GRADIENT TO
SLIDE SOUTH OF THE FORECAST AREA. NON SEVERE UPPER PART OF THE
LINE SEEMS TO BE CONTINUING EASTWARD PROGRESSION. OVERALL...LOOKS
LIKE LINE OF THUNDERSTORMS WILL AFFECT SOUTHERN WISCONSIN THIS
EVENING...WITH THE BEST CHANCE FOR STRONGER STORMS SOUTHWEST OF
MADISON TOWARD HIGHER CAPES. ONLY WENT CHANCE POPS IN THE
NORTHEAST HALF OF THE FORECAST AREA WHERE IT IS DRIER AND MORE
STABLE...THOUGH MAY NEED TO BUMP POPS UP IF THIS MCS KEEPS ON
ROLLING EAST.
MORE SHOWERS AND STORMS EXPECTED SUNDAY...ESPECIALLY IN THE
AFTERNOON AS BROAD SFC TROUGH PUSHES INTO THE AREA. MODELS HAVE
TRENDED TOWARD PUSHING SFC BOUNDARY FARTHER NORTH...SNEAKING THE
WARM SECTOR INTO SOUTHWEST AND SOUTH CENTRAL WISCONSIN BY
AFTERNOON. THIS WOULD LEAD TOWARD MUCH MORE UNSTABLE CONDITIONS
THAN THE LAST COUPLE DAYS...AND SPC HAS THUS PUSHED THE DAY 2
SLIGHT RISK FOR SEVERE THUNDERSTORMS INTO THE ENTIRE FORECAST
AREA. SHOULD BE A BIT MILDER TOMORROW WITH THE SFC BOUNDARY
GETTING INTO THE AREA...THOUGH STILL EXPECTING BIG TEMP GRADIENT
ACROSS THE CWA...WITH COOLEST TEMPS AGAIN NEAR THE LAKE UNDER
EASTERLY WINDS.
SUNDAY NIGHT - CONFIDENCE...MEDIUM
ONGOING COMPLEX PROGGD TO BE AFFECTING THE AREA AT THE START OF THIS
PERIOD BEING FED BY SUSTAINED 850 WARM AIR ADVECTION...600 MILLIBAR
FRONTOGENESIS AND SOME DIVERGENCE FROM RIGHT RER QUAD OF JET CORE
PASSING TO OUR NORTHWEST. ELEVATED INSTABILITY QUITE PRONOUNCED SO
HAIL/HEAVY RAINS THE MAIN THREAT AS THIS MOVES THROUGH. WILL CARRY
HEFTY POPS.
MONDAY - CONFIDENCE...LOW TO MEDIUM
INVERTED TROUGH LINGERS INTO AT LEAST THE MORNING HOURS. ECMWF IS
MORE SUGGESTIVE OF A SECONDARY WEAK WAVE MOVING ALONG IN THE WSW
FLOW THAT COULD MAINTAIN PRECIP INTO THE AFTERNOON HOURS. THE GFS
SHOWS PRECIP LINGERING BUT SLOWER ON TROUGH PASSAGE. WILL CONTINUE
CHANCY TYPE POPS INTO THE AFTERNOON WITH THE HIGHEST IN THE EAST.
TUESDAY AND WEDNESDAY - CONFIDENCE...MEDIUM
CONSENSUS IS THERE FOR MID LEVEL TROUGH AXIS/STRONG VORT MAX TO
SWING THROUGH LATER TUESDAY INTO EARLY WEDNESDAY. PLENTY OF COLD AIR
UPSTAIRS. 500 MILLIBAR COLD AIR ADVECTION PROGGD TO INCREASE TUESDAY
AFTERNOON WITH 500 TEMPS REACHING A MINIMUM OF -24 TO -26C LATER
TUESDAY NIGHT INTO WEDNESDAY MORNING. COLD POCKET STILL EXPECTED TO
LINGER INTO WEDNESDAY AFTERNOON. 50/20 RULE NOT QUITE INVOKED THOUGH
ECMWF SURFACE DEWS IN THE MID 40S WITH 500 TEMPS IN THE -MID 20S.
KEEPING SHRA/ISOLD THUNDER STILL SEEMS THE WAY TO GO AT THIS POINT.
THURSDAY - CONFIDENCE...MEDIUM
UPPER LEVEL RIDGE BEGINS TO WORK INTO THE AREA. COLD POCKET WELL
EAST. GFS TRYING TO STILL GENERATE SOME WAA PRECIP BUT HAVE BACKED
OFF ON THIS SCENARIO SINCE MODEL RUNS FROM YESTERDAY. STILL
GENERATING LIGHT QPF IN THE AFTERNOON BUT ECMWF IS DRY AND WITH LACK
OF DECENT WAA...EVEN ON THE GFS...HARD TO JUMP ON THIS SOMEWHAT
WETTER SCENARIO PLAYED OUT BY THE GFS.
FRIDAY AND SATURDAY - CONFIDENCE...LOW
UPPER FLOW PROGGD TO FLATTEN WITH WEAK VORTICITY ADVECTION AND COOL
FRONT PASSAGE DURING THIS PERIOD.
AVIATION/00Z TAFS/...IFR TO MVFR CIGS WILL CONTINUE TO IMPROVE
THROUGH LATE AFTERNOON AND EVENING...WITH A RETURN TO VFR
POSSIBLE BY AROUND MIDNIGHT. OTHERWISE...MAIN CONCERN IS AREA OF
SHOWERS AND STORMS OVER SOUTHEAST MINNESOTA. INCREASING CONFIDENCE
THAT THIS WILL PUSH ACROSS SOUTHERN WISCONSIN THIS
EVENING...THOUGH PROBABLY REMAIN BELOW SEVERE LEVELS. IF THIS CAN
HOLD TOGETHER...WILL REACH MADISON BY 01Z AND EASTERN TAF SITES BY
03Z.
WIDESPREAD SHOWERS AND STORMS EXPECTED TO SPREAD INTO THE AREA
WEST TO EAST AGAIN BY TOMORROW AFTERNOON...REACHING THE LAKE BY
EVENING.
LOWER CIGS AND VSBYS LIKELY WITHIN SHOWERS AND STORMS THAT MAY
AFFECT THE AREA THIS EVENING AND THAT ARE EXPECTED TOMORROW.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/SUNDAY AND AVIATION/MARINE...DDV
SUNDAY NIGHT THROUGH SATURDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
229 PM CDT FRI MAY 4 2012
.SHORT TERM...TONIGHT AND SATURDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LAST NIGHTS
COLD FRONT DRIFTING SOUTH OVER NORTHERN ILLINOIS/INDIANA WHILE
HUDSON BAY HIGH PRESSURE IS BUILDING SOUTHWARD INTO THE WESTERN
GREAT LAKES. LOW CLOUDS HAVE STUCK AROUND ALL DAY OVER CENTRAL
WISCONSIN WHERE MOISTURE REMAINS PLENTIFUL...BUT NORTHERN WISCONSIN
HAS CLEARED OUT NICELY. LOOKING UPSTREAM...SHORTWAVE TROUGH OVER
SOUTH-CENTRAL CANADA HAS HELPED RETURN FLOW KICK OFF SHOWERS AND
THUNDERSTORMS OVER WESTERN MINNESOTA AND EASTERN SOUTH DAKOTA.
THESE STORMS HAVE BEEN RIDING ALONG THE MOST UNSTABLE CAPE
GRADIENT...WHICH STRETCHES FROM SOUTHERN MINNESOTA INTO SW
WISCONSIN. AS THE RETURN FLOW SHIFTS EAST TONIGHT...SHOWER AND
THUNDERSTORM CHANCES ARE THE MAIN FORECAST CONCERN.
TONIGHT...WEAK SHORTWAVE ACTIVITY WILL CLIMB OVER TOP THE MID-LEVEL
RIDGE INTO FAR SOUTH-CENTRAL CANADA TONIGHT. RETURN FLOW OVER THE
NORTHERN PLAINS WILL MOVE EAST INTO WESTERN WISCONSIN BY 06Z AND
CENTRAL WISCONSIN BY 12Z. CLUSTER OF SHOWERS AND STORMS WILL SPREAD
EAST WITH THE ISENTROPIC ASCENT ON THE 300-305K SURFACES IN A REGION
OF GOOD MOISTURE ADVECTION. HAVE NOT SEEN ANY SIGNS YET THAT THE
DRY AIR ON MPX/S SOUNDING IS ERODING THIS CLUSTER OF STORMS...SO THE
LATEST TIMING WOULD HAVE PRECIP ARRIVING LATE IN THE EVENING INTO
CENTRAL WISCONSIN. WILL INCREASE POPS AND BRING THEM FARTHER SOUTH. LIKE
THE PREVIOUS SHIFT...COULDNT FIND MUCH INSTABILITY...BUT CANT ARGUE
WITH THE CURRENT THUNDERSTORM ACTIVITY ONGOING...SO WILL ADD TO THE
FORECAST AS WELL. PRECIP WILL SPREAD EAST OVERNIGHT...BUT WILL
ENCOUNTER DRIER AIR OVER THE NORTH-CENTRAL GREAT LAKES...WHICH AM
COUNTING ON TO FINALLY SLOW ITS FORWARD PROGRESSION. SO WILL KEEP
THE LOWEST CHANCES OVER THE EAST. LOWS MAINLY IN THE 40S.
SATURDAY...300-305K ISENTROPIC ASCENT WILL CONTINUE TO SPREAD EAST
DURING THE MORNING...WHILE THE 850MB BAROCLINIC ZONE STALLS OVER
NORTHEAST WISCONSIN. FORCING LOOKS THE BEST DURING THE MORNING WHEN
WILL HAVE THE HIGHEST CHANCES OF POPS. IN THE AFTERNOON...WE LOSE
SOME OF THE LOWER CONDENSATION PRESSURE DEFICITS AND DRIER AIR
ARRIVES IN THE MID AND UPPER LEVELS. SEEMS REASONABLE TO THINK THAT
MOST OF THE PRECIP WILL FALL DURING THE MORNING AND ONLY SPOTTY
SHOWERS OR MAYBE EVEN DRIZZLE LEFT FOR THE AFTERNOON. PLENTY OF
SATURATION BELOW 800MB...SO HAVE A TOUGH TIME SEEING CLEARING
OCCURRING. LOTS OF CLOUDS...PRECIP...AND AN EAST WIND DOES NOT BODE
WELL FOR WARM TEMPS TOMORROW. WILL MAYBE DROP THE PREV SHIFT/S
TEMPS BY A DEGREE IN SPOTS.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY. SATURDAY NIGHT
INTO SUNDAY NIGHT WILL BE DOMINATED BY THE UPPER DIFFLUENCE
REGION AHEAD OF A DEEPENING UPPER LOW DRIFTING OVER THE NORTHERN
PLAINS. A SURFACE TROUGH IS PROGGED TO TRACK OVER THE WESTERN
GREAT LAKES REGION WITH RESPECT TO THIS SYSTEM. TWO SURFACE LOWS
PRESSURE REGIONS OF NOTE...ONE NEAR THE UPPER LOW OVER THE
NORTHERN PLAINS AND A SECOND NEAR THE MORE UNSTABLE AND DEEPER
MOISTURE REGION OVER THE CENTRAL PLAINS AND MID MISSISSIPPI VALLEY
REGION. THIS SOURCE OF MOIST UNSTABLE AIR IN THE RETURN FLOW IS
THE FOCUS OF POTENTIALLY ANOTHER ROUND OF HEAVY RAIN FALL FOR
SOMEWHERE IN THE STATE. AT THIS TIME BEST AMOUNTS COULD BE OVER
NORTHERN OR NORTHEAST THIRD OF THE STATE WHERE THE H8 BAROCLINIC
ZONE EXTENDS DURING THE PERIOD. NORTHERN WISCONSIN IS ALSO CLOSER
TO THE UPPER JET DYNAMICS. WHEREAS THE AIR MASS A LITTLE MORE
UNSTABLE TOWARD SOUTHERN WISCONSIN. GOING FORECAST OF THE EVENT
LOOKS GOOD...AND ANTICIPATE ONLY MINOR CHANGES WITH RESPECT TO
TIMING. 12Z RUNS INDICATED THE GFS IS MUCH SLOWER WITH DEPARTING
THE SOUTHERN STREAM SURFACE LOW ON MONDAY.
WHILE A DIMINISHED PCPN TREND IS EXPECTED LATER MONDAY INTO MONDAY
NIGHT AS THE SURFACE FRONTAL SYSTEM SHIFTS EAST AND HIGH PRESSURE
SLIDES INTO THE CENTRAL PLAINS...THE UPPER LOW IS PROGGED TO PIVOT
OVER THE GREAT LAKES REGION ON TUESDAY FOR A PERIOD OF CLOUDS AND
PERHAPS DIURNAL TYPE PCPN.
MEDIUM RAIN PROGS BUILD A SURFACE AND UPPER RIDGE INTO THE AREA
FOR MID WEEK BEFORE THE NEXT NORTHERN STREAM SYSTEM APPROACHES
FROM THE NORTHERN PLAINS.
&&
.AVIATION...VFR CONDITIONS OVER NORTHERN WISCONSIN THROUGH MUCH OF
THIS EVENING. AREAS OF MVFR STRATUS OVER CENTRAL WISCONSIN WILL
GRADUALLY LIFT TO VFR WITH BREAKS IN THE CLOUDS ENLARGING THROUGH
THE AFTERNOON. NEXT AREA OF SHOWERS AND THUNDERSTORMS OVER
MINNESOTA WILL PUSH ACROSS THE TAF SITES EARLY OVERNIGHT THROUGH
TOMORROW MORNING. DRY AIR WILL IMPEDE ITS PROGRESS SOMEWHAT...SO
HAVE A SLOWER TIMING INTO EASTERN WISCONSIN. DIDNT INCLUDE THUNDER
AT THIS TIME...BUT PLENTY OF THUNDER OVER EASTERN SD...SO THAT MAY
NEED TO BE UPDATED LATER. AS THE RAIN ARRIVES LATE...EXPECT CIGS TO
FALL TO LOW END MVFR TO HIGH END IFR OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN. DO NOT EXPECT MUCH IMPROVEMENT IN CONDITIONS THROUGH
MIDDAY TOMORROW AS SCATTERED SHOWERS WILL REMAIN PRESENT.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/TDH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
259 AM CDT SUN MAY 6 2012
.DISCUSSION...
ISSUED 257 AM CDT SUN MAY 6 2012
FRONTAL BOUNDARY HAS NOT REALLY MOVED OVER THE LAST SEVERAL
HOURS...EXTENDING FROM NORTHWEST IOWA TO NEAR SPRINGFIELD AND
SOUTHEAST INTO SOUTH CENTRAL INDIANA. DEW POINTS IN THE 65-70F
RANGE WERE POOLING ALONG THIS BOUNDARY. SOME LIGHT FOG WAS
OBSERVED NORTH OF THE FRONT WITH VISIBILITIES OF 3-5 MILES. LARGE
MCS STRETCHING FROM CENTRAL MINNESOTA INTO NORTHERN NEBRASKA HAS
PUSHED INTO FAR NORTHWEST IOWA.
SEVERE WEATHER POTENTIAL THROUGH MONDAY REMAINS THE PRIMARY
FORECAST CONCERN.
SHORT TERM...TODAY THROUGH MONDAY...
NORTHWARD SPREAD OF THE WARM SECTOR MAY BE TEMPERED BY THE
INFLUENCES OF THE MCS DEBRIS...BUT SHOULD GET FAR ENOUGH NORTH TO
CLEAR OUR NORTHERN CWA TOWARD MIDDAY. INSTABILITY SHOULD NOT BE A
PROBLEM AS CAPES APPROACH 3000 J/KG BY MIDDAY AND CONVECTIVE
INHIBITION VALUES WANE. TIMING OF THE CONVECTION IS THE TRICKY
PART...WITH THE HRRR LEANING TOWARD EARLY AFTERNOON DEVELOPMENT
WEST OF THE MISSISSIPPI RIVER...AND THE NAM AND LOCAL WRF MODELS
FROM ST LOUIS AND CHICAGO NWS OFFICES BRINGING SOME OF THE MCS
REMNANTS INTO THE NORTHERN CWA LATE THIS MORNING. ATTENDANT COLD
FRONT IS LIKELY TO MOVE INTO THE NORTHWEST CWA EARLY THIS
EVENING...CONTINUING THE STORM THREAT OVERNIGHT. MOST OF THE CWA
REMAINS IN A SLIGHT RISK OF SEVERE WEATHER...EXCEPT EAST OF
I-57...WHERE SEVERE THREAT MAY BE VERY LATE TONIGHT OR MONDAY
MORNING INSTEAD. HAVE CONTINUED WITH RAIN CHANCES MAINLY WEST OF
I-55 THIS AFTERNOON...AND OVERSPREADING THE REMAINDER OF THE CWA
THIS EVENING. HEAVIEST RAIN THREAT LOOKS TO BE JUST TO OUR
NORTH...BUT WILL NEED TO WATCH THE FAR NORTHERN CWA WHICH HAD 1-3
INCHES OF RAIN THURSDAY NIGHT AND FRIDAY MORNING FOR ANY POTENTIAL
HYDROLOGICAL CONCERNS. TIMING OF FRONTAL PASSAGE ON MONDAY SHOULD
BE EARLY AFTERNOON ACROSS THE EASTERN CWA...AND HAVE KEPT LIKELY
POPS GOING IN THAT AREA DURING THE DAY...DIMINISHING IN THE
EVENING.
TEMPERATURE-WISE...WILL LIKELY SEE HIGHS DEEP INTO THE 80S OVER
THE ENTIRE FORECAST AREA...POTENTIALLY NUDGING 90 ACROSS THE
SOUTHWEST CWA. MOST RECORDS TODAY ARE IN THE LOWER 90S AND LIKELY
JUST OUT OF REACH...ALTHOUGH SPRINGFIELD HAS A RECORD HIGH OF 88
WHICH IS IN JEOPARDY. WILL PROBABLY SEE SOME 80 DEGREE READINGS
AGAIN ACROSS THE SOUTHEAST ON MONDAY AHEAD OF THE FRONT...BUT THAT
WILL BE THE LAST OF THE 80S ACROSS OUR CWA FOR THE REMAINDER OF
THE WEEK.
LONG TERM...TUESDAY THROUGH SATURDAY...
A MUCH COOLER AND QUIETER REGIME SETS UP THE REMAINDER OF THE
WEEK. AN UPPER LOW...CURRENTLY LOCATED OVER FAR NORTH CENTRAL
MONTANA PER WATER VAPOR IMAGERY...SHOULD MOVE TO NEAR LAKE
SUPERIOR BY TUESDAY MORNING. ASSOCIATED SURFACE AND UPPER TROUGH
WILL SWING THROUGH THE GREAT LAKES TUESDAY AND WEDNESDAY...WITH
THE COLDER AIR ALOFT HELPING TO TRIGGER A FEW SHOWERS. STILL LOOKS
LIKE THE BEST SUPPORT FOR THIS WILL BE FURTHER TO OUR NORTH...BUT
HAVE INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHEAST CWA ON
WEDNESDAY AS THE TROUGH FULLY PUSHES THROUGH THE STATE.
UPPER RIDGING ACROSS THE ROCKIES AT MIDWEEK WILL RESULT IN A
NORTHWEST FLOW...AND BELOW NORMAL TEMPERATURES...FOR A COUPLE
DAYS IN OUR AREA. LONGER RANGE MODELS SHOWING THE RIDGING PUSHING
EASTWARD LATE IN THE WEEK...WITH A BIT OF MODERATION IN
TEMPERATURES. SURFACE HIGH PRESSURE OVER THE MIDWEST TO PROVIDE
FAIR WEATHER FOR THURSDAY AND FRIDAY...AHEAD OF A SHORTWAVE WHICH
WILL PUSH ACROSS THE NORTHERN STATES LATE IN THE WEEK. MOISTURE
RETURN IN OUR AREA WILL BE MEAGER AHEAD OF THIS SYSTEM...SO RAIN
CHANCES ARE NOT ESPECIALLY HIGH AT THIS TIME. HOWEVER...THE
NORTHWEST CWA SHOULD SEE A FEW SHOWERS AND THUNDERSTORMS BY
SATURDAY AFTERNOON.
GEELHART
&&
.AVIATION...
ISSUED 1130 PM CDT SAT MAY 5 2012
CIGS AND VSBYS THE MAIN CONCERN...ESP ACRS THE NORTH OVERNIGHT.
SATELLITE DATA AND SURFACE OBS TO OUR NORTH SUGGEST LOW MVFR AND
IFR CIGS BEGINNING TO GET A BIT MORE OF A SOUTHWARD PUSH THAN
EARLIER EXPECTED THANKS TO AN OUTFLOW BOUNDARY FROM A COMPLEX
OF STORMS THAT MOVED ACRS SOUTHERN WISCONSIN THIS EVE. THE LOWER
CIGS LOOK TO BE ALONG AND NORTH OF I-80 WITH THE LAST FEW SATELLITE
LOOPS SUGGESTING THE SOUTHWARD PUSH HAS SLOWED SOMEWHAT. LOW LEVEL
WINDS ARE FORECAST TO GO MORE INTO AN ESE DIRECTION WHICH SHOULD
KEEP MOST OF THE CLOUDS ALONG AND NORTH OF A PIA TO BMI LINE.
VSBYS WILL LOWER TO MVFR AND POSSIBLY IFR AT BMI FOR A TIME AFTR 06Z
WITH 2 TO 4 MILES PREVAILING ELSEWHERE DURING THE EARLY MORNING
HOURS. WHAT FOG AND LOW CLOUDS WE HAVE SHOULD LIFT QUICKLY AFTR
13Z WITH VFR CONDITIONS PREVAILING THRU 00Z.
A COLD FRONT WILL APPROACH THE AREA LATE TOMORROW EVENING AND
OVERNIGHT BRINGING THE THREAT FOR SCATTERED THUNDERSTORMS TO THE
TAF SITES BUT COVERAGE IS UNCERTAIN AT THIS TIME SO WILL TRY TO
HIT THE TIMING WITH VCTS AT EACH SITE TOMORROW EVENING. SFC WINDS
WILL BE OUT OF THE EAST AROUND 10 KTS TONIGHT AND THEN WINDS WILL
VEER MORE INTO THE SOUTH TOMORROW WITH SPEEDS OF BETWEEN 12 AND
17 KTS...WITH FORECAST SOUNDINGS SUGGESTING WIND GUSTS UP TO 25 KTS
POSSIBLE IN THE AFTERNOON.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
340 AM CDT SUN MAY 6 2012
...UPDATE TO LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 117 AM CDT SUN MAY 6 2012
AT 00Z SUNDAY AN UPPER LEVEL TROUGH WHICH WAS ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN WYOMING. A SURFACE COLD FRONT
EXTENDED FROM NORTHEAST COLORADO INTO NORTHEAST NEBRASKA. SOUTH OF
THIS COLD FRONT WARM MID LEVEL TEMPERATURES WERE PRESENT ACROSS
WESTERN KANSAS WITH KDDC INDICATING 700MB TEMPERATURES AT +13C. AS
OF 06Z SURFACE ANALYSIS INDICATED THIS COLD FRONT WAS ALREADY
SURGING SOUTHEAST TOWARDS WEST CENTRAL KANSAS WITH LOW CLOUDS AND
NORTHWEST WINDS AROUND 25KNOTS DEVELOPING IN ITS WAKE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 117 AM CDT SUN MAY 6 2012
BASED ON 925-850MB MOISTURE PROFILES THE MODELS THIS MORNING
REMAIN IN GOOD AGREEMENT IN LOW LEVEL MOISTURE RETURNING TO
SOUTHWEST KANSAS BEHIND A COLD FRONT THAT WAS CURRENTLY MOVING
INTO WEST CENTRAL KANSAS. NAM AND GFS 300-305 ISENTROPIC SURFACES
EVEN SUGGEST SOME WEAK LIFT WILL CONTINUE THROUGH 00Z MONDAY.
BASED ON THIS WEAK LIFT AND DEPTH OF THIS MOIST LAYER WILL KEEP A
MENTION OF DRIZZLE GOING THROUGH MUCH OF THE DAY, ESPECIALLY
NORTHEAST OF DODGE CITY WHERE THE ISENTROPIC LIFT IS A LITTLE
BETTER. GIVEN THE CHANCE FOR DRIZZLE ALONG WITH CLOUDY CONDITIONS
THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH AFTERNOON
TEMPERATURES RANGING FROM THE LOW TO MID 60S WITH THE EXCEPTION
BEING SOUTH CENTRAL KANSAS. WILL HAVE TO MONITOR HOW QUICKLY THIS
FRONT WILL CROSS SOUTH CENTRAL KANSAS EARLY THIS MORNING BUT AT
THIS TIME BASED ON 06Z SURFACE OBSERVATION ACROSS NORTHWEST KANSAS
IT APPEARS THAT THE NAM MAY BE A LITTLE SLOW SO ADJUSTING THE
TIMING OF THIS FRONT CLOSE TO THE HRRR WILL CONTINUE TO FAVOR
SLIGHTLY COOLER TEMPERATURES IN THE MEDICINE LODGE AREA THAN WHAT
THE NAM/GFS SUGGEST.
BOUNDARY LAYER AND 0-0.5KM LAYER WINDS BEHIND THIS COLD FRONT
ACROSS WESTERN KANSAS EARLY TODAY BOTH WERE FORECAST TO RANGE BETWEEN
30 AND 35 KNOTS BEHIND THIS FRONT. GIVEN THIS AND THE LOCATION OF
WHERE THE STRONGER LOW LEVEL WINDS ARE FORECAST TO BE BETWEEN 09Z
AND 15Z SUNDAY WILL KEEP CURRENT WIND ADVISORY AS IS FOR NOW.
MARGINAL WIND ADVISORY WINDS HOWEVER STILL APPEAR POSSIBLE A
LITTLE FURTHER SOUTHEAST, HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT
THIS TIME TO EXPAND THE PREVIOUS ADVISORY.
SURFACE HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE ARE EARLY
TONIGHT AND 300-305 ISENTROPIC DOWN GLIDE DEVELOPS. LOW LEVEL
MOISTURE STILL PRESENT OVER WESTERN KANSAS THROUGH MUCH OF THE
NIGHT BUT GIVEN THE SUBSIDENCE/DOWN GLIDE SUGGESTED WILL BEGIN TO
SHOW A DECREASING TREND IN CLOUD COVER BY OR SHORTLY AFTER
MIDNIGHT...ESPECIALLY IN THE NORTH. IN AREAS WHERE THE SKIES ARE
EXPECTED TO CLEAR WILL TREND TOWARDS THE COOLER MET/MAV ON
TEMPERATURES WHILE FURTHER SOUTHEAST WILL CONTINUE TO FAVOR THE
WARMER MOSGUIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 6 2012
MONDAY:
A RATHER BROAD UPPER LEVEL TROUGH WILL BE WEST OF KANSAS MONDAY. WESTERN
KANSAS WILL BE IN A QUASI COUPLED JET REGION WITH THE LEFT EXIT REGION
OF A 250 HPA 70 KT JET ACROSS THE EASTERN SECTIONS OF THE DESERT SOUTHWEST
AND THE RIGHT ENTRANCE REGION OF A 250 HPA 65 KT JET ACROSS NEBRASKA.
AS A RESULT, HAVE KEPT POPS MAINLY ACROSS FAR SOUTHWEST KANSAS WHERE
BETTER LIFT WILL BE PRESENT VERSUS FURTHER EAST. NOT PARTICULARLY IMPRESSED
OVERALL AS MOST OF THE QPF SHOULD REMAIN ACROSS THE HIGHER TERRAIN ALSO
IN ASSOCIATION WITH OROGRAPHIC LIFT AND UPSLOPE FLOW IN A POST FRONTAL
ENVIRONMENT. A 1025 HPA HIGH WILL SLIDE DOWN THE PLAINS IN THE WAKE
OF THE AFOREMENTIONED FRONT. THIS AIRMASS WILL BE CHARACTERIZED AS PLEASANT
WITH 850 HPA TEMPERATURES NOT TOO WARM (~10-12 DEG C). UPPER 60SN DEG
F TO LOWER 70S DEG F IS EXPECTED FOR THE BEGINNING OF THE WORKWEEK WHICH
IS JUST A HAIR BELOW CLIMATOLOGY.
TUESDAY:
THE DESERT SOUTHWEST SYSTEM WILL CONTINUE TO SINK SOUTHWARD INTO THE
BAJA REGION WHILE THE NORTHERN SYSTEM MOVES EAST. SOUTHWEST KANSAS WILL
BE LEFT IN A COL POINT AT THE UPPER LEVELS. AT THE SURFACE, THE COOL
HIGH PRESSURE CENTER WILL CONTINUE TO DOMINATE. RICH BOUNDARY MOISTURE
WILL BE ADVECTED WELL SOUTH INTO TEXAS WITH FAIRLY LOW DEWPOINTS ACROSS
THE SUNFLOWER STATE. AS A RESULT, OVERNIGHT LOWS INTO TUESDAY MORNING
WILL BE MAINLY IN THE 40S DEG F EXCEPT NEAR KP28 WHERE AROUND 50 DEG
F IS EXPECTED. LOW TEMPERATURES IN THE 40S DEG F ARE NEAR CLIMATOLOGY.
A LACK OF DYNAMICS ALOFT AND HIGH PRESSURE AT THE SURFACE WILL LEAD
TO A DRY FORECAST FOR TUESDAY.
WEDNESDAY/THURSDAY:
MAXIMUM TEMPERATURES WILL MODERATE WEDNESDAY WITH HIGHS IN THE MID 70S
DEG F OR ABOUT NEAR NORMAL AS THE COOL HIGH PRESSURE SLIDES OFF TO THE
EAST AND LEE TROUGHING AND RESULTANT WARM AIR ADVECTION DEVELOPS ACROSS
THE HIGH PLAINS. POPS WILL REMAIN NEAR ZERO AS THE 500 HPA RIDGE AXIS
SLIDES EAST THROUGH THE DAY AHEAD OF ANOTHER SHORTWAVE TROUGH MOVING
ONSHORE ACROSS THE PACIFIC NORTHWEST. THURSDAY WILL BE THE WARMEST DURING
MY PERIOD AS 850 HPA TEMPERATURES WARM INTO THE LOWER 20 DEG C AND LEE
TROUGHING STRENGTHENS WITH SOUTHERLY WINDS CONTINUING FROM THE SURFACE
AND THROUGH THE 850 HPA CONSTANT PRESSURE LAYER. RETURN OF RICH BOUNDARY
LAYER MOISTURE IS NOT EXPECTED AT THIS POINT AS A COLD FRONT WILL SCOUR
HIGHER DEWPOINTS SOUTHWARD ACROSS THE NORTHERN GULF OF MEXICO BASIN.
FRIDAY AND BEYOND:
THE FORECAST TURNS MORE UNSETTLED BY THE END OF NEXT WEEK ALTHOUGH UNCERTAINTY
IS PRETTY HIGH AS THIS POINT. PRECIPITATION MAY OCCUR EITHER FROM A
NORTHERN SYSTEM BRINGING IN A COLD FRONT OR FROM THE BAJA SYSTEM BRING
IN MOISTURE FROM THE SOUTH. AT THIS POINT, THE EXACT SOLUTION IS UNKNOWN.
PREFER THE DRIER SOLUTION FROM THE ECMWF. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE AS LIFT AND MOISTURE ADVECTION INCREASES DURING THIS
PERIOD. EVEN IF YOU WERE TO BUY THE WETTER GFS SOLUTION, DEWPOINTS
RETURNING TO KANSAS ARE NOT THAT IMPRESSIVE FOR MAY - 50S DEG F.
DEWPOINTS IN THE 60S/70S DEG F ARE STILL FORECAST TO BE REMAIN WELL
SOUTH INTO THE GULF OF MEXICO. LASTLY, UPPER LEVEL JET DYNAMICS IS
ALSO WEAK WITH THE CUT OFF LOW REMAINING WELL SOUTH ACROSS TEXAS AND
THE STRONGER POLAR JET FORECAST WELL NORTH NEAR THE INTERNATIONAL
BORDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1213 AM CDT SUN MAY 6 2012
04Z SURFACE ANALYSIS INDICATED A COLD FRONT MOVING SOUTH ACROSS
NORTHWEST KANSAS. THIS FRONT APPEARS TO BE MOVING QUICKER THAN
WHAT THE 00Z NAM OR 00Z GFS SUGGESTED. HRRR APPEARS TO BE MORE
REPRESENTATIVE SO WILL FOLLOW THE QUICKER HRRR ON TIMING OF WIND
SHIFT LATER THIS MORNING AS THIS FRONT CROSSES SOUTHWEST KANSAS.
GUSTY NORTH WINDS WILL DEVELOP BEHIND THIS FRONT EARLY SUNDAY
MORNING WITH SUSTAINED WINDS OF AROUND 25KTS POSSIBLE FOR SEVERAL
HOURS FOLLOWING FROPA. LOW CLOUDS, IFR CIGS, CAN ALSO BE EXPECTED
BEHIND THIS COLD FRONT EARLY SUNDAY. BASED ON ISENTROPIC LIFT
ALONG WITH THE DEPTH OF THIS MOIST LAYER SOME LIGHT DRIZZLE WILL
ALSO BE POSSIBLE. IFR CONDITIONS SHOULD BEGIN TO IMPROVE BY MID
AFTERNOON WITH LOW VFR CONDITIONS BECOMING POSSIBLE TOWARDS 00Z
MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 50 68 46 / 20 10 10 10
GCK 65 44 67 45 / 10 10 20 20
EHA 70 46 65 45 / 10 10 20 20
LBL 71 47 68 46 / 10 10 20 20
HYS 67 46 69 45 / 30 20 10 10
P28 79 57 71 50 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
129 AM CDT SUN MAY 6 2012
...UPDATED SYNOPSIS AND SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 117 AM CDT SUN MAY 6 2012
AT 00Z SUNDAY AN UPPER LEVEL TROUGH WHICH WAS ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN WYOMING. A SURFACE COLD FRONT
EXTENDED FROM NORTHEAST COLORADO INTO NORTHEAST NEBRASKA. SOUTH OF
THIS COLD FRONT WARM MID LEVEL TEMPERATURES WERE PRESENT ACROSS
WESTERN KANSAS WITH KDDC INDICATING 700MB TEMPERATURES AT +13C. AS
OF 06Z SURFACE ANALYSIS INDICATED THIS COLD FRONT WAS ALREADY
SURGING SOUTHEAST TOWARDS WEST CENTRAL KANSAS WITH LOW CLOUDS AND
NORTHWEST WINDS AROUND 25KNOTS DEVELOPING IN ITS WAKE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 117 AM CDT SUN MAY 6 2012
BASED ON 925-850MB MOISTURE PROFILES THE MODELS THIS MORNING
REMAIN IN GOOD AGREEMENT IN LOW LEVEL MOISTURE RETURNING TO
SOUTHWEST KANSAS BEHIND A COLD FRONT THAT WAS CURRENTLY MOVING
INTO WEST CENTRAL KANSAS. NAM AND GFS 300-305 ISENTROPIC SURFACES
EVEN SUGGEST SOME WEAK LIFT WILL CONTINUE THROUGH 00Z MONDAY.
BASED ON THIS WEAK LIFT AND DEPTH OF THIS MOIST LAYER WILL KEEP A
MENTION OF DRIZZLE GOING THROUGH MUCH OF THE DAY, ESPECIALLY
NORTHEAST OF DODGE CITY WHERE THE ISENTROPIC LIFT IS A LITTLE
BETTER. GIVEN THE CHANCE FOR DRIZZLE ALONG WITH CLOUDY CONDITIONS
THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH AFTERNOON
TEMPERATURES RANGING FROM THE LOW TO MID 60S WITH THE EXCEPTION
BEING SOUTH CENTRAL KANSAS. WILL HAVE TO MONITOR HOW QUICKLY THIS
FRONT WILL CROSS SOUTH CENTRAL KANSAS EARLY THIS MORNING BUT AT
THIS TIME BASED ON 06Z SURFACE OBSERVATION ACROSS NORTHWEST KANSAS
IT APPEARS THAT THE NAM MAY BE A LITTLE SLOW SO ADJUSTING THE
TIMING OF THIS FRONT CLOSE TO THE HRRR WILL CONTINUE TO FAVOR
SLIGHTLY COOLER TEMPERATURES IN THE MEDICINE LODGE AREA THAN WHAT
THE NAM/GFS SUGGEST.
BOUNDARY LAYER AND 0-0.5KM LAYER WINDS BEHIND THIS COLD FRONT
ACROSS WESTERN KANSAS EARLY TODAY BOTH WERE FORECAST TO RANGE BETWEEN
30 AND 35 KNOTS BEHIND THIS FRONT. GIVEN THIS AND THE LOCATION OF
WHERE THE STRONGER LOW LEVEL WINDS ARE FORECAST TO BE BETWEEN 09Z
AND 15Z SUNDAY WILL KEEP CURRENT WIND ADVISORY AS IS FOR NOW.
MARGINAL WIND ADVISORY WINDS HOWEVER STILL APPEAR POSSIBLE A
LITTLE FURTHER SOUTHEAST, HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT
THIS TIME TO EXPAND THE PREVIOUS ADVISORY.
SURFACE HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE ARE EARLY
TONIGHT AND 300-305 ISENTROPIC DOWN GLIDE DEVELOPS. LOW LEVEL
MOISTURE STILL PRESENT OVER WESTERN KANSAS THROUGH MUCH OF THE
NIGHT BUT GIVEN THE SUBSIDENCE/DOWN GLIDE SUGGESTED WILL BEGIN TO
SHOW A DECREASING TREND IN CLOUD COVER BY OR SHORTLY AFTER
MIDNIGHT...ESPECIALLY IN THE NORTH. IN AREAS WHERE THE SKIES ARE
EXPECTED TO CLEAR WILL TREND TOWARDS THE COOLER MET/MAV ON
TEMPERATURES WHILE FURTHER SOUTHEAST WILL CONTINUE TO FAVOR THE
WARMER MOSGUIDE.
.LONG TERM...(TUESDAY MORNING THROUGH SATURDAY) ISSUED AT 349 PM CDT SAT
MAY 5 2012
AN UPPER-LEVEL LOW WILL BE SITUATED ACROSS THE DESERT SOUTHWEST FROM
TUESDAY INTO WEDNESDAY, WITH AN UPPER-LEVEL TROUGH MOVING FROM THE
UPPER MIDWEST INTO THE GREAT LAKES. DESPITE THE TROUGH DEVELOPING
ACROSS THE SOUTHWEST, WHICH IS OFTEN A FAVORABLE PATTERN FOR
PRECIPITATION ACROSS THE HIGH PLAINS IN MAY, SURFACE TO 850MB HIGH
PRESSURE IN THE WAKE OF THE GREAT LAKES TROUGH WILL MOVE SOUTHWARD
INTO THE CENTRAL PLAIN, SHUNTING THE LOW-LEVEL MOISTURE INTO THE
SOUTHERN PLAINS. ALSO, THE NORTHERN STREAM JET ENERGY WILL TEND TO
SUPPRESS THE SOUTHWESTERN UPPER-LEVEL TROUGH FURTHER SOUTH.
NEVERTHELESS, FRONTOGENESIS ALONG THE EXTREMITY OF THE UPPER MIDWEST
TROUGH, ALONG WITH SOME LOW TO MID-LEVEL MOISTURE, MAY PROMOTE
SHOWER DEVELOPMENT TUESDAY, ESPECIALLY IN FAR WESTERN KANSAS.
AS THE SOUTHWESTERN UPPER-LEVEL SYSTEM PROGRESSES ACROSS THE SOUTHERN
ROCKIES AND INTO TEXAS THROUGH THURSDAY AND FRIDAY, THE BULK (IF NOT
ALL) OF THE PRECIPITATION WILL STAY TO OUR SOUTH. THE BRUNT OF THE
COOLING WITH THE GREAT LAKES TROUGH IS PROGGED BY THE ECMWF/GEM TO
STAY TO OUR NORTH AND EAST. SO HIGH TEMPERATURES OUGHT TO STILL
REACH INTO THE 70S TUESDAY AND WEDNESDAY AND PERHAPS AS HIGH AS 80
BY THURSDAY, WITH LOWS IN THE MID 40S TO LOWER 50S. THESE TEMPERATURES
ARE SEASONABLE FOR EARLY MAY. EVEN AFTER THURSDAY, NO PARTICULARLY
STRONG COLD FRONTS OR HEAT WAVES ARE EXPECTED, WITH MAINLY A
CONTINUATION OF MODERATE TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1213 AM CDT SUN MAY 6 2012
04Z SURFACE ANALYSIS INDICATED A COLD FRONT MOVING SOUTH ACROSS
NORTHWEST KANSAS. THIS FRONT APPEARS TO BE MOVING QUICKER THAN
WHAT THE 00Z NAM OR 00Z GFS SUGGESTED. HRRR APPEARS TO BE MORE
REPRESENTATIVE SO WILL FOLLOW THE QUICKER HRRR ON TIMING OF WIND
SHIFT LATER THIS MORNING AS THIS FRONT CROSSES SOUTHWEST KANSAS.
GUSTY NORTH WINDS WILL DEVELOP BEHIND THIS FRONT EARLY SUNDAY
MORNING WITH SUSTAINED WINDS OF AROUND 25KTS POSSIBLE FOR SEVERAL
HOURS FOLLOWING FROPA. LOW CLOUDS, IFR CIGS, CAN ALSO BE EXPECTED
BEHIND THIS COLD FRONT EARLY SUNDAY. BASED ON ISENTROPIC LIFT
ALONG WITH THE DEPTH OF THIS MOIST LAYER SOME LIGHT DRIZZLE WILL
ALSO BE POSSIBLE. IFR CONDITIONS SHOULD BEGIN TO IMPROVE BY MID
AFTERNOON WITH LOW VFR CONDITIONS BECOMING POSSIBLE TOWARDS 00Z
MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 64 50 69 48 / 20 10 20 20
GCK 61 44 68 47 / 10 10 20 20
EHA 63 46 66 47 / 10 10 30 20
LBL 64 47 69 47 / 10 10 20 20
HYS 64 46 70 49 / 30 20 10 10
P28 78 57 73 52 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1222 AM CDT SUN MAY 6 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 942 PM CDT SAT MAY 5 2012
A COLD FRONT LOCATED ACROSS SOUTHERN NEBRASKA WAS AHEAD OF SCHEDULE
THIS EVENING. THE HIGH RESOLUTION RAPID REFRESH MODEL AND NAM
BRING THIS FRONT THROUGH DODGE CITY BY 5 AM. BOTH MODELS INDICATE LOW
STRATUS CLOUDS DEVELOPING AND THE NAM SHOWS THE LOW LEVEL CLOUD
DECK ABOUT 3000 FT THICK. THIS COULD LEAD TO AREAS OF DRIZZLE MUCH
OF THE DAY SUNDAY, ESPECIALLY FROM DODGE CITY NORTH AND EAST TO HAYS.
THIS MAKES SENSE BASED ON THE MOIST AIR MASS NORTH OF THE FRONT IN
NEBRASKA AND SOUTH DAKOTA WHERE DEWPOINTS WERE IN THE 50S TO LOWER
60S. A STRONGER COLD FRONT WAS MOVING THROUGH THE NEBRASKA
PANHANDLE AND INTO SOUTHERN SOUTH DAKOTA THIS EVENING AND THE
PASSAGE OF THIS FRONT WILL LEAD TO STEADY TEMPERATURES EVEN DURING
THE DAY SUNDAY. TEMPERATURES WERE LOWERED SEVERAL DEGREES TO MORE
REFLECT THE MAGNITUDE OF THE COOL AIR MASS. THE WIND ADVISORY WAS
STARTED EARLIER AT 08 UTC DUE TO THE FASTER ARRIVAL OF THE FRONT.
.LONG TERM...(TUESDAY MORNING THROUGH SATURDAY) ISSUED AT 349 PM CDT SAT
MAY 5 2012
AN UPPER-LEVEL LOW WILL BE SITUATED ACROSS THE DESERT SOUTHWEST FROM
TUESDAY INTO WEDNESDAY, WITH AN UPPER-LEVEL TROUGH MOVING FROM THE
UPPER MIDWEST INTO THE GREAT LAKES. DESPITE THE TROUGH DEVELOPING
ACROSS THE SOUTHWEST, WHICH IS OFTEN A FAVORABLE PATTERN FOR
PRECIPITATION ACROSS THE HIGH PLAINS IN MAY, SURFACE TO 850MB HIGH
PRESSURE IN THE WAKE OF THE GREAT LAKES TROUGH WILL MOVE SOUTHWARD
INTO THE CENTRAL PLAIN, SHUNTING THE LOW-LEVEL MOISTURE INTO THE
SOUTHERN PLAINS. ALSO, THE NORTHERN STREAM JET ENERGY WILL TEND TO
SUPPRESS THE SOUTHWESTERN UPPER-LEVEL TROUGH FURTHER SOUTH.
NEVERTHELESS, FRONTOGENESIS ALONG THE EXTREMITY OF THE UPPER MIDWEST
TROUGH, ALONG WITH SOME LOW TO MID-LEVEL MOISTURE, MAY PROMOTE
SHOWER DEVELOPMENT TUESDAY, ESPECIALLY IN FAR WESTERN KANSAS.
AS THE SOUTHWESTERN UPPER-LEVEL SYSTEM PROGRESSES ACROSS THE SOUTHERN
ROCKIES AND INTO TEXAS THROUGH THURSDAY AND FRIDAY, THE BULK (IF NOT
ALL) OF THE PRECIPITATION WILL STAY TO OUR SOUTH. THE BRUNT OF THE
COOLING WITH THE GREAT LAKES TROUGH IS PROGGED BY THE ECMWF/GEM TO
STAY TO OUR NORTH AND EAST. SO HIGH TEMPERATURES OUGHT TO STILL
REACH INTO THE 70S TUESDAY AND WEDNESDAY AND PERHAPS AS HIGH AS 80
BY THURSDAY, WITH LOWS IN THE MID 40S TO LOWER 50S. THESE TEMPERATURES
ARE SEASONABLE FOR EARLY MAY. EVEN AFTER THURSDAY, NO PARTICULARLY
STRONG COLD FRONTS OR HEAT WAVES ARE EXPECTED, WITH MAINLY A
CONTINUATION OF MODERATE TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1213 AM CDT SUN MAY 6 2012
04Z SURFACE ANALYSIS INDICATED A COLD FRONT MOVING SOUTH ACROSS
NORTHWEST KANSAS. THIS FRONT APPEARS TO BE MOVING QUICKER THAN
WHAT THE 00Z NAM OR 00Z GFS SUGGESTED. HRRR APPEARS TO BE MORE
REPRESENTATIVE SO WILL FOLLOW THE QUICKER HRRR ON TIMING OF WIND
SHIFT LATER THIS MORNING AS THIS FRONT CROSSES SOUTHWEST KANSAS.
GUSTY NORTH WINDS WILL DEVELOP BEHIND THIS FRONT EARLY SUNDAY
MORNING WITH SUSTAINED WINDS OF AROUND 25KTS POSSIBLE FOR SEVERAL
HOURS FOLLOWING FROPA. LOW CLOUDS, IFR CIGS, CAN ALSO BE EXPECTED
BEHIND THIS COLD FRONT EARLY SUNDAY. BASED ON ISENTROPIC LIFT
ALONG WITH THE DEPTH OF THIS MOIST LAYER SOME LIGHT DRIZZLE WILL
ALSO BE POSSIBLE. IFR CONDITIONS SHOULD BEGIN TO IMPROVE BY MID
AFTERNOON WITH LOW VFR CONDITIONS BECOMING POSSIBLE TOWARDS 00Z
MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 69 48 70 / 10 20 20 10
GCK 50 68 47 70 / 10 20 20 20
EHA 48 66 47 68 / 10 30 20 20
LBL 50 69 47 68 / 10 20 20 20
HYS 51 70 49 71 / 10 10 10 10
P28 58 73 52 71 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SHORT TERM...FINCH
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
350 AM CDT SUN MAY 6 2012
.DISCUSSION...
MCS IS CURRENTLY ONGOING ACROSS THE CWA AND THERE IS STILL SOME
QUESTION AS TO REDEVELOPMENT POTENTIAL LATER THIS AFTERNOON. A
COLD FRONT WILL SLIDE THROUGH THE REGION SUNDAY NIGHT...WITH
COOLER AND DRIER WEATHER EXPECTED THIS WEEK. THE EXCEPTION WILL BE
TUESDAY...WHEN A POSITIVELY TILTED NORTHERN STREAM WAVE MOVES
ACROSS THE REGION...AND FRIDAY...WHEN ANOTHER COLD FRONT MOVES
THROUGH THE REGION.
TODAY...TRAILING STRATIFORM THUNDERSTORMS COMPLEX CONTINUES TO
MOVE EASTWARD AT A SLIGHTLY FASTER CLIP THAN SHORTRANGE MODELS
INDICATE. THE HRRR IS CONSISTENTLY ABOUT 2 HOURS TOO SLOW...AND
THE 00Z SPC WRF ABOUT AN HOUR TARDY ON ITS EASTWARD PROGRESSION.
AS THIS SYSTEM CLEARS OUT...COULD SEE SOME BOUNDARY LAYER
DESTABILIZATION THIS AFTERNOON NEAR THE IA/MN BORDER.
THIS INSTABILITY IN COMBINATION WITH SEVERAL OUTFLOW BOUNDARIES
AND SOUTHWESTERLY FLOW ALOFT WITH A FEW EMBEDDED WEAK SHORTWAVES
COULD BE THE FOCUS FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON. THE MARGINAL SHEAR AND CAPE VALUES SHOULD KEEP
THE SEVERE THREAT SOUTH AND EAST OF THE CWA.
SUNDAY NIGHT THROUGH SATURDAY...A SURFACE COLD FRONT WILL HAVE
PUSHED THROUGH THE REGION BY SUNDAY NIGHT...WITH MUCH DRIER AIR
IN PLACE BY MONDAY. SHOULD BE A DRY DAY...WITH A FEW AFTERNOON
CUMULUS DEVELOPING. ON TUESDAY THE UPPER LEVEL LOW DRIVING THE
AFOREMENTIONED SURFACE FRONT WILL SLIDE IN FROM THE NORTHWEST. A
WEAK SHORTWAVE WILL ROTATE AROUND THIS UPPER LEVEL LOW...AND COLD
H850 TEMPS WILL STREAM IN FROM THE NORTHWEST. THIS SHOULD SET THE
STAGE FOR A COOL OVERCAST DAY AND SOME AFTERNOON SHOWERS CENTERED
AROUND PEAK HEATING. FOR THE REST OF THE WEEK...HIGHLY AMPLIFIED
FLOW WILL BE THE NAME OF THE GAME. FOR STARTERS...UPPER LEVEL
SUBSIDENCE DOWNSTREAM OF A RIDGE CENTERED OVER MONTANA WILL CAUSE
AN AREA OF SURFACE HIGH PRESSURE TO BUILD OVER THE UPPER MIDWEST
ON WEDNESDAY. THIS WILL QUICKLY BE FOLLOWED BY AN UPPER LEVEL
TROUGH ON THURSDAY...WHICH WILL DEVELOP A SURFACE LOW OUT WEST AND
CAUSE SOUTHERLY WINDS AND WARM AIR ADVECTION TO MOVE ACROSS THE
REGION. AS THIS LOW TRACKS EASTWARD ON FRIDAY...EXPECT ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
HOURS. FINALLY...ANOTHER AREA OF SURFACE HIGH PRESSURE WILL BUILD
IN THE WAKE OF FRIDAY(S) SYSTEM...WHICH SHOULD LEAD TO A DRY
WEEKEND WITH SEASONAL TEMPERATURES.
&&
.AVIATION... /06Z TAF ISSUANCE/
LINE OF CONVECTION EXITING KSTC THROUGH KRWF IS MOVING NEAR 35 KNOTS.
THIS WILL IMPACT THE KMSP AND KRNH AIRFIELDS BETWEEN 07Z AND 09Z.
WEST TO NORTHWEST WINDS REACHING 35 KNOTS ARE POSSIBLE AS THIS
LINE MOVES THROUGH. AN EXTENSIVE AREA OF SHOWERS AND ISOLATED
THUNDERSTORMS WILL OCCUR IN THE WAKE OF THE LINE. KAXN WILL BE ON
THE WESTERN FRINGE. CEILINGS REMAIN A PROBLEM THROUGH THE TAF
PERIOD WITH BKN-OVC008-012 COMMON THROUGH AT LEAST 15Z WITH MVFR
CEILINGS DEVELOPING BY AFTERNOON...ALTHOUGH CONFIDENCE IS NOT
HIGH. SLOW IMPROVEMENT FROM MVFR TO VFR SUNDAY EVENING ALONG WITH
SURFACE WINDS BECOMING NORTHWEST.
KMSP...MAIN CONCERN IS CONVECTION MOVING THROUGH BY 09Z. SOME
THREAT FOR WEST TO NORTHWEST WINDS GUSTING TO 35 KNOTS. CEILINGS
MAY TEMPORARILY IMPROVE TO VFR WITH THE STORMS...BUT EXTENSIVE LOW
MVFR/IFR SHOULD FILL BACK IN BEHIND THIS ACTIVITY. SHOWERS AND
ISOLATED THUNDERSTORMS REMAIN POSSIBLE DURING THE LATE NIGHT
HOURS/SUNDAY MORNING WITH DRY WEATHER FOR THE AFTERNOON. CEILINGS
IMPROVING SUNDAY EVENING TO VFR ALONG WITH INCREASING NORTHWEST
WINDS.
OUTLOOK...
MONDAY...VFR WITH NORTHWEST WINDS 15-20KTS.
TUESDAY...MVFR CIGS POSSIBLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR BLUE EARTH-
BROWN-CARVER-CHIPPEWA-FARIBAULT-FREEBORN-KANDIYOHI-LAC QUI
PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-NICOLLET-POPE-REDWOOD-
RENVILLE-RICE-SCOTT-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-
WASECA-WATONWAN-WRIGHT-YELLOW MEDICINE.
WI...NONE.
&&
$$
JRB/RAH
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
130 AM CDT SUN MAY 6 2012
.AVIATION...
06Z TAFS. MVFR CEILINGS TO HOLD AT KVTN UNTIL 12Z...THEN BKN100.
MVFR CEILING WILL REACH KLBF BY 07Z AND ALSO PERSIST UNTIL 12Z.
WINDS 34015G25KTS THROUGH 00Z/7TH...TO DECOUPLE THEREAFTER. THERE
IS A SLIGHT CHANCE FOR RAIN SHOWERS AT KLBF UNTIL 18Z.
&&
.PREV DISCUSSION... /ISSUED 852 PM CDT SAT MAY 5 2012/
UPDATE...
STORMS HAVE BEEN SLOW TO DEVELOP THIS AFTN AND EVENING AS A STRONG
CAP HAS BEEN IN PLACE. THE CAP APPEARS TO HAVE WEAKENED SOME AFTER
SUNSET AND STORMS HAVE BEGUN TO FIRE ACROSS NCNTL NEB. THIS IS
CLOSE TO THE RUC13 SOLN WHICH WAS THE BASIS FOR A FCST UPDATE THIS
EVENING. WE ALSO SLOW THE DEPARTURE OF THE TSTMS OVERNIGHT AS THE
MODELS APPEAR TO BE TOO FAST AND CARRY LIKELY POPS ACROSS THE
NORTHEAST ZONES TIL MORNING.
HEAVY RAIN APPEARS TO BE THE OPERATIVE MODE IN ADDITION TO THE
SEVERE WEATHER THREAT. THE 310K MOISTURE TRANSPORT VECTORS IN THE
RUC13 ARE THROUGH THE ROOF AND PRECIPITABLE WATER IS FCST TO
APPROACH 1.5 INCHES. NESDIS HAS SENT TWO MESSAGES ALERTING NRN NEB
ABOUT THE POTENTIAL FOR HEAVY RAINFALL.
PREV DISCUSSION... /ISSUED 623 PM CDT SAT MAY 5 2012/
UPDATE...
AVIATION...
SCATTERED SEVERE THUNDERSTORMS MAY PERSIST UNTIL 12Z EAST OF
HIGHWAY 83. ISOLATED STRONG TO SEVERE THUNDESTORMS WEST OF HIGHWAY
83 SHOULD MOVE THROUGH BY 06Z. MVFR CIGS ARE EXPECTED WITH THE
PASSAGE OF A STRONG COLD FRONT CURRENTLY OVER NORTHEAST WYOMING.
VFR IS EXPECTED ALL AREAS BY 12Z. FLIGHT CONDITIONS WILL IMPROVE
FROM WEST TO EAST WITH THE PASSAGE OF THE COLD FRONT THIS EVENING
AND OVERNIGHT.
PREV DISCUSSION... /ISSUED 302 PM CDT SAT MAY 5 2012/
DISCUSSION...STRONG COLD FRONT PLOWS INTO WESTERN AND NORTH CENTRAL
NEB EARLY THIS EVENING...MOISTURE AND INSTABILITY POOLING JUST TO
THE NORTH OF A STATIONARY OUTFLOW BOUNDARY BISECTING THE
AREA...SHOULD ALLOW FOR TSTM DEVELOPMENT ALONG THE FRONT AS IT
MOVES SOUTHEAST. STORMS SHOULD MOVE SOUTHEAST OF THE AREA AFTER
MIDNIGHT AS NORTH WINDS INCREASE BEHIND THE FRONT.
IN THE WAKE OF THE STRONG COLD FRONTAL PASSAGE...MUCH COOLER AND
LESS HUMID CONDITIONS ARE EXPECTED FOR SUNDAY INTO MONDAY. BREEZY TO
WINDY CONDITIONS ARE ALSO EXPECTED SUNDAY MORNING IN THE WAKE OF THE
FRONT. STRONG COLD AIR ADVECTION...COUPLED WITH NAM MODEL FORECASTED
500 METER WINDS AROUND 30 KTS...COULD ALLOW FOR SOME SUSTAINED WINDS
AROUND 25 TO 30 MPH DURING THE MORNING. WINDS SHOULD DECREASE SOME
DURING THE AFTERNOON...AS THE PRESSURE GRADIENT RELAXES AND CAA
ADVECTION WEAKENS. A SECONDARY COLD FRONTAL SURGE IS EXPECTED
MONDAY...WITH NORTHWEST WINDS INCREASING AGAIN.
IN THE UPPER LEVELS...A STRONG UPPER LEVEL LOW...LOCATED ACROSS THE
NORTHERN PLAINS...WILL COMBINE WITH A DISTURBANCE DROPPING SOUTH
THROUGH THE NORTHERN ROCKIES...AND KEEP OUR AREA IN SOUTHWEST FLOW
ALOFT THOUGH MONDAY. WILL INCLUDE A SLIGHT CHANCE FOR SHOWERS ACROSS
FAR SOUTHWEST NEB AND INTO THE SOUTHERN NEB PANHANDLE AS THE
AFOREMENTIONED NORTHERN ROCKIES DISTURBANCE DIVES SOUTH. BEYOND
MONDAY...BOTH THE ECMWF AND GFS MODELS AGREE THAT THE NORTHERN
PLAINS UPPER LEVEL LOW WILL MOVE SOUTHEAST INTO THE GREAT LAKES
REGION. THIS TURNS THE UPPER FLOW TO NORTHWEST ALOFT TUESDAY AND
WEDNESDAY. WITH LIMITED LOW LEVEL MOISTURE...AND NO DISTINCT
SHORTWAVES NOTED WITHIN THE UPPER FLOW...EXPECTING MAINLY DRY
CONDITIONS. LATE IN THE WEEK...THE GREAT LAKES UPPER LEVEL LOW WILL
BE KICKED EAST AS A NEW NORTHERN STREAM ENERGY MOVES INTO SOUTHERN
CANADA. THIS SHOULD DRIVE ANOTHER COLD FRONT SOUTH INTO THE
AREA...ALONG WITH SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS. AT
THIS TIME IT APPEARS THAT LIMITED LOW LEVEL MOISTURE SHOULD KEEP ANY
PRECIPITATION ISOLATED.
TEMPERATURE WISE...MILD CONDITIONS ARE ANTICIPATED SUNDAY THROUGH
TUESDAY...WITH HIGHS IN THE 60S. LOOKING AT THE FROST POTENTIAL FOR
MONDAY MORNING...APPEARS WINS WILL STAY UP ENOUGH TO PRECLUDE MUCH
THREAT. TUESDAY MORNING COULD BE A DIFFERENT STORY...AS SFC HIGH
PRESSURE WILL BE LOCATED JUST WEST OF THE AREA. THIS MAY ALLOW WINDS
ACROSS THE PANHANDLE TO GO NEARLY CALM...AND SOME FROST LOOKS
POSSIBLE IN THAT AREA. TEMPERATURES SHOULD BEGIN TO MODIFY...WITH
HIGHS IN THE 70S WEDNESDAY AND THURSDAY...BEFORE A COOL DOWN BACK
INTO THE 60S FRIDAY AND SATURDAY.
AVAIATION...FOR KVTN AND KLBF...SHORT TERM MODEL GUIDANCE IS
STRUGGLING WITH A SOUTHWARD ADVANCING BOUNDARY GENERATED FROM EARLY
CONVECTION ACROSS CENTRAL SOUTH DAKOTA. SINCE THE SHORT TERM
SOLUTIONS ARE STRUGGLING...CONFIDENCE REMAINS LOW TO MODERATE FOR
THE REMAINING TAF CYCLE...ESPECIALLY IN REGARDS TO STORM COVERAGE
THIS AFTERNOON AND WIND SPEED/DIRECTION. A WARM FRONT WILL LIFT
NORTH ACROSS NORTH CENTRAL NEBRASKA THIS AFTERNOON AND SHOULD
PROVIDE A FOCUS FOR STORM DEVELOPMENT...SOME OF WHICH MAY BE
SEVERE. AS OF NOW THE HIGHEST CONVECTIVE POTENTIAL REMAINS ACROSS
NORTH CENTRAL NEBRASKA...POSSIBLE AFFECTING THE KANW AND KONL
TERMINALS. FURTHER SOUTH HOWEVER...MODELS INDICATE AN ADVANCING
DRYLINE WHICH MAY SUPPORT ADDITIONAL STORM DEVELOPMENT. DUE TO THE
SPORADIC NATURE OF CONVECTIVE STORMS...AND THE FACT THE MODELS ARE
NOT CORRECTLY ASSESSING WHERE CONVECTIVE BOUNDARIES EXIST...FELT IT
WAS BEST TO MENTION IN THIS DISCUSSION AND LEAVE STORM MENTION OUT OF
THE OFFICIAL TAF FORECAST FOR KLBF AND KVTN FOR NOW. HOWEVER NOTE
THAT A VERY UNSTABLE ATMOSPHERE IS EXPECTED LATE THIS AFTERNOON
ALONG AND SOUTH OF THE WARM FRONT. LARGE HAIL...STRONG ERRATIC
THUNDERSTORM WIND GUSTS...AND POSSIBLY TORNADOES WOULD BE POSSIBLE
LATE THIS AFTERNOON/EARLY EVENING WITHIN THIS ENVIRONMENT.
ATTENTION NOW TURNS TO THE WIND POTENTIAL TONIGHT AND LATE IN THE
TAF FORECAST PERIOD. AN UPPER LEVEL WAVE CROSSING THE NORTHERN HIGH
PLAINS WILL DRAG A COLD FRONT THROUGH AREA EARLY THIS EVENING
/00Z-03Z AT VTN...AFTER 03Z AT LBF/. STRONG COLD AIR ADVECTION AND
PRESSURE RISES WILL ALLOW FOR GUSTY NORTHWEST WIND OVERNIGHT...WITH
GUSTS POSSIBLY EXCEEDING 30KTS. EXPECT WIND SPEEDS TO RELAX SOME
LATE IN THE TAF PERIOD /AFTER 15Z/. OTHERWISE STRATUS IS EXPECTED
BEHIND THE FRONTAL PASSAGE...SO IFR WOULD BE EXPECTED AT ALL AREA
TERMINALS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...WFO LBF
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1134 PM CDT SAT MAY 5 2012
.DISCUSSION... SEE AVIATION DISCUSSION BELOW
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS HAVE WEAKENED AND ARE CONFINED TO
MASON...SAN SABA...MCCULLOCH AND ONE ISOLATED SHOWER IN CONCHO
COUNTIES. SEVERE THUNDERSTORMS EARLIER TONIGHT HAVE WEAKENED AND
THE REMAINING SHOWER AREA IS MAINLY MODERATE RAIN AND A STEADILY
LOWERING LIGHTNING THREAT. CURRENTLY THE LINE OF SHOWERS IS MOVING
SOUTHEAST AND SHOULD EXIST THE FORECAST AREA WITHIN THE NEXT FEW
HOURS. THIS SHOWER AREA COMBINED WITH HIGH CLOUDS MOVING OVER THE
AREA FROM THE SOUTHWEST IS CAUSING OVERCAST HIGH CLOUDS OVER MOST
OF THE WARNING AREA. SOME PARTIAL CLEARING OF HIGH CLOUDS FROM
WEST TO EAST IS EXPECTED TOMORROW.
MOST AREAS WILL HAVE VFR FLYING CONDITIONS THE NEXT 24
HOURS...EXCEPT FOR COUNTIES WITH SHOWERS THE NEXT FEW HOURS.
FARTHER SOUTH FORMATION OF LOW CLOUDS OVERNIGHT INTO EARLY MORNING
HOURS PRIMARILY NEAR SONORA AND JUNCTION WILL RESULT IN MVFR OR
LOCALLY IFR CONDITIONS. WINDS WILL CONTINUE GENERALLY FROM THE
SOUTH AT LOW LEVELS AND AT THE SURFACE OVERNIGHT AND INTO TOMORROW
AND REMAIN MOSTLY LESS THAN 15 KTS.
&&
.PREV DISCUSSION... /ISSUED 517 PM CDT SAT MAY 5 2012/
DISCUSSION...
SEE AVIATION DISCUSSION BELOW
AVIATION...
A LINE OF CUMULUS CLOUDS AND ISOLATED SHOWERS IS BEGINNING TO
DEVELOP ALONG A WEAK DRY LINE AXIS FROM JUST EAST OF SONORA TX TO
NORTHWESTERN BROWN COUNTY WITH A SECOND LINE OF CLOUDS EXTENDING
FROM JUST NORTHEAST OF JUNCTION TX TO THE VICINITY OF BRADY TX.
SOME COULD BECOME SEVERE LATER THIS EVENING...A SEVERE THUNDERSTORM WATCH
UNTIL 10 PM CDT HAS BEEN ISSUED FOR COUNTIES NEAR AND EAST OF THIS
LINE...INCLUDING CONCHO...COLEMAN...BROWN...MCCULLOCH...SAN
SABA...MENARD...MASON AND KIMBLE COUNTIES TX. ALONG THIS LINE OF
CUMULUS AND DEVELOPING SHOWERS LOCALLY MVFR AND IFR CONDITIONS ARE
POSSIBLE ALONG WITH GUSTY WINDS NEAR THUNDERSTORMS...SOME
HAIL...LOCALLY HEAVY RAIN AND DANGEROUS LIGHTNING. THESE LOCALLY
LIMITING CONDITIONS ARE LIKELY TO SUBSIDE AFTER MIDNIGHT.
HOWEVER LOCALLY MVFR AND POSSIBLY LOCALLY IFR CONDITIONS ARE
EXPECTED TO DEVELOP ACROSS THE SOUTHEASTERN COUNTIES ESPECIALLY
WHERE RAIN HAS FALLEN BEFORE DAWN AND LINGERING THROUGH EARLY
MORNING HOURS DUE TO DEVELOPMENT OF LOW CLOUDS WITH CAUSING
CEILINGS NEAR OR BELOW 1500 FEET...MOSTLY LIKELY IN KIMBLE...
MASON AND SUTTON COUNTIES TX.
ANOTHER SMALLER AND WEAKER LINE OF DEVELOPING CUMULUS
IS SEEN OVER EAST CENTRAL THROCKMORTON COUNTY...MOVING EAST
SLOWLY. A VAIL OF BROKEN TO TEMPORARILY OVERCAST HIGH CLOUDS IS
STREAMING TOWARD THE NORTHEAST OVER MOST OF THE FORECAST AREA.
MOSTLY VFR CONDITIONS SHOULD PREVAIL NORTH AND WEST OF A LINE FROM
SONORA TX TO SAN ANGELO TX THROUGH ABILENE TX.
PREV DISCUSSION... /ISSUED 400 PM CDT SAT MAY 5 2012/
SHORT TERM...
DRYLINE HAS MOVED EAST INTO OUR WESTERN COUNTIES EARLY THIS
AFTERNOON AND SHOULD CONTINUE TO MOVE QUICKLY EAST AND OVER OUR
EASTERN COUNTIES BY LATE THIS AFTERNOON. LATEST NAM AND RUC ARE
SHOWING AN UPPER SHORTWAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT
MOVING OVER OUR EASTERN COUNTIES...AND THE DRYLINE...BY EARLY THIS
EVENING. GIVEN STRONG AFTERNOON HEARING...SHOULD SEE CONVECTIVE
INITIATION ALONG THE DRYLINE LATER THIS AFTERNOON CONTINUING THROUGH
THE EVENING HOURS. WILL GO WITH A 20 PERCENT CHANCE OF STORMS OVER
THE EASTERN HALF OF THE CWA THROUGH THE EVENING. ANY STORMS THAT
DEVELOP SHOULD ABATE QUICKLY AFTER SUNSET...WILL KEEP A DRY FORECAST
THROUGH THE REMAINDER OF THE NIGHT AND INTO TOMORROW AFTERNOON.
AFTER WARM MORNING LOWS IN THE 70S TOMORROW MORNING...WILL NOT BE
QUITE AS HOT TOMORROW AFTERNOON WITH HIGHS GENERALLY IN THE UPPER
90S ACROSS THE AREA.
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL CONTINUE THIS AFTERNOON WEST OF
A LINE FROM THROCKMORTON TO SAN ANGELO. FIRE WEATHER CONDITIONS
SHOULD EASE SUNDAY WITH ELEVATED CONCERNS CONFINED TO THE WESTERN
CONCHO VALLEY AND WESTERN NORTHERN EDWARDS PLATEAU. MINIMAL FIRE
WEATHER CONDITIONS ARE EXPECTED BEGINNING MONDAY AND CONTINUING
THROUGH THE REMAINDER OF THE WEEK.
LONG TERM...
BIG CHANGES IN STORE FOR WEST CENTRAL TEXAS NEXT WEEK WITH MUCH
COOLER TEMEPERATURES EXPECTED ALONG WITH INCREASING RAIN CHANCES.
A POTENT SHORT WAVE MOVING ACROSS THE NORTHERN ROCKIES WILL SEND
A COLD FRONT SOUTH ACROSS THE AREA SUNDAY NIGHT AND EARLY MONDAY.
THE NAM STALLS THE FRONT JUST SOUTH OF THE I-10 CORRIDOR ON MONDAY
WHILE THE GFS STALLS IT OVER THE CONCHO VALLEY AND HEARTLAND. THINK
THE NAM IS MORE REALISTIC GIVEN ITS BETTER RESOLUTION SO I HAVE THE
FRONT STALLING JUST SOUTH OF THE I-10 CORRDIOR BY MONDAY AFTERNOON.
THE FRONT WILL BRING COOLER TEMPERATURES ON MONDAY WITH AFTERNOON
HIGHS RANGING FROM NEAR 80 ACROSS THE BIG COUNTRY...TO THE LOW TO
MID 80S ELSEWHERE. RAIN CHANCES WILL INCREASE ALONG AND NORTH OF
THE FRONT LATE MONDAY AFTERNOON AND ESPECIALLY MONDAY NIGHT AS LOW
LEVEL WARM AIR ADVECTION INCREASES ATOP THE FRONT AND SYNOPTIC
SCALE LIFT INCREASES AS LEFT EXIT REGION OF THE SUBTROPICAL JET
OVERSPREADS THE AREA.
ON TUESDAY...MODELS SHOW A STRONG SURFACE RIDGE BUILDING SOUTH
ACROSS THE PLAINS WHICH WILL DRIVE THE COLD FRONT WELL SOUTH OF
THE AREA AND BRING BELOW NORMAL TEMPERATURES TO WEST CENTRAL TEXAS
THROUGH THE END OF THE WEEK. A POTENT CLOSED UPPER LOW IS STILL
PROGGED TO MOVE EAST FROM THE BAHA REGION BY MID WEEK AND MOVE
ACROSS WEST TEXAS BY WEEKS END. WHILE THE EXACT EVOLUTION OF THIS
SYSTEM IS STILL IN QUESTION...CINFIDENCE IS INCREASING THAT BENEFICIAL
RAINFALL...POSSIBLY HEAVY....WILL AFFECT WEST CENTRAL TEXAS THIS
COMING WEEK. CURRENT HIGHS ARE FORECAST TO BE IN THE 70S TUESDAY
THROUGH FRIDAY AND THESE NUMBERS MAY BE TOO WARM...ESPECIALLY ON
THURSDAY AS THE UPPER LOW MOVES ACROSS THE AREA. STAY TUNED!
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 72 97 64 81 62 / 20 10 10 20 30
SAN ANGELO 70 100 66 84 64 / 20 10 10 20 40
JUNCTION 71 95 68 87 64 / 30 10 20 20 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/99
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
329 AM CDT SUN MAY 6 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
STRONG 250 MB JET MAX OF 130 KNOTS JUST NORTH OF THE UPPER GREAT
LAKES REGION. A WEAK UPPER RIDGE EXTENDS ACROSS THE MISSISSIPPI
RIVER VALLEY WITH AN UPPER TROUGH OVER THE NORTHERN ROCKIES. THE
RIDGE PUSHES SLOWLY EAST AS THE TROUGH APPROACHES THE NORTHERN
PLAINS LATE TONIGHT. THE STRONGEST UPPER DIVERGENCE OCCURS ACROSS
NORTHERN WISCONSIN CLOSER TO THE ENTRANCE REGION OF THE
JET...ALTHOUGH SOME UPPER DIVERGENCE REMAINS THROUGH MUCH OF THE
DAY AND INTO TONIGHT ACROSS SOUTHERN WISCONSIN.
MAIN MORNING CONCERN IS WITH THE MCS ACROSS MINNESOTA THAT IS
OCCURRING ON THE NOSE OF A MODERATE 850 TO 700 MB JET AROUND 35
KNOTS. THE 700 MB WIND MAX PUSHES INTO WISCONSIN THIS MORNING WITH
THE NOSE OF THE WIND MAX OVER NORTHERN WISCONSIN. MEANWHILE THE
850 MB JET WEAKENS AS IT PUSHES TOWARD WISCONSIN...BEFORE
INCREASING SLIGHTLY THIS AFTERNOON. THE STRONGEST MOISTURE
CONVERGENCE OCCURS NORTH NEAR THE 850 MB WARM FRONT THAT WILL
EXTEND ACROSS NORTHERN WISCONSIN THIS AFTERNOON. AT THE SURFACE
THE WARM FRONT WILL PUSH NORTH AND MAY PUSH INTO FAR SOUTH CENTRAL
WISCONSIN WHERE THE NAM HAS AROUND 1300 J/KG OF 0 TO 1 KM CAPE.
NORTHEAST AREAS AND ALONG LAKE MICHIGAN IN THE SOUTHEAST HAVE
LITTLE CAPE.
LATER TONIGHT THE SURFACE TROUGH/COLD FRONT WILL APPROACH AND PUSH
ACROSS MOST OF THE FORECAST AREA EXCEPT THE FAR EAST. HOWEVER A
WEAK LOW WILL MOVE ACROSS NORTHERN ILLINOIS AS THE WARM FRONT SAGS
BACK SOUTH.
THE 05Z RAPID REFRESH MODEL WEAKENS THE MINNESOTA MCS AND FOCUSES
MOST OF THE PRECIPITATION ACROSS NORTHWEST WISCONSIN WITH JUST
SOME SCATTERED SHOWERS OVER SOUTH CENTRAL WISCONSIN CLOSER TO THE
WEAK CONVERGENCE WITH THE DEVELOPING 850 MB SOUTHWEST FLOW. THE
LOCAL 03Z 4KM WRF MODEL IS MORE AGGRESSIVE AND TAKES THE MCS INTO
THE DELLS AREA AROUND 8 AM CDT AND KEEPS GOING BEFORE REACHING THE
KENOSHA AREA BY NOON CDT.
THE 03Z HRRR IS SOMEWHAT IN BETWEEN WITH A WEAKENING MCS AFFECTING
MAINLY CENTRAL WISCONSIN...ALTHOUGH A BAND OF
SHOWERS/THUNDERSTORMS DO AFFECT THE SOUTH.
FORECAST SOUNDINGS SHOW A MODERATE TO STRONG INVERSION BELOW 2 TO
3 THSD FT...EVEN IN THE SOUTHWEST AREAS THIS MORNING. MID LEVEL
LAPSE RATES ARE AROUND 7 TO 8 C/KM.
00Z NAM INDICATES A WEAKENING MCS THAT WILL AFFECT THE FORECAST
AREA THIS MORNING...THEN THE MAIN FOCUS OF PRECIPITATION SOUTH
ALONG THE SURFACE BOUNDARY AND NORTH ACROSS THE BETTER 850MB
CONVERGENCE... ALTHOUGH QPF OVER MUCH OF THE TIME PERIOD.
THIS APPEARS TO BE THE CONSENSUS SO WILL GO WITH HIGH POPS BUT
WITH NO SPECIAL WORDING. THE NORTH AREAS ACROSS MARQUETTE...GREEN
LAKE AND INTO FOND DU LAC COUNTY IS OF CONCERN DUE TO HEAVY RAIN
THERE A FEW DAYS AGO BUT FLASH FLOOD GUIDANCE VALUES HAVE
RECOVERED TO 2.5 INCH IN ONE HOUR TO 3.3 INCHES IN 6 HOURS...SO
WILL NOT ISSUE ANY FLASH FLOOD WATCHES.
AS FOR SEVERE THREAT...THE HIGHEST AREA ON THE LOCAL CWASP
PROBABILITIES RISE TO 70 PCT AT 18Z OVER SOUTHWEST WISCONSIN THEN
DROP TO 65 PERCENT ACROSS NORTHWEST ILLINOIS BY EARLY EVENING.
THIS MATCHES WELL WITH SPC SLIGHT RISK...AND IS IN AREA OF
MODERATE CAPE VALUES...AND IN THE AREA WHERE THE CAP SHOULD WEAKEN
THIS AFTERNOON. APPEARS HAIL AND TO A SOMEWHAT LESSER EXTENT HIGH
WINDS WILL BE THE THREATS.
TEMPERATURES WILL BE A LITTLE DIFFICULT SINCE THE STABLE COOL AIR
WILL COVER MUCH OF THE FORECAST AREA WITH THE POTENTIAL OF THE
SURFACE BOUNDARY APPROACHING THE FAR SOUTHWEST AREA.
.SHORT TERM...MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM TO HIGH.
SHORT TERM MODELS IN DECENT AGREEMENT WITH PUSHING INVERTED TROUGH
THROUGH THE AREA MONDAY MORNING...ACCOMPANIED BY A SHORTWAVE
TROUGH CLIPPING THE AREA FROM THE SOUTH. WILL KEEP LIKELY POPS
GOING FOR THE MORNING ON MONDAY IN THE EAST...LOWER IN THE WEST.
COLD AIR ADVECTION THEN MOVES INTO THE AREA MONDAY
AFTERNOON...WHICH WILL GRADUALLY DRY OUT AIR COLUMN. TRENDED
DOWNWARD WITH POPS MONDAY AFTERNOON TO REFLECT THIS. TEMPERATURES
WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS INLAND...WITH
SOMEWHAT COOLER READINGS WITH ONSHORE FLOW NEAR THE LAKE.
MODEST COLD AIR ADVECTION CONTINUES MONDAY NIGHT...AND INTO
TUESDAY AND TUESDAY NIGHT. THIS SHOULD BRING ONLY SLIGHTLY COOLER
TEMPERATURES TO THE REGION. MAIN FEATURE WILL BE UPPER LEVEL
TROUGH SLIDING SOUTHEAST THROUGH THE REGION MONDAY NIGHT THROUGH
WEDNESDAY. NAM/GFS FORECAST SOUNDINGS FROM AROUND THE AREA SHOW
WEAK INSTABILITY DEVELOPING TUESDAY AFTERNOON...WITH SOME MOISTURE
AROUND 5000 FEET ABOVE GROUND LEVEL.
GIVEN STEEP LOW LEVEL LAPSE RATES WITH DAYTIME HEATING...WITH
DECENT MID LEVEL LAPSE RATES AS WELL...CONTINUED TO MENTION POPS
FOR SHOWERS. THUNDERSTORM CHANCES APPEAR SMALL GIVEN LACK OF
INSTABILITY REACHING BEYOND THE 10 DEGREE BELOW ZERO CELSIUS
LEVEL. FOR NOW...WILL CONTINUE TO MENTION SLIGHT CHANCES FOR
THUNDER...BUT CONFIDENCE IS MIXED. CONTINUED LOWER END POPS FOR
SHOWERS TUESDAY NIGHT INTO WEDNESDAY AS TROUGH MOVES THROUGH.
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY...FORECAST
CONFIDENCE IS MEDIUM TO HIGH.
ECMWF/GFS IN FAIRLY GOOD AGREEMENT WITH FEATURES IN THIS PERIOD.
THEY SHOW HIGH PRESSURE SLIDING SOUTHEAST ACROSS THE REGION
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...WITH AN UPPER LEVEL RIDGE
PASSING THROUGH. THIS SHOULD BRING QUIET WEATHER WITH SEASONABLE
TEMPERATURES.
NEXT WEATHER SYSTEM IS A COLD FRONT SHIFTING SOUTHEAST THROUGH
THE REGION FRIDAY INTO SATURDAY. MAIN UPPER TROUGH AND VORTICITY
MAXIMA REMAIN NORTH OF THE AREA...BUT ENOUGH MOISTURE AND UPWARD
VERTICAL MOTION WITH FRONT TO MENTION POPS FOR PORTIONS OF THIS
PERIOD.
&&
.AVIATION/12Z TAFS/...
EXPECT MVFR/IFR CIGS OVER MUCH OF THE FORECAST AREA. THE SURFACE
BOUNDARY WILL REMAIN SOUTH OF WISCONSIN FOR THE MOST PART...BUT
MAY TRY TO PUSH NEAR AREAS SOUTHWEST OF MADISON THIS AFTERNOON.
SOME SHOWERS/SCATTERED THUNDERSTORMS AS THE MINNESOTA MCS PUSHES
EAST...BUT IT SHOULD WEAKEN DUE TO THE MORE STABLE AIR OVER
WISCONSIN.
MORE REDEVELOPMENT EXPECTED THIS AFTERNOON/EVENING AS A FRONT
APPROACHES FROM THE WEST TONIGHT.
&&
.MARINE...
PERSISTENT EAST FLOW BUT WINDS SHOULD BE BELOW SMALL CRAFT
CRITERIA. THE WAVES SHOULD REMAIN BELOW CRITERIA. SOME
THUNDERSTORMS ARE ALSO POSSIBLE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
MONDAY THROUGH SATURDAY...WOOD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1030 AM CDT SUN MAY 6 2012
.DISCUSSION...
ISSUED 1030 AM CDT SUN MAY 6 2012
10 AM SFC MAP PLACED A NORTHWARD MOVING WARM FRONT JUST SOUTH OF
I-74. SOUTH OF THE BOUNDARY SOUTHERLY WINDS WERE TRANSPORTING LOW 70S
DEWPOINTS INTO CENTRAL IL. COMBINATION OF VERY WARM/HUMID BOUNDARY
LAYER AND STEEP LAPSE RATES/COOL AIR ALOFT WILL LEAD TO A VERY
UNSTABLE AIRMASS THIS AFTERNOON WITH SURFACE BASED CAPES IN EXCESS
OF 4K J/KG ACROSS THE WESTERN THIRD OF THE CWA. ONE POSSIBLE
MITIGATING FACTOR FOR SEVERE STORMS AT LEAST THROUGH MID AFTERNOON
WILL BE INITIALLY VERY WEAK WIND FIELDS ALOFT. DEEP LAYER SHEAR
SHOULD INCREASE LATE THIS AFTERNOON AND EVENING BASED ON FORECAST
SOUNDINGS...AHEAD OF A SHORT WAVE AND COLD FRONT TO OUR WEST.
THROUGH MID AFTERNOON WILL WATCH FOR CONVECTION AHEAD OF A
WEAKENING THUNDERSTORM COMPLEX MOVING INTO SE IA...AND ALSO ANY
DEVELOPMENT ACROSS THE NRN CWA ALONG AND AHEAD OF THE NORTHWARD
MOVING WARM FRONT. STILL APPEARS BEST TIMEFRAME FOR SEVERE STORMS
WILL BE AFTER 6 PM IN THE WEST. VERY WARM AND HUMID AFTERNOON ON
TAP WITH HIGHS NEAR 90 IN THE FAR SW.
25
&&
.AVIATION...
ISSUED 655 AM CDT SUN MAY 6 2012...FOR THE 12Z TAFS
IFR FOG WILL AFFECT BMI/CMI FOR A COUPLE OF HOURS AT THE START OF THE
TAF PERIOD...WITH MVFR FOG AT DEC/PIA DURING THAT TIME. VERY HIGH
DEWPOINTS IN THE LOW TO MID 60S WILL SET THE STAGE FOR
THUNDERSTORMS TO ARRIVE LATER THIS AFTERNOON AND INTENSIFY AS THE
REACH THE TAF SITES THIS EVENING. THE EXACT TIMING FOR EACH
TERMINAL REMAINS IN QUESTION...SO WE LEFT A VCTS STARTING AT 23Z
FOR PIA AND PROGRESSED TO A 02Z ARRIVAL FOR CMI. LARGE HAIL AND
DAMAGING WINDS WILL BE POSSIBLE TONIGHT AS THE STORMS BECOME MORE
WIDESPREAD.
A WARM FRONT LIFTING NORTH TODAY SHOULD HELP SHIFT THE WIND
DIRECTION SLIGHTLY FROM AN ESE TO A SSE DIRECTION. WIND SPEEDS
THIS AFTERNOON SHOULD SUSTAIN IN THE 12-14KT RANGE WITH GUSTS TO
23-25KT RANGE.
THE COLD FRONT IS NOT EXPECTED TO ARRIVE UNTIL SOMETIME ON
MONDAY...WHICH IS OUTSIDE OF THIS TAF PERIOD. WE CAN NOT RULE OUT
SOME MVFR/IFR FOG LATER TONIGHT BEHIND THE LINE OF THUNDERSTORMS
AND AHEAD OF THE COLD FRONT.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 257 AM CDT SUN MAY 6 2012
FRONTAL BOUNDARY HAS NOT REALLY MOVED OVER THE LAST SEVERAL
HOURS...EXTENDING FROM NORTHWEST IOWA TO NEAR SPRINGFIELD AND
SOUTHEAST INTO SOUTH CENTRAL INDIANA. DEW POINTS IN THE 65-70F
RANGE WERE POOLING ALONG THIS BOUNDARY. SOME LIGHT FOG WAS
OBSERVED NORTH OF THE FRONT WITH VISIBILITIES OF 3-5 MILES. LARGE
MCS STRETCHING FROM CENTRAL MINNESOTA INTO NORTHERN NEBRASKA HAS
PUSHED INTO FAR NORTHWEST IOWA.
SEVERE WEATHER POTENTIAL THROUGH MONDAY REMAINS THE PRIMARY
FORECAST CONCERN.
SHORT TERM...TODAY THROUGH MONDAY...
NORTHWARD SPREAD OF THE WARM SECTOR MAY BE TEMPERED BY THE
INFLUENCES OF THE MCS DEBRIS...BUT SHOULD GET FAR ENOUGH NORTH TO
CLEAR OUR NORTHERN CWA TOWARD MIDDAY. INSTABILITY SHOULD NOT BE A
PROBLEM AS CAPES APPROACH 3000 J/KG BY MIDDAY AND CONVECTIVE
INHIBITION VALUES WANE. TIMING OF THE CONVECTION IS THE TRICKY
PART...WITH THE HRRR LEANING TOWARD EARLY AFTERNOON DEVELOPMENT
WEST OF THE MISSISSIPPI RIVER...AND THE NAM AND LOCAL WRF MODELS
FROM ST LOUIS AND CHICAGO NWS OFFICES BRINGING SOME OF THE MCS
REMNANTS INTO THE NORTHERN CWA LATE THIS MORNING. ATTENDANT COLD
FRONT IS LIKELY TO MOVE INTO THE NORTHWEST CWA EARLY THIS
EVENING...CONTINUING THE STORM THREAT OVERNIGHT. MOST OF THE CWA
REMAINS IN A SLIGHT RISK OF SEVERE WEATHER...EXCEPT EAST OF
I-57...WHERE SEVERE THREAT MAY BE VERY LATE TONIGHT OR MONDAY
MORNING INSTEAD. HAVE CONTINUED WITH RAIN CHANCES MAINLY WEST OF
I-55 THIS AFTERNOON...AND OVERSPREADING THE REMAINDER OF THE CWA
THIS EVENING. HEAVIEST RAIN THREAT LOOKS TO BE JUST TO OUR
NORTH...BUT WILL NEED TO WATCH THE FAR NORTHERN CWA WHICH HAD 1-3
INCHES OF RAIN THURSDAY NIGHT AND FRIDAY MORNING FOR ANY POTENTIAL
HYDROLOGICAL CONCERNS. TIMING OF FRONTAL PASSAGE ON MONDAY SHOULD
BE EARLY AFTERNOON ACROSS THE EASTERN CWA...AND HAVE KEPT LIKELY
POPS GOING IN THAT AREA DURING THE DAY...DIMINISHING IN THE
EVENING.
TEMPERATURE-WISE...WILL LIKELY SEE HIGHS DEEP INTO THE 80S OVER
THE ENTIRE FORECAST AREA...POTENTIALLY NUDGING 90 ACROSS THE
SOUTHWEST CWA. MOST RECORDS TODAY ARE IN THE LOWER 90S AND LIKELY
JUST OUT OF REACH...ALTHOUGH SPRINGFIELD HAS A RECORD HIGH OF 88
WHICH IS IN JEOPARDY. WILL PROBABLY SEE SOME 80 DEGREE READINGS
AGAIN ACROSS THE SOUTHEAST ON MONDAY AHEAD OF THE FRONT...BUT THAT
WILL BE THE LAST OF THE 80S ACROSS OUR CWA FOR THE REMAINDER OF
THE WEEK.
LONG TERM...TUESDAY THROUGH SATURDAY...
A MUCH COOLER AND QUIETER REGIME SETS UP THE REMAINDER OF THE
WEEK. AN UPPER LOW...CURRENTLY LOCATED OVER FAR NORTH CENTRAL
MONTANA PER WATER VAPOR IMAGERY...SHOULD MOVE TO NEAR LAKE
SUPERIOR BY TUESDAY MORNING. ASSOCIATED SURFACE AND UPPER TROUGH
WILL SWING THROUGH THE GREAT LAKES TUESDAY AND WEDNESDAY...WITH
THE COLDER AIR ALOFT HELPING TO TRIGGER A FEW SHOWERS. STILL LOOKS
LIKE THE BEST SUPPORT FOR THIS WILL BE FURTHER TO OUR NORTH...BUT
HAVE INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHEAST CWA ON
WEDNESDAY AS THE TROUGH FULLY PUSHES THROUGH THE STATE.
UPPER RIDGING ACROSS THE ROCKIES AT MIDWEEK WILL RESULT IN A
NORTHWEST FLOW...AND BELOW NORMAL TEMPERATURES...FOR A COUPLE
DAYS IN OUR AREA. LONGER RANGE MODELS SHOWING THE RIDGING PUSHING
EASTWARD LATE IN THE WEEK...WITH A BIT OF MODERATION IN
TEMPERATURES. SURFACE HIGH PRESSURE OVER THE MIDWEST TO PROVIDE
FAIR WEATHER FOR THURSDAY AND FRIDAY...AHEAD OF A SHORTWAVE WHICH
WILL PUSH ACROSS THE NORTHERN STATES LATE IN THE WEEK. MOISTURE
RETURN IN OUR AREA WILL BE MEAGER AHEAD OF THIS SYSTEM...SO RAIN
CHANCES ARE NOT ESPECIALLY HIGH AT THIS TIME. HOWEVER...THE
NORTHWEST CWA SHOULD SEE A FEW SHOWERS AND THUNDERSTORMS BY
SATURDAY AFTERNOON.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
655 AM CDT SUN MAY 6 2012
.DISCUSSION...
ISSUED 257 AM CDT SUN MAY 6 2012
FRONTAL BOUNDARY HAS NOT REALLY MOVED OVER THE LAST SEVERAL
HOURS...EXTENDING FROM NORTHWEST IOWA TO NEAR SPRINGFIELD AND
SOUTHEAST INTO SOUTH CENTRAL INDIANA. DEW POINTS IN THE 65-70F
RANGE WERE POOLING ALONG THIS BOUNDARY. SOME LIGHT FOG WAS
OBSERVED NORTH OF THE FRONT WITH VISIBILITIES OF 3-5 MILES. LARGE
MCS STRETCHING FROM CENTRAL MINNESOTA INTO NORTHERN NEBRASKA HAS
PUSHED INTO FAR NORTHWEST IOWA.
SEVERE WEATHER POTENTIAL THROUGH MONDAY REMAINS THE PRIMARY
FORECAST CONCERN.
SHORT TERM...TODAY THROUGH MONDAY...
NORTHWARD SPREAD OF THE WARM SECTOR MAY BE TEMPERED BY THE
INFLUENCES OF THE MCS DEBRIS...BUT SHOULD GET FAR ENOUGH NORTH TO
CLEAR OUR NORTHERN CWA TOWARD MIDDAY. INSTABILITY SHOULD NOT BE A
PROBLEM AS CAPES APPROACH 3000 J/KG BY MIDDAY AND CONVECTIVE
INHIBITION VALUES WANE. TIMING OF THE CONVECTION IS THE TRICKY
PART...WITH THE HRRR LEANING TOWARD EARLY AFTERNOON DEVELOPMENT
WEST OF THE MISSISSIPPI RIVER...AND THE NAM AND LOCAL WRF MODELS
FROM ST LOUIS AND CHICAGO NWS OFFICES BRINGING SOME OF THE MCS
REMNANTS INTO THE NORTHERN CWA LATE THIS MORNING. ATTENDANT COLD
FRONT IS LIKELY TO MOVE INTO THE NORTHWEST CWA EARLY THIS
EVENING...CONTINUING THE STORM THREAT OVERNIGHT. MOST OF THE CWA
REMAINS IN A SLIGHT RISK OF SEVERE WEATHER...EXCEPT EAST OF
I-57...WHERE SEVERE THREAT MAY BE VERY LATE TONIGHT OR MONDAY
MORNING INSTEAD. HAVE CONTINUED WITH RAIN CHANCES MAINLY WEST OF
I-55 THIS AFTERNOON...AND OVERSPREADING THE REMAINDER OF THE CWA
THIS EVENING. HEAVIEST RAIN THREAT LOOKS TO BE JUST TO OUR
NORTH...BUT WILL NEED TO WATCH THE FAR NORTHERN CWA WHICH HAD 1-3
INCHES OF RAIN THURSDAY NIGHT AND FRIDAY MORNING FOR ANY POTENTIAL
HYDROLOGICAL CONCERNS. TIMING OF FRONTAL PASSAGE ON MONDAY SHOULD
BE EARLY AFTERNOON ACROSS THE EASTERN CWA...AND HAVE KEPT LIKELY
POPS GOING IN THAT AREA DURING THE DAY...DIMINISHING IN THE
EVENING.
TEMPERATURE-WISE...WILL LIKELY SEE HIGHS DEEP INTO THE 80S OVER
THE ENTIRE FORECAST AREA...POTENTIALLY NUDGING 90 ACROSS THE
SOUTHWEST CWA. MOST RECORDS TODAY ARE IN THE LOWER 90S AND LIKELY
JUST OUT OF REACH...ALTHOUGH SPRINGFIELD HAS A RECORD HIGH OF 88
WHICH IS IN JEOPARDY. WILL PROBABLY SEE SOME 80 DEGREE READINGS
AGAIN ACROSS THE SOUTHEAST ON MONDAY AHEAD OF THE FRONT...BUT THAT
WILL BE THE LAST OF THE 80S ACROSS OUR CWA FOR THE REMAINDER OF
THE WEEK.
LONG TERM...TUESDAY THROUGH SATURDAY...
A MUCH COOLER AND QUIETER REGIME SETS UP THE REMAINDER OF THE
WEEK. AN UPPER LOW...CURRENTLY LOCATED OVER FAR NORTH CENTRAL
MONTANA PER WATER VAPOR IMAGERY...SHOULD MOVE TO NEAR LAKE
SUPERIOR BY TUESDAY MORNING. ASSOCIATED SURFACE AND UPPER TROUGH
WILL SWING THROUGH THE GREAT LAKES TUESDAY AND WEDNESDAY...WITH
THE COLDER AIR ALOFT HELPING TO TRIGGER A FEW SHOWERS. STILL LOOKS
LIKE THE BEST SUPPORT FOR THIS WILL BE FURTHER TO OUR NORTH...BUT
HAVE INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHEAST CWA ON
WEDNESDAY AS THE TROUGH FULLY PUSHES THROUGH THE STATE.
UPPER RIDGING ACROSS THE ROCKIES AT MIDWEEK WILL RESULT IN A
NORTHWEST FLOW...AND BELOW NORMAL TEMPERATURES...FOR A COUPLE
DAYS IN OUR AREA. LONGER RANGE MODELS SHOWING THE RIDGING PUSHING
EASTWARD LATE IN THE WEEK...WITH A BIT OF MODERATION IN
TEMPERATURES. SURFACE HIGH PRESSURE OVER THE MIDWEST TO PROVIDE
FAIR WEATHER FOR THURSDAY AND FRIDAY...AHEAD OF A SHORTWAVE WHICH
WILL PUSH ACROSS THE NORTHERN STATES LATE IN THE WEEK. MOISTURE
RETURN IN OUR AREA WILL BE MEAGER AHEAD OF THIS SYSTEM...SO RAIN
CHANCES ARE NOT ESPECIALLY HIGH AT THIS TIME. HOWEVER...THE
NORTHWEST CWA SHOULD SEE A FEW SHOWERS AND THUNDERSTORMS BY
SATURDAY AFTERNOON.
GEELHART
&&
.AVIATION...
ISSUED 655 AM CDT SUN MAY 6 2012...FOR THE 12Z TAFS
IFR FOG WILL AFFECT BMI/CMI FOR A COUPLE OF HOURS AT THE START OF THE
TAF PERIOD...WITH MVFR FOG AT DEC/PIA DURING THAT TIME. VERY HIGH
DEWPOINTS IN THE LOW TO MID 60S WILL SET THE STAGE FOR
THUNDERSTORMS TO ARRIVE LATER THIS AFTERNOON AND INTENSIFY AS THE
REACH THE TAF SITES THIS EVENING. THE EXACT TIMING FOR EACH
TERMINAL REMAINS IN QUESTION...SO WE LEFT A VCTS STARTING AT 23Z
FOR PIA AND PROGRESSED TO A 02Z ARRIVAL FOR CMI. LARGE HAIL AND
DAMAGING WINDS WILL BE POSSIBLE TONIGHT AS THE STORMS BECOME MORE
WIDESPREAD.
A WARM FRONT LIFTING NORTH TODAY SHOULD HELP SHIFT THE WIND
DIRECTION SLIGHTLY FROM AN ESE TO A SSE DIRECTION. WIND SPEEDS
THIS AFTERNOON SHOULD SUSTAIN IN THE 12-14KT RANGE WITH GUSTS TO
23-25KT RANGE.
THE COLD FRONT IS NOT EXPECTED TO ARRIVE UNTIL SOMETIME ON
MONDAY...WHICH IS OUTSIDE OF THIS TAF PERIOD. WE CAN NOT RULE OUT
SOME MVFR/IFR FOG LATER TONIGHT BEHIND THE LINE OF THUNDERSTORMS
AND AHEAD OF THE COLD FRONT.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
646 AM CDT SUN MAY 6 2012
...UPDATE TO AVIATION...
.DISCUSSION...
00Z UPPER AIR DATA AND RECENT WATER VAPOR IMAGERY SHOW THE MAIN
SYSTEM OF NOTE AS THE UPPER LOW SPINNING OVER THE NORTHERN ROCKIES
WITH ANOTHER SHORTWAVE TAKING SHAPE OVER SOUTHERN CALIFORNIA. 0Z
700MB RAOBS SUPPORT A WEAK MID LEVEL WAVE IN SOUTH CENTRAL
COLORADO. PRECIPITABLE WATER LEVELS IN THE CENTRAL AND SOUTHERN
PLAINS WERE COMMONLY IN THE 1-1.5 INCH RANGE...AROUND 150 PERCENT
OF NORMAL. 850MB DEWPOINTS FROM KTOP TO KOUN AND KFWD WERE AROUND
15C. 07Z SURFACE OBSERVATIONS PUT A COLD FRONT FROM SOUTHWEST
KANSAS INTO NORTHWEST IOWA WITH CONVECTION BECOMING MORE
WIDESPREAD IN RECENT HOURS JUST BEHIND IT.
MAIN SYNOPTIC BOUNDARY IS STILL PROGGED TO MOVE THROUGH TODAY FROM
NORTHWEST TO SOUTHEAST...BUT QUESTIONS ARISE WITH WHAT EFFECT THE
UPSTREAM CONVECTION WILL HAVE ON LOW LEVEL CONDITIONS. MODELS OF
VARIOUS SCALES ATTEMPT TO BRING AN OUTFLOW BOUNDARY THROUGH AROUND
MIDDAY...AND GIVEN INCREASING PRECIP IN NEBRASKA...THIS CANNOT BE
DISCOUNTED. ALSO...MID/HIGH CLOUD IS MAKING NORTHEAST PROGRESS OUT
OF TEXAS AND MAY LIMIT INSOLATION. DESPITE THESE CONCERNS...LITTLE
SHOULD CHANGE WITH LARGER SCALE THERMODYNAMICS WITH STEEP LAPSE
RATES UNDER VERY WARM/MOIST LOW LEVELS FOR AT LEAST HIGH INSTABILITY
TO REDEVELOP EVEN AFTER ANY EARLY DAY BOUNDARY/PRECIP COULD MOVE
THROUGH. WILL KEEP PRECIP CHANCES FAIRLY HIGH FOR ESPECIALLY
EASTERN AREAS WHERE MOISTURE/INSTABILITY SHOULD BE GREATER FOR MUCH
OF TODAY AND THIS EVENING. DEEP LAYER SHEAR STILL APPEARS TO BE ON
THE LOWER SIDE THOUGH SOME VEERING IN HEIGHT WILL BE IN PLACE FOR A
MAINLY PULSE EVENT WITH LARGE HAIL AND DOWNBURST WIND POTENTIAL.
PRECIPITABLE WATER VALUES BREACH 1.5 INCHES WITH MULTIPLE ROUNDS OF
PRECIP POSSIBLE TO PRODUCE LOCALLY HEAVY RAINS. WEAK MID LEVEL WAVE
SHOULD PASS THIS EVENING AS WELL FOR ELEVATED SHOWER CHANCES IN
WESTERN AREAS AS WELL. FRONT SHOULD DEEPEN ENOUGH FOR PRECIP TO EXIT
EAST CENTRAL KANSAS BY 12Z MONDAY. HAVE KEPT TODAYS TEMPS ON THE
MODERATE SIDE OF POSSIBILITIES WITH CONFIDENCE IN THE SPECIFICS LOW.
AFTER SKIES CLEAR MONDAY...MAINLY CLEAR AND SEASONABLE CONDITIONS
FOR MUCH OF THE COMING WEEK WITH SLOW MOVING NORTHERN STATES WAVE
MAKING EAST-SOUTHEAST PROGRESS THROUGH THE GREAT LAKES AND THE
CALIFORNIA WAVE CROSSING NORTHWEST MEXICO. REINFORCING SURFACE HIGH
PASSES THROUGH AROUND WEDNESDAY MORNING FOR POTENTIALLY THE COOLEST
TEMPS...THOUGH STILL IN THE 40S. HOW THE MEXICO WAVE AND THE NEXT
FASTER NORTHERN STREAM SYSTEM INTERACT FOR THE LATE WEEK IS MUCH TO
BE DETERMINED...BUT A LEAST SMALL PRECIP CHANCES ARE STILL IN ORDER.
65
&&
.AVIATION...
OUTFLOW BOUNDARY FROM NEBRASKA CONVECTION HAS MOVED THROUGH MHK
TERMINAL ALREADY AND LOWERING CIGS TO MVFR AND SHIFTING WINDS TO
THE NORTH. THIS SHOULD LAST UNTIL ABOUT 15Z THEN BECOME VFR AGAIN.
FURTHER EAST TO TOP AND FOE THE HRRR WASHES OUT THE BOUNDARY THIS
MORNING. WINDS MAY BECOME LIGHT AND VARIABLE THEN BECOME SOUTHEAST
TO SOUTH AGAIN. TIMING OF CONVECTION A LITTLE TRICKY AS MAIN COLD
FRONT WILL MOVE THROUGH LATER TODAY...WENT VCTS AFTER 18Z THEN
ADDED A TEMPO GROUP FOR TOP AND FOE WITH MVFR CIGS AND VSBYS.
CONVECTION SHOULD CLEAR THE TERMINALS BY 03Z WITH SOME -SHRA
THEREAFTER.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
600 AM CDT SUN MAY 6 2012
...UPDATE TO AVIATION FOR 12Z TAFS...
.SYNOPSIS...
ISSUED AT 117 AM CDT SUN MAY 6 2012
AT 00Z SUNDAY AN UPPER LEVEL TROUGH WHICH WAS ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN WYOMING. A SURFACE COLD FRONT
EXTENDED FROM NORTHEAST COLORADO INTO NORTHEAST NEBRASKA. SOUTH OF
THIS COLD FRONT WARM MID LEVEL TEMPERATURES WERE PRESENT ACROSS
WESTERN KANSAS WITH KDDC INDICATING 700MB TEMPERATURES AT +13C. AS
OF 06Z SURFACE ANALYSIS INDICATED THIS COLD FRONT WAS ALREADY
SURGING SOUTHEAST TOWARDS WEST CENTRAL KANSAS WITH LOW CLOUDS AND
NORTHWEST WINDS AROUND 25KNOTS DEVELOPING IN ITS WAKE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 117 AM CDT SUN MAY 6 2012
BASED ON 925-850MB MOISTURE PROFILES THE MODELS THIS MORNING
REMAIN IN GOOD AGREEMENT IN LOW LEVEL MOISTURE RETURNING TO
SOUTHWEST KANSAS BEHIND A COLD FRONT THAT WAS CURRENTLY MOVING
INTO WEST CENTRAL KANSAS. NAM AND GFS 300-305 ISENTROPIC SURFACES
EVEN SUGGEST SOME WEAK LIFT WILL CONTINUE THROUGH 00Z MONDAY.
BASED ON THIS WEAK LIFT AND DEPTH OF THIS MOIST LAYER WILL KEEP A
MENTION OF DRIZZLE GOING THROUGH MUCH OF THE DAY, ESPECIALLY
NORTHEAST OF DODGE CITY WHERE THE ISENTROPIC LIFT IS A LITTLE
BETTER. GIVEN THE CHANCE FOR DRIZZLE ALONG WITH CLOUDY CONDITIONS
THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH AFTERNOON
TEMPERATURES RANGING FROM THE LOW TO MID 60S WITH THE EXCEPTION
BEING SOUTH CENTRAL KANSAS. WILL HAVE TO MONITOR HOW QUICKLY THIS
FRONT WILL CROSS SOUTH CENTRAL KANSAS EARLY THIS MORNING BUT AT
THIS TIME BASED ON 06Z SURFACE OBSERVATION ACROSS NORTHWEST KANSAS
IT APPEARS THAT THE NAM MAY BE A LITTLE SLOW SO ADJUSTING THE
TIMING OF THIS FRONT CLOSE TO THE HRRR WILL CONTINUE TO FAVOR
SLIGHTLY COOLER TEMPERATURES IN THE MEDICINE LODGE AREA THAN WHAT
THE NAM/GFS SUGGEST.
BOUNDARY LAYER AND 0-0.5KM LAYER WINDS BEHIND THIS COLD FRONT
ACROSS WESTERN KANSAS EARLY TODAY BOTH WERE FORECAST TO RANGE BETWEEN
30 AND 35 KNOTS BEHIND THIS FRONT. GIVEN THIS AND THE LOCATION OF
WHERE THE STRONGER LOW LEVEL WINDS ARE FORECAST TO BE BETWEEN 09Z
AND 15Z SUNDAY WILL KEEP CURRENT WIND ADVISORY AS IS FOR NOW.
MARGINAL WIND ADVISORY WINDS HOWEVER STILL APPEAR POSSIBLE A
LITTLE FURTHER SOUTHEAST, HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT
THIS TIME TO EXPAND THE PREVIOUS ADVISORY.
SURFACE HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE ARE EARLY
TONIGHT AND 300-305 ISENTROPIC DOWN GLIDE DEVELOPS. LOW LEVEL
MOISTURE STILL PRESENT OVER WESTERN KANSAS THROUGH MUCH OF THE
NIGHT BUT GIVEN THE SUBSIDENCE/DOWN GLIDE SUGGESTED WILL BEGIN TO
SHOW A DECREASING TREND IN CLOUD COVER BY OR SHORTLY AFTER
MIDNIGHT...ESPECIALLY IN THE NORTH. IN AREAS WHERE THE SKIES ARE
EXPECTED TO CLEAR WILL TREND TOWARDS THE COOLER MET/MAV ON
TEMPERATURES WHILE FURTHER SOUTHEAST WILL CONTINUE TO FAVOR THE
WARMER MOSGUIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 6 2012
MONDAY:
A RATHER BROAD UPPER LEVEL TROUGH WILL BE WEST OF KANSAS MONDAY. WESTERN
KANSAS WILL BE IN A QUASI COUPLED JET REGION WITH THE LEFT EXIT REGION
OF A 250 HPA 70 KT JET ACROSS THE EASTERN SECTIONS OF THE DESERT SOUTHWEST
AND THE RIGHT ENTRANCE REGION OF A 250 HPA 65 KT JET ACROSS NEBRASKA.
AS A RESULT, HAVE KEPT POPS MAINLY ACROSS FAR SOUTHWEST KANSAS WHERE
BETTER LIFT WILL BE PRESENT VERSUS FURTHER EAST. NOT PARTICULARLY IMPRESSED
OVERALL AS MOST OF THE QPF SHOULD REMAIN ACROSS THE HIGHER TERRAIN ALSO
IN ASSOCIATION WITH OROGRAPHIC LIFT AND UPSLOPE FLOW IN A POST FRONTAL
ENVIRONMENT. A 1025 HPA HIGH WILL SLIDE DOWN THE PLAINS IN THE WAKE
OF THE AFOREMENTIONED FRONT. THIS AIRMASS WILL BE CHARACTERIZED AS PLEASANT
WITH 850 HPA TEMPERATURES NOT TOO WARM (~10-12 DEG C). UPPER 60S DEG
F TO LOWER 70S DEG F IS EXPECTED FOR THE BEGINNING OF THE WORKWEEK
WHICH IS JUST A HAIR BELOW CLIMATOLOGY.
TUESDAY:
THE DESERT SOUTHWEST SYSTEM WILL CONTINUE TO SINK SOUTHWARD INTO THE
BAJA REGION WHILE THE NORTHERN SYSTEM MOVES EAST. SOUTHWEST KANSAS WILL
BE LEFT IN A COL POINT AT THE UPPER LEVELS. AT THE SURFACE, THE COOL
HIGH PRESSURE CENTER WILL CONTINUE TO DOMINATE. RICH BOUNDARY MOISTURE
WILL BE ADVECTED WELL SOUTH INTO TEXAS WITH FAIRLY LOW DEWPOINTS ACROSS
THE SUNFLOWER STATE. AS A RESULT, OVERNIGHT LOWS INTO TUESDAY MORNING
WILL BE MAINLY IN THE 40S DEG F EXCEPT NEAR KP28 WHERE AROUND 50 DEG
F IS EXPECTED. LOW TEMPERATURES IN THE 40S DEG F ARE NEAR CLIMATOLOGY.
A LACK OF DYNAMICS ALOFT AND HIGH PRESSURE AT THE SURFACE WILL LEAD
TO A DRY FORECAST FOR TUESDAY.
WEDNESDAY/THURSDAY:
MAXIMUM TEMPERATURES WILL MODERATE WEDNESDAY WITH HIGHS IN THE MID 70S
DEG F OR ABOUT NEAR NORMAL AS THE COOL HIGH PRESSURE SLIDES OFF TO THE
EAST AND LEE TROUGHING AND RESULTANT WARM AIR ADVECTION DEVELOPS ACROSS
THE HIGH PLAINS. POPS WILL REMAIN NEAR ZERO AS THE 500 HPA RIDGE AXIS
SLIDES EAST THROUGH THE DAY AHEAD OF ANOTHER SHORTWAVE TROUGH MOVING
ONSHORE ACROSS THE PACIFIC NORTHWEST. THURSDAY WILL BE THE WARMEST DURING
MY PERIOD AS 850 HPA TEMPERATURES WARM INTO THE LOWER 20 DEG C AND LEE
TROUGHING STRENGTHENS WITH SOUTHERLY WINDS CONTINUING FROM THE SURFACE
AND THROUGH THE 850 HPA CONSTANT PRESSURE LAYER. RETURN OF RICH BOUNDARY
LAYER MOISTURE IS NOT EXPECTED AT THIS POINT AS A COLD FRONT WILL SCOUR
HIGHER DEWPOINTS SOUTHWARD ACROSS THE NORTHERN GULF OF MEXICO BASIN.
FRIDAY AND BEYOND:
THE FORECAST TURNS MORE UNSETTLED BY THE END OF NEXT WEEK ALTHOUGH UNCERTAINTY
IS PRETTY HIGH AS THIS POINT. PRECIPITATION MAY OCCUR EITHER FROM A
NORTHERN SYSTEM BRINGING IN A COLD FRONT OR FROM THE BAJA SYSTEM BRING
IN MOISTURE FROM THE SOUTH. AT THIS POINT, THE EXACT SOLUTION IS UNKNOWN.
PREFER THE DRIER SOLUTION FROM THE ECMWF. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE AS LIFT AND MOISTURE ADVECTION INCREASES DURING THIS
PERIOD. EVEN IF YOU WERE TO BUY THE WETTER GFS SOLUTION, DEWPOINTS
RETURNING TO KANSAS ARE NOT THAT IMPRESSIVE FOR MAY - 50S DEG F.
DEWPOINTS IN THE 60S/70S DEG F ARE STILL FORECAST TO BE REMAIN WELL
SOUTH INTO THE GULF OF MEXICO. LASTLY, UPPER LEVEL JET DYNAMICS IS
ALSO WEAK WITH THE CUT OFF LOW REMAINING WELL SOUTH ACROSS TEXAS AND
THE STRONGER POLAR JET FORECAST WELL NORTH NEAR THE INTERNATIONAL
BORDER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 600 AM CDT SUN MAY 6 2012
MVFR/IFR CIGS EXPECTED TODAY IN ASSOCIATION WITH POST FRONTAL STRATUS.
CIGS SHOULD IMPROVE TO VFR BY THE EARLY AFTERNOON. SECOND CONCERN IS
WINDS WHICH SHOULD BE IN THE NORTHERLY 20 TO 30 KT RANGE WITH GUSTS
35 TO 40 KT. THE STRONGEST WINDS ARE EXPECTED AT KGCK AND THE LOWEST
CIGS ARE EXPECTED AT KHYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 50 68 46 / 20 10 10 10
GCK 65 44 67 45 / 10 10 20 20
EHA 70 46 65 45 / 10 10 20 20
LBL 71 47 68 46 / 10 10 20 20
HYS 67 46 69 45 / 20 20 10 10
P28 79 57 71 50 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1145 AM EDT SUN MAY 6 2012
.SYNOPSIS...
ISSUED AT 400 AM EDT SUN MAY 6 2012
HIGH PRESSURE WILL RESULT IN DRY WEATHER ACROSS LOWER MICHIGAN
THROUGH MIDDAY SUNDAY. THE NEXT LOW PRESSURE SYSTEM WILL BRING A
CHANCE OF SHOWERS AND A FEW TSTORMS AS EARLY AS THIS AFTERNOON. RAIN
AND THUNDERSTORMS ARE LIKELY ACROSS OUR AREA TONIGHT INTO MONDAY. A
FEW SHOWERS WILL LINGER THROUGH MIDWEEK BEFORE HIGH PRESSURE BUILDS
IN AND BRINGS FAIR WEATHER LATE IN THE WEEK.
&&
.UPDATE...
ISSUED AT 1145 AM EDT SUN MAY 6 2012
I HAVE ONCE AGAIN UPDATED THE GRIDS AND ZONES TO REFLECT AN
INCREASED THREAT FOR MID TO LATE AFTERNOON THUNDERSTORMS OVER THE
WESTERN CWA. THE LATEST RUC DATA SHOWS THE CONVECTION IS FOLLOWING
THE 1000 TO 850 MOISTURE TRANSPORT VECTOR CONVERGENCE AXIS. THIS
AREA MOVES INTO SOUTHWEST LOWER MICHIGAN (NEAR AND WEST OF US-131)
BY 4 PM. THE ADJUSTED TIME TOOL INFO SLOWS THE ARRIVAL TO OUR
BEACHES ON LAKE MICHIGAN UNTIL 330 PM. WE WILL CONTINUE TO MONITOR
THIS SITUATION. THE RAP SHOWS THE LLJ WEAKEN AS IT MOVES INTO
SOUTHWEST MICHIGAN AND MOST UNSTABLE CAPE STRUGGLES TO MAKE US-31
EVEN BY 00Z. SO THE STORMS SHOULD WEAKEN BUT THE WESTERN SECTIONS
SHOULD AT LEAST SEE SOME SHOWERS MID TO LATE AFTERNOON.
.SHORT TERM...(TODAY THROUGH MONDAY AFTERNOON)
ISSUED AT 400 AM EDT SUN MAY 6 2012
SHORT TERM FCST CONCERNS INVOLVE TIMING OF RAIN/CONVECTION INTO OUR
AREA THIS AFTERNOON THROUGH MONDAY.
RGNL IR SAT/RADAR TRENDS AND A CONSENSUS OF 00Z SHORT RANGE GUIDANCE
ALL SUGGEST THAT DRY CONDITIONS WILL PREVAIL ACROSS OUR FCST AREA
THROUGH MIDDAY/EARLY AFTN.
WE WILL MAINTAIN CHC POPS FOR SHOWERS FOR PORTIONS OF OUR AREA THIS
AFTN AS A LARGE AREA OF RAIN AND TSTORMS OVER MN EARLY THIS MORNING
MOVES ESE INTO WI LATER THIS MORNING. RAIN MAY REACH OUR WESTERN
FCST AREA TOWARD MID AFTERNOON. CONVECTION WILL LIKELY BE
DISSIPATING AS SUGGESTED BY 00Z 4KM WRF-NMM SIM Z GUIDANCE. SO IT
SHOULD BE JUST DISSIPATING SHOWERS TRYING TO MOVE IN FROM THE WNW
TOWARD MID TO LATE AFTN... PERHAPS AN ISOLATED STORM DEPENDING ON
HOW WELL THE MCV HOLDS TOGETHER.
RAIN WILL INCREASE IN COVERAGE LATE TONIGHT THROUGH MONDAY ALONG
WITH SOME TSTORMS AS ELEVATED INSTABILITY INCREASES WITH H8 LI/S
FALLING TO AROUND 0 TO -1 OVERNIGHT THROUGH MONDAY. UPPER DIVERGENCE
IS ALSO FAVORABLE FOR SOME TSTORMS TONIGHT AND PRECIPITABLE WATER
VALUES RAMP UP TO AROUND 1.5 INCHES LATE TONIGHT THROUGH MONDAY
AFTN. SO WE WILL MAINTAIN LIKELY POPS TONIGHT/MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 AM EDT SUN MAY 6 2012
EARLY WEEK SYSTEM WILL BE SLIDING JUST EAST OF THE AREA MONDAY
NIGHT...TAKING SHOWERS AND A FEW STORMS OFF TO THE EAST DURING THE
EVENING. EXPECT A DRY OVERNIGHT MONDAY NIGHT.
MAIN LONG TERM FEATURE WILL BE AN UPPER TROUGH SWINGING THROUGH THE
GREAT LAKES REGION MID WEEK. THE TROUGH PIVOTS IN FROM THE NORTHWEST
ON TUESDAY...CENTERED OVER THE FORECAST AREA TUESDAY NIGHT AND
WEDNESDAY. BEST CHANCES FOR SHOWERS ASSOCIATED WITH THE UPPER TROUGH
WILL COME TUESDAY NIGHT AND WEDNESDAY. OVERALL...MOISTURE DEPTH IS
NOT REAL IMPRESSIVE...SO HAVE CHANCE POPS IN THE FORECAST FOR
NOW...30/40 PCT.
DRY WEATHER SHOULD RETURN FOR WEDNESDAY NIGHT THROUGH FRIDAY AS
RIDGING BUILDS BACK INTO THE AREA. A FRONT APPROACHES AND MOVES
THROUGH FROM THE NORTHWEST FRIDAY NIGHT AND SATURDAY. CHANCE POPS
FOR SHOWERS FOR NOW AS A NARROW RIBBON OF MOISTURE MOVES THROUGH.
A COOLING TREND IS EXPECTED INTO MID WEEK AS THE UPPER TROUGH SWINGS
THROUGH. 850MB TEMPS DROP INTO THE 0 TO +4C RANGE. WEDNESDAY LOOKS
TO BE THE COOLEST DAY WITH HIGHS ONLY REACHING THE MID TO UPPER 50S
IN MOST SPOTS. SOUTHWEST FLOW BRINGS A RETURN OF WARMER AIR FOR
FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 746 AM EDT SUN MAY 6 2012
VFR CEILINGS WITH BASES AROUND 3500FT WERE PREVALENT ACROSS
SOUTHWEST LOWER MICHIGAN AT 1130Z. MVFR CEILINGS WERE NOTED AT
KGRR AND KMKG. THE EXPECTATION IS THE MVFR CEILINGS WILL LIFT TO
VFR LEVELS BY 15Z...WITH VFR CONDITIONS PERSISTING THROUGH THE
AFTERNOON.
MAIN CONCERN TODAY WILL BE THE UPSTREAM SHOWERS AND THUNDERSTORMS
OVER WISCONSIN. IT WILL TAKE UNTIL ABOUT 18Z FOR THEM TO REACH
WESTERN LOWER MICHIGAN AT THE CURRENT PACE. THE SHOWERS AND STORMS
SHOULD OUT RUN BETTER INSTABILITY AND BEGIN TO DISSIPATE AS THEY
HIT LAKE MICHIGAN. ITS CONCEIVABLE SOME SHOWERS WILL SURVIVE AND
MOVE INTO THE AREA THIS AFTERNOON...BUT FEEL STORMS WILL HOLD OFF
UNTIL TONIGHT.
A BETTER CHANCE FOR SHOWERS AND STORMS EXISTS TONIGHT AFTER ABOUT
02Z...AS MOISTURE FEEDS INTO THE AREA ON SOUTHERLY WINDS ALOFT.
LOOK FOR MVFR CONDITIONS TO DEVELOP OVERNIGHT AS THE SHOWERS AND
STORMS BECOME MORE NUMEROUS.
&&
.MARINE...
ISSUED AT 400 AM EDT SUN MAY 6 2012
RATHER MINIMAL WAVE ACTION ANTICIPATED TODAY THROUGH TONIGHT INTO
MONDAY DUE TO OFFSHORE EASTERLY WINDS..
&&
.HYDROLOGY...
ISSUED AT 400 AM EDT SUN MAY 6 2012
LOW PRESSURE MOVING IN FROM THE WEST WILL BRING A CHANCE OF SHOWERS
THIS AFTERNOON FOLLOWED BY MORE WIDESPREAD RAINFALL AND TSTORMS
TONIGHT AND MONDAY. LOCALLY HEAVY RAINFALL IS POSSIBLE LATE TONIGHT
THROUGH MONDAY AS PRECIPITABLE WATER VALUES CLIMB TO AROUND 1.5
INCHES IN THAT TIME FRAME.
1000-850 MB MOISTURE TRANSPORT DOES NOT LOOK VERY IMPRESSIVE BUT
DEEPER MOISTURE DOES MOVE IN TONIGHT AND MONDAY. BASIN AVG QPF
AMOUNTS TONIGHT THROUGH MONDAY SHOULD AVERAGE AROUND A HALF AN INCH
TO AN INCH... WITH LOCALLY HIGHER VALUES TO TWO INCHES POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
618 AM CDT SUN MAY 6 2012
.DISCUSSION...
MCS IS CURRENTLY ONGOING ACROSS THE CWA AND THERE IS STILL SOME
QUESTION AS TO REDEVELOPMENT POTENTIAL LATER THIS AFTERNOON. A
COLD FRONT WILL SLIDE THROUGH THE REGION SUNDAY NIGHT...WITH
COOLER AND DRIER WEATHER EXPECTED THIS WEEK. THE EXCEPTION WILL BE
TUESDAY...WHEN A POSITIVELY TILTED NORTHERN STREAM WAVE MOVES
ACROSS THE REGION...AND FRIDAY...WHEN ANOTHER COLD FRONT MOVES
THROUGH THE REGION.
TODAY...TRAILING STRATIFORM THUNDERSTORMS COMPLEX CONTINUES TO
MOVE EASTWARD AT A SLIGHTLY FASTER CLIP THAN SHORTRANGE MODELS
INDICATE. THE HRRR IS CONSISTENTLY ABOUT 2 HOURS TOO SLOW...AND
THE 00Z SPC WRF ABOUT AN HOUR TARDY ON ITS EASTWARD PROGRESSION.
AS THIS SYSTEM CLEARS OUT...COULD SEE SOME BOUNDARY LAYER
DESTABILIZATION THIS AFTERNOON NEAR THE IA/MN BORDER.
THIS INSTABILITY IN COMBINATION WITH SEVERAL OUTFLOW BOUNDARIES
AND SOUTHWESTERLY FLOW ALOFT WITH A FEW EMBEDDED WEAK SHORTWAVES
COULD BE THE FOCUS FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON. THE MARGINAL SHEAR AND CAPE VALUES SHOULD KEEP
THE SEVERE THREAT SOUTH AND EAST OF THE CWA.
SUNDAY NIGHT THROUGH SATURDAY...A SURFACE COLD FRONT WILL HAVE
PUSHED THROUGH THE REGION BY SUNDAY NIGHT...WITH MUCH DRIER AIR
IN PLACE BY MONDAY. SHOULD BE A DRY DAY...WITH A FEW AFTERNOON
CUMULUS DEVELOPING. ON TUESDAY THE UPPER LEVEL LOW DRIVING THE
AFOREMENTIONED SURFACE FRONT WILL SLIDE IN FROM THE NORTHWEST. A
WEAK SHORTWAVE WILL ROTATE AROUND THIS UPPER LEVEL LOW...AND COLD
H850 TEMPS WILL STREAM IN FROM THE NORTHWEST. THIS SHOULD SET THE
STAGE FOR A COOL OVERCAST DAY AND SOME AFTERNOON SHOWERS CENTERED
AROUND PEAK HEATING. FOR THE REST OF THE WEEK...HIGHLY AMPLIFIED
FLOW WILL BE THE NAME OF THE GAME. FOR STARTERS...UPPER LEVEL
SUBSIDENCE DOWNSTREAM OF A RIDGE CENTERED OVER MONTANA WILL CAUSE
AN AREA OF SURFACE HIGH PRESSURE TO BUILD OVER THE UPPER MIDWEST
ON WEDNESDAY. THIS WILL QUICKLY BE FOLLOWED BY AN UPPER LEVEL
TROUGH ON THURSDAY...WHICH WILL DEVELOP A SURFACE LOW OUT WEST AND
CAUSE SOUTHERLY WINDS AND WARM AIR ADVECTION TO MOVE ACROSS THE
REGION. AS THIS LOW TRACKS EASTWARD ON FRIDAY...EXPECT ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
HOURS. FINALLY...ANOTHER AREA OF SURFACE HIGH PRESSURE WILL BUILD
IN THE WAKE OF FRIDAY(S) SYSTEM...WHICH SHOULD LEAD TO A DRY
WEEKEND WITH SEASONAL TEMPERATURES.
&&
.AVIATION... /12Z TAF ISSUANCE/
BACK EDGE OF THE SHOWER/TSTM ACTIVITY OVER THE MIDWEST CONTINUE TO
SLOWLY MOVE EAST THROUGH EASTERN MN AND WESTERN WISCONSIN THIS
MORNING. EXPECT SOME ISOLATED THUNDERSTORMS TO LINGER INTO THE
AFTERNOON OVER PARTS OF WEST CENTRAL WISCONSIN...BEFORE THE PRECIP
FINALLY PUSH OUT EARLY THIS EVENING. AN UPPER LOW PRESSURE AREA
OVER THE NORTHERN PLAINS...WILL CONTINUE TO LIFT NORTHEAST AS DRIER
AIR BEGINS TO FILTER INTO WESTERN MN TODAY AND INTO WESTERN
WISCONSIN TONIGHT. IFR/MVFR CONDITIONS PREVAILING THROUGH MUCH OF
THE DAY. BECOMING VFR OVER WESTERN MINNESOTA THIS EVENING...AS HIGH
PRESSURE BUILDS OVER THE AREA. CONDITIONS IMPROVING OVER THE REST OF
THE FORECAST AREA TONIGHT.
KMSP...WIDESPREAD CEILINGS BELOW 1000 FEET AGL THIS MORNING...RAIN
SLOWLY MOVING OFF TO THE EAST BY EARLY AFTERNOON. WEATHER CONDITIONS
IMPROVING LATER TODAY...THEN BECOMING MOSTLY CLEAR SKIES AFTER
MIDNIGHT. WINDS EASTERLY 10-15 KNOTS...THEN BECOMING WESTERLY AROUND
10 KNOTS BY THIS EVENING.
OUTLOOK...
MONDAY...VFR WITH NORTHWEST WINDS 15-20KTS.
TUESDAY...MVFR CIGS POSSIBLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JRB/JVM
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
956 AM CDT SUN MAY 6 2012
.UPDATE...
WIND SPEEDS HAVE DIMINISHED BELOW CRITERIA LEVEL THIS
MORNING...THUS WILL CANCEL THE ADVISORY EARLY...HOWEVER NORTHERLY
WINDS GUSTS TO 25 MPH MAY STILL BE POSSIBLE THROUGH EARLY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 640 AM CDT SUN MAY 6 2012/
AVIATION...
12Z TAFS.
RECENT MVFR CEILINGS HAVE BECOME SCT020 AT KLBF. VFR CEILING NEAR
BKN080 MAY BE SCT080 AT TIMES...ARE FORECAST FOR REMAINDER OF
KLBF TAF. ALSO VFR CONDITIONS FOR REMAINDER OF KVTN TAF. STRONGER
WINDS 34022G28KT AT KLBF UNTIL 18Z TO GRADUALLY DIMINISH THROUGH
THE AFTERNOON. THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS OR AN
ISOLATED TSRA AT KLBF. WILL NOT MENTION ATTM...WITH NO RADAR
RETURNS AND RUC FORECAST DRY.
PREV DISCUSSION... /ISSUED 400 AM CDT SUN MAY 6 2012/
SYNOPSIS...
COLD FRONT HAS PUSHED INTO FAR NW CWA...AS OF 09Z. TEMPS IN THE
40S BEHIND THE FRONT ACROSS THE PANHANDLE...AND IN THE LOWER 30S
ACROSS MUCH OF WY. SECONDARY FRONT ALONG THE EASTERN ZONES. BOTH
BOUNDARIES ARE PRODUCING SOME RAIN SHOWERS...WITH MORE COVERAGE
AND A FEW LIGHTNING STRIKES WITH THE EASTERN ONE. NORTH WINDS HAVE
PICKED UP ACROSS THE AREA...WITH A FEW SITES CLOSE TO ADVISORY
CRITERIA...30 MPH.
DISCUSSION...
COLD FRONT WILL CONTINUE TO PUSH EAST ACROSS THE AREA THIS
MORNING. ISOLATED TO SCATTERED RAIN SHOWERS WILL FOLLOW NEAR THE
FRONT. ALSO MODELS INCREASE 850 MB WINDS THIS MORNING ACROSS SW
INTO CENTRAL NEB CLOSE TO 50 KTS. HAVING MIXED SOME HIGHER WINDS
TO THE SURFACE ALREADY...WENT AHEAD AND HOISTED A SHORT DURATION
WIND ADVISORY WHERE HIGHEST WINDS THIS MORNING AREA EXPECTED. HIGH
PRESSURE WILL BEGIN TO PUSH INTO THE REGION THIS AFTERNOON AND
TONIGHT...WHICH SHOULD DECREASE WINDS BELOW ADVISORY CRITERIA.
ALSO EXPECTED LINGERING SHOWERS POSSIBLY INTO THE EARLY AFTERNOON
HOURS. A BETTER SHOT FOR PRECIP WILL BE DURING THE MORNING HOURS.
HIGHS WILL HOLD NEAR OR BELOW NORMAL DUE TO AN INCREASE OF CLOUD
COVER...IN THE 60S.
TONIGHT INTO MID WEEK A GENERALLY QUITE WEATHER PATTERN DEVELOPS.
HIGHS IN THE 60S AND A FEW LOWER 70S. STORM TRACK TO THE NORTH
WITH DRY CONDITIONS TO PREVAIL OVER THE HIGH PLAINS...HOWEVER
COULD SEE SOME HIGH CLOUDS AT TIMES. WILL NEED TO MONITOR THE
CENTER OF THE SURFACE HIGH. CURRENT TRACK FROM THE MODELS VARY.
IF THE CENTER IS OVER THE CWA...TEMPS LIKELY TO DROP WELL INTO THE
30S BENEATH THE HIGH...WITH THE POTENTIAL FOR A FROST OR EVEN A
FREEZE HEADLINE. WILL CONTINUE TO MONITOR THE LOCATION OF THE
HIGH...HOWEVER FORECAST IS CONSERVATIVE AND ADDED SOME PATCHY
FROST IN THE FORECAST.
NEXT LARGE SYSTEM ARRIVES THURSDAY NIGHT INTO FRIDAY WITH THIS
BEING THE NEXT SHOT FOR WIDESPREAD PRECIP. AHEAD OF THE COLD
FRONT TEMPS SURGE INTO THE 70S AND A FEW LOW 80S. HOWEVER HEAT IS
SHORT LIVED WITH A RETURN TO MORE SEASONAL CONDITIONS FOR THE
WEEKEND...AROUND 70.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...MASEK
AVIATION...WFO LBF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
640 AM CDT SUN MAY 6 2012
.AVIATION...
12Z TAFS.
RECENT MVFR CEILINGS HAVE BECOME SCT020 AT KLBF. VFR CEILING NEAR
BKN080 MAY BE SCT080 AT TIMES...ARE FORECAST FOR REMAINDER OF
KLBF TAF. ALSO VFR CONDITIONS FOR REMAINDER OF KVTN TAF. STRONGER
WINDS 34022G28KT AT KLBF UNTIL 18Z TO GRADUALLY DIMINISH THROUGH
THE AFTERNOON. THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS OR AN
ISOLATED TSRA AT KLBF. WILL NOT MENTION ATTM...WITH NO RADAR
RETURNS AND RUC FORECAST DRY.
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT SUN MAY 6 2012/
SYNOPSIS...
COLD FRONT HAS PUSHED INTO FAR NW CWA...AS OF 09Z. TEMPS IN THE
40S BEHIND THE FRONT ACROSS THE PANHANDLE...AND IN THE LOWER 30S
ACROSS MUCH OF WY. SECONDARY FRONT ALONG THE EASTERN ZONES. BOTH
BOUNDARIES ARE PRODUCING SOME RAIN SHOWERS...WITH MORE COVERAGE
AND A FEW LIGHTNING STRIKES WITH THE EASTERN ONE. NORTH WINDS HAVE
PICKED UP ACROSS THE AREA...WITH A FEW SITES CLOSE TO ADVISORY
CRITERIA...30 MPH.
DISCUSSION...
COLD FRONT WILL CONTINUE TO PUSH EAST ACROSS THE AREA THIS
MORNING. ISOLATED TO SCATTERED RAIN SHOWERS WILL FOLLOW NEAR THE
FRONT. ALSO MODELS INCREASE 850 MB WINDS THIS MORNING ACROSS SW
INTO CENTRAL NEB CLOSE TO 50 KTS. HAVING MIXED SOME HIGHER WINDS
TO THE SURFACE ALREADY...WENT AHEAD AND HOISTED A SHORT DURATION
WIND ADVISORY WHERE HIGHEST WINDS THIS MORNING AREA EXPECTED. HIGH
PRESSURE WILL BEGIN TO PUSH INTO THE REGION THIS AFTERNOON AND
TONIGHT...WHICH SHOULD DECREASE WINDS BELOW ADVISORY CRITERIA.
ALSO EXPECTED LINGERING SHOWERS POSSIBLY INTO THE EARLY AFTERNOON
HOURS. A BETTER SHOT FOR PRECIP WILL BE DURING THE MORNING HOURS.
HIGHS WILL HOLD NEAR OR BELOW NORMAL DUE TO AN INCREASE OF CLOUD
COVER...IN THE 60S.
TONIGHT INTO MID WEEK A GENERALLY QUITE WEATHER PATTERN DEVELOPS.
HIGHS IN THE 60S AND A FEW LOWER 70S. STORM TRACK TO THE NORTH
WITH DRY CONDITIONS TO PREVAIL OVER THE HIGH PLAINS...HOWEVER
COULD SEE SOME HIGH CLOUDS AT TIMES. WILL NEED TO MONITOR THE
CENTER OF THE SURFACE HIGH. CURRENT TRACK FROM THE MODELS VARY.
IF THE CENTER IS OVER THE CWA...TEMPS LIKELY TO DROP WELL INTO THE
30S BENEATH THE HIGH...WITH THE POTENTIAL FOR A FROST OR EVEN A
FREEZE HEADLINE. WILL CONTINUE TO MONITOR THE LOCATION OF THE
HIGH...HOWEVER FORECAST IS CONSERVATIVE AND ADDED SOME PATCHY
FROST IN THE FORECAST.
NEXT LARGE SYSTEM ARRIVES THURSDAY NIGHT INTO FRIDAY WITH THIS
BEING THE NEXT SHOT FOR WIDESPREAD PRECIP. AHEAD OF THE COLD
FRONT TEMPS SURGE INTO THE 70S AND A FEW LOW 80S. HOWEVER HEAT IS
SHORT LIVED WITH A RETURN TO MORE SEASONAL CONDITIONS FOR THE
WEEKEND...AROUND 70.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 1 PM CDT
/NOON MDT/ THIS AFTERNOON FOR NEZ038-058-059-069>071.
&&
$$
SHORT TERM/EXTENDED...MASEK
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1103 AM EDT SUN MAY 6 2012
.SYNOPSIS...
A NEARLY STATIONARY FRONT WILL REMAIN OVER TENNESSEE AND GEORGIA
TODAY AND TONIGHT. EXPECT A COLD FRONT TO APPROACH FROM THE
MISSISSIPPI AND OHIO VALLEYS DURING THE FIRST HALF OF THE WEEK WITH
A GOOD MOIST FLOW FROM THE GULF. EXPECT DRIER...COOLER HIGH
PRESSURE TO BUILD ACROSS OUR AREA IN THE LAST HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM EDT...THE LOW CLOUD SHIELD ON MOIST NE FLOW ACROSS THE
REGION IS STARTING TO LIFT A BIT...WITH SOME BREAKS SHOWING UP.
DESPITE THE NE FLOW...DEWPOINTS HAVE NOT DRIED UP VERY MUCH...SO
CUMULUS WILL LIKELY FILL IN TO PRODUCE MORE CLOUDS THAN NOT MOST
AREAS THIS AFTN. HAVE LOWERED MAXES A COUPLE OF DEGREES IN THE NC
PIEDMONT WHERE MORNING CLOUDS HAVE BEEN MOST ABUNDANT. WINDS SHOULD
CONTINUE TO VEER GRADUALLY TOWARD EASTERLY...WITH AN UPSLOPE
COMPONENT DEVELOPING INTO THE HIGHER TERRAIN. TRIGGERING SHOULD
OCCUR FIRST OVER THE MTNS...WITH THE FOCUS FOR CONVECTIVE
DEVELOPMENT THE EXTREME SE MTNS. SOME MESOSCALE MODELS ALSO DEPICT
ISOLD CONVECTION OUT OVER THE PIEDMONT EARLY THIS AFTN FROM FORCING
WITH THE UPPER VORT EMBEDDED IN THE RIDGE AXIS. THIS FORCING MAY BE
OVERDONE...AND THE MODELS ALSO DO NOT HAVE A GOOD HANDLE ON ANY
DIFFERENTIAL SFC HEATING. THE MAIN CHANGE HAS BEEN TO ADD A THUNDER
MENTION OVER MORE OF THE UPSTATE AND EXTEND IT TO THE NC FOOTHILLS
THIS AFTN. PROFILES ARE NOT ESPECIALLY FAVORABLE FOR SEVERE TSTMS
THIS AFTN...BUT SOME LOCALIZED HEAVY RAIN IS POSSIBLE IN WEAK
STEERING FLOW.
LOW CLOUDS AND MAYBE SOME FOG WILL DEVELOP TONIGHT ACROSS MUCH OF
THE FA...THOUGH THERE MAY BE ENOUGH DRY AIR OVER THE SOUTHERN AND
EASTERN FRINGE OF ZONES TO PREVENT CLOUDS FROM DEVELOPING IN THESE
AREAS. LIGHT SHRA OR DRIZZLE WILL BE POSSIBLE ACROSS THE
APPALACHIANS AS LIGHT UPSLOPE FLOW PERSISTS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT 230 AM SUNDAY...A BACK DOOR COLD FRONT WILL PUSH SOUTH ACROSS OUR
FORECAST AREA SUNDAY NIGHT AND REMAINS JUST TO OUR SOUTH BY MONDAY
MORNING. THE BEST UPPER FORCING AND MOISTURE ALONG THE FRONT WILL
REMAIN SOUTH OF OUR AREA ON MONDAY. HOWEVER...A WEAK EASTERLY
UPSLOPE FLOW AND ELEVATED INSTABILITY MAY TRIGGER SCATTERED
CONVECTION OVER NC/GA MOUNTAINS. SO LOW END CHANCE POP WAS MENTIONED
THERE WITH SLIGHT CHANCE OVER THE PIEDMONT. BY MONDAY
NIGHT...MOISTURE ASSOCIATED WITH THE FRONT RETURNS NORTH ACROSS THE
UPPER SAVANNAH RIVER VALLEY IN ADVANCE OF AN APPROACHING COLD FRONT
FROM THE NORTHWEST. THE FRONT WILL BECOME STATIONARY OVER THE
APPALACHIANS ON TUESDAY WHICH WILL PROVIDE GOOD UPPER FORCING AND
PLENTY OF MOISTURE INTO OUR CWA. THAT IN MIND...LIKELY POP WAS
MENTIONED OVER THE NORTHERN HALF OF OUR CWA AND HIGH END CHANCE POPS
ELSEWHERE ON TUESDAY. ALSO THUNDER WAS MENTIONED DUE TO DECENT
INSTABILITY. DAYTIME HIGH WILL DROP INTO THE UPPER 70S OVER THE
PIEDMONT MONDAY AND BACK INTO THE LOW 80S TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...THE LATEST MODELS INDICATE THAT AN UPPER
TROUGH OVER THE GREAT LAKES AREA WILL DROP INTO THE SOUTHEAST STATES
BY WEDNESDAY. AS A RESULT...THE FRONT IS EXPECTED TO PUSH SE ACROSS
OUR CWA EARLY WED AND OFF THE ATLANTIC COAST BY WED NIGHT. THEN
BROAD CANADIAN HIGH PRESSURE WILL BUILD INTO THE EASTERN CONUS AND
LINGERS THROUGH SAT FOR COOLER TEMPS AND DRY WEATHER ACROSS OUR
FORECAST AREA. DAYTIME HIGHS WILL REMAIN IN THE UPPER 70S OVER THE
PIEDMONT WITH 60S IN THE MOUNTAINS THROUGHOUT THE PERIOD.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT KCLT...THE LATEST HRRR RUN PLACES WEAK CONVECTIVE DEVELOPMENT IN
THE VICINITY OF KCLT 16Z TO 18Z...BUT THIS APPEARS TO BE DUE TO
MISPLACEMENT OF THE DIFFERENTIAL HEATING BOUNDARY AND POOR HANDLING
OF THE UPPER VORT MAX UNDER THE RIDGE. WILL KEEP KCLT FREE OF ANY
PERCIP/TSRA MENTION...WITH LOWER VFR CIGS THROUGH THE AFTN/EVENING.
LOW CIGS ARE LIKELY AGAIN TONIGHT...AND MODEL SOUNDINGS CONTINUE TO
IMPLY THAT A VERY LOW DECK MAY BE POSSIBLE DURING THE EARLY MORNING
HOURS. ANTICIPATE WINDS STAYING NE TO ENE THROUGH THE PERIOD.
ELSEWHERE...MVFR CIGS WILL STEADILY LIFT THROUGH 16Z...WITH VFR CIGS
LIKELY THROUGH THE AFTN AND EVENING HOURS. ANY CONVECTIVE POTENTIAL
APPEARS BEST NEAR KAVL CIRCA 18Z AS UPSLOPE FLOW DEVELOPS AND
INSTABILITY MAXIMIZES. WILL KEEP THE FOOTHILLS TAFS DRY AND FREE OF
TS FOR NOW. WINDS WILL GRADUALLY VEER TO THE E OR ENE BY EARLY
AFTN...EXCEPT SE AT KAVL. MODEL SOUNDINGS AND MOS GUIDANCE IMPLY
VERY LOW CIGS ACROSS THE REGION TNGT. THE CURRENT FORECAST MAY BE ON
THE OPTIMISTIC SIDE.
OUTLOOK...SCT MAINLY DIURNAL SHWRS/TSTMS MON...MAINLY MTNS. TSTM
COVERAGE WILL INCREASE TUE-WED WITH A FRONT. MUCH DRIER CONDITIONS
ARE EXPECTED BEHIND THE FRONT THU AND FRI. PATCHY FOG AND STRATUS
WILL BE PSBL MON-WED MORNING.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...HG
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...HG
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1057 AM CDT SUN MAY 6 2012
.DISCUSSION...COMPLEX FORECAST FOR TODAY. PER SURFACE ANALYSIS AND
VISIBLE SAT IMAGERY...THE OUTFLOW BOUNDARY FROM LAST NIGHT/S MCS
TO OUR NORTH IS CURRENTLY DRAPED FROM WEST TO EAST FROM JUST NORTH
OF LAREDO TO JUST SOUTH OF DOWNTOWN CORPUS CHRISTI. AN ADDITIONAL
BOUNDARY ON THE BACK SIDE OF AN MCV IS CURRENTLY INITIATING
ISOLATED CONVECTION ACROSS NE ZONES. MESO ANALYSIS PLACES A HIGHLY
UNSTABLE AIRMASS ACROSS MUCH OF S TX THIS MORNING AND WITH
BOUNDARIES IN THE AREA CAN NOT RULE OUT ISOLATED STORMS THE
REMAINDER OF THE DAY. ADDITIONAL STORM CHANCES MAY COME LATE THIS
AFTERNOON AND INTO THE EVENING ACROSS RIO GRANDE PLAINS AND
EVENTUALLY THE BRUSH COUNTRY. 12Z HRRR WANTS TO DEVELOP CONVECTION
ACROSS OLD MEX BY MID AFTERNOON WITH STRONG STORMS CROSSING THE
RIVER INTO CRP CWA BY LATE AFTERNOON. WILL CONTINUE TO MONITOR
SITUATION WITH FULL UPDATE COMING WITH MAIN AFTERNOON FORECAST
PACKAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 92 74 92 74 89 / 20 10 10 10 10
VICTORIA 90 72 92 72 87 / 20 10 10 10 10
LAREDO 100 74 100 76 94 / 20 20 10 10 20
ALICE 97 73 97 73 91 / 20 10 10 10 10
ROCKPORT 86 76 87 76 85 / 10 10 10 10 10
COTULLA 99 71 99 72 90 / 20 20 10 20 20
KINGSVILLE 95 73 95 75 90 / 20 10 10 10 10
NAVY CORPUS 87 75 87 76 86 / 20 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
UPDATE...HART/79
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1019 AM CDT SUN MAY 6 2012
.UPDATE...
CHALLENGING FORECAST THIS MORNING REGARDING THUNDERSTORM POTENTIAL
LATER THIS AFTERNOON. REMNANTS OF LAST NIGHTS MCS REMAIN TO OUR
WEST WHERE AN MCV HAS FORMED AND SOME REDEVELOPMENT IS OCCURRING
ACROSS GONZALES COUNTY. 12Z NAM SOUNDINGS SUGGEST THE CAP IS
BREAKABLE ACROSS THE NORTHERN HALF OF SOUTHEAST TEXAS THIS
AFTERNOON WITH CAPE VALUES BETWEEN 1400-2000 J/KG AND LI`S OF -5
TO -7. THE 11Z AND 12Z HRRR FORECAST REFLECTIVITIES HAVE TRENDED
WELL WITH THE ACTIVITY ONGOING THIS MORNING AND SUGGEST AN OVERALL
DOWNWARD TREND IN ACTIVITY THIS MORNING BEFORE REDEVELOPING ACROSS
PORTIONS OF HARRIS AND MONTGOMERY COUNTIES LATER THIS AFTERNOON.
GIVEN THIS AND THE UNCAPPED PROFILE FOR IAH AT 21Z IN THE NAM
GUIDANCE HAVE GONE AHEAD AND RAISED POPS ACROSS THE REGION INTO
THE EVENING HOURS. HAVE ALSO INCLUDED A MENTION OF SEVERE
GENERALLY ALONG AND NORTH OF THE US 59 CORRIDOR AS INVERTED V
SIGNATURE ON THE FORECAST SOUNDINGS SUGGESTS THE POTENTIAL FOR
SOME DAMAGING WIND GUSTS WITH THESE THUNDERSTORMS. 38
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT SUN MAY 6 2012/
AVIATION...
SHOWERS AND ISOLATED THUNDERSTORMS WERE DEVELOPING WEST OF KSGR
AND KLBX AT 1130Z...AND FELT THAT AT LEAST ISOLATED SHOWERS WERE
POSSIBLE FROM KHOU AND KSGR TO THE COAST THIS MORNING. THE MODELS
AGREED THAT A VORTICITY CENTER AT 500 MB WILL MOVE UP FROM NEAR
MATAGORDA BAY INTO SE TX. THE MODELS INDICATED THAT THE BEST
CHANCES FOR ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WILL
BE OVER THE WESTERN AND NORTHERN TERMINAL SITES OUTSIDE OF METRO
HOUSTON AND KGLS. OVERNIGHT TONIGHT THERE IS AN OUTSIDE CHANCE
FOR MVFR TO IFR CONDITIONS TO FORM...ESPECIALLY OUTSIDE OF THE BIG
AIRPORTS.
40
PREV DISCUSSION... /ISSUED 414 AM CDT SUN MAY 6 2012/
DISCUSSION...
AN MCS OVER CENTRAL TEXAS CONTINUES TO EDGE TOWARD SE TX THIS
MORNING. FEEL THIS AREA OF CONVECTION WILL WEAKEN BUT WILL LIKELY
BRING SOME RAIN TO PARTS OF JACKSON...WHARTON AND COLORADO
COUNTIES BEFORE FALLING APART. THE RESIDUAL BOUNDARY AND COLD POOL
WILL LIE CLOSE TO SOUTHEAST TEXAS THIS AFTERNOON AND MAY BECOME A
PLAYER FOR LATE AFTERNOON AND EARLY EVENING THUNDERSTORMS. THE
NAM12 FORECAST SOUNDINGS ARE CONDITIONALLY UNSTABLE WITH PW VALUES
EXCEEDING 1.7 INCHES...LAPSE RATES ABOVE 7.0 DEGREES AND CAPE
EXCEEDING 3000. THE AREA IS PROGGED TO BE CAPPED WITH A CONVECTIVE
TEMP NEAR 90. THE CAP LOOKS BREAKABLE OVER PARTS OF THE NORTHWEST
ZONES BY 21Z. CLOUD DEBRIS FROM THIS MCS MAY RETARD HEATING BUT
THINK THERE WILL BE ENOUGH BREAKS THIS AFTERNOON FOR MAX TEMPS TO
WARM INTO THE LOWER 90S OVER THE NORTH AND NORTHWEST PARTS OF
SOUTHEAST TEXAS. THE ECMWF SUPPORTS A BURST OF CONVECTION THIS
EVENING WHILE THE GFS KEEPS THE REGION CAPPED AND RAIN FREE. A
TOUGH CALL FOR SURE BUT WILL SIDE WITH THE NAM AND ADD CHANCE POPS
OVER THE NORTHWEST AND ALSO MENTION THE POTENTIAL FOR SEVERE
STORMS DUE TO THE LAPSE RATES AND INVERTED V SIGNATURE IN THE
SOUNDING. IF CLOUDS HANG IN...CONVECTIVE POTENTIAL FOR THIS
EVENING WILL BE NIL.
A PACIFIC COLD FRONT WILL SLOWLY CROSS SOUTHEAST TEXAS ON TUESDAY
AND WEDNESDAY. STILL SOME TIMING DIFFERENCES WITH THE GFS NOW THE
SLOWEST MODEL. RAIN CHANCES SHOULD BE INCREASING OVER THE NORTH ON
TUESDAY CLOSER TO THE BEST SURFACE CONVERGENCE. THIS AREA WILL
SHIFT SOUTH ON WEDNESDAY WITH THE BETTER RAIN CHANCES CLOSER TO
THE COAST. THE FRONT WILL BE OFF THE COAST ON THURSDAY AND
MOISTURE LEVELS DROP SO HAVE PARED POPS BACK. ONSHORE FLOW
REDEVELOPS RATHER QUICKLY THURSDAY NIGHT AS A POTENT UPPER LEVEL
LOW NEAR THE BIG BEND KICKS SLOWLY EAST. PW VALUES POP BACK UP TO
1.6 INCHES FOR FRIDAY AND UPPER LEVEL WINDS BECOME STRONGLY
DIVERGENT. RAIN CHANCES WILL INCREASE AHEAD OF THE UPPER TROUGH.
LONG RANGE MODELS SEEM TO PINGING THE SOUTHERN HALF OF THE REGION
AND AREAS OFFSHORE WITH THE HEAVIEST PRECIP. THE POSITION OF THE
UPPER LOW WOULD SEEM TO FAVOR AREAS A BIT FURTHER NORTH (INLAND).
THE ECMWF AND CANADIAN ARE FASTER THAN THE GFS AND LEANED TOWARD
THE FASTER SOLUTIONS...BRINGING THE RAIN ACROSS THE REGION ON
FRIDAY.
TEMPS WILL TREND COOLER AS THE WEEK PROGRESS AS HEIGHTS FALL AND
CLOUD COVER INCREASES. GFS AND ECMWF HINTING AT SOME 50S FOR
OVERNIGHT LOWS OVER THE EXTREME NORTHEAST ZONES BY NEXT SATURDAY.
43
MARINE...
MODERATE ONSHORE WINDS EARLY THIS MORNING ARE MAINLY IN RESPONSE TO
THE MCS APPROACHING THE MID TEXAS COASTAL AREAS FROM THE HILL
COUNTRY. THE MODELS ARE IN AGREEMENT WITH DECREASING WIND SPEEDS
LATER THIS MORNING. EXPECT WINDS TO BE UNDER CAUTION CRITERIA LATER
THIS MORNING THROUGH MID WEEK.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 92 72 89 70 83 / 30 30 20 20 40
HOUSTON (IAH) 90 72 90 71 87 / 20 20 10 10 30
GALVESTON (GLS) 85 76 85 74 84 / 20 10 10 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...38
AVIATION/MARINE...46
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
936 AM CDT SUN MAY 6 2012
.UPDATE...
QUICK UPDATE THIS MORNING TO CAPTURE STRONGER WINDS BEHIND A COLD
FRONT STRETCHING FROM SRN BAILEY COUNTY NORTHEAST TO NRN BRISCOE
COUNTY AS OF 14Z. SUSTAINED NLY WINDS PER VARIOUS WEST TX MESONET
STATIONS IN THE SWRN PANHANDLE HAVE ALREADY REACHED IN EXCESS OF
30 MPH OCCASIONALLY THANKS TO 40 KNOTS AROUND 2K FT AGL AS SAMPLED
BY AMA`S VWP. THIS WINDS ARE LOCATED WITHIN A NORTHERLY LLJ AXIS
POISED ACROSS THE WRN PANHANDLE...BUT ARE PROGGED TO WEAKEN IN THE
COMING HOURS. WILL THEREFORE REFRAIN FROM ISSUING A WIND ADVISORY
AS THIS WINDOW LOOKS TO BE TOO SHORT LIVED AND MARGINAL IN NATURE.
ALTHOUGH THE FRONT IS RUNNING A BIT AHEAD OF SCHEDULE...IT IS
STILL EXPECTED TO ENCOUNTER RESISTANCE LATER ON AS THE PRE-FRONTAL
BOUNDARY LAYER BECOMES DEEPLY-MIXED ULTIMATELY SLOWING THE FRONT`S
PROGRESSION SOUTHWARD. DID LOWER MAX TEMPS BY SEVERAL DEGREES
ACROSS THE NWRN SOUTH PLAINS WHILE KEEPING REMAINING AREAS LARGELY
INTACT. LATEST NAM AND RUC INDICATE THIS BOUNDARY WILL STALL NEAR
OUR SRN BORDER BY MIDDAY BEFORE ACCELERATING SOUTH NEAR SUNSET AS
PRE-FRONTAL BOUNDARY LAYER DECOUPLING ENSUES. THIS SHOULD PREVENT
ELEVATED FIRE WEATHER CONDITIONS FROM DEVELOPING AS WINDS REMAIN
TOO MARGINAL TO FAN FIRES. NO OTHER UPDATES AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 627 AM CDT SUN MAY 6 2012/
AVIATION...
SOUTHERLY WINDS EARLY THIS MORNING WILL QUICKLY SHIFT TO THE NORTH
AND BECOME BREEZY LATER THIS MORNING DUE TO A COLD FRONT. STRONG
WINDS ARE EXPECTED TO PERSIST FOR MUCH OF THE AFTERNOON AND LESSEN
LATE IN THE AFTERNOON BUT STILL REMAINING BREEZY OVERNIGHT
TONIGHT. BY EARLY MONDAY MORNING...LOW LEVEL MOISTURE WILL
INCREASE AND AS A RESULT LOW STRATUS MAY FORM AT BOTH TAF SITES
FROM NORTH TO SOUTH.
PREV DISCUSSION... /ISSUED 439 AM CDT SUN MAY 6 2012/
SHORT TERM...
UPPER LEVEL SHORT WAVE AXIS WILL MOVE OVER THE AREA TODAY HOWEVER
THERE WILL BE LITTLE LIFT ASSOCIATED WITH IT BY THE TIME IT REACHES
THE AREA. THE DRYLINE WILL NOT MAKE MUCH MORE WESTWARD MOVEMENT THIS
MORNING BEFORE MIXING EAST. REGARDLESS...THE COLD FRONT EXPECTED
LATER THIS MORNING WILL OVERTAKE THE DRYLINE. THE COLD FRONT WAS
ENTERING THE NORTHERN TEXAS PANHANDLE EARLY THIS MORNING AND IS
STILL ANTICIPATED TO MOVE THROUGH THE REGION FROM LATE MORNING INTO
THE LATE AFTERNOON. BECAUSE OF THIS...THERE WILL BE A SHARP GRADIENT
OF MAXIMUM TEMPERATURES THIS AFTERNOON. AREAS SOUTH OF THE FRONT BY
THE AFTERNOON WILL CONTINUE TO SEE 90S INTO THE LOWER 100S WITH
UPPER 70S IN THE SOUTHWESTERN TEXAS PANHANDLE. HOWEVER...ONE GOOD
THING IS THAT JUST ABOUT EVERYWHERE WILL SEE COOLER TEMPERATURES
THAN OBSERVED OVER THE PREVIOUS FEW DAYS. THE FRONT WILL ALSO BRING
IN MORE PLEASANT SURFACE DEW POINTS. ALL MODELS SHOW LOW LEVEL
MOISTURE/STRATUS SPILLING INTO THE AREA FROM THE NORTH BY EARLY
MONDAY MORNING. JDV
LONG TERM...
A SIGNIFICANT PATTERN CHANGE WILL RESULT IN A MUCH COOLER AND MORE
DAMP PATTERN EXPECTED TO PERSIST THE ENTIRE COMING WEEK...IF NOT
BEYOND. CHANGE WILL BE INITIATED BY STRONG UPPER LOW CHARGING EAST
ALONG THE US-CANADIAN BORDER THEN DEEPENING INTO SLOW MOVING UPPER
TROUGH OVER THE EASTERN US. MUCH COOLER WEST TO NORTHWEST FLOW
WILL FOLLOW EAST OF THE ROCKIES WITH A COOL SURFACE HIGH PRESSURE
RIDGE SETTLING SOUTHWARD INTO THE SOUTHERN PLAINS EARLY IN THE
WEEK. RAINFALL AMOUNTS IN THIS PATTERN REMAIN HIGHLY UNCERTAIN...
CONNECTED LARGELY TO MESO-SCALE FEATURES TOO DISTANT TO FULLY
ANTICIPATE AT THIS POINT. BUT THE MOST SIGNIFICANT RAINFALL DOES
SEEM MORE LIKELY JUST TO OUR SOUTH-SOUTHWEST WITH THIS PATTERN
NEARER TO A QUASI-STATIONARY FRONTAL BOUNDARY THAT SHOULD LIE SOUTH
OF THE PECOS...PERHAPS NEAR THE RIO GRANDE MUCH OF THE WEEK.
THIS SET-UP WILL ALLOW POTENTIAL FOR OVER-RUNNING ISENTROPIC LIFT
FROM A WEAK CONVECTIVE ENHANCED WAVE EXPECTED TO EDGE NORTHEAST
INTO OUR AREA LATE MONDAY NIGHT AND TUESDAY. THIS SYSTEM ALSO WILL
FEATURE DYNAMIC LIFT FROM UPPER DIVERGENCE AND FAVORABLE LEFT-EXIT
JET REGION...AS WELL AS RIGHT-ENTRANCE JET PASSING NORTH OF THE
AREA AT THE SAME TIME. LOWER LEVELS FAIRLY DRY IN TERMS OF SURFACE
DEWPOINTS...BUT AIRMASS SHOULD COOL TOWARDS SATURATION WITH THE
PERIOD OF LIFT EXPECTED AND MOISTENING FROM CONVECTIVE SHOWERS
SPREADING INTO THE AREA FROM THE SOUTH-SOUTHWEST LATE ON MONDAY.
WE HAVE INCREASED THUNDERSTORM MENTION TO MEDIUM AND HIGH CHANCE
LEVELS FOR MONDAY NIGHT AND TUESDAY. AND DROPPED HIGH TEMPERATURES
TUESDAY ANOTHER NOTCH WITH MOIST AND COOL CONDITIONS AND 1020+ MB
SURFACE HIGH PRESSURE RIDGE SETTLING INTO THE AREA. TEMPERATURES
TUESDAY AS MUCH AS 30 TO 40 DEGREES COOLER THAN EXPERIENCED FOR
THE PAST WEEK...JACKETS AND SWEATERS RETURN AND AC GETS A BREAK.
SHOWERS SHOULD BE ON THE DECLINE LATE TUESDAY WITH DEPARTING WEAK
UPPER WAVE.
WEDNESDAY APPEARS LIKELY TO REMAIN COOL WITH LESSER SHOWER
CHANCES AND MORE LIMITED DYNAMIC LIFT AND INSTABILITY...WHILE
SURFACE FRONT WILL REMAIN LOCKED FAR TO OUR SOUTH. THUNDERSTORMS
DEVELOPING NEAR THIS FRONT COULD TEND TO DRIFT NORTHEASTWARD WHICH
WILL SUPPORT SMALL CHANCE MENTION SPREADING INTO THE AREA LATE IN
THE DAY AND WEDNESDAY NIGHT.
THE NEXT SIGNIFICANT EVENT IS EXPECTED TO BE THE PASSAGE OF A
VERY SLOW MOVING CLOSED UPPER LOW FROM NORTHERN MEXICO ACROSS THE
RIO GRANDE INTO WEST TEXAS THURSDAY NIGHT AND PERSISTING IN THE
AREA JUST TO OUR SOUTH THROUGH FRIDAY OR FRIDAY NIGHT. THIS SYSTEM
SHOULD ADEQUATELY DESTABILIZE AIRMASS TO SUPPORT INCREASING
THUNDER CHANCES LATE THURSDAY THROUGH FRIDAY AT LEAST. BEYOND
FRIDAY...MODEL MESS STARTS TO DEVELOP THOUGH LEAN GIVEN AT THIS
POINT TOWARDS MAINTAINING A COOL NORTHWEST FLOW AT LEAST INTO THE
WEEKEND PER FAVORED ECMWF SOLUTION. WILL ADDRESS PRECIPITATION
POTENTIAL FOR NEXT WEEKEND WITH LATER FORECASTS. RMCQUEEN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 76 47 68 47 63 / 10 10 20 50 50
TULIA 78 50 69 50 62 / 10 10 20 40 50
PLAINVIEW 81 51 70 50 62 / 10 10 20 40 50
LEVELLAND 88 53 72 51 64 / 10 10 20 50 50
LUBBOCK 88 55 72 52 64 / 10 10 20 40 50
DENVER CITY 92 53 76 52 63 / 0 10 20 60 50
BROWNFIELD 93 54 75 52 64 / 10 10 20 60 50
CHILDRESS 88 58 73 56 69 / 10 10 20 30 40
SPUR 97 56 74 54 66 / 10 10 20 40 50
ASPERMONT 102 61 76 57 68 / 10 10 20 40 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/40
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1222 PM CDT SUN MAY 6 2012
.DISCUSSION...
ISSUED 1030 AM CDT SUN MAY 6 2012
10 AM SFC MAP PLACED A NORTHWARD MOVING WARM FRONT JUST SOUTH OF
I-74. SOUTH OF THE BOUNDARY SOUTHERLY WINDS WERE TRANSPORTING LOW 70S
DEWPOINTS INTO CENTRAL IL. COMBINATION OF VERY WARM/HUMID BOUNDARY
LAYER AND STEEP LAPSE RATES/COOL AIR ALOFT WILL LEAD TO A VERY
UNSTABLE AIRMASS THIS AFTERNOON WITH SURFACE BASED CAPES IN EXCESS
OF 4K J/KG ACROSS THE WESTERN THIRD OF THE CWA. ONE POSSIBLE
MITIGATING FACTOR FOR SEVERE STORMS AT LEAST THROUGH MID AFTERNOON
WILL BE INITIALLY VERY WEAK WIND FIELDS ALOFT. DEEP LAYER SHEAR
SHOULD INCREASE LATE THIS AFTERNOON AND EVENING BASED ON FORECAST
SOUNDINGS...AHEAD OF A SHORT WAVE AND COLD FRONT TO OUR WEST.
THROUGH MID AFTERNOON WILL WATCH FOR CONVECTION AHEAD OF A
WEAKENING THUNDERSTORM COMPLEX MOVING INTO SE IA...AND ALSO ANY
DEVELOPMENT ACROSS THE NRN CWA ALONG AND AHEAD OF THE NORTHWARD
MOVING WARM FRONT. STILL APPEARS BEST TIMEFRAME FOR SEVERE STORMS
WILL BE AFTER 6 PM IN THE WEST. VERY WARM AND HUMID AFTERNOON ON
TAP WITH HIGHS NEAR 90 IN THE FAR SW.
&&
.AVIATION...
ISSUED 1222 PM CDT SUN MAY 6 2012
TIMING OF CONVECTION DIFFICULT TO PIN DOWN AT THIS POINT...BUT
FROM LATE THIS AFTERNOON THROUGH THE REMAINDER OF THIS TAF CYCLE
PERIODIC STORMS WILL ROAM THE AREA. CURRENT THINKING HAS INITIAL
ROUND OF STORMS DEVELOPING OVER WESTERN IL LATE THIS AFTERNOON
ALONG REMNANT OUTFLOW BOUNDARY AND SLOWLY TRACKING EAST/SOUTHEAST
THIS EVENING. ADDITIONAL STORMS SHOULD FORM ALONG A COLD FRONT
CURRENTLY IN IA/MO...WHICH WOULD AFFECT US DURING THE OVERNIGHT
HOURS. STORMS MAY CONTINUE INTO MONDAY MORNING AS THE FRONT SLOWLY
PUSHES ACROSS THE STATE. NOT TOO CONFIDENT IN ANY PARTICULAR
TIMEFRAME FOR STORMS TO IMPACT A PARTICULAR TAF SITE SO LEFT VCTS
FOR NOW. WARM FRONT HAS PUSHED NORTH OF THE AREA THIS
AFTERNOON...SO SOUTHERLY WINDS WILL CONTINUE INTO EARLY EVENING.
AROUND 00Z WINDS WILL BECOME LIGHTER AND BACK MORE TO THE ESE
AHEAD OF THE SURFACE LOW WHICH WILL BE SHIFTING INTO MO. ANOTHER
WIND SHIFT TO THE NORTHWEST IS EXPECTED FROM 10-14Z MONDAY AS THE
COLD FRONT PUSHES THROUGH THE STATE.
25
&&
.PREV DISCUSSION...
ISSUED 257 AM CDT SUN MAY 6 2012
FRONTAL BOUNDARY HAS NOT REALLY MOVED OVER THE LAST SEVERAL
HOURS...EXTENDING FROM NORTHWEST IOWA TO NEAR SPRINGFIELD AND
SOUTHEAST INTO SOUTH CENTRAL INDIANA. DEW POINTS IN THE 65-70F
RANGE WERE POOLING ALONG THIS BOUNDARY. SOME LIGHT FOG WAS
OBSERVED NORTH OF THE FRONT WITH VISIBILITIES OF 3-5 MILES. LARGE
MCS STRETCHING FROM CENTRAL MINNESOTA INTO NORTHERN NEBRASKA HAS
PUSHED INTO FAR NORTHWEST IOWA.
SEVERE WEATHER POTENTIAL THROUGH MONDAY REMAINS THE PRIMARY
FORECAST CONCERN.
SHORT TERM...TODAY THROUGH MONDAY...
NORTHWARD SPREAD OF THE WARM SECTOR MAY BE TEMPERED BY THE
INFLUENCES OF THE MCS DEBRIS...BUT SHOULD GET FAR ENOUGH NORTH TO
CLEAR OUR NORTHERN CWA TOWARD MIDDAY. INSTABILITY SHOULD NOT BE A
PROBLEM AS CAPES APPROACH 3000 J/KG BY MIDDAY AND CONVECTIVE
INHIBITION VALUES WANE. TIMING OF THE CONVECTION IS THE TRICKY
PART...WITH THE HRRR LEANING TOWARD EARLY AFTERNOON DEVELOPMENT
WEST OF THE MISSISSIPPI RIVER...AND THE NAM AND LOCAL WRF MODELS
FROM ST LOUIS AND CHICAGO NWS OFFICES BRINGING SOME OF THE MCS
REMNANTS INTO THE NORTHERN CWA LATE THIS MORNING. ATTENDANT COLD
FRONT IS LIKELY TO MOVE INTO THE NORTHWEST CWA EARLY THIS
EVENING...CONTINUING THE STORM THREAT OVERNIGHT. MOST OF THE CWA
REMAINS IN A SLIGHT RISK OF SEVERE WEATHER...EXCEPT EAST OF
I-57...WHERE SEVERE THREAT MAY BE VERY LATE TONIGHT OR MONDAY
MORNING INSTEAD. HAVE CONTINUED WITH RAIN CHANCES MAINLY WEST OF
I-55 THIS AFTERNOON...AND OVERSPREADING THE REMAINDER OF THE CWA
THIS EVENING. HEAVIEST RAIN THREAT LOOKS TO BE JUST TO OUR
NORTH...BUT WILL NEED TO WATCH THE FAR NORTHERN CWA WHICH HAD 1-3
INCHES OF RAIN THURSDAY NIGHT AND FRIDAY MORNING FOR ANY POTENTIAL
HYDROLOGICAL CONCERNS. TIMING OF FRONTAL PASSAGE ON MONDAY SHOULD
BE EARLY AFTERNOON ACROSS THE EASTERN CWA...AND HAVE KEPT LIKELY
POPS GOING IN THAT AREA DURING THE DAY...DIMINISHING IN THE
EVENING.
TEMPERATURE-WISE...WILL LIKELY SEE HIGHS DEEP INTO THE 80S OVER
THE ENTIRE FORECAST AREA...POTENTIALLY NUDGING 90 ACROSS THE
SOUTHWEST CWA. MOST RECORDS TODAY ARE IN THE LOWER 90S AND LIKELY
JUST OUT OF REACH...ALTHOUGH SPRINGFIELD HAS A RECORD HIGH OF 88
WHICH IS IN JEOPARDY. WILL PROBABLY SEE SOME 80 DEGREE READINGS
AGAIN ACROSS THE SOUTHEAST ON MONDAY AHEAD OF THE FRONT...BUT THAT
WILL BE THE LAST OF THE 80S ACROSS OUR CWA FOR THE REMAINDER OF
THE WEEK.
LONG TERM...TUESDAY THROUGH SATURDAY...
A MUCH COOLER AND QUIETER REGIME SETS UP THE REMAINDER OF THE
WEEK. AN UPPER LOW...CURRENTLY LOCATED OVER FAR NORTH CENTRAL
MONTANA PER WATER VAPOR IMAGERY...SHOULD MOVE TO NEAR LAKE
SUPERIOR BY TUESDAY MORNING. ASSOCIATED SURFACE AND UPPER TROUGH
WILL SWING THROUGH THE GREAT LAKES TUESDAY AND WEDNESDAY...WITH
THE COLDER AIR ALOFT HELPING TO TRIGGER A FEW SHOWERS. STILL LOOKS
LIKE THE BEST SUPPORT FOR THIS WILL BE FURTHER TO OUR NORTH...BUT
HAVE INCLUDED SOME SLIGHT CHANCES ACROSS THE NORTHEAST CWA ON
WEDNESDAY AS THE TROUGH FULLY PUSHES THROUGH THE STATE.
UPPER RIDGING ACROSS THE ROCKIES AT MIDWEEK WILL RESULT IN A
NORTHWEST FLOW...AND BELOW NORMAL TEMPERATURES...FOR A COUPLE
DAYS IN OUR AREA. LONGER RANGE MODELS SHOWING THE RIDGING PUSHING
EASTWARD LATE IN THE WEEK...WITH A BIT OF MODERATION IN
TEMPERATURES. SURFACE HIGH PRESSURE OVER THE MIDWEST TO PROVIDE
FAIR WEATHER FOR THURSDAY AND FRIDAY...AHEAD OF A SHORTWAVE WHICH
WILL PUSH ACROSS THE NORTHERN STATES LATE IN THE WEEK. MOISTURE
RETURN IN OUR AREA WILL BE MEAGER AHEAD OF THIS SYSTEM...SO RAIN
CHANCES ARE NOT ESPECIALLY HIGH AT THIS TIME. HOWEVER...THE
NORTHWEST CWA SHOULD SEE A FEW SHOWERS AND THUNDERSTORMS BY
SATURDAY AFTERNOON.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1221 PM CDT SUN MAY 6 2012
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 117 AM CDT SUN MAY 6 2012
AT 00Z SUNDAY AN UPPER LEVEL TROUGH WHICH WAS ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET EXTENDED FROM
NORTHEAST COLORADO INTO EASTERN WYOMING. A SURFACE COLD FRONT
EXTENDED FROM NORTHEAST COLORADO INTO NORTHEAST NEBRASKA. SOUTH OF
THIS COLD FRONT WARM MID LEVEL TEMPERATURES WERE PRESENT ACROSS
WESTERN KANSAS WITH KDDC INDICATING 700MB TEMPERATURES AT +13C. AS
OF 06Z SURFACE ANALYSIS INDICATED THIS COLD FRONT WAS ALREADY
SURGING SOUTHEAST TOWARDS WEST CENTRAL KANSAS WITH LOW CLOUDS AND
NORTHWEST WINDS AROUND 25KNOTS DEVELOPING IN ITS WAKE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 117 AM CDT SUN MAY 6 2012
BASED ON 925-850MB MOISTURE PROFILES THE MODELS THIS MORNING
REMAIN IN GOOD AGREEMENT IN LOW LEVEL MOISTURE RETURNING TO
SOUTHWEST KANSAS BEHIND A COLD FRONT THAT WAS CURRENTLY MOVING
INTO WEST CENTRAL KANSAS. NAM AND GFS 300-305 IS ENTROPIC SURFACES
EVEN SUGGEST SOME WEAK LIFT WILL CONTINUE THROUGH 00Z MONDAY.
BASED ON THIS WEAK LIFT AND DEPTH OF THIS MOIST LAYER WILL KEEP A
MENTION OF DRIZZLE GOING THROUGH MUCH OF THE DAY, ESPECIALLY
NORTHEAST OF DODGE CITY WHERE THE ISENTROPIC LIFT IS A LITTLE
BETTER. GIVEN THE CHANCE FOR DRIZZLE ALONG WITH CLOUDY CONDITIONS
THE PREVIOUS FORECAST STILL LOOKS ON TRACK WITH AFTERNOON
TEMPERATURES RANGING FROM THE LOW TO MID 60S WITH THE EXCEPTION
BEING SOUTH CENTRAL KANSAS. WILL HAVE TO MONITOR HOW QUICKLY THIS
FRONT WILL CROSS SOUTH CENTRAL KANSAS EARLY THIS MORNING BUT AT
THIS TIME BASED ON 06Z SURFACE OBSERVATION ACROSS NORTHWEST KANSAS
IT APPEARS THAT THE NAM MAY BE A LITTLE SLOW SO ADJUSTING THE
TIMING OF THIS FRONT CLOSE TO THE HRRR WILL CONTINUE TO FAVOR
SLIGHTLY COOLER TEMPERATURES IN THE MEDICINE LODGE AREA THAN WHAT
THE NAM/GFS SUGGEST.
BOUNDARY LAYER AND 0-0.5KM LAYER WINDS BEHIND THIS COLD FRONT
ACROSS WESTERN KANSAS EARLY TODAY BOTH WERE FORECAST TO RANGE BETWEEN
30 AND 35 KNOTS BEHIND THIS FRONT. GIVEN THIS AND THE LOCATION OF
WHERE THE STRONGER LOW LEVEL WINDS ARE FORECAST TO BE BETWEEN 09Z
AND 15Z SUNDAY WILL KEEP CURRENT WIND ADVISORY AS IS FOR NOW.
MARGINAL WIND ADVISORY WINDS HOWEVER STILL APPEAR POSSIBLE A
LITTLE FURTHER SOUTHEAST, HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT
THIS TIME TO EXPAND THE PREVIOUS ADVISORY.
SURFACE HIGH PRESSURE WILL THEN BEGIN TO BUILD INTO THE ARE EARLY
TONIGHT AND 300-305 ISENTROPIC DOWN GLIDE DEVELOPS. LOW LEVEL
MOISTURE STILL PRESENT OVER WESTERN KANSAS THROUGH MUCH OF THE
NIGHT BUT GIVEN THE SUBSIDENCE/DOWN GLIDE SUGGESTED WILL BEGIN TO
SHOW A DECREASING TREND IN CLOUD COVER BY OR SHORTLY AFTER
MIDNIGHT...ESPECIALLY IN THE NORTH. IN AREAS WHERE THE SKIES ARE
EXPECTED TO CLEAR WILL TREND TOWARDS THE COOLER MET/MAV ON
TEMPERATURES WHILE FURTHER SOUTHEAST WILL CONTINUE TO FAVOR THE
WARMER MOSGUIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 6 2012
MONDAY:
A RATHER BROAD UPPER LEVEL TROUGH WILL BE WEST OF KANSAS MONDAY. WESTERN
KANSAS WILL BE IN A QUASI COUPLED JET REGION WITH THE LEFT EXIT REGION
OF A 250 HPA 70 KT JET ACROSS THE EASTERN SECTIONS OF THE DESERT SOUTHWEST
AND THE RIGHT ENTRANCE REGION OF A 250 HPA 65 KT JET ACROSS NEBRASKA.
AS A RESULT, HAVE KEPT POPS MAINLY ACROSS FAR SOUTHWEST KANSAS WHERE
BETTER LIFT WILL BE PRESENT VERSUS FURTHER EAST. NOT PARTICULARLY IMPRESSED
OVERALL AS MOST OF THE QPF SHOULD REMAIN ACROSS THE HIGHER TERRAIN ALSO
IN ASSOCIATION WITH OROGRAPHIC LIFT AND UPSLOPE FLOW IN A POST FRONTAL
ENVIRONMENT. A 1025 HPA HIGH WILL SLIDE DOWN THE PLAINS IN THE WAKE
OF THE AFOREMENTIONED FRONT. THIS AIRMASS WILL BE CHARACTERIZED AS PLEASANT
WITH 850 HPA TEMPERATURES NOT TOO WARM (~10-12 DEG C). UPPER 60S DEG
F TO LOWER 70S DEG F IS EXPECTED FOR THE BEGINNING OF THE WORKWEEK
WHICH IS JUST A HAIR BELOW CLIMATOLOGY.
TUESDAY:
THE DESERT SOUTHWEST SYSTEM WILL CONTINUE TO SINK SOUTHWARD INTO THE
BAJA REGION WHILE THE NORTHERN SYSTEM MOVES EAST. SOUTHWEST KANSAS WILL
BE LEFT IN A COL POINT AT THE UPPER LEVELS. AT THE SURFACE, THE COOL
HIGH PRESSURE CENTER WILL CONTINUE TO DOMINATE. RICH BOUNDARY MOISTURE
WILL BE ADVECTED WELL SOUTH INTO TEXAS WITH FAIRLY LOW DEWPOINTS ACROSS
THE SUNFLOWER STATE. AS A RESULT, OVERNIGHT LOWS INTO TUESDAY MORNING
WILL BE MAINLY IN THE 40S DEG F EXCEPT NEAR KP28 WHERE AROUND 50 DEG
F IS EXPECTED. LOW TEMPERATURES IN THE 40S DEG F ARE NEAR CLIMATOLOGY.
A LACK OF DYNAMICS ALOFT AND HIGH PRESSURE AT THE SURFACE WILL LEAD
TO A DRY FORECAST FOR TUESDAY.
WEDNESDAY/THURSDAY:
MAXIMUM TEMPERATURES WILL MODERATE WEDNESDAY WITH HIGHS IN THE MID 70S
DEG F OR ABOUT NEAR NORMAL AS THE COOL HIGH PRESSURE SLIDES OFF TO THE
EAST AND LEE TROUGHING AND RESULTANT WARM AIR ADVECTION DEVELOPS ACROSS
THE HIGH PLAINS. POPS WILL REMAIN NEAR ZERO AS THE 500 HPA RIDGE AXIS
SLIDES EAST THROUGH THE DAY AHEAD OF ANOTHER SHORTWAVE TROUGH MOVING
ONSHORE ACROSS THE PACIFIC NORTHWEST. THURSDAY WILL BE THE WARMEST DURING
MY PERIOD AS 850 HPA TEMPERATURES WARM INTO THE LOWER 20 DEG C AND LEE
TROUGHING STRENGTHENS WITH SOUTHERLY WINDS CONTINUING FROM THE SURFACE
AND THROUGH THE 850 HPA CONSTANT PRESSURE LAYER. RETURN OF RICH BOUNDARY
LAYER MOISTURE IS NOT EXPECTED AT THIS POINT AS A COLD FRONT WILL SCOUR
HIGHER DEWPOINTS SOUTHWARD ACROSS THE NORTHERN GULF OF MEXICO BASIN.
FRIDAY AND BEYOND:
THE FORECAST TURNS MORE UNSETTLED BY THE END OF NEXT WEEK ALTHOUGH UNCERTAINTY
IS PRETTY HIGH AS THIS POINT. PRECIPITATION MAY OCCUR EITHER FROM A
NORTHERN SYSTEM BRINGING IN A COLD FRONT OR FROM THE BAJA SYSTEM BRING
IN MOISTURE FROM THE SOUTH. AT THIS POINT, THE EXACT SOLUTION IS UNKNOWN.
PREFER THE DRIER SOLUTION FROM THE ECMWF. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE AS LIFT AND MOISTURE ADVECTION INCREASES DURING THIS
PERIOD. EVEN IF YOU WERE TO BUY THE WETTER GFS SOLUTION, DEWPOINTS
RETURNING TO KANSAS ARE NOT THAT IMPRESSIVE FOR MAY - 50S DEG F.
DEWPOINTS IN THE 60S/70S DEG F ARE STILL FORECAST TO BE REMAIN WELL
SOUTH INTO THE GULF OF MEXICO. LASTLY, UPPER LEVEL JET DYNAMICS IS
ALSO WEAK WITH THE CUT OFF LOW REMAINING WELL SOUTH ACROSS TEXAS AND
THE STRONGER POLAR JET FORECAST WELL NORTH NEAR THE INTERNATIONAL
BORDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1221 PM CDT SUN MAY 6 2012
MVFR CONDITIONS WILL BE OBSERVED ACROSS THE TAF SITES THIS
AFTERNOON AS LOW CLOUDS ENVELOP THE AREA AOA015. THIS IS DUE TO A
COLD FRONT THAT MOVED THROUGH THE AREA EARLY THIS MORNING CAUSING
LOWER AND MID LEVEL LIFT. A FEW SHOWERS WILL BE POSSIBLE AT THE
HAYS TERMINAL THIS AFTERNOON BUT HAVE ONLY PLACED VCSH DUE TO
UNCERTAINTY IN TIMING AND INTENSITY. WINDS WILL GENERALLY BE FROM
THE NORTH AROUND 25 KNOTS GUSTING TO OVER 30 KNOTS AT TIMES. WINDS
DECREASE THIS EVENING INTO THE OVERNIGHT HOURS AS THE PRESSURE
GRADIENT SLACKENS AND HIGH PRESSURE BUILDS INTO THE AREA. CLOUDS
AOA050 ARE FORECASTED TO BE OBSERVED THIS EVENING INTO THE
OVERNIGHT HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 50 68 46 / 20 10 10 10
GCK 65 44 67 45 / 10 10 20 20
EHA 70 46 65 45 / 10 10 20 20
LBL 71 47 68 46 / 10 10 20 20
HYS 67 46 69 45 / 20 20 10 10
P28 79 57 71 50 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 3 PM CDT /2 PM MDT/ THIS AFTERNOON FOR
KSZ030-031-043>045-061>064-074>077-084>086.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...HOVORKA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
125 PM CDT SUN MAY 6 2012
.UPDATE...
UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
MCS IS CURRENTLY ONGOING ACROSS THE CWA AND THERE IS STILL SOME
QUESTION AS TO REDEVELOPMENT POTENTIAL LATER THIS AFTERNOON. A
COLD FRONT WILL SLIDE THROUGH THE REGION SUNDAY NIGHT...WITH
COOLER AND DRIER WEATHER EXPECTED THIS WEEK. THE EXCEPTION WILL BE
TUESDAY...WHEN A POSITIVELY TILTED NORTHERN STREAM WAVE MOVES
ACROSS THE REGION...AND FRIDAY...WHEN ANOTHER COLD FRONT MOVES
THROUGH THE REGION.
TODAY...TRAILING STRATIFORM THUNDERSTORMS COMPLEX CONTINUES TO
MOVE EASTWARD AT A SLIGHTLY FASTER CLIP THAN SHORTRANGE MODELS
INDICATE. THE HRRR IS CONSISTENTLY ABOUT 2 HOURS TOO SLOW...AND
THE 00Z SPC WRF ABOUT AN HOUR TARDY ON ITS EASTWARD PROGRESSION.
AS THIS SYSTEM CLEARS OUT...COULD SEE SOME BOUNDARY LAYER
DESTABILIZATION THIS AFTERNOON NEAR THE IA/MN BORDER.
THIS INSTABILITY IN COMBINATION WITH SEVERAL OUTFLOW BOUNDARIES
AND SOUTHWESTERLY FLOW ALOFT WITH A FEW EMBEDDED WEAK SHORTWAVES
COULD BE THE FOCUS FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON. THE MARGINAL SHEAR AND CAPE VALUES SHOULD KEEP
THE SEVERE THREAT SOUTH AND EAST OF THE CWA.
SUNDAY NIGHT THROUGH SATURDAY...A SURFACE COLD FRONT WILL HAVE
PUSHED THROUGH THE REGION BY SUNDAY NIGHT...WITH MUCH DRIER AIR
IN PLACE BY MONDAY. SHOULD BE A DRY DAY...WITH A FEW AFTERNOON
CUMULUS DEVELOPING. ON TUESDAY THE UPPER LEVEL LOW DRIVING THE
AFOREMENTIONED SURFACE FRONT WILL SLIDE IN FROM THE NORTHWEST. A
WEAK SHORTWAVE WILL ROTATE AROUND THIS UPPER LEVEL LOW...AND COLD
H850 TEMPS WILL STREAM IN FROM THE NORTHWEST. THIS SHOULD SET THE
STAGE FOR A COOL OVERCAST DAY AND SOME AFTERNOON SHOWERS CENTERED
AROUND PEAK HEATING. FOR THE REST OF THE WEEK...HIGHLY AMPLIFIED
FLOW WILL BE THE NAME OF THE GAME. FOR STARTERS...UPPER LEVEL
SUBSIDENCE DOWNSTREAM OF A RIDGE CENTERED OVER MONTANA WILL CAUSE
AN AREA OF SURFACE HIGH PRESSURE TO BUILD OVER THE UPPER MIDWEST
ON WEDNESDAY. THIS WILL QUICKLY BE FOLLOWED BY AN UPPER LEVEL
TROUGH ON THURSDAY...WHICH WILL DEVELOP A SURFACE LOW OUT WEST AND
CAUSE SOUTHERLY WINDS AND WARM AIR ADVECTION TO MOVE ACROSS THE
REGION. AS THIS LOW TRACKS EASTWARD ON FRIDAY...EXPECT ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
HOURS. FINALLY...ANOTHER AREA OF SURFACE HIGH PRESSURE WILL BUILD
IN THE WAKE OF FRIDAY(S) SYSTEM...WHICH SHOULD LEAD TO A DRY
WEEKEND WITH SEASONAL TEMPERATURES.
&&
.AVIATION.../18Z TAF ISSUANCE/
OCCLUDED FRONT MAKING ITS WAY ACRS MN THIS AFTN WILL SHIFT INTO WI
THIS EVENING...FOLLOWED BY WEAK HIGH PRESSURE THROUGH THE DAY
TMRW. LOW CLOUDS WITH WEAK LOW LEVEL STEERING FLOW WILL PERSIST
THROUGH AT LEAST THE EVENING HRS. ALL SITES /EXCEPT KRWF DUE TO A
NARROW BINOVC CROSSING THE VICINITY/ INITIALIZED AT IFR OR LOWER
MVFR RANGE. CEILINGS ARE EXPECTED TO REMAIN LOW THROUGH THE
EVENING THEN AS DRIER AIR MOVES OVER...CEILINGS WILL SLOWLY
DISSIPATE TO SCATTERED COVERAGE THEN LIFT OUT TMRW. AM NOT
EXPECTING ANY PRECIP NOR ANY VSBY RESTRICTIONS...THOUGH IF SOME
SITES BECOME CALM THEN PATCHY FOG MAY DEVELOP DURING THE PRE-DAWN
HOURS. REGARDING WINDS... DIRECTIONS THROUGH THE REST OF THE DAY
INTO THE EVENING HOURS WILL BE DIFFICULT TO PIN DOWN. HAVE ALREADY
SEEN A VARIETY OF DIRECTIONS FROM KMSP WESTWARD...BUT WITH SPEEDS
AOB 7 KT... THERE SHOULD BE MINIMAL IMPACTS. DIRECTIONS SETTLE
DOWN IN THE 270-290 RANGE OVERNIGHT THROUGH TMRW WITH INCRG SPEEDS
AS THE LOW-LEVEL PRESSURE GRADIENT TIGHTENS.
MSP...CEILINGS IN THE 1200-1400FT RANGE WILL PERSIST AT MSP
THROUGH THE REST OF THE AFTN INTO THE EARLY EVE HOURS. CIGS WILL
LIFT SLIGHTLY BUT AM HAVING A HARD TIME BELIEVING CIGS WILL RISE
ABOVE 1700 FT BEFORE MIDNIGHT. AFTER MIDNIGHT...MVFR CIGS WILL
REMAIN BUT...BY THEN...WITH SOME LOWER MOISTURE BEING SCOURED OUT
WILL LOOK FOR CIGS TO RISE TO 2000-3000FT. LOW LEVEL MOISTURE WILL
CONTINUE TO DIMINISH WHILE MIXING INCREASES DUE TO AN INCOMING
TIGHTENED PRESSURE GRADIENT WHICH WILL ENHANCE SFC WINDS. WIND
DIRECTIONS WILL BE A BIT PROBLEMATIC THROUGH THE REST OF TODAY
INTO THIS EVENING WITH THE FRONT MOVING ACROSS. WINDS WILL VARY
FROM NW THRU NE WITH SPEEDS AOB 7 KT...THEN BECOME MORE W TO WNW
OVERNIGHT THROUGH TMRW WITH SPEEDS INCRG ABOVE 12 KT AFTER
DAYBREAK.
OUTLOOK...
MON NIGHT...VFR WITH NW WINDS 10-20 KT.
TUE...MVFR CONDITIONS WITH SCATTERED SHWRS/TSTMS.
WED-THU...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
229 PM CDT SUN MAY 6 2012
.DISCUSSION...
//MESOSCALE DISCUSSION ISSUED AT 208 PM//
AN OUTFLOW BOUNDARY CONTINUES TO MOVE ACROSS SOUTHWEST
MISSOURI...AND WILL NEED TO BE WATCHED CLOSELY FOR SEVERE
THUNDERSTORM DEVELOPMENT.
AN EXTREMELY UNSTABLE ENVIRONMENT EXISTS ACROSS SOUTHERN AND CENTRAL
MISSOURI. RUC SUGGESTS THAT 4000 J/KG OF MIXED LAYER CAPE IS NOW
PRESENT FOR UPDRAFTS TO WORK WITH. THE ONE MITIGATING FACTOR IS
SHEAR VALUES...WHICH ARE VERY LOW. DEEP LAYER SHEAR IS ONLY ABOUT
10 TO 20 KNOTS...WHILE LOW LEVEL HELICITIES ARE UNDER 50 M2S2.
THE PRIMARY RISK WITH STORMS THAT DEVELOP WILL BE DAMAGING DOWNBURST
WINDS IN EXCESS OF 70 MPH...AND LARGE HAIL TO THE SIZE OF GOLF
BALLS. A 0-4KM THETA E DIFFERENTIAL RANGING BETWEEN 35 AND 40
DEGREES...SUGGESTS A HIGH LIKELIHOOD OF DOWNBURSTS.
CURRENTLY...THE LINE SEGMENT MOVING INTO BARRY COUNTY WILL HAVE A
HIGH RISK FOR PRODUCING DAMAGING WIND GUSTS. WE WILL NEED TO
MONITOR FOR IMPACTS OVER TABLE ROCK LAKE...AS MANY BOATERS ARE ON
THE LAKE THIS AFTERNOON. THIS STORM IS CATCHING ABOUT 25 KNOTS OF
0-3 KM SHEAR...WITH A NEAR PERPENDICULAR INTERACTION...WHICH COULD
INCREASE THE STRENGTH OF THE LINE SEGMENT FOR THE NEXT HOUR OR SO.
CRAMER
FOR TONIGHT...COLD FRONT WILL BE SLOWER TO MOVE INTO THE
AREA...BUT WILL BE THE SECONDARY FOCUS FOR STRONG TO SEVERE
CONVECTION WITH THIS SYSTEM. IN ADDITION...A WEAK SHORTWAVE WILL
TRACK EAST-NORTHEAST OUT OF OKLAHOMA THIS AFTERNOON INTO WESTERN
MISSOURI THIS EVENING INTO THE OVERNIGHT HOURS. THE SHORTWAVE AND
COLD FRONT WILL INTERACT WITH AN UNSTABLE ENVIRONMENT TO PRODUCE
STRONG TO SEVERE STORMS. SHEAR VALUES LOOK TO BE ON THE WEAK SIDE
HOWEVER WITH THE STRONG INSTABILITY AND LARGE THETA-E DIFFERENCES
WILL SEE A THREAT FOR DOWNBURSTS ALONG WITH LARGE HAIL. SEVERE
RISKS WILL BEGIN TO WEAKEN TOWARDS THE LATE EVENING INTO THE
OVERNIGHT HOURS AS THE INSTABILITY DIMINISHES.
THERE WILL ALSO BE A RISK OF TRAINING STORMS TONIGHT ALONG THE
FRONT AND COULD SEE SOME FLASH FLOODING DEVELOP IF THIS
OCCURS...ESPECIALLY OVER SOUTHEAST KANSAS INTO WEST CENTRAL
MISSOURI WHICH HAD THE HEAVIEST RAINFALL WITH THE PAST SYSTEM.
THUNDERSTORM CHANCES WILL CONTINUE INTO MONDAY AS THE FRONT WILL
SLOWLY TRACKS SOUTHEAST THROUGH THE AREA. THERE WILL REMAIN A RISK
OF SEVERE STORMS OVER SOUTH CENTRAL MISSOURI...ESPECIALLY DURING
THE LATE MORNING AND AFTERNOON HOURS WHERE THE INSTABILITY WILL
INCREASE AHEAD OF THE FRONT.
THE FRONT SHOULD CLEAR THE AREA BY MONDAY NIGHT WITH A STRONG
UPPER LEVEL TROUGH EXPECTED TO SWING SOUTHEAST THROUGH THE AREA
TUESDAY NIGHT AND WEDNESDAY. THIS SHOULD BRING A COOLER AND DRIER
AIR MASS TO THE AREA. NORTHWEST FLOW ALOFT WILL ESTABLISH OVER THE
FORECAST AREA FOR A GOOD PORTION OF THE REMAINDER OF THE WEEK
WHICH SHOULD KEEP THE COOLER TEMPERATURES OVER THE REGION.
THE NEXT SYSTEM TO AFFECT THE AREA WILL ARRIVE FRIDAY NIGHT INTO
THE WEEKEND WHICH WILL BRING THE NEXT CHANCE OF THUNDERSTORMS.
LINDENBERG
&&
.AVIATION...
PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS WILL
NEED TO MONITOR RADAR TRENDS THIS AFTERNOON...THIS EVENING...AND
THROUGH TONIGHT.
A COLD FRONT IS APPROACHING THE REGION...WHICH WILL TRIGGER
SCATTERED SHOWERS AND THUNDERSTORMS. ANY SHOWER OR THUNDERSTORM
THAT DIRECTLY IMPACTS AN AIRFIELD...COULD CAUSE SOME VERY GUSTY
WINDS...HEAVY RAIN...AND CLOUD TO GROUND LIGHTNING. THE
ENVIRONMENT THIS AFTERNOON AND EVENING WILL BE IDEAL FOR DOWNBURST
WIND GUSTS.
RAIN WILL EXIT THE REGION AFTER MIDNIGHT TONIGHT...GIVING WAY TO
FAIR WEATHER FOR SEVERAL DAYS STARTING TOMORROW MORNING.
AS THE FRONT SHIFTS THROUGH SOUTHERN MISSOURI TONIGHT...SURFACE
WINDS WILL SHIFT TO THE WEST AND NORTHWEST.
CRAMER
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
208 PM CDT SUN MAY 6 2012
...MESOSCALE CONVECTIVE DISCUSSION...
THE NATIONAL WEATHER SERVICE WILL BE MONITORING FOR SEVERE
THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND THIS EVENING.
AN OUTFLOW BOUNDARY CONTINUES TO MOVE ACROSS SOUTHWEST
MISSOURI...AND WILL NEED TO BE WATCHED CLOSELY FOR SEVERE
THUNDERSTORM DEVELOPMENT.
AN EXTREMELY UNSTABLE ENVIRONMENT EXISTS ACROSS SOUTHERN AND CENTRAL
MISSOURI. RUC SUGGESTS THAT 4000 J/KG OF MIXED LAYER CAPE IS NOW
PRESENT FOR UPDRAFTS TO WORK WITH. THE ONE MITIGATING FACTOR IS
SHEAR VALUES...WHICH ARE VERY LOW. DEEP LAYER SHEAR IS ONLY ABOUT
10 TO 20 KNOTS...WHILE LOW LEVEL HELICITIES ARE UNDER 50 M2S2.
THE PRIMARY RISK WITH STORMS THAT DEVELOP WILL BE DAMAGING DOWNBURST
WINDS IN EXCESS OF 70 MPH...AND LARGE HAIL TO THE SIZE OF GOLF
BALLS. A 0-4KM THETA E DIFFERENTIAL RANGING BETWEEN 35 AND 40
DEGREES...SUGGESTS A HIGH LIKELIHOOD OF DOWNBURSTS.
CURRENTLY...THE LINE SEGMENT MOVING INTO BARRY COUNTY WILL HAVE A
HIGH RISK FOR PRODUCING DAMAGING WIND GUSTS. WE WILL NEED TO
MONITOR FOR IMPACTS OVER TABLE ROCK LAKE...AS MANY BOATERS ARE ON
THE LAKE THIS AFTERNOON. THIS STORM IS CATCHING ABOUT 25 KNOTS OF
0-3 KM SHEAR...WITH A NEAR PERPENDICULAR INTERACTION...WHICH COULD
INCREASE THE STRENGTH OF THE LINE SEGMENT FOR THE NEXT HOUR OR SO.
CRAMER
&&
.DISCUSSION...
IT LOOKS TO BE A MESSY NEXT 24 TO 36 HOURS ACROSS THE CWA AS
WEAKLY ORGANIZED CONVECTION MOVES THROUGH THE AREA. ONCE THIS
APPROACHING SYSTEM MOVES THROUGH HOWEVER...A COMFORTABLE STRETCH OF
SPRING WEATHER APPEARS TO BE ON TAP FOR THE REGION.
STARTING OUT EARLY THIS MORNING...RATHER COMPLEX BUT GENERALLY WEAK
SOUTHWEST FLOW IS IN PLACE ALOFT OVER THE AREA. AT THE
SURFACE...LOW PRESSURE CONTINUES TO ORGANIZE OVER THE HIGH
PLAINS...WITH EXPANSIVE SURFACE TROUGHING EXTENDING INTO THE
NORTHERN PLAINS ALONG A SHARPENING SURFACE FRONT. A LARGE LINEAR
MCS HAD DEVELOPED OVERNIGHT FROM NEBRASKA THROUGH MUCH OF SOUTHERN
MINNESOTA.
OUTFLOW HAS SURGED WELL AHEAD OF THIS CONVECTION AS OF 07Z THIS
MORNING...AND THIS BOUNDARY WILL LIKELY BE THE INITIAL FOCUS FOR
CONVECTION OVER THE SGF CWA BY MIDDAY. SUSPECT THAT THIS BOUNDARY
WILL BEGIN TO IMPINGE ON THE NORTHWESTERN PERIPHERY OF THE CWA
BETWEEN 18Z AND 21Z TODAY...ABOUT THE TIME THAT A VERY UNSTABLE
AIRMASS WILL BE EFFECTIVELY UNCAPPED. ONCE SURFACE INHIBITION
ERODES...LIFT ALONG THE OUTFLOW WILL HAVE A VERY WARM AND MOIST LOW
LEVEL AIRMASS AVAILABLE TO TAP INTO...WITH RATHER STEEP MID LEVEL LAPSE
RATES ALOFT. AS A RESULT...4000+ J/KG OF SFC CAPE WILL BE COMMON
OVER THE REGION...WITH FORECAST SOUNDINGS SUGGESTING NEARLY 1000
J/KG AVAILABLE THROUGH THE HAIL GROWTH LAYER. WHILE INSTABILITY
WILL BE HIGH TO EXTREME IN NATURE...OVERALL WEAK BULK SHEAR VALUES
(AROUND 20 KTS THROUGH 0-6 KM LAYER) WILL MAKE CONVECTIVE
ORGANIZATION DIFFICULT TO COME BY. WITH THAT IN MIND...DO BELIEVE
THE GREATEST SEVERE THREAT WILL BE FROM LARGE (PERHAPS VERY LARGE IN
A FEW INSTANCES) HAIL AS STORMS INITIALLY DEVELOP...AS WELL AS LOCALIZED
DOWNBURSTS DUE TO PRECIP LOADING PROCESSES. THE TORNADO THREAT
APPEARS QUITE LOW AT THIS TIME...THOUGH ANY STORM MERGERS AND/OR
BOUNDARY INTERACTIONS THAT MAY ACT TO LOCALLY INCREASE HELICITY
VALUES WILL NEED TO BE WATCHED VERY VERY CAREFULLY...DUE TO THE VERY
HIGH INSTABILITY ALREADY IN PLACE.
ALONG WITH THE SEVERE WEATHER THREAT...WILL ALSO NEED TO BE MINDFUL
OF HEAVY RAIN POTENTIAL. OVERALL STORM MOTIONS ARE EXPECTED TO BE
RATHER SLOW...AS WELL AS BOUNDARY-PARALLEL. WHEN COMBINED WITH PWAT
VALUES APPROACHING 2 INCHES...THIS SUGGESTS THAT HEAVY RAIN/FLASH
FLOODING COULD BE POSSIBLE IN AT LEAST A LOCALIZED FASHION. MOST
FAVORED AREA FOR THIS WILL BE WEST OF U.S. 65 AND NORTH OF
I-44...WHERE HEAVY RAIN FELL LAST WEEK. FOR THE REMAINDER OF THE
AREA...HOPEFULLY THIS WILL SIMPLY SERVE AS A MUCH NEEDED DOSE OF
RAINFALL.
MUCH OF TODAY`S INITIAL CONVECTION WILL BE WELL AHEAD OF THE
SYNOPTIC COLD FRONT...WHICH LOOKS TO SLOWLY MAKE ITS WAY ACROSS THE
CWA THROUGH MID MORNING MONDAY. RIGHT NOW...IT IS SOMEWHAT UNCLEAR
AS HOW CONVECTION WILL EVOLVE THROUGH THE OVERNIGHT HOURS INTO
MONDAY MORNING. SUSPECT THAT EITHER NEW OUTFLOW WILL SERVE AS THE
FOCUS...OR ELSE ADDITIONAL DEVELOPMENT WILL BE REALIZED ALONG THE
ACTUAL FRONT THROUGH THE OVERNIGHT HOURS. HAVE MAINTAINED HIGH POPS
THROUGH MONDAY MORNING TO ACCOUNT...THOUGH DO THINK THAT THE OVERALL
SEVERE WEATHER THREAT SHOULD DECREASE A BIT THROUGH THE OVERNIGHT
HOURS TONIGHT.
AS ALLUDED TO ABOVE...SYNOPTIC FRONT SHOULD FINALLY CLEAR THE CWA BY
MIDDAY MONDAY...WITH HIGH PRESSURE THEN TAKING CONTROL FOR MOST OF
THE REMAINDER OF THE WEEK. THIS LOOKS TO RESULT IN SOME OF THE MOST
COMFORTABLE CONDITIONS WE`VE SEEN IN QUITE A WHILE ACROSS THE
REGION...WITH NEAR NORMAL HIGHS IN THE LOW 70S AND LOW TEMPS IN THE
LOW 50S.
BOXELL
&&
.AVIATION...
PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS WILL
NEED TO MONITOR RADAR TRENDS THIS AFTERNOON...THIS EVENING...AND
THROUGH TONIGHT.
A COLD FRONT IS APPROACHING THE REGION...WHICH WILL TRIGGER
SCATTERED SHOWERS AND THUNDERSTORMS. ANY SHOWER OR THUNDERSTORM
THAT DIRECTLY IMPACTS AN AIRFIELD...COULD CAUSE SOME VERY GUSTY
WINDS...HEAVY RAIN...AND CLOUD TO GROUND LIGHTNING. THE
ENVIRONMENT THIS AFTERNOON AND EVENING WILL BE IDEAL FOR DOWNBURST
WIND GUSTS.
RAIN WILL EXIT THE REGION AFTER MIDNIGHT TONIGHT...GIVING WAY TO
FAIR WEATHER FOR SEVERAL DAYS STARTING TOMORROW MORNING.
AS THE FRONT SHIFTS THROUGH SOUTHERN MISSOURI TONIGHT...SURFACE
WINDS WILL SHIFT TO THE WEST AND NORTHWEST.
CRAMER
&&
.CLIMATE...
RECORD HIGHS AND WARM LOWS THROUGH THE WEEKEND...
MAY 6TH...
SITE...REC HIGH...REC WARM LOW
SGF....90/1952...73/2007
JLN....90/2007...73/1940
UNO....89/1949...69/2007
VIH....88/1956...68/2007
BOXELL
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
511 PM CDT SUN MAY 6 2012
.AVIATION...00Z KGRI TAF. WIND WILL BE THE BIGGEST ISSUE FOR THIS
FORECAST. NORTH WIND WILL CALM DOWN BY AROUND 02Z BUT WILL PICK
BACK UP AGAIN FOR MONDAY. THERE SHOULD BE A CONSIDERABLE AMOUNT OF
MID-LEVEL CLOUDINESS HANGING AROUND FOR MOST IF NOT ALL OF THIS
FORECAST. ANY SHOWER ACTIVITY SHOULD REMAIN EAST OF THE TERMINAL
FOR THE MOST PART.
&&
.PREV DISCUSSION... /ISSUED 400 PM CDT SUN MAY 6 2012/
SHORT TERM...TONIGHT AND MONDAY. MAIN FORECAST CONCERNS WILL BE
CHANCE FOR PRECIPITATION THIS EVENING AND TEMPERATURES.
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE TO THE NORTHEAST
THROUGH THE FORECAST AREA THIS AFTERNOON. CLOUDS CONTINUE ACROSS
MUCH OF THE AREA AS WELL. SURFACE ANALYSIS HAS THE MAIN BOUNDARY
WELL INTO CENTRAL AND EASTERN KANSAS. LOCAL RADAR HAS SHOWN A FEW
WEAK BOUNDARIES AND THAT IS WHAT THE SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED ON THIS AFTERNOON.
AN UPPER LEVEL WAVE WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA
THIS EVENING AND EXPECT THERE WILL BE SOME SCATTERED SHOWERS AND
MAYBE AN ISOLATED THUNDERSTORM THIS AFTERNOON...BUT THIS EVENING
SHOULD BE SHOWERS. THE HRRR AND WRF AS WELL AS THE NAM AND GFS ALL
CONTINUE SOME SHOWERS AROUND THE AREA THROUGH THE EVENING. AS THE
UPPER LEVEL WAVE MOVES TO THE EAST THIS EVENING THE PRECIPITATION
SHOULD COME TO AN END AND SKIES SHOULD START TO CLEAR OUT AS DRIER
AIR MOVES INTO THE AREA. TEMPERATURES TONIGHT SHOULD BE MUCH COOLER
THAN LAST NIGHT.
THERE IS A WEAK SURFACE HIGH THAT NOSES INTO THE AREA ON MONDAY.
THIS SHOULD BRING CLEARING TO THE AREA. DESPITE THE SUNSHINE...THERE
WILL CONTINUE TO BE COOLER TEMPERATURES ACROSS THE AREA.
LONG TERM...MAIN CONCERNS FOR THE EXTENDED PERIODS ARE THE CHANCE
FOR SOME PATCHY FROST ACROSS THE WESTERN FRINGES OF THE FORECAST
AREA TUESDAY MORNING AS WELL AS THE CHANCE FOR SHOWERS AND
THUNDERSTORMS LATE IN THE WEEK AND INTO NEXT WEEKEND.
A RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE CENTRAL
AND NORTHERN PLAINS THROUGH MID WEEK...PEAKING ON THURSDAY...WHICH
WILL LIKELY BE THE WARMEST DAY OF THE WEEK. THE UPPER RIDGE IS
EXPECTED TO BREAK DOWN LATE THURSDAY NIGHT AS NEXT UPPER TROUGH
APPROACHES THE REGION...AND THE ASSOCIATED COLD FRONT SHOULD COOL
TEMPERATURES BACK DOWN BELOW CLIMATOLOGY AND BRING A RETURN OF
SOME SHOWERS AND THUNDERSTORMS TO THE LOCAL AREA BEGINNING IN THE
NORTHWEST THURSDAY NIGHT...AND SPREADING ACROSS THE ENTIRE
FORECAST AREA FRIDAY. SOME MINOR DISCREPANCIES BETWEEN LATEST EC
AND GFS ON EXACT TIMING OF FRONTAL BOUNDARY AS IT MOVES ACROSS THE
CENTRAL PLAINS...BUT BOTH HAVE THE FRONTAL BOUNDARY STALLING ALONG
OR JUST SOUTH OF THE FORECAST AREA BY SATURDAY MORNING AS THE
UPPER LEVEL FLOW BECOMES MORE ZONAL. AS A RESULT...KEPT SOME SMALL
POPS FROM THURSDAY NIGHT ON FOR MOST AREAS...WITH A DECREASING
CHANCE OF THUNDERSTORMS BY SATURDAY NIGHT AND SUNDAY AS
INSTABILITY BEGINS TO WANE.
IN THE MEANTIME...FOCUS IS THE POTENTIAL FOR FROST ACROSS WESTERN
PORTIONS OF THE FORECAST AREA TUESDAY MORNING AS AN AREA OF
SURFACE HIGH PRESSURE NUDGES IN FROM THE WEST. AT THIS TIME OPTED
NOT TO INCLUDE MENTION OF FROST IN THE FORECAST FOR DAWSON AND
VALLEY COUNTIES...BUT WILL NEED TO CONTINUE TO MONITOR PLACEMENT
OF SURFACE HIGH TUESDAY MORNING...AS GUIDANCE IS VERY NEAR THE 36
DEGREE THRESHOLD FOR FROST OVER THIS TIME PERIOD. OTHERWISE...THE
REMAINDER OF THE FORECAST FOR THE WEEK LOOKS PLEASANT...WITH DRY
CONDITIONS AND SEASONAL TEMPERATURES PREVAILING TUESDAY THROUGH
THURSDAY...AS THE UPPER LEVEL RIDGE AMPLIFIES ALOFT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...HEINLEIN
SHORT TERM...JCB
LONG TERM...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 PM CDT SUN MAY 6 2012
.SHORT TERM...TONIGHT AND MONDAY. MAIN FORECAST CONCERNS WILL BE
CHANCE FOR PRECIPITATION THIS EVENING AND TEMPERATURES.
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE TO THE NORTHEAST
THROUGH THE FORECAST AREA THIS AFTERNOON. CLOUDS CONTINUE ACROSS
MUCH OF THE AREA AS WELL. SURFACE ANALYSIS HAS THE MAIN BOUNDARY
WELL INTO CENTRAL AND EASTERN KANSAS. LOCAL RADAR HAS SHOWN A FEW
WEAK BOUNDARIES AND THAT IS WHAT THE SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED ON THIS AFTERNOON.
AN UPPER LEVEL WAVE WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA
THIS EVENING AND EXPECT THERE WILL BE SOME SCATTERED SHOWERS AND
MAYBE AN ISOLATED THUNDERSTORM THIS AFTERNOON...BUT THIS EVENING
SHOULD BE SHOWERS. THE HRRR AND WRF AS WELL AS THE NAM AND GFS ALL
CONTINUE SOME SHOWERS AROUND THE AREA THROUGH THE EVENING. AS THE
UPPER LEVEL WAVE MOVES TO THE EAST THIS EVENING THE PRECIPITATION
SHOULD COME TO AN END AND SKIES SHOULD START TO CLEAR OUT AS DRIER
AIR MOVES INTO THE AREA. TEMPERATURES TONIGHT SHOULD BE MUCH COOLER
THAN LAST NIGHT.
THERE IS A WEAK SURFACE HIGH THAT NOSES INTO THE AREA ON MONDAY.
THIS SHOULD BRING CLEARING TO THE AREA. DESPITE THE SUNSHINE...THERE
WILL CONTINUE TO BE COOLER TEMPERATURES ACROSS THE AREA.
.LONG TERM...MAIN CONCERNS FOR THE EXTENDED PERIODS ARE THE CHANCE
FOR SOME PATCHY FROST ACROSS THE WESTERN FRINGES OF THE FORECAST
AREA TUESDAY MORNING AS WELL AS THE CHANCE FOR SHOWERS AND
THUNDERSTORMS LATE IN THE WEEK AND INTO NEXT WEEKEND.
A RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE CENTRAL
AND NORTHERN PLAINS THROUGH MID WEEK...PEAKING ON THURSDAY...WHICH
WILL LIKELY BE THE WARMEST DAY OF THE WEEK. THE UPPER RIDGE IS
EXPECTED TO BREAK DOWN LATE THURSDAY NIGHT AS NEXT UPPER TROUGH
APPROACHES THE REGION...AND THE ASSOCIATED COLD FRONT SHOULD COOL
TEMPERATURES BACK DOWN BELOW CLIMATOLOGY AND BRING A RETURN OF
SOME SHOWERS AND THUNDERSTORMS TO THE LOCAL AREA BEGINNING IN THE
NORTHWEST THURSDAY NIGHT...AND SPREADING ACROSS THE ENTIRE
FORECAST AREA FRIDAY. SOME MINOR DISCREPANCIES BETWEEN LATEST EC
AND GFS ON EXACT TIMING OF FRONTAL BOUNDARY AS IT MOVES ACROSS THE
CENTRAL PLAINS...BUT BOTH HAVE THE FRONTAL BOUNDARY STALLING ALONG
OR JUST SOUTH OF THE FORECAST AREA BY SATURDAY MORNING AS THE
UPPER LEVEL FLOW BECOMES MORE ZONAL. AS A RESULT...KEPT SOME SMALL
POPS FROM THURSDAY NIGHT ON FOR MOST AREAS...WITH A DECREASING
CHANCE OF THUNDERSTORMS BY SATURDAY NIGHT AND SUNDAY AS
INSTABILITY BEGINS TO WANE.
IN THE MEANTIME...FOCUS IS THE POTENTIAL FOR FROST ACROSS WESTERN
PORTIONS OF THE FORECAST AREA TUESDAY MORNING AS AN AREA OF
SURFACE HIGH PRESSURE NUDGES IN FROM THE WEST. AT THIS TIME OPTED
NOT TO INCLUDE MENTION OF FROST IN THE FORECAST FOR DAWSON AND
VALLEY COUNTIES...BUT WILL NEED TO CONTINUE TO MONITOR PLACEMENT
OF SURFACE HIGH TUESDAY MORNING...AS GUIDANCE IS VERY NEAR THE 36
DEGREE THRESHOLD FOR FROST OVER THIS TIME PERIOD. OTHERWISE...THE
REMAINDER OF THE FORECAST FOR THE WEEK LOOKS PLEASANT...WITH DRY
CONDITIONS AND SEASONAL TEMPERATURES PREVAILING TUESDAY THROUGH
THURSDAY...AS THE UPPER LEVEL RIDGE AMPLIFIES ALOFT.
&&
.PREV DISCUSSION... /ISSUED 1224 PM CDT SUN MAY 6 2012/
AVIATION...18Z TAF. LOW CLOUDS CONTINUE TO MOVE THROUGH THE KGRI
TERMINAL AREA. THEY SHOULD BE LIFTING IN THE NEXT HOUR OR TWO AS
AN UPPER LEVEL WAVE MOVES TO THE EAST OF THE AREA THIS AFTERNOON.
A FEW SHOWERS HAVE DEVELOPED TO THE SOUTHWEST OF THE KGRI TERMINAL
AND WILL MOVE TOWARD THE KGRI TERMINAL EARLY THIS AFTERNOON. CLOUDS
SHOULD CONTINUE TO LIFT DURING THE AFTERNOON. WINDS WILL BE FROM
THE NORTH DECREASING AS THE SUN SETS AND INCREASING AGAIN IN THE
MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...JCB
LONG TERM...ROSSI
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
315 PM CDT SUN MAY 6 2012
.SHORT TERM...TONIGHT
UPPER AIR CHARTS FROM 12Z SHOWED THE FOLLOWING. AT 300 MB...PRIMARY
JETSTREAM STRETCHED FROM UTAH INTO ONTARIO WITH A JET MAX OF AROUND
90-100 KNOTS OVER NORTH DAKOTA. AT 500 MB...A FAIRLY TIGHT/COMPACT
CLOSED LOW WAS NOTED NEAR KGGW...CLOSE TO THE BORDER OF MONTANA AND
SASKATCHEWAN. 12 HOUR 500 MB HEIGHT FALL AT KGGW WAS 110 METERS BUT
THE ESTIMATED MAX VALUE WAS ABOUT 140 METERS A LITTLE FARTHER NORTH.
MODEST SOUTHWESTERLY FLOW WAS NOTED FROM THE DESERT SOUTHWEST INTO
THE NORTHERN PLAINS. DECENT MOISTURE WAS IN PLACE AT 850 MB...WITH
DEWPOINTS IN THE TEENS FROM KANSAS INTO ILLINOIS. AT THE SURFACE...
AN OCCLUDED FRONT CURVED FROM LOW PRESSURE OVER SASKATCHWAN INTO
MINNESOTA...THEN A COLD FRONT TRAILED SOUTH THROUGH WESTERN IOWA...
AND DOWN INTO WESTERN OKLAHOMA. SURFACE PATTERN ACROSS SOUTHEAST
NEBRASKA WAS SOMEWHAT AFFECTED/CONTAMINATED BY EARLIER MCS THAT
PRODUCED OUTFLOW.
ALTHOUGH THE MAIN SURFACE FRONT WILL CONTINUE TO PUSH SOUTHEAST OR
EAST TONIGHT...THERE IS STILL ENOUGH LINGERING ELEVATED MOISTURE AND
INSTABILITY OVER ABOUT THE SOUTHEASTERN 1/2 OF THE FORECAST AREA FOR
SCATTERED THUNDERSTORMS AT LEAST THROUGH MIDNIGHT. THIS IS CLOSER
TO THE 850 MB FRONT. 12Z NAM WAS MORE A BIT MORE AGRESSIVE WITH
PRECIPITATION COMPARED TO THE GFS. 17Z RUN OF THE HRRR THOUGH
SUGGESTED 12Z NAM WAS REASONABLE.
.LONG TERM...MONDAY THROUGH SUNDAY.
TEMPERATURES WILL PROVIDE THE MAIN CHALLENGES THROUGH MUCH OF THE
WEEK WITH HIGHER CHANCES FOR SHOWERS/THUNDERSTORMS NOT ARRIVING
UNTIL ABOUT FRIDAY.
CLOSED LOW AT 500 MB WILL TRACK EASTWARD JUST NORTH OF THE BORDER OF
THE U.S. AND CANADA ON MONDAY...WHILE THE TROUGH ASSOCIATED WITH
IT TRACKS ACROSS THE NORTHERN AND CENTRAL PLAINS. IT APPEARS THAT
PRECIPITATION CHANCES WILL BE MINIMAL IN OUR AREA. SOME LIGHT
SHOWERS COULD LINGER IN FAR SOUTHEAST NEBRASKA PAST 6 AM...SO LEFT
A LOW POP THERE UNTIL ABOUT 9 AM. ON TUESDAY...FELT BETTER CHANCES
FOR SHOWERS WOULD STAY TO OUR NORTH OR NORTHEAST.
A RIDGE OF HIGH PRESSURE AT THE SURFACE WILL BUILD INTO THE AREA
MONDAY NIGHT INTO TUESDAY...SETTING THE STAGE FOR WHAT LOOKS LIKE A
COOL EARLY MORNING FOR WEDNESDAY. WENT SEVERAL DEGREES BELOW
GUIDANCE FOR LOWS TUESDAY NIGHT/WEDNESDAY MORNING WITH MAINLY CLEAR
SKIES AND LIGHT WINDS EXPECTED.
A MID TROPOSPHERIC RIDGE WILL BUILD ACROSS THE REGION WEDNESDAY
THROUGH THURSDAY WITH DRY CONDITIONS AND MILDER TEMPERATURES. MODELS
SHOW NEXT COLD FRONT APPROCHING THE AREA FROM THE NORTHWEST BY LATE
THURSDAY NIGHT. THEN HAVE LOW POPS FOR PARTS OF THE AREA INTO NEXT
WEEKEND.
MILLER
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP/BECOME MORE WIDESPREAD ACROSS EASTERN NEBRASKA THIS
AFTERNOON. ACTIVITY COULD LINGER INTO EARLY TONIGHT AT KLNK/KOMA
BUT THUNDERSTORMS SHOULD BE MOSTLY SE OF TAF SITES EARLY THIS
EVENING. CIGS SHOULD LIFT MOSTLY INTO UPPER REACHES OF MVFR
CATEGORY OR ABOVE 3K FT AGL BY MID AFTERNOON...BUT COULD BE
LOWERED BACK DOWN IN AND NEAR SHOWERS. FOUR-HOUR TEMPO GROUPS OF
THUNDERSTORMS WERE MENTIONED AT KLNK/KOMA WHEN BEST CHANCES WERE
BELIEVED TO EXIST...BUT SOME RISK REMAINS EITHER SIDE OF THAT
WINDOW. TSTM CHANCES APPEARED TOO LOW TO CARRY MENTION AT KOFK.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
312 PM EDT SUN MAY 6 2012
.SYNOPSIS...
AN AREA OF HIGH PRESSURE OVER THE MID ATLANTIC WILL EXTEND SOUTHWARD
INTO THE CAROLINAS THROUGH MONDAY. A COLD FRONT WILL APPROACH THE
REGION LATE TUESDAY AND WEDNESDAY...BRINGING UNSETTLED WEATHER FOR
THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 305 PM SUNDAY...
THIS MORNINGS STRATUS HAS FINALLY BEGUN TO BREAK...WITH WIDESPREAD
STRATOCU ACROSS THE CWA THIS AFTERNOON BUT STILL MOSTLY CLOUDY FOR
MUCH OF THE AREA. A WEAK LOW PRESSURE OFFSHORE OF KILM CAN BE SEEN
ON VISIBLE SATELLITE IMAGERY. THIS LOW WILL DRIFT SOUTHEAST
TONIGHT...WHILE HIGH PRESSURE SURGES INTO THE AREA FROM THE MID
ATLANTIC COAST. WITH LIMITED HEATING TODAY...MLCAPE GREATER THAN
500 J/KG IS TO THE SOUTH AND WEST OF THE CWA. PW REMAINS HIGH NEAR
1.3-1.5 INCHES...AND A FEW SPOTTY LIGHT SHOWERS HAVE DEVELOP NEAR
THE NC/SC BORDER...DRIFTING SOUTH INTO SC. THE HRRR ALSO SHOWS
SHOWERS DEVELOPING OVER THE VA MOUNTAINS AND DRIFTING SOUTH TOWARD
THE NORTHWEST PIEDMONT. HOWEVER...VERY LITTLE HAS DEVELOPED SO FAR
AND ANY THAT DO FORM SHOULD REMAIN OUTSIDE OF THE CWA PRIOR TO
SUNSET.
THE MAIN FORECAST CONCERN TONIGHT WILL THE POTENTIAL FOR FOG AND
STRATUS. WINDS WILL BE LIGHT AND REMAIN EAST-NORTHEASTERLY AND AS
THE STRATOCU DECK CONTINUES TO ERODE..SKIES SHOULD BECOME AT LEAST
PARTLY CLOUDY THIS EVENING. HOWEVER...WITH ALL OF THE MOISTURE
FOCUSED IN THE LOWEST 3000 FT...THE LOW LEVEL AIRMASS SHOULD BEING
TO RESATURATE BY MIDNIGHT. THE SURFACE RIDGE AXIS IS FORECAST TO
LIE NORTHEAST TO SOUTHEAST ACROSS CENTRAL NC. NEITHER FORECAST
SOUNDINGS OR SREF PROBABILITIES POINT STRONGLY TOWARD STRATUS OR
FOG...BUT GIVEN THAT MANY AREAS RECEIVED ONE TO TWO INCHES OF RAIN
LAST EVENING...WE WILL INCLUDE AT LEAST PATCHY FOG FOR TONIGHT.
LOWS IN THE UPPER 50S.
THE SURFACE RIDGE AXIS WILL SHIFT SLIGHTLY EASTWARD ON MONDAY AS
UPPER RIDGING BUILDS OVER THE CAROLINAS. SOUTHEASTERLY RETURN FLOW
WILL BEGIN TO DEVELOP BY MONDAY AFTERNOON. 1000-850MB THICKNESSES
ARE PROGGED TO RANGE FROM 1400M IN THE SOUTHWEST TO AROUND 1375M IN
THE NORTHEAST. MORNING STRATUS...IF ANY...SHOULD LIFT QUICKLY AND
THERE SHOULD BE A A FULL DAY OF HEATING....AND WITH NEUTRAL AIRMASS
ADVECTION OVER THE AREA...HIGHS WILL BE IN THE MID AND UPPER 70S
BASED ON THICKNESSES VALUES. RETURN FLOW SHOWERS AND STORMS WILL BE
POSSIBLE OVER THE HIGHER TERRAIN BUT THE COMBINATION OF THE SURFACE
HIGH AND WEAK MID LEVEL FLOW SHOULD KEEP EVERYTHING WEST OF THE
YADKIN RIVER.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 255 PM SUNDAY...
FOR MONDAY NIGHT: LOW STRATUS SHOULD FILL BACK IN OVERNIGHT WITHIN
THE LOW LEVEL WARM AIR ADVECTION REGIME. AS THE NORTHERN STREAM MID
LEVEL VORTEX DROPS SOUTHWARD INTO THE UPPER MIDWEST... THE SURFACE
COLD FRONT PUSHES INTO THE MID MISS VALLEY AND OHIO VALLEY (BENEATH
A WEAK SHORTWAVE WELL OUT AHEAD OF THE MAIN TROUGH)... WITH A FAIRLY
STRONG SURFACE LOW TRACKING ALONG THE FRONT THROUGH OH/LK ERIE/LK
ONTARIO. MODELS INDICATE SHALLOW AND WEAK MOIST ISENTROPIC UPGLIDE
NEAR THE GROUND IN THE TRIAD AREA MONDAY NIGHT ALONG WITH A BRIEF
SURGE IN LOW LEVEL MOISTURE TRANSPORT... HOWEVER THE BEST LOW LEVEL
WIND FIELD WILL SLIDE TO OUR NW AND NORTH... CLOSER TO THE SURFACE
LOW... AND ANY APPRECIABLE RAIN SHOULD STAY NW OF CENTRAL NC. WILL
RETAIN A MENTION OF JUST ISOLATED SPRINKLES IN THE FAR NW CWA. LOWS
59-63 WITH CLOUDY SKIES WEST AND PARTLY TO MOSTLY CLOUDY SKIES EAST
OVERNIGHT.
FOR TUESDAY/TUESDAY NIGHT: THE SURFACE HIGH OFF THE EAST COAST
CONTINUES MOVING EASTWARD RESULTING IN A STEADY VEERING OF LOW LEVEL
WINDS OVER CENTRAL NC TO SOUTHERLY AND SWRLY... FURTHER MOISTENING
THE COLUMN VIA MOISTURE ADVECTION. THE UPPER-MIDWEST MID LEVEL LOW
OPENS UP AS IT DROPS SOUTHEAST THROUGH MI THROUGH TUESDAY NIGHT...
AND THE AFOREMENTIONED PRECEDING WEAK WAVE DISSIPATES AS IT CROSSES
THE APPALACHIANS AND NORTHEAST... RESULTING IN VERY MINIMAL HEIGHT
FALLS INTO CENTRAL NC. BUT THE IMPROVING LOW LEVEL MASS CONVERGENCE
(WITH BOTH GULF AND ATLANTIC MOISTURE SOURCES) AND POTENTIAL FOR AT
LEAST MARGINAL INSTABILITY WILL NECESSITATE LEAVING SCATTERED
SHOWERS AND A FEW STORMS IN THE FORECAST... MAINLY IN THE AFTERNOON
THROUGH MID EVENING HOURS. WITH PERIODS OF PARTIAL SUNSHINE...
ABOVE-NORMAL THICKNESSES... AND A SOUTHWESTERLY BREEZE... EXPECT
HIGHS OF 78-83. THE SURFACE FRONT SHOULD STILL BE JUST TO OUR
NORTHWEST TUESDAY NIGHT... BUT PREFRONTAL LOW AND MID LEVEL WINDS
WILL STEADILY STRENGTHEN WITH HIGH PRECIPITABLE WATER ADVECTING INTO
THE REGION. MID LEVEL HEIGHTS BEGIN TO FALL SLOWLY WITH THE TROUGH`S
APPROACH... AND FORECAST SOUNDINGS DEPICT ENOUGH LOW LEVEL WARMTH
FOR A COUPLE HUNDRED J/KG OF MLCAPE OVERNIGHT. THE RESULTING LIFT
OVER WRN NC IS SUFFICIENT TO KEEP A RISK OF SCATTERED SHOWERS/STORMS
GOING IN THE WESTERN PORTION OF THE FORECAST AREA THROUGH TUESDAY
NIGHT... WITH LESSER CHANCES IN THE EAST WHERE THE MOISTURE
TRANSPORT WILL BE A BIT LOWER WITH LITTLE INSTABILITY BENEATH
LINGERING SLIGHTLY ANTICYCLONIC LOW LEVEL FLOW. WARM AND MUGGY LOWS
OF 63-67.
FOR WEDNESDAY/WEDNESDAY NIGHT: CONFIDENCE CONTINUES TO RISE THAT
WE`LL SEE A PERIOD OF WIDESPREAD SHOWERS AND STORMS. THE MID LEVEL
TROUGH CONTINUES TO DROP ESE INTO THE INTERIOR NORTHEAST AND
MIDATLANTIC STATES... LEADING TO STRENGTHENING DYNAMIC FORCING FOR
ASCENT OVER NC... A RESULT OF MID LEVEL HEIGHT FALLS AND UPPER
DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A STRENGTHENING 130+ KT
JET OVER THE EASTERN GREAT LAKES. MODELS HAVE BEEN SLOWING DOWN THIS
SYSTEM IN RECENT RUNS... AND THE GFS NOW HOLDS OFF FRONTAL PASSAGE
UNTIL AFTER NIGHTFALL WEDNESDAY EVENING. GIVEN EXPECTATIONS OF
PLENTIFUL MOISTURE (PRECIPITABLE WATER NEARLY 200% OF NORMAL) AHEAD
OF THE FRONT AND AUGMENTATION OF LIFT BY PROJECTED 800-1200 J/KG OF
(SKINNY) SURFACE CAPE... WILL RAISE POPS TO HIGH LIKELY AND LOW
CATEGORICAL FOR WEDNESDAY AFTERNOON AND EVENING. EXPECT RAIN CHANCES
TO DECREASE OVERNIGHT -- BUT NOT END -- AS THE MID LEVEL TROUGH AXIS
LAGS THE SURFACE FRONT RESULTING IN A DELAY IN DRYING ALOFT. HAVE
NUDGED HIGHS DOWN A BIT TO 73-80 WITH THICK CLOUDS EXPECTED. LOWS
55-61. -GIH
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 PM SUNDAY...
FOR THURSDAY/THURSDAY NIGHT: WILL DELAY THE END OF RAIN CHANCES AND
CLEARING OF CLOUDS UNTIL THURSDAY MORNING BASED ON MODEL TRENDS...
ALTHOUGH DOWNSLOPE LOW LEVEL FLOW SHOULD ALLOW FOR PARTLY TO MOSTLY
SUNNY SKIES IN THE AFTERNOON. THE NEW 12Z ECMWF HAS BACKED OFF FROM
ITS 00Z RUN WHICH BROUGHT A CLOSED MID LEVEL VORTEX WELL SOUTH
ACROSS NRN/ERN VA THURSDAY NIGHT INTO FRIDAY. THE 12Z RUN MORE
CLOSELY RESEMBLES THE GFS WITH A MORE OPEN AND PROGRESSIVE TROUGH...
SO HAVE GONE THIS ROUTE WITH IMPROVING CONDITIONS BY MIDDAY
THURSDAY. LOW LEVEL THICKNESSES DROP TO 10-15 METERS BELOW NORMAL...
SUPPORTING HIGHS OF 72-77. LOWS 46-52 WITH CHILLY HIGH PRESSURE
STARTING TO BUILD IN FROM THE NW AND THICKNESSES EXPECTED TO FALL
INTO THE 1340S.
FOR FRIDAY THROUGH SUNDAY: GENERALLY COOL AND DRY WITH A MODERATING
TREND BACK TOWARD NORMAL OVER THE WEEKEND. EXPECT HIGHS OF 70-75
FRIDAY WITH MODEL THICKNESSES OVER 30 METERS BELOW NORMAL. HIGH
PRESSURE CONTINUES TO BUILD IN AS THE MID LEVEL TROUGH COVERING THE
NORTHEAST STATES LIFTS TO THE ENE. THE CLOSED LOW OVER AZ EARLY IN
THE WEEK WEAKENS AS IT SHIFTS ACROSS NRN MEXICO AND TX THROUGH
SATURDAY... THEN MOVES INTO THE INTERIOR SOUTHEAST STATES ON SUNDAY.
WHILE THE MODELS DEPICT THE SURFACE HIGH CENTER MOVING OFFSHORE WITH
LOW LEVEL FLOW BECOMING EASTERLY AND SOUTHEASTERLY... THE COLUMN
SHOULD REMAIN FAIRLY DRY WITH STABLE MID LEVELS... AND ANY MID LEVEL
DPVA APPEARS TOO LOW/WEAK FOR ANYTHING MORE THAN A SLIGHT CHANCE OF
SHOWERS AT MOST ON SUNDAY. BELOW-NORMAL HIGHS IN THE LOW 70S SHOULD
TREND BACK UP TO THE MID 70S THEN UPPER 70S TO NEAR 80 OVER THE
WEEKEND. -GIH
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 155 PM SUNDAY...
VISIBLE SATELLITE IMAGERY IS BEGINNING TO SHOW MORE BREAKS IN THE
WIDESPREAD STRATUS ACROSS CENTRAL NC...WITH MORE REPORTS OF BKN
1500-2500 CEILINGS AROUND THE AREA. THIS TREND WILL CONTINUE INTO
THE AFTERNOON...ALTHOUGH MVFR CEILINGS MAY REMAIN PREDOMINATE SINCE
THE BREAKS IN CLOUDS ARE SMALL AND VARIABLE FROM HOUR TO HOUR. A
STEADY NORTHEASTERLY WIND...STRONGER OVER EASTERN NC...WILL CONTINUE
INTO THE EVENING HOURS WHILE A WEAK LOW PRESSURE OFF THE CAROLINA
COAST DRIFTS AWAY FROM THE AREA.
TONIGHT..MODELS SHOW ANOTHER SURGE OF HIGH PRESSURE FROM THE MID
ATLANTIC COAST...WHICH MAY KEEP WINDS FROM GOING COMPLETELY CALM.
MOST GUIDANCE SHOWS A 3-5KT WIND OVERNIGHT..WHICH WOULD HELP TO KEEP
FOG FROM BEING WIDESPREAD AND DENSE...WITH BETTER POTENTIAL FOR
STRATUS. HOWEVER...MANY AREAS RECEIVED ONE TO TWO INCHES OF RAIN
LAST EVENING AND IT IS POSSIBLE THAT VSBYS WILL BE LOWER THAN WHAT
GUIDANCE GIVES. THUS...THERE IS HIGHER CONFIDENCE IN MVFR TO IFR
STRATUS AFTER MIDNIGHT...BUT IFR OR LOWER VSBYS CANNOT BE RULED
OUT. STRATUS SHOULD LIFT MUCH MORE QUICKLY MONDAY MORNING...WITH
VFR CONDITIONS POSSIBLE PRIOR TO 18Z.
OUTLOOK...
A CONTINUED MOIST AIRMASS OVER CENTRAL NC MAY PROMOTE
STRATUS/FOG AGAIN TUESDAY MORNING. A COLD FRONT WILL THEN APPROACH
THE REGION FROM THE NORTHWEST THROUGH THE MIDDLE OF THE
WEEK...LEADING TO UNSETTLED WEATHER AND THE POTENTIAL FOR ADVERSE
AVIATION CONDITIONS THROUGH THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 PM EDT SUN MAY 6 2012
.SYNOPSIS...
AN AREA OF HIGH PRESSURE OVER THE MID ATLANTIC WILL EXTEND SOUTHWARD
INTO THE CAROLINAS THROUGH MONDAY. A COLD FRONT WILL APPROACH THE
REGION LATE TUESDAY AND WEDNESDAY...BRINGING UNSETTLED WEATHER FOR
THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 305 PM SUNDAY...
THIS MORNINGS STRATUS HAS FINALLY BEGUN TO BREAK...WITH WIDESPREAD
STRATOCU ACROSS THE CWA THIS AFTERNOON BUT STILL MOSTLY CLOUDY FOR
MUCH OF THE AREA. A WEAK LOW PRESSURE OFFSHORE OF KILM CAN BE SEEN
ON VISIBLE SATELLITE IMAGERY. THIS LOW WILL DRIFT SOUTHEAST
TONIGHT...WHILE HIGH PRESSURE SURGES INTO THE AREA FROM THE MID
ATLANTIC COAST. WITH LIMITED HEATING TODAY...MLCAPE GREATER THAN
500 J/KG IS TO THE SOUTH AND WEST OF THE CWA. PW REMAINS HIGH NEAR
1.3-1.5 INCHES...AND A FEW SPOTTY LIGHT SHOWERS HAVE DEVELOP NEAR
THE NC/SC BORDER...DRIFTING SOUTH INTO SC. THE HRRR ALSO SHOWS
SHOWERS DEVELOPING OVER THE VA MOUNTAINS AND DRIFTING SOUTH TOWARD
THE NORTHWEST PIEDMONT. HOWEVER...VERY LITTLE HAS DEVELOPED SO FAR
AND ANY THAT DO FORM SHOULD REMAIN OUTSIDE OF THE CWA PRIOR TO
SUNSET.
THE MAIN FORECAST CONCERN TONIGHT WILL THE POTENTIAL FOR FOG AND
STRATUS. WINDS WILL BE LIGHT AND REMAIN EAST-NORTHEASTERLY AND AS
THE STRATOCU DECK CONTINUES TO ERODE..SKIES SHOULD BECOME AT LEAST
PARTLY CLOUDY THIS EVENING. HOWEVER...WITH ALL OF THE MOISTURE
FOCUSED IN THE LOWEST 3000 FT...THE LOW LEVEL AIRMASS SHOULD BEING
TO RESATURATE BY MIDNIGHT. THE SURFACE RIDGE AXIS IS FORECAST TO
LIE NORTHEAST TO SOUTHEAST ACROSS CENTRAL NC. NEITHER FORECAST
SOUNDINGS OR SREF PROBABILITIES POINT STRONGLY TOWARD STRATUS OR
FOG...BUT GIVEN THAT MANY AREAS RECEIVED ONE TO TWO INCHES OF RAIN
LAST EVENING...WE WILL INCLUDE AT LEAST PATCHY FOG FOR TONIGHT.
LOWS IN THE UPPER 50S.
THE SURFACE RIDGE AXIS WILL SHIFT SLIGHTLY EASTWARD ON MONDAY AS
UPPER RIDGING BUILDS OVER THE CAROLINAS. SOUTHEASTERLY RETURN FLOW
WILL BEGIN TO DEVELOP BY MONDAY AFTERNOON. 1000-850MB THICKNESSES
ARE PROGGED TO RANGE FROM 1400M IN THE SOUTHWEST TO AROUND 1375M IN
THE NORTHEAST. MORNING STRATUS...IF ANY...SHOULD LIFT QUICKLY AND
THERE SHOULD BE A A FULL DAY OF HEATING....AND WITH NEUTRAL AIRMASS
ADVECTION OVER THE AREA...HIGHS WILL BE IN THE MID AND UPPER 70S
BASED ON THICKNESSES VALUES. RETURN FLOW SHOWERS AND STORMS WILL BE
POSSIBLE OVER THE HIGHER TERRAIN BUT THE COMBINATION OF THE SURFACE
HIGH AND WEAK MID LEVEL FLOW SHOULD KEEP EVERYTHING WEST OF THE
YADKIN RIVER.
.SHORT TERM /MONDAY NIGHT/...
AS OF 320 AM SUNDAY...
LITTLE CHANGE REQUIRED TO FORECAST.
ICREASING CLOUD COVERAGE AND A STEADY S-SW FLOW SHOULD RESULT IN
MILD OVERNIGHT TEMPS IN THE 60S WITH MIN TEMPS LOWER 60S SOUTH AND
WEST AND UPPER 50S FAR NE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 240 AM SUNDAY...
TUESDAY TROUGH WEDNESDAY NIGHT:
MID/UPPER LEVEL RIDGE AXIS IS EXPECTED TO BE TO THE EAST OF THE AREA
BY THE START OF THIS PERIOD... WHILE A MID/UPPER LEVEL DISTURBANCE
CENTERED ACROSS THE NORTH CENTRAL U.S./WESTERN GREAT LAKES REGION
BEGINS TO AMPLIFY AND TRANSLATE EASTWARD. THIS WILL ALLOW A COLD
FRONT TO APPROACH OUR REGION ON TUESDAY INTO TUESDAY NIGHT. AHEAD OF
THE FRONT EXPECT SOUTHERLY RETURN FLOW WILL HELP WARM TEMPS BACK
INTO THE UPPER 70S TO LOWER 80S. GIVEN THE IMPROVING INSTABILITY AND
POTENTIAL FOR WEAK MID/UPPER LEVEL ENERGY TO TRACK ACROSS THE AREA
IN GENERALLY WSW`EARLY FLOW... EXPECT WE CLOUD SEE SOME SHOWERS AND
THUNDERSTORMS DEVELOP IN THE AFTERNOON/EVENING... WITH THE HIGHEST
POTENTIAL (CHANCE) ACROSS THE WESTERN PIEDMONT. ALSO... WILL NEED TO
KEEP AN EYE ON A SLOW MOVING SHEAR AXIS TO THE SOUTH OF THE AREA ON
TUESDAY. BOTH THE NAM AND GFS OVER THE PAST COUPLE OF RUNS AT TIMES
HAVE SHOWN THIS FEATURE DRIFTING NORTHWARD AND AFFECTING PORTIONS OF
CENTRAL NC... ALLOWING FOR THE DEVELOPMENT OF SOME SHOWERS AND
STORMS ACROSS OUR SOUTH AND EAST. HOWEVER... GIVEN LACK OF MODEL
AGREEMENT AND RUN TO RUN CONSISTENCY... WILL KEEP HIGHEST POPS WEST
FOR NOW ON TUESDAY AND TUESDAY NIGHT. GIVEN THE MOSTLY CLOUDY/CLOUDY
SKIES COUPLED WITH THE APPROACHING FRONT... EXPECT LOW TEMPS
WEDNESDAY MORNING WILL BE IN THE MID 60S.
THE AFOREMENTIONED COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA
ON WEDNESDAY... WITH LOCATIONS ACROSS THE EASTERN HALF/TWO-THIRDS OF
CENTRAL NC POTENTIALLY EXPERIENCING WIDESPREAD SHOWERS AND STORMS...
AS THE FRONT WILL BE MOVING THROUGH THE EASTERN HALF/TWO-THIRDS OF
THE AREA DURING PEAK HEATING (AS IT STANDS NOW)... COUPLED WITH
LARGE SCALE LIFT . THUS... WILL CONTINUE CURRENT POP FORECAST...
CHANCE FAR WEST... TO LOW END LIKELY ACROSS THE REMAINDER OF THE
AREA ON WEDNESDAY. WITH REGARD TO THE POTENTIAL FOR STRONG TO SEVERE
STORMS... AT LEAST WEAK TO MODERATE INSTABILITY IS EXPECTED ACROSS
THE AREA... WITH DEEP LAYER SHEAR VALUES RANGING FROM 20-25 KTS
SOUTH TO 30-35 KTS NORTH. THUS... EXPECT WE COULD SEE SOME ORGANIZED
SHOWERS AND STORMS... WITH SOME POTENTIAL STRONG TO SEVERE STORMS.
HOWEVER... GIVEN RATHER WEAK LAPSE RATES AS PW`S ARE EXPECTED TO
RISE TO 1.5-1.75 INCHES ON WEDNESDAY... NOT SURE HOW MUCH IF ANY
SEVERE STORMS WE WILL HAVE. FOR NOW WILL GO WITH HIGHS ON WEDNESDAY
RANGING FROM 76-82 DEGREES IN A NW TO SE FASHION WITH MOSTLY CLOUDY
TO OVERCAST SKIES.
LEAD MID/UPPER LEVEL IMPULSE WITH THE ASSOCIATED COLD FRONT IS
PROGGED TO MOVE THROUGH THE AREA WEDNESDAY NIGHT/THURSDAY MORNING...
WITH TIMING OF PRECIP EXITING THE SYSTEM A LITTLE SLOWER THAN LAST
NIGHTS MODELS INDICATED (3-9 HOURS SLOWER). THUS... WILL CONTINUE AT
LEAST CHANCE POPS INTO EARLY THURSDAY MORNING ACROSS THE COASTAL
PLAIN. THE 12Z ECWMF WANTS TO LINGER CHANCE FOR PRECIP INTO PAST
SUNRISE THURSDAY EVEN. WILL NOT GO THIS SLOW... AND ELECT TO END
POPS ACROSS THE ENTIRE CWA BEFORE DAYBREAK THURSDAY. FOR NOW WILL GO
WITH OVERNIGHT LOWS RANGING FROM THE MID TO UPPER 50S.
THURSDAY THROUGH FRIDAY:
MID TO UPPER TROUGH AXIS IS EXCEPTED TO SLOWLY SHIFT EASTWARD ACROSS
THE AREA THURSDAY INTO FRIDAY... WITH THE CORE OF THE TROUGH
REMAINING TO THE NORTH/NORTHEAST OF THE AREA. THUS... WITH SURFACE
HIGH PRESSURE BUILDING ACROSS THE AREA THURSDAY INTO SATURDAY EXPECT
AT LEAST MOSTLY SUNNY/CLEAR TO PARTLY SUNNY/CLOUDY SKIES... WITH DRY
CONDITIONS. HIGHS AREA EXPECTED TO BE IN THE 70S... LOWS IN THE
50S.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD INTO THE AREA LATE WEEK
INTO THE WEEKEND... RESULTING IN A RETURN TO DRIER AND COOLER
WEATHER. HIGHS ARE GENERALLY EXPECTED TO BE IN THE 70S... LOWS IN
THE UPPER 40S TO 50S DURING THIS TIME FRAME.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 155 PM SUNDAY...
VISIBLE SATELLITE IMAGERY IS BEGINNING TO SHOW MORE BREAKS IN THE
WIDESPREAD STRATUS ACROSS CENTRAL NC...WITH MORE REPORTS OF BKN
1500-2500 CEILINGS AROUND THE AREA. THIS TREND WILL CONTINUE INTO
THE AFTERNOON...ALTHOUGH MVFR CEILINGS MAY REMAIN PREDOMINATE SINCE
THE BREAKS IN CLOUDS ARE SMALL AND VARIABLE FROM HOUR TO HOUR. A
STEADY NORTHEASTERLY WIND...STRONGER OVER EASTERN NC...WILL CONTINUE
INTO THE EVENING HOURS WHILE A WEAK LOW PRESSURE OFF THE CAROLINA
COAST DRIFTS AWAY FROM THE AREA.
TONIGHT..MODELS SHOW ANOTHER SURGE OF HIGH PRESSURE FROM THE MID
ATLANTIC COAST...WHICH MAY KEEP WINDS FROM GOING COMPLETELY CALM.
MOST GUIDANCE SHOWS A 3-5KT WIND OVERNIGHT..WHICH WOULD HELP TO KEEP
FOG FROM BEING WIDESPREAD AND DENSE...WITH BETTER POTENTIAL FOR
STRATUS. HOWEVER...MANY AREAS RECEIVED ONE TO TWO INCHES OF RAIN
LAST EVENING AND IT IS POSSIBLE THAT VSBYS WILL BE LOWER THAN WHAT
GUIDANCE GIVES. THUS...THERE IS HIGHER CONFIDENCE IN MVFR TO IFR
STRATUS AFTER MIDNIGHT...BUT IFR OR LOWER VSBYS CANNOT BE RULED
OUT. STRATUS SHOULD LIFT MUCH MORE QUICKLY MONDAY MORNING...WITH
VFR CONDITIONS POSSIBLE PRIOR TO 18Z.
OUTLOOK...
A CONTINUED MOIST AIRMASS OVER CENTRAL NC MAY PROMOTE
STRATUS/FOG AGAIN TUESDAY MORNING. A COLD FRONT WILL THEN APPROACH
THE REGION FROM THE NORTHWEST THROUGH THE MIDDLE OF THE
WEEK...LEADING TO UNSETTLED WEATHER AND THE POTENTIAL FOR ADVERSE
AVIATION CONDITIONS THROUGH THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...HARTFIELD
LONG TERM...BSD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
103 PM CDT SUN MAY 6 2012
.DISCUSSION...
MAIN UPDATES EARLY THIS AFTERNOON WERE TO ADJUST
SKY...TEMPS...AND POPS BASED ON LATEST OBSERVATIONS...TRENDS...AND
NEAR TERM MODEL OUTPUT.
STACKED LOW PRESSURE CONTINUES TO MOVE SLOWLY NORTHEAST ACROSS
SOUTHERN SASKATCHEWAN. WRAP AROUND MOISTURE INCREASING CLOUDS
WEST INTO CENTRAL...WITH RAIN SHOWERS AT THE MOMENT STILL OFF TO
OUR WEST ACROSS NORTH CENTRAL MONTANA ADVECTING EAST-SOUTHEAST
TOWARDS EASTERN MT. A FEW LIGHT RETURNS OVER NORTH CENTRAL ND.
CONTINUES TO SEEM THE BEST FORCING FOR SHOWERS THIS AFTERNOON
INTO THIS EVENING SHOULD BE CONFINED FROM WEST CENTRAL
ND...NORTHEAST INTO NORTH CENTRAL ND...WITH THE BEST CHANCES FOR
RAIN TODAY/THIS EVENING ACROSS THE NORTHWEST. THE HRRR MODEL
SUPPORTS LATEST RADAR AND LEANED TOWARDS ITS SOLUTION FOR THE NEXT
6-9 HOURS.
WIND ADVISORY STILL LOOKS GOOD SO PLAN NO ADJUSTMENTS TO
HEADLINES WITH THE AFTERNOON UPDATE.
&&
.AVIATION...
VFR WITH SOME SCATTERED MVFR CIGS IN EASTERN MONTANA CONTINUE TO
MOVE INTO WESTERN NORTH DAKOTA AND WILL AFFECT KISN/KDIK/KMOT FOR
THE REST OF THE DAY. VFR CIGS TO MOVE INTO KBIS AND KJMS THIS
AFTERNOON...THEN GRADUALLY MVFR CIGS AFT 06Z. THE MAIN AVIATION
IMPACT WILL BE THE WINDS. WESTERLY WINDS COULD GUST AS HIGH AS 40
KNOTS THIS AFTERNOON AND EARLY EVENING...MAINLY AT KISN/KDIK/KMOT
TAFS. SOME RAIN SHOWERS THIS AFTERNOON AT KISN BUT BETTER CHANCE
FROM 00Z-06Z. MVFR CIGS TO SPREAD OVER ALL TAF SITES EVENTUALLY AFT
06Z. BEGINNING 15Z MONDAY EXPECT NORTHWEST WINDS TO INCREASE AGAIN
TO ABOVE 23 KNOTS WITH DIMINISHING MVFR CIGS TO VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NDZ001>003-009>011-017>021-031>034-040>045.
&&
$$
UPDATE...NH
AVIATION...JV
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
444 PM CDT SUN MAY 6 2012
.UPDATE...
QUICK UPDATE TO ADD AN ISOLATED THUNDERSTORM MENTION FOR THE NEXT
COUPLE OF HOURS ACROSS THE EXTREME SOUTHEAST ZONES...WHERE HIGH-
BASED STORMS WERE DEVELOPING. NO OTHER CHANGES MADE TO THE
FORECAST ATTM.
&&
.PREV DISCUSSION... /ISSUED 257 PM CDT SUN MAY 6 2012/
SHORT TERM...
COLD FRONT HAS SLOWED THIS AFTN AND AS OF 19Z EXTENDED ALONG A LINE
FROM SEMINOLE-POST-PADUCAH NORTHWEST OF A DRYLINE FROM NEAR LAKE ALAN
HENRY TO GUTHRIE. ENHANCED CONVERGENCE WHERE THESE TWO BOUNDARIES
MEET IS EVIDENT ON LAPS DATA...HOWEVER A LACK OF CU THUS FAR
CONFIRMS CAPPING IS STILL QUITE ROBUST. HRRR SEEMS AWFUL BULLISH IN
CONVECTING NEAR KING AND STONEWALL COUNTIES BY 20Z. TEND TO BELIEVE
IF STORMS MATERIALIZE THEY WILL BE DELAYED IN TIME AND DISPLACED
FARTHER EAST...SO POPS WERE LEFT SILENT FOR NOW.
TONIGHT...THE AXIS OF A SURFACE HIGH WILL SHARPEN SSW INTO ERN NM
ALLOWING WINDS AROUND 850MB TO VEER NELY AND BEGIN TAPPING A RICHER
FIELD OF MOISTURE PRESENTLY IN NWRN OK. LOW CLOUDS ALREADY IN THE
CENTRAL TX PANHANDLE SHOULD EXPAND SOUTH TONIGHT IN RESPONSE TO THIS
PROCESS.
MONDAY...INITIAL COOL SURFACE RIDGING IS FORECAST TO WEAKEN IN
RESPONSE TO INCREASING WARM ADVECTION AND PRESSURE FALLS FROM SRN NM
INTO THE PERMIAN BASIN. DRIVING FORCE BEHIND THIS IS TIED TO AN
APPROACHING UPPER TROUGH CURRENTLY NEAR BAJA CA AND AN ASSOCIATED
TROPOPAUSE JET STREAK DOWNSTREAM. BRUNT OF THIS FORCING WILL NOT
AFFECT OUR CWA UNTIL THE FOLLOWING PERIOD...HOWEVER SUSTAINED LIGHT
ELY UPSLOPE FLOW THROUGHOUT THE LOWEST 5K FEET COMBINED WITH AN
ELEVATED BUT SHARPENING BAROCLINIC ZONE APPEAR SUFFICIENT FOR
CONVECTION IN ERN NM BY MIDDAY. FORECAST SOUNDINGS HERE BY LATE AFTN
INDICATE SBCAPE AND ELEVATED CAPE OF 500-1000 J/KG EMBEDDED WITHIN
STRONG 0-6KM BULK SHEAR OF 50-60 KNOTS. CURRENT THINKING IS STORMS
IN NM COULD THREATEN THE WRN SOUTH PLAINS BY LATE AFTN WITH A
CONDITIONAL THREAT OF SOME BEING SEVERE. DID REMOVE POP MENTION OFF
THE CAPROCK TOMORROW AS LIFT HERE APPEARS MUCH TOO SHALLOW TO
OVERCOME A STOUT EML AROUND 750MB. WITH STRATUS EXPECTED TO LINGER
MUCH OF THE DAY...TEMPS AREA WIDE WILL FALL BELOW NORMAL FOR THE
FIRST TIME SINCE MID APRIL!
LONG TERM...
THE CLOSED LOW PROGGED TO BE PINCHED OFF FROM THE UL TROF EDGING
ACROSS THE ROCKIES WILL DIVE SOUTH OUT OF UT INTO NRN MEXICO THRU
WED EVENING. FROM THERE GUIDANCE HAS COME TO BETTER AGREEMENT WITH
THE TRACK OF THE LOW AS IT PUSHES EASTWARD INTO WTX...ALBEIT A SLOW
PROGRESSION. THIS COMBINED WITH A QUASI-STATIONARY FRONT TO THE
SOUTH...POSSIBLE AS FAR SOUTH AS THE RGV...WILL CONTRIBUTE TO
CONTINUED PRECIP CHANCES EACH DAY DURING THE WEEK.
THE FIRST AND BEST PRECIP CHANCE REMAINS ON TUE AS A SECONDARY 850
FRONT PUSHES THRU THE AREA AS THE SFC RIDGE BUILDS IN OVER THE
PANHANDLE. NAM/GFS AGREE UPON SOME 305K ISENTROPIC UPGLIDE AOA 12Z
TUE. THIS COMBINED WITH THE CONTINUED UL DIVERGENT REGION OVER THE
REGION TUE...THE BEST CHANCES FOR HEAVY PRECIP LOOKS TO REMAIN IN
THE MORNING HOURS...WITH CHANCES TRENDING DOWN FROM THERE AS THE SFC
RIDGE SETTLES IN TO THE NORTH. THIS EVENT CONTINUES TO LOOK LIKE A
DESCENT RAIN MAKER...WITH ONLY LIMIT INSTABILITY /GENERALLY UNDER
200 J/KG MUCAPE/. THEREFORE...HAVE ONCE AGAIN LOWER THUNDER TO ONLY
AN ISOLATED MENTION.
WED 00Z ON...THE BEST PRECIP CHANCES WILL BE TIED TO THE FRONT TO
THE SOUTH AND THE AFOREMENTIONED UL LOW EDGING EAST.
THEREFORE...MOST OF THE LATER HALF OF THE WEEK HAVE CONTINUED SLGT
CHANCE POPS MAINLY ACROSS THE SWRN ZONES. HOWEVER...BY THE WEEKEND
THERE REMAINS SOME SLIGHT DIFFERENCE ON SPEED AND TRACK OF THE UL
LOW OVER THE REGION AS WELL AS THE ONE OFF THE ERN CONUS.
THEREFORE...WILL CONTINUE ECMWF TREND FROM PREVIOUS THINKING.
MEADOWS
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 49 64 44 58 44 / 10 30 50 50 20
TULIA 52 66 48 60 45 / 10 20 40 40 20
PLAINVIEW 52 68 49 59 47 / 10 20 40 40 20
LEVELLAND 53 74 52 60 50 / 10 20 60 60 20
LUBBOCK 54 74 53 60 48 / 10 10 50 60 20
DENVER CITY 52 78 52 64 50 / 10 30 70 70 20
BROWNFIELD 52 76 52 60 50 / 10 20 60 70 20
CHILDRESS 59 75 54 70 50 / 10 10 30 40 20
SPUR 57 76 54 64 49 / 10 10 40 40 20
ASPERMONT 60 80 56 70 50 / 10 10 40 40 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/23
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
327 PM CDT SUN MAY 6 2012
.SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN FORECAST
CHALLENGE IN SHORT TERM PERIOD IS CONVECTIVE CHANCES TONIGHT AND
AGAIN MON NIGHT. SEVERAL BOUNDARIES WERE EMITTED LAST NIGHT FROM
MCS THAT REMAINED JUST TO OUR NORTH. ONE BOUNDARY HAS RECENTLY PUSHED
OFF THE LOWER TX COAST WHILE ANOTHER LOST ITS CHARACTERISTICS OVER
CRP CWA. SEA BREEZE IS TRYING TO PUSH INLAND BUT MAY NOT BE ABLE
TO COMPENSATE FOR SLIGHT CIN VALUES ACROSS COASTAL PLAINS...THUS
ISO CONVECTION MAY BE VERY LIMITED ACROSS THE EAST REMAINDER OF
THIS AFTERNOON. FOCUS FOR LATE AFTERNOON AND THIS EVENING TURNS TO
WESTERN ZONES WHERE CONVECTION MAY DEVELOP OR MOVE IN FROM OLD
MEX. SURFACE DRYLINE/TROUGH CURRENTLY EXTENDS FROM ACROSS EDWARDS
PLATEAU AND FARTHER SOUTH INTO MEX. CONVECTION IS ALREADY
DEVELOPING ALONG BOUNDARY AND IN HIGHER ELEVATIONS IN MEX AND SOME
OF THIS CONVECTION MAY APPROACH WESTERN ZONES THIS EVENING.
SEVERAL CONSECUTIVE RUNS OF HRRR WANT TO BRING CONVECTION THROUGH
WESTERN ZONES OVERNIGHT WHILE OTHER 4KM WRF RUNS WERE DRIER. DO NOT
WANT TO COMPLETELY DISCOUNT HRRR AS OTHER RUNS DID NOT HANDLE THIS
MORNING/S MCS AND RESULTANT MCV WELL AND THUS HAVE DECIDED TO GO
WITH LOW CHANCE POPS TONIGHT OUT WEST. ANY STORMS THAT OCCUR MAY
BECOME STRONG WITH AN ISOLATED SEVERE THREAT POSSIBLE. WILL ALSO
NEED TO WATCH FOR POTENTIAL CONVECTION ACROSS EWX CWA AS CORFIDI
VECTORS INDICATE POTENTIAL MOVEMENT INTO OUR NORTHERN ZONES. IF
CONVECTION DOES AFFECT CWA THERE IS A SLIGHT CHANCE IT MAY REACH
THE COASTAL PLAINS LATE TONIGHT BUT THOSE CHANCES ARE CURRENTLY
LOW AS CIN VALUES FARTHER EAST WILL BE INCREASING OVERNIGHT. FOR
MONDAY...MID LEVEL RIDGING SHOULD HELP KEEP S TX HOT WITH HIGHS
AROUND 100 ACROSS WESTERN ZONES AND 90S ACROSS THE EAST UNDER
PARTLY TO MOSTLY SUNNY SKIES IN THE AFTERNOON. GFS AND CMC WANT TO
DEVELOP CONVECTION TO OUR NW IN EWX CWA MON AFTERNOON WITH
CONVECTION MOVING SOUTHEAST TOWARDS OUR AREA DURING THE EVENING.
NAM AND ECMWF ARE LESS ROBUST AND KEEP MOST ACTIVITY TO OUR NORTH.
FOR NOW...GIVEN BETTER UPPER LEVEL DYNAMICS PROG TO EXIST...HAVE
GONE WITH CHANCE POPS ACROSS NW AREAS.
&&
.LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN ISSUES FOR THE
EXTENDED PART OF THE FORECAST WILL BE CONVECTION THROUGHOUT THE
WEEK. PERIOD WILL START OF WILL UPPER LEVEL RIDGE MOVING EAST AND
DAMPENING AS UPPER LEVEL LOW DEEPENS OVER SOUTHERN CA/AZ. COLD
FRONT WILL BE MOVING SOUTHWARD ACROSS TEXAS DURING THE DAY ON
TUESDAY. MODELS PROG LEFT EXIT REGION OF UPPER JET TO BE
APPROACHING THE AREA AS WELL DURING THIS TIME. MOISTURE WILL BE IN
PLACE AS PWATS CLIMB TO ABOUT 1.4 TO 1.5 INCHES OVER SOUTH TEXAS.
THIS WILL LEAD TO SHOWERS AND STORMS DEVELOPING ALONG THE BOUNDARY
TUESDAY NIGHT INTO WEDNESDAY. NAM/GFS IN FAIRLY GOOD AGREEMENT ON
EVOLUTION OF THE FRONT SO WAS COMFORTABLE RAISING POPS FOR THESE
PERIOD. WILL CARRY 50 POPS OUT WEST TO 20 POPS OVER THE COASTAL
PLAINS TUESDAY NIGHT WITH 40 POPS OVER LAND ON WEDNESDAY.
CONVECTIVE ACTIVITY WILL BE HIGHLY DEPENDENT ON WHERE FRONT ENDS
UP AND HOW LONG IT LINGERS OVER THE CWA. THESE DETAILS WILL BE
FINE TUNED OVER THE NEXT SEVERAL DAYS. UPPER LOW WILL BE MOVING
OUT OF MEXICO AND WEST TEXAS TO THE EAST NORTHEAST THURSDAY INTO
FRIDAY. MOISTURE WILL STILL REMAIN OVER SOUTH TEXAS AS PWAT VALUES
CONTINUE TO BE ABOVE NORMAL FOR THIS TIME OF YEAR. SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE FOR THE SECOND HALF OF THE WORK
WEEK. HAVE ALSO RAISED POPS DURING THE THURSDAY NIGHT AND FRIDAY
TIME FRAME. OVERALL...A WET PERIOD MAY MATERIALIZE ACROSS SOUTH
TEXAS THIS UPCOMING WEEK WITH PERIODS OF LOCALLY HEAVY RAINFALL
POSSIBLE. AFTERNOON HIGH TEMPERATURES WEDNESDAY THROUGH FRIDAY
WILL BE AT OR BELOW NORMAL FOR THIS TIME OF YEAR DUE TO CLOUD
COVER AND PRECIP CHANCES. UPPER SYSTEM WILL BEGIN TO MOVE
NORTHEAST OF THE REGION ON SATURDAY...WITH RAIN CHANCES ENDING
FROM WEST TO EAST.
&&
.MARINE...SCEC CONDITIONS TO PERSIST TONIGHT THROUGH AT LEAST
MONDAY WITH LITTLE CHANGE EXPECTED TO SEA CONDITIONS. AREAS OF
HAZE FROM AGRICULTURAL FIRES IN MEXICO MAY EXIST MONDAY ACROSS THE
OPEN WATERS OF THE MIDDLE TEXAS COAST. A LATE SEASON COLD FRONT
AND STRONG UPPER LEVEL WEATHER DISTURBANCE MAY AFFECT THE AREA BY
THE MIDDLE OF THIS WEEK WITH SHOWER AND THUNDERSTORM CHANCES
INCREASING AT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 74 92 74 89 72 / 10 10 10 10 20
VICTORIA 70 92 72 87 70 / 10 10 10 20 20
LAREDO 75 101 75 94 72 / 30 10 20 10 40
ALICE 72 97 73 91 71 / 10 10 10 10 30
ROCKPORT 76 86 76 85 76 / 10 10 10 10 20
COTULLA 72 99 71 91 70 / 30 20 30 20 50
KINGSVILLE 74 96 75 90 73 / 10 10 10 10 20
NAVY CORPUS 75 86 76 86 75 / 10 10 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
RH/79/LK/84...SHORT TERM/MARINE
TB/78...LONG TERM
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
257 PM CDT SUN MAY 6 2012
.SHORT TERM...
COLD FRONT HAS SLOWED THIS AFTN AND AS OF 19Z EXTENDED ALONG A LINE
FROM SEMINOLE-POST-PADUCAH NORTHWEST OF A DRYLINE FROM NEAR LAKE ALAN
HENRY TO GUTHRIE. ENHANCED CONVERGENCE WHERE THESE TWO BOUNDARIES
MEET IS EVIDENT ON LAPS DATA...HOWEVER A LACK OF CU THUS FAR
CONFIRMS CAPPING IS STILL QUITE ROBUST. HRRR SEEMS AWFUL BULLISH IN
CONVECTING NEAR KING AND STONEWALL COUNTIES BY 20Z. TEND TO BELIEVE
IF STORMS MATERIALIZE THEY WILL BE DELAYED IN TIME AND DISPLACED
FARTHER EAST...SO POPS WERE LEFT SILENT FOR NOW.
TONIGHT...THE AXIS OF A SURFACE HIGH WILL SHARPEN SSW INTO ERN NM
ALLOWING WINDS AROUND 850MB TO VEER NELY AND BEGIN TAPPING A RICHER
FIELD OF MOISTURE PRESENTLY IN NWRN OK. LOW CLOUDS ALREADY IN THE
CENTRAL TX PANHANDLE SHOULD EXPAND SOUTH TONIGHT IN RESPONSE TO THIS
PROCESS.
MONDAY...INITIAL COOL SURFACE RIDGING IS FORECAST TO WEAKEN IN
RESPONSE TO INCREASING WARM ADVECTION AND PRESSURE FALLS FROM SRN NM
INTO THE PERMIAN BASIN. DRIVING FORCE BEHIND THIS IS TIED TO AN
APPROACHING UPPER TROUGH CURRENTLY NEAR BAJA CA AND AN ASSOCIATED
TROPOPAUSE JET STREAK DOWNSTREAM. BRUNT OF THIS FORCING WILL NOT
AFFECT OUR CWA UNTIL THE FOLLOWING PERIOD...HOWEVER SUSTAINED LIGHT
ELY UPSLOPE FLOW THROUGHOUT THE LOWEST 5K FEET COMBINED WITH AN
ELEVATED BUT SHARPENING BAROCLINIC ZONE APPEAR SUFFICIENT FOR
CONVECTION IN ERN NM BY MIDDAY. FORECAST SOUNDINGS HERE BY LATE AFTN
INDICATE SBCAPE AND ELEVATED CAPE OF 500-1000 J/KG EMBEDDED WITHIN
STRONG 0-6KM BULK SHEAR OF 50-60 KNOTS. CURRENT THINKING IS STORMS
IN NM COULD THREATEN THE WRN SOUTH PLAINS BY LATE AFTN WITH A
CONDITIONAL THREAT OF SOME BEING SEVERE. DID REMOVE POP MENTION OFF
THE CAPROCK TOMORROW AS LIFT HERE APPEARS MUCH TOO SHALLOW TO
OVERCOME A STOUT EML AROUND 750MB. WITH STRATUS EXPECTED TO LINGER
MUCH OF THE DAY...TEMPS AREA WIDE WILL FALL BELOW NORMAL FOR THE
FIRST TIME SINCE MID APRIL!
&&
.LONG TERM...
THE CLOSED LOW PROGGED TO BE PINCHED OFF FROM THE UL TROF EDGING
ACROSS THE ROCKIES WILL DIVE SOUTH OUT OF UT INTO NRN MEXICO THRU
WED EVENING. FROM THERE GUIDANCE HAS COME TO BETTER AGREEMENT WITH
THE TRACK OF THE LOW AS IT PUSHES EASTWARD INTO WTX...ALBEIT A SLOW
PROGRESSION. THIS COMBINED WITH A QUASI-STATIONARY FRONT TO THE
SOUTH...POSSIBLE AS FAR SOUTH AS THE RGV...WILL CONTRIBUTE TO
CONTINUED PRECIP CHANCES EACH DAY DURING THE WEEK.
THE FIRST AND BEST PRECIP CHANCE REMAINS ON TUE AS A SECONDARY 850
FRONT PUSHES THRU THE AREA AS THE SFC RIDGE BUILDS IN OVER THE
PANHANDLE. NAM/GFS AGREE UPON SOME 305K ISENTROPIC UPGLIDE AOA 12Z
TUE. THIS COMBINED WITH THE CONTINUED UL DIVERGENT REGION OVER THE
REGION TUE...THE BEST CHANCES FOR HEAVY PRECIP LOOKS TO REMAIN IN
THE MORNING HOURS...WITH CHANCES TRENDING DOWN FROM THERE AS THE SFC
RIDGE SETTLES IN TO THE NORTH. THIS EVENT CONTINUES TO LOOK LIKE A
DESCENT RAIN MAKER...WITH ONLY LIMIT INSTABILITY /GENERALLY UNDER
200 J/KG MUCAPE/. THEREFORE...HAVE ONCE AGAIN LOWER THUNDER TO ONLY
AN ISOLATED MENTION.
WED 00Z ON...THE BEST PRECIP CHANCES WILL BE TIED TO THE FRONT TO
THE SOUTH AND THE AFOREMENTIONED UL LOW EDGING EAST.
THEREFORE...MOST OF THE LATER HALF OF THE WEEK HAVE CONTINUED SLGT
CHANCE POPS MAINLY ACROSS THE SWRN ZONES. HOWEVER...BY THE WEEKEND
THERE REMAINS SOME SLIGHT DIFFERENCE ON SPEED AND TRACK OF THE UL
LOW OVER THE REGION AS WELL AS THE ONE OFF THE ERN CONUS.
THEREFORE...WILL CONTINUE ECMWF TREND FROM PREVIOUS THINKING.
MEADOWS
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 49 64 44 58 44 / 10 30 50 50 20
TULIA 52 66 48 60 45 / 10 20 40 40 20
PLAINVIEW 52 68 49 59 47 / 10 20 40 40 20
LEVELLAND 53 74 52 60 50 / 10 20 60 60 20
LUBBOCK 54 73 52 60 48 / 10 10 50 60 20
DENVER CITY 52 78 52 64 50 / 10 30 70 70 20
BROWNFIELD 52 76 52 60 50 / 10 20 60 70 20
CHILDRESS 59 75 54 70 50 / 10 10 30 40 20
SPUR 57 76 54 64 49 / 10 10 40 40 20
ASPERMONT 60 80 56 70 50 / 10 10 40 40 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/40
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1242 PM CDT SUN MAY 6 2012
.AVIATION...
EXPECT NLY WINDS OF 15-20 KNOTS TO PREVAIL TODAY IN THE WAKE OF A
COLD FRONT NOW ENTERING THE LOW ROLLING PLAINS AND NRN PERMIAN
BASIN. UPTICK IN DEWPOINTS BEHIND THIS FRONT IS ALREADY YIELDING
MVFR CIGS IN THE CENTRAL PANHANDLE AND WE EXPECT CDS AND LBB TO
SEE SIMILAR LOW CIGS DEVELOP LATE TONIGHT AS EVEN RICHER MOISTURE
IN NWRN OKLAHOMA IS CHANNELED SSW. THERE IS A DISTINCT POSSIBILITY
THESE BKN-OVC CIGS MAY RISE TO VFR BY LATE MON MORNING SHOULD
ENOUGH MIXING DEVELOP...BUT PATTERN CLIMATOLOGY AND MOS GUIDANCE
FAVOR MVFR THRU AT LEAST 07/18Z.
&&
.PREV DISCUSSION... /ISSUED 936 AM CDT SUN MAY 6 2012/
UPDATE...
QUICK UPDATE THIS MORNING TO CAPTURE STRONGER WINDS BEHIND A COLD
FRONT STRETCHING FROM SRN BAILEY COUNTY NORTHEAST TO NRN BRISCOE
COUNTY AS OF 14Z. SUSTAINED NLY WINDS PER VARIOUS WEST TX MESONET
STATIONS IN THE SWRN PANHANDLE HAVE ALREADY REACHED IN EXCESS OF
30 MPH OCCASIONALLY THANKS TO 40 KNOTS AROUND 2K FT AGL AS SAMPLED
BY AMA`S VWP. THIS WINDS ARE LOCATED WITHIN A NORTHERLY LLJ AXIS
POISED ACROSS THE WRN PANHANDLE...BUT ARE PROGGED TO WEAKEN IN THE
COMING HOURS. WILL THEREFORE REFRAIN FROM ISSUING A WIND ADVISORY
AS THIS WINDOW LOOKS TO BE TOO SHORT LIVED AND MARGINAL IN NATURE.
ALTHOUGH THE FRONT IS RUNNING A BIT AHEAD OF SCHEDULE...IT IS
STILL EXPECTED TO ENCOUNTER RESISTANCE LATER ON AS THE PRE-FRONTAL
BOUNDARY LAYER BECOMES DEEPLY-MIXED ULTIMATELY SLOWING THE FRONT`S
PROGRESSION SOUTHWARD. DID LOWER MAX TEMPS BY SEVERAL DEGREES
ACROSS THE NWRN SOUTH PLAINS WHILE KEEPING REMAINING AREAS LARGELY
INTACT. LATEST NAM AND RUC INDICATE THIS BOUNDARY WILL STALL NEAR
OUR SRN BORDER BY MIDDAY BEFORE ACCELERATING SOUTH NEAR SUNSET AS
PRE-FRONTAL BOUNDARY LAYER DECOUPLING ENSUES. THIS SHOULD PREVENT
ELEVATED FIRE WEATHER CONDITIONS FROM DEVELOPING AS WINDS REMAIN
TOO MARGINAL TO FAN FIRES. NO OTHER UPDATES AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 76 47 68 43 57 / 10 10 20 50 50
TULIA 78 50 69 48 59 / 10 10 20 40 50
PLAINVIEW 81 51 70 49 58 / 10 10 20 40 50
LEVELLAND 88 53 72 49 59 / 10 10 20 60 60
LUBBOCK 88 55 72 50 59 / 10 10 20 50 60
DENVER CITY 92 53 76 49 63 / 0 10 20 70 70
BROWNFIELD 93 54 75 50 59 / 10 10 20 60 70
CHILDRESS 88 58 73 56 70 / 10 10 20 30 40
SPUR 97 56 74 52 64 / 10 10 20 40 50
ASPERMONT 102 61 76 56 71 / 10 10 20 40 50
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/40/93
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
545 PM CDT SUN MAY 6 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
251 PM CDT SUN MAY 6 2012
MAIN FORECAST PROBLEM IS WITH THE RAIN CHANCES TONIGHT AND AGAIN
TUESDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A WEAK AREA OF LOW PRESSURE
OVER CENTRAL IOWA. A WARM FRONT EXTENDS EAST FROM THE LOW INTO
NORTHERN ILLINOIS. A TROUGH OF LOW PRESSURE EXTENDS SOUTHWEST TO
ANOTHER AREA OF LOW PRESSURE OVER OKLAHOMA. REGIONAL RADARS SHOW
MOST OF THE CONVECTIVE ACTIVITY IS CONFINED TO THE WARM SECTOR
SOUTH OF THE WARM FRONT AND EAST OF THE TROUGH OF LOW PRESSURE.
THE MAIN CONCERN FOR RAIN CHANCES TONIGHT IS WHERE WILL THE
CONVECTION REDEVELOP THROUGH THE REMAINDER OF THE AFTERNOON. THIS
MORNINGS MCS HAS KEPT THE WARM FRONT SOUTH OF THE FORECAST AREA
BUT RECENT TRENDS SUGGEST IT IS STARTING TO RETURN SLOWLY TO THE
NORTH. WINDS AT KAWG IN SOUTHEAST IOWA HAVE TURNED FROM THE
NORTHEAST TO THE SOUTHEAST. NOT SURE HOW FAR NORTH THE FRONT WILL
MAKE IT...BUT IT COULD GET CLOSE ENOUGH TO ALLOW SOME OVERRUNNING
ACTIVITY TO AFFECT THE SOUTHEAST PORTIONS OF THE FORECAST AREA.
LOOKING AT THE 06.14Z HRRR AND 06.12Z HI-RES ARW AND NMM...ALL
THESE MODELS SHOW THE DEVELOPING CONVECTION THIS AFTERNOON AND
EVENING STAYING SOUTH OF THE FORECAST AREA. THIS ADDS A LEVEL OF
UNCERTAINTY TO THE FORECAST BUT EXPECTING A SHORT WAVE TROUGH TO
COME OUT OF SOUTHERN KANSAS AND MOVE TOWARD NORTHERN ILLINOIS THIS
EVENING. THIS WOULD KEEP THE BEST FORCING SOUTH OF THE AREA ALONG
WITH MOST THE ACTIVITY LIKE THE HI-RES MODELS ARE SUGGESTING. HAVE
LOWERED THE RAIN CHANCES ACROSS THE ENTIRE AREA WITH THE IDEA THAT
THE ACTIVITY WILL PRIMARILY STAY TO THE SOUTH.
THE NEXT CHANCE OF RAIN THEN COMES TUESDAY AS THE UPPER LEVEL LOW
CURRENTLY OVER SOUTHERN SASKATCHEWAN DROPS SOUTHEAST ACROSS THE
GREAT LAKES. BOTH THE 06.12Z NAM AND GFS SHOW AT LEAST ONE SHORT
WAVE TROUGH ASSOCIATED WITH THE UPPER LEVEL LOW THAT WILL PRODUCE
ANYWHERE FROM 4 TO 12 PVU/S OF VORTICITY ADVECTION IN THE 500-300
MB LAYER. THIS FORCING COMBINED WITH THE CYCLONIC FLOW AROUND THE
LOW SHOULD BE ENOUGH TO GENERATE SCATTERED SHOWERS FOR MUCH OF THE
AREA. AS THE COLD POOL ALOFT COMES ACROSS THE AREA...500 MB
TEMPERATURES DROP TO AROUND -25C...LAPSE RATES SHOULD BECOME STEEP
ENOUGH TO SUPPORT SOME ISOLATED THUNDER AS WELL. NAM BUFKIT
SOUNDING FOR CENTRAL WISCONSIN SHOW THE POTENTIAL FOR LAPSE RATES
OF 7C/KM UP THROUGH AT LEAST 500 MB. THIS ACTIVITY IS THEN
EXPECTED TO DISSIPATE/MOVE OFF TO THE EAST TUESDAY EVENING AS THE
LOW MOVES AWAY AND THE LAPSE RATES DECREASE.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
251 PM CDT SUN MAY 6 2012
HIGH PRESSURE WILL SET UP OVER THE UPPER MIDWEST AND PROVIDE SOME
DRY WEATHER FOR WEDNESDAY AND THURSDAY. THE GFS AND 06.12Z ECMWF
ARE IN PRETTY GOOD AGREEMENT OF BRINGING A COLD FRONT ACROSS THE
AREA FRIDAY AND SATURDAY WITH THE RAIN CHANCES MAINLY ALONG AND
BEHIND THE FRONT. SOME RAIN CHANCES WILL THEN LINGER THROUGH
SUNDAY AS THE UPPER LEVEL TROUGH AXIS MOVES ACROSS SOUTHERN CANADA
AND THE UPPER MIDWEST.
&&
.AVIATION...TONIGHT AND MONDAY
545 PM CDT SUN MAY 6 2012
MAIN CHALLENGES WITH THIS TAF CYCLE IS WITH THE LOW CEILINGS AND
WHETHER A BATCH OF SHOWERS CURRENTLY IN WESTERN IOWA MAKES IT INTO
THE TAF SITES. CEILINGS HAVE GENERALLY IMPROVED TO MVFR AT
1200-2500FT ACROSS MUCH OF THE REGION THOUGH THERE IS A BAND OF
IFR STRETCHING FROM NORTHERN WISCONSIN INTO CENTRAL MINNESOTA.
WINDS WILL GENERALLY BE OUT OF THE NORTH BEFORE A COLD FRONT
SLOWLY MOVES THROUGH OVERNIGHT AND BRINGS THEM OUT OF THE
NORTHWEST. AHEAD OF THE FRONT...SOME SHOWERS OR DRIZZLE COULD MOVE
IN LATER THIS EVENING AND BRING CEILINGS/VISIBILITY DOWN BRIEFLY.
INSTABILITY LOOKS TO DROP OFF QUICKLY TONIGHT...SO DO NOT THINK
THAT IF/WHEN THE SHOWERS MOVE IN THAT THEY WILL PRODUCE ANY
THUNDER. HOW FAST CEILINGS CLEAR TOMORROW MORNING IS THE NEXT
QUESTION FOR FORECAST GUIDANCE SUGGESTING THAT RST CLEARS OUT
AROUND 15Z WHILE LSE CLEARS AT 18Z. CEILINGS SHOULD STAY AT MVFR
OR POSSIBLY IFR OVERNIGHT UNTIL THIS CLEARING OCCURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 PM CDT SUN MAY 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
251 PM CDT SUN MAY 6 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
251 PM CDT SUN MAY 6 2012
MAIN FORECAST PROBLEM IS WITH THE RAIN CHANCES TONIGHT AND AGAIN
TUESDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A WEAK AREA OF LOW PRESSURE
OVER CENTRAL IOWA. A WARM FRONT EXTENDS EAST FROM THE LOW INTO
NORTHERN ILLINOIS. A TROUGH OF LOW PRESSURE EXTENDS SOUTHWEST TO
ANOTHER AREA OF LOW PRESSURE OVER OKLAHOMA. REGIONAL RADARS SHOW
MOST OF THE CONVECTIVE ACTIVITY IS CONFINED TO THE WARM SECTOR
SOUTH OF THE WARM FRONT AND EAST OF THE TROUGH OF LOW PRESSURE.
THE MAIN CONCERN FOR RAIN CHANCES TONIGHT IS WHERE WILL THE
CONVECTION REDEVELOP THROUGH THE REMAINDER OF THE AFTERNOON. THIS
MORNINGS MCS HAS KEPT THE WARM FRONT SOUTH OF THE FORECAST AREA
BUT RECENT TRENDS SUGGEST IT IS STARTING TO RETURN SLOWLY TO THE
NORTH. WINDS AT KAWG IN SOUTHEAST IOWA HAVE TURNED FROM THE
NORTHEAST TO THE SOUTHEAST. NOT SURE HOW FAR NORTH THE FRONT WILL
MAKE IT...BUT IT COULD GET CLOSE ENOUGH TO ALLOW SOME OVERRUNNING
ACTIVITY TO AFFECT THE SOUTHEAST PORTIONS OF THE FORECAST AREA.
LOOKING AT THE 06.14Z HRRR AND 06.12Z HI-RES ARW AND NMM...ALL
THESE MODELS SHOW THE DEVELOPING CONVECTION THIS AFTERNOON AND
EVENING STAYING SOUTH OF THE FORECAST AREA. THIS ADDS A LEVEL OF
UNCERTAINTY TO THE FORECAST BUT EXPECTING A SHORT WAVE TROUGH TO
COME OUT OF SOUTHERN KANSAS AND MOVE TOWARD NORTHERN ILLINOIS THIS
EVENING. THIS WOULD KEEP THE BEST FORCING SOUTH OF THE AREA ALONG
WITH MOST THE ACTIVITY LIKE THE HI-RES MODELS ARE SUGGESTING. HAVE
LOWERED THE RAIN CHANCES ACROSS THE ENTIRE AREA WITH THE IDEA THAT
THE ACTIVITY WILL PRIMARILY STAY TO THE SOUTH.
THE NEXT CHANCE OF RAIN THEN COMES TUESDAY AS THE UPPER LEVEL LOW
CURRENTLY OVER SOUTHERN SASKATCHEWAN DROPS SOUTHEAST ACROSS THE
GREAT LAKES. BOTH THE 06.12Z NAM AND GFS SHOW AT LEAST ONE SHORT
WAVE TROUGH ASSOCIATED WITH THE UPPER LEVEL LOW THAT WILL PRODUCE
ANYWHERE FROM 4 TO 12 PVU/S OF VORTICITY ADVECTION IN THE 500-300
MB LAYER. THIS FORCING COMBINED WITH THE CYCLONIC FLOW AROUND THE
LOW SHOULD BE ENOUGH TO GENERATE SCATTERED SHOWERS FOR MUCH OF THE
AREA. AS THE COLD POOL ALOFT COMES ACROSS THE AREA...500 MB
TEMPERATURES DROP TO AROUND -25C...LAPSE RATES SHOULD BECOME STEEP
ENOUGH TO SUPPORT SOME ISOLATED THUNDER AS WELL. NAM BUFKIT
SOUNDING FOR CENTRAL WISCONSIN SHOW THE POTENTIAL FOR LAPSE RATES
OF 7C/KM UP THROUGH AT LEAST 500 MB. THIS ACTIVITY IS THEN
EXPECTED TO DISSIPATE/MOVE OFF TO THE EAST TUESDAY EVENING AS THE
LOW MOVES AWAY AND THE LAPSE RATES DECREASE.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
251 PM CDT SUN MAY 6 2012
HIGH PRESSURE WILL SET UP OVER THE UPPER MIDWEST AND PROVIDE SOME
DRY WEATHER FOR WEDNESDAY AND THURSDAY. THE GFS AND 06.12Z ECMWF
ARE IN PRETTY GOOD AGREEMENT OF BRINGING A COLD FRONT ACROSS THE
AREA FRIDAY AND SATURDAY WITH THE RAIN CHANCES MAINLY ALONG AND
BEHIND THE FRONT. SOME RAIN CHANCES WILL THEN LINGER THROUGH
SUNDAY AS THE UPPER LEVEL TROUGH AXIS MOVES ACROSS SOUTHERN CANADA
AND THE UPPER MIDWEST.
&&
.AVIATION...THROUGH 18Z MONDAY
1244 PM CDT SUN MAY 6 2012
LOOKS LIKE THE BEST THREAT FOR SHOWERS AND THUNDERSTORMS HAS
SHIFTED SOUTH OF THE KRST/KLSE TAF SITES. MEANWHILE...PLAN ON IFR
STRATUS AT KRST AND MVFR STRATUS AT KLSE CONTINUING INTO THIS
EVENING WITH GENERALLY LIGHT AND VARIABLE SURFACE WINDS. EXPECTING KLSE
TO SLIP INTO IFR STRATUS ALONG WITH KRST AFTER 04Z TONIGHT AS THE
MOIST BOUNDARY LAYER COOLS. AS A OCCLUDED FRONT MAKES PASSAGE EAST
OF THE AREA MONDAY MORNING...EXPECT CLOUDS TO SCATTER OUT AT KRST
AROUND 12Z WITH KLSE FOLLOWING SUIT AFTER 14Z. WINDS WILL ALSO
PICK UP SOME FROM THE NORTHWEST WITH GUSTS NEARING 20KT AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
251 PM CDT SUN MAY 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DAS