Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/27/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
302 PM MDT SAT MAY 25 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM MDT SAT MAY 25 2013
...FIRE WEATHER CONCERNS CONTINUE ACROSS THE MTS...AND INCREASE
ACROSS THE SOUTHERN PLAINS ON SUNDAY..
DEEPENING SFC LOW IN VCNTY OF KLHX HAS SPREAD SOME GUSTY SOUTHWEST
WINDS ACROSS THE MOUNTAINS AND SOUTHERN PORTIONS OF THE SE PLAINS.
AS OF 20Z...SFC DRY LINE IS LOCATED ALONG A LINE FROM JUST EAST OF
KLAA...TO NEAR KSPD. TO THE WEST OF THIS LINE...DEW POINTS HAVE BEEN
DROPPING INTO THE SINGLE DIGITS...TEENS AND EVEN SOME NEGATIVE
READINGS ACROSS THE MOUNTAINS. TO THE EAST OF THE DRY LINE...DEW
POINTS ARE STILL IN THE UPPER 40S TO LOWER 50S. LATEST HRRR STILL
PUSHES THE DRY LINE INTO WESTERN KS BY 22Z...WITH DEW POINTS
DROPPING INTO THE 30S ALONG THE EASTERN BORDER. STILL CONCERNED
THAT SOME INITIAL CONVECTION MAY FIRE ALONG THE DRY LINE LATE THIS
AFTERNOON...SO WILL MAINTAIN SOME ISOLATED POPS OUT THAT WAY. MOST
OF IT WILL BE HIGH BASED...WITH GUSTY WINDS AND LIGHTNING THE MOST
LIKELY THREATS. COULDN`T RULE OUT SOME MARGINAL SEVERE HAIL AND
WIND GUSTS NEAR THE CO/KS BORDER IF CAPES CAN STAY UP HIGH ENOUGH.
SPC HAS UPDATED THE LATEST OUTLOOK TO INCLUDE EASTERN
KIOWA...PROWERS...AND BACA COUNTIES. INITIALLY 0-6 KM SHEAR VALUES
ARE AROUND 20-30 KTS WHICH IS MARGINAL FOR SEVERE...BUT THESE VALUES
DO INCREASE INTO THE EVENING...SO THIS AREA WILL NEED TO BE
MONITORED. EXPECT CONVECTION TO SHIFT QUICKLY EASTWARD INTO KS
THROUGH THE LATE AFTN/EARLY EVENING...THOUGH OUTFLOWS MAY AID
WESTWARD RETREAT OF THE DRY LINE.
OVERNIGHT...DRY LINE PROGRESSES BACK WESTWARD BEFORE MIXING BACK
EASTWARD DURING THE DAY ON SUNDAY AS AN UPPER JET IN SOUTHWEST FLOW
ALOFT MOVES ACROSS THE AREA. CURRENT FIRE WEATHER WATCH WILL BE
UPGRADED TO A RED FLAG WARNING WITH THE AFTERNOON PACKAGE AS ALL
AREAS LOOK TO MEET CRITICAL FIRE WEATHER CONDITIONS. SFC BOUNDARY
HANGS UP JUST NORTH OF THE AREA AND WITH DRY LINE EXPECTED TO PUSH
INTO WESTERN KS DURING THE AFTERNOON...WILL GO WITH NIL POPS FOR THE
ENTIRE CWA. LOOKS LIKE HIGHS TOMORROW SHOULD STAY AROUND 3-5 DEGREES
BELOW RECORDS (COS 90...2012 PUB 97...2012 ALS 84...1969)...THOUGH
STILL WAY ABOVE CLIMATOLOGICAL AVERAGES. -KT
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM MDT SAT MAY 25 2013
SUNDAY NIGHT-MONDAY NIGHT...MODERATE WARM AND DRY SOUTHWEST FLOW
ALOFT CONTINUES ACROSS THE REGION AS A BROAD UPPER TROUGH SLOWLY
DIGS ACROSS THE PAC NORTHWEST AND INTO THE GREAT BASIN. MODELS
CONTINUE TO INDICATE A WEAK EMBEDDED SHORT WAVE TRANSLATING ACROSS
THE ROCKIES SUNDAY NIGHT WITH ANOTHER MINOR WAVE MOVING ACROSS THE
STATE LATE MONDAY AFTERNOON. FIRST WAVE SENDS A WEAK BACKDOOR COLD
FRONT ACROSS EASTERN COLORADO EARLY MONDAY MORNING BEFORE FRONT
MIXES OUT THROUGH THE EARLY AFTERNOON. MODELS ALSO INDICATING
INCREASING MID AND HIGH LEVEL MOISTURE ASSOCIATED WITH SECOND WAVE
SPREADING ACROSS THE AREA THROUGH THE DAY ON MONDAY...WHICH LOOKS TO
LIMIT STRONGER WINDS ALOFT FROM MIXING DOWN THROUGH THE AFTERNOON.
AT ANY RATE...COULD SEE BRIEF RED FLAG CONDITIONS DEVELOPING ACROSS
THE EASTERN MTS LATE MONDAY AFTERNOON...BUT LOOKS TO BE TOO MARGINAL
TO ISSUE ANY HIGHLIGHTS AT THIS TIME. WITH THE PASSING WAVES...COULD
SEE SOME HIGH BASED CONVECTION MONDAY AFTERNOON AND EARLY EVENING
ACROSS MAINLY THE CENTRAL AND EASTERN MTS WITH HIGHS EXPECTED TO BE
ONLY SLIGHTLY COOLER THAN SUNDAY.
TUESDAY-THURSDAY NIGHT...FIRE DANGER EXPECTED TO INCREASE ACROSS
SOUTHERN COLORADO AS GREAT BASIN UPPER TROUGH SLOWLY LIFTS OUT
ACROSS THE NORTHERN ROCKIES THROUGH THE PERIOD. INCREASING SOUTH TO
SOUTHWEST FLOW ACROSS THE AREA TUESDAY DEVELOPS A LA JUNTA LOW
TUESDAY AFTERNOON SUPPORTING THE POTENTIAL FOR CRITICAL FIRE WEATHER
CONDITIONS ACROSS THE SOUTHERN MTS AND ADJACENT PLAINS AS WELL AS
ACROSS THE FAR SOUTHEAST PLAINS...WITH SOME MORE HIGH BASED STORMS
POSSIBLE ACROSS THE CENTRAL MTS AND SOUTHWEST MTS. MORE WIDESPREAD
CRITICAL FIRE WEATHER CONDITIONS LOOK TO BE POSSIBLE ACROSS SOUTHERN
COLORADO WEDNESDAY AND THURSDAY WITH BREEZY TO WINDY WEST TO
SOUTHWEST FLOW ALOFT. PASSING TROUGH KEEPS CHANCE AND SLIGHT CHANCES
OF THUNDERSTORMS ACROSS THE AREA TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH BEST CHANCES ACROSS NORTHERN PORTIONS OF THE AREA.
MODELS KEEP BEST LOW LEVEL MOISTURE WELL INTO WESTERN KANSAS
THOUGH LATEST ECMWF IS A TAD FURTHER WEST WITH DRY LINE WEDNESDAY
AFTERNOON AND WILL NEED TO MONITOR FOR POSSIBLE STORMS ACROSS THE
FAR SE PLAINS. AS FOR TEMPS...SHOULD SEE HIGHS FALLING BACK TO
AROUND SEASONAL AVERAGES THROUGH THE PERIOD WITH COOLING ALOFT.
FRIDAY-SATURDAY...COOL AND DRY NORTHWEST FLOW PROGGED TO DEVELOP
BEHIND PASSING TROUGH...KEEPING SLIGHT POPS DIURNAL POPS IN PLACE
ACROSS THE HIGH TERRAIN ALONG WITH TEMPERATURES SLIGHTLY BELOW
AVERAGE INTO THE EARLY WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 301 PM MDT SAT MAY 25 2013
VFR CONDITIONS EXPECTED AT TAF SITES WITH BREEZY SOUTH TO SOUTHWEST
WINDS GUSTING TO 25-30 KTS DECREASING TOWARDS 02Z. SHOULD SEE LIGHT
DIURNALLY DRIVEN WINDS OVERNIGHT...WITH BREEZY SOUTHWEST WINDS
RETURNING FOR THE TAF SITES SUNDAY AFTERNOON. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ221-222-225-
227.
RED FLAG WARNING FROM 11 AM TO 9 PM MDT SUNDAY FOR COZ221-222-
225-227-233-237.
&&
$$
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1105 AM MDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1009 AM MDT SAT MAY 25 2013
WINDS HAVE ALREADY BEEN QUITE GUSTY ACROSS SOUTHERN PORTIONS OF
THE SOUTHEAST PLAINS AND SOME MOUNTAIN AREAS THIS MORNING...AND IS
FORECAST TO SPREAD INTO MOST OF THE LOWER ELEVATIONS BY THIS
AFTERNOON. WHERE FUELS ARE CRITICAL THIS WILL RESULT IN HIGH FIRE
DANGER. MAIN CHANGE TO THE GRIDS WAS TO DROP SFC DEW POINTS ACROSS
THE MTS/I-25 CORRIDOR AS YESTERDAY THEY DROPPED INTO THE SINGLE
DIGITS AND LOWER TEENS AND SEE NO REASON WHY THEY WON`T DO THE
SAME TODAY. HRRR SEEMS TO HAVE LATCHED ON TO THIS WELL AND HAVE
USED THESE GRIDS TO BLEND TOWARDS. SHORT RANGE HIGH RES MODELS
POINT TO BEST POTENTIAL FOR THUNDERSTORMS ALONG THE CO/KS BORDER
DURING THE LATE AFTERNOON. HAVE TRIMMED BACK WESTERN EXTENT OF
POPS TO BETTER REFLECT THIS.
LOOKS LIKE PORTIONS OF EASTERN LAS ANIMAS AND WESTERN BACA COUNTY
COULD SEE AN HOUR OR TWO OF CRITICAL TO NEAR CRITICAL FIRE WEATHER
CONDITIONS THIS AFTERNOON. HOWEVER DRY LINE SHOULD WAVER BACK
WESTWARD INTO BACA COUNTY EARLY THIS EVENING AS CONVECTION FIRES
ALONG THE DRY LINE. WINDS ALSO APPEAR TO SLACKEN OFF SOME ACROSS
EASTERN LAS ANIMAS COUNTY AS THE SFC TROF DEEPENS AND BEST GRADIENT
SHIFTS SOUTH AND EASTWARD. THUS WILL HOLD OFF ON FIRE WEATHER
HIGHLIGHTS FOR THESE AREAS. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM MDT SAT MAY 25 2013
...HOT...
JULY-LIKE WX EXPECTED TODAY AS DRY SW WINDS ALOFT CONTINUE TO
OVERSPREAD THE AREA...AND PRECIP REMAINS MOSTLY OUTSIDE OUR CWA.
H7 TEMPS RISE ANOTHER DEGREE OR SO...AND AFTER GETTING BURNED BY MX
TEMPS YESTERDAY ACROSS THE PLAINS...WILL NOT MAKE THE SAME MISTAKE
TODAY AND HAVE GONE ON THE HIGH SIDE OF GUIDANCE...GIVING US LOWER
TO MID 90S ACROSS THE PLAINS. FORECAST HIGH OF 95 FOR KPUB THIS
AFTERNOON WOULD BREAK THE OLD RECORD OF 94 FOR THIS DATE.
FIRE WX STILL A CONCERN THRU THIS AFTERNOON. RED FLAG CONDITIONS
LOOK A BIT SPOTTY ACROSS THE AREA TODAY...MAINLY DUE TO MARGINAL
WIND GUSTS...BUT WITH DRY AND VERY WARM CONDITIONS WILL KEEP THE
RED FLAG WARNING GOING AS ISSUED. WITH THE HOLIDAY WEEKEND...IT
WILL BE PARTICULARLY IMPORTANT TO GUARD AGAINST FIRE STARTS THE
NEXT COUPLE DAYS.
THUNDERSTORMS ACROSS THE NM BORDER ARE SLOWLY DIMINISHING THIS
MORNING AND SHOULD WRAP UP BY SUNRISE. THE DRYLINE RETREATS TO THE
KS BORDER THIS AFTERNOON...SO ONLY A SLIGHT THREAT FOR TS
ACTIVITY...MAINLY ALONG AND E OF HGWY 287 THROUGH BACA...PROWERS AND
KIOWA COUNTIES. THERE COULD POTENTIALLY BE A STRONG STORM OR TWO
RIGHT NR THE BORDER BY LATER THIS AFTERNOON. STORMS WILL GRADUALLY
DIMINISH AFTER SUNSET. WILL BE A RATHER MILD NIGHT AS TEMPS ALOFT
STAY RATHER HIGH...AND S-SW WINDS ARE SLOW TO DIMINISH THROUGH THE
NIGHT...PARTICULARLY OVER THE FAR ERN COUNTIES. ROSE
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT MAY 25 2013
.SUNDAY AND MONDAY...DRY AND WARM SOUTHWEST FLOW ALOFT CONTINUES
OVER THE REGION AHEAD OF THE TROUGH OVER THE PACIFIC NORTHWEST.
DRY LINE MAY MOVE WEST OF THE KANSAS BORDER DURING THE NIGHT...BUT
IT WILL MOVE EAST OF THE KANSAS BORDER DURING THE DAY. HAVE
ISSUED A FIRE WEATHER WATCH FOR SUNDAY FOR ALL REGIONS OF THE CWA
WITH CRITICAL FUELS. THERE WILL NOT BE MUCH OF A PROBLEM REACHING
THE RELATIVE HUMIDITY CRITERIA AS MINIMUM HUMIDITIES ARE MOSTLY IN
THE SINGLE DIGITS. WINDS ARE MORE OF A CONCERN...BUT THERE SHOULD
BE FREQUENT GUSTS ABOVE 25 MPH ON SUNDAY. ON MONDAY...WINDS MAY BE
LIGHTER...ESPECIALLY OVER THE NORTHERN SECTIONS. WOULD NOT BE
SURPRISED LATER SHIFTS ISSUE FIRE WEATHER WATCHES FOR MONDAY FOR
PARTS OF THE REGION. GRIDS ONLY HAVE SILENT POPS FOR BOTH DAYS
GIVEN DRY AIRMASS OVER THE REGION.
.TUESDAY...UPPER TROUGH WILL START APPROACHING COLORADO. MID
LEVEL MOISTURE WILL MOVE INTO CENTRAL COLORADO...WITH A CHANCE FOR
SOME AFTERNOON THUNDERSTORMS OVER THE CENTRAL MOUNTAINS. DRY
SOUTHWEST FLOW MAY CONTINUE OVER THE EASTERN TWO THIRDS OF THE
CWA. SOME FIRE WEATHER HIGHLIGHTS MAY EVENTUALLY BE NEEDED FOR
PORTIONS OF THE CWA ON TUESDAY.
.WEDNESDAY THROUGH FRIDAY...EC AND GFS CONTINUE TO DISAGREE ON THE
SPEED AND TRAJECTORY OF THE STRONGER UPPER TROUGH. EC HAS
CONSISTENTLY BEEN MORE AMPLIFIED AND SLOWER WITH THE TROUGH. THE
EC SOLUTION COULD ALLOW FOR SOME LOW LEVEL MOISTURE TO ADVECT INTO
EASTERN COLORADO RESULTING IN PRECIPITATION OVER MUCH OF THE
REGION WEDNESDAY. THE GFS IS FASTER AND FURTHER NORTH...KEEPING
WESTERLY WINDS OVER MUCH OF THE REGION. THE GFS SOLUTION WOULD
ONLY PRODUCE LIGHT RAIN...IF ANY...FOR MUCH OF THE REGION. A FEW
ENSEMBLE MEMBERS SUPPORT THE EC SOLUTION...BUT A MAJORITY FOLLOW
THE OPERATIONAL GFS. GEM ALSO FOLLOWS GFS SOLUTION. WHILE MAJORITY
OF GUIDANCE FOLLOWS GFS...AM NOT DISMISSING EC SOLUTION YET GIVEN
EC PAST TRACK RECORD.
.THURSDAY AND FRIDAY...MODELS AGREE WITH UPPER LOW DEVELOPING OVER
THE NORTHERN ROCKIES...THEN MOVING EASTWARD INTO THE NORTHERN
PLAINS. THIS PATTERN WOULD CONFINE PRECIPITATION MOSTLY TO
NORTHERN AND CENTRAL COLORADO MOUNTAINS. TEMPERATURES WILL BE
COOLER DUE TO COOLER AIR ALOFT...BUT WESTERLY FLOW WOULD LIMIT ANY
PRECIPITATION TO LIGHT SHOWERS. --PGW--
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1104 AM MDT SAT MAY 25 2013
VFR CONDITIONS EXPECTED AT TAF SITES WITH GUSTY SOUTH TO SOUTHWEST
WINDS EXPECTED TO INCREASE FOR ALL THREE LOCATIONS DURING THE
AFTERNOON. GUSTS TO 25KTS WILL BE POSSIBLE...WITH HIGHER GUSTS TO
AROUND 30-35 KTS POSSIBLE OVER/NEAR THE MOUNTAINS THROUGH THE
AFTERNOON. WINDS SHOULD DECREASE AROUND 02Z...WITH LIGHT DRAINAGE
WINDS EXPECTED OVERNIGHT. ISOLATED -TSRA WILL BE POSSIBLE LATE
THIS AFTERNOON THROUGH THIS EVENING ALONG THE CO/KS BORDER.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ221-222-225-
227.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR COZ221-222-225-227-233-237.
&&
$$
UPDATE...KT
SHORT TERM...ROSE
LONG TERM...PGW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1022 AM MDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1009 AM MDT SAT MAY 25 2013
WINDS HAVE ALREADY BEEN QUITE GUSTY ACROSS SOUTHERN PORTIONS OF
THE SOUTHEAST PLAINS AND SOME MOUNTAIN AREAS THIS MORNING...AND IS
FORECAST TO SPREAD INTO MOST OF THE LOWER ELEVATIONS BY THIS
AFTERNOON. WHERE FUELS ARE CRITICAL THIS WILL RESULT IN HIGH FIRE
DANGER. MAIN CHANGE TO THE GRIDS WAS TO DROP SFC DEW POINTS ACROSS
THE MTS/I-25 CORRIDOR AS YESTERDAY THEY DROPPED INTO THE SINGLE
DIGITS AND LOWER TEENS AND SEE NO REASON WHY THEY WON`T DO THE
SAME TODAY. HRRR SEEMS TO HAVE LATCHED ON TO THIS WELL AND HAVE
USED THESE GRIDS TO BLEND TOWARDS. SHORT RANGE HIGH RES MODELS
POINT TO BEST POTENTIAL FOR THUNDERSTORMS ALONG THE CO/KS BORDER
DURING THE LATE AFTERNOON. HAVE TRIMMED BACK WESTERN EXTENT OF
POPS TO BETTER REFLECT THIS.
LOOKS LIKE PORTIONS OF EASTERN LAS ANIMAS AND WESTERN BACA COUNTY
COULD SEE AN HOUR OR TWO OF CRITICAL TO NEAR CRITICAL FIRE WEATHER
CONDITIONS THIS AFTERNOON. HOWEVER DRY LINE SHOULD WAVER BACK
WESTWARD INTO BACA COUNTY EARLY THIS EVENING AS CONVECTION FIRES
ALONG THE DRY LINE. WINDS ALSO APPEAR TO SLACKEN OFF SOME ACROSS
EASTERN LAS ANIMAS COUNTY AS THE SFC TROF DEEPENS AND BEST GRADIENT
SHIFTS SOUTH AND EASTWARD. THUS WILL HOLD OFF ON FIRE WEATHER
HIGHLIGHTS FOR THESE AREAS. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 440 AM MDT SAT MAY 25 2013
...HOT...
JULY-LIKE WX EXPECTED TODAY AS DRY SW WINDS ALOFT CONTINUE TO
OVERSPREAD THE AREA...AND PRECIP REMAINS MOSTLY OUTSIDE OUR CWA.
H7 TEMPS RISE ANOTHER DEGREE OR SO...AND AFTER GETTING BURNED BY MX
TEMPS YESTERDAY ACROSS THE PLAINS...WILL NOT MAKE THE SAME MISTAKE
TODAY AND HAVE GONE ON THE HIGH SIDE OF GUIDANCE...GIVING US LOWER
TO MID 90S ACROSS THE PLAINS. FORECAST HIGH OF 95 FOR KPUB THIS
AFTERNOON WOULD BREAK THE OLD RECORD OF 94 FOR THIS DATE.
FIRE WX STILL A CONCERN THRU THIS AFTERNOON. RED FLAG CONDITIONS
LOOK A BIT SPOTTY ACROSS THE AREA TODAY...MAINLY DUE TO MARGINAL
WIND GUSTS...BUT WITH DRY AND VERY WARM CONDITIONS WILL KEEP THE
RED FLAG WARNING GOING AS ISSUED. WITH THE HOLIDAY WEEKEND...IT
WILL BE PARTICULARLY IMPORTANT TO GUARD AGAINST FIRE STARTS THE
NEXT COUPLE DAYS.
THUNDERSTORMS ACROSS THE NM BORDER ARE SLOWLY DIMINISHING THIS
MORNING AND SHOULD WRAP UP BY SUNRISE. THE DRYLINE RETREATS TO THE
KS BORDER THIS AFTERNOON...SO ONLY A SLIGHT THREAT FOR TS
ACTIVITY...MAINLY ALONG AND E OF HGWY 287 THROUGH BACA...PROWERS AND
KIOWA COUNTIES. THERE COULD POTENTIALLY BE A STRONG STORM OR TWO
RIGHT NR THE BORDER BY LATER THIS AFTERNOON. STORMS WILL GRADUALLY
DIMINISH AFTER SUNSET. WILL BE A RATHER MILD NIGHT AS TEMPS ALOFT
STAY RATHER HIGH...AND S-SW WINDS ARE SLOW TO DIMINISH THROUGH THE
NIGHT...PARTICULARLY OVER THE FAR ERN COUNTIES. ROSE
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 440 AM MDT SAT MAY 25 2013
.SUNDAY AND MONDAY...DRY AND WARM SOUTHWEST FLOW ALOFT CONTINUES
OVER THE REGION AHEAD OF THE TROUGH OVER THE PACIFIC NORTHWEST.
DRY LINE MAY MOVE WEST OF THE KANSAS BORDER DURING THE NIGHT...BUT
IT WILL MOVE EAST OF THE KANSAS BORDER DURING THE DAY. HAVE
ISSUED A FIRE WEATHER WATCH FOR SUNDAY FOR ALL REGIONS OF THE CWA
WITH CRITICAL FUELS. THERE WILL NOT BE MUCH OF A PROBLEM REACHING
THE RELATIVE HUMIDITY CRITERIA AS MINIMUM HUMIDITIES ARE MOSTLY IN
THE SINGLE DIGITS. WINDS ARE MORE OF A CONCERN...BUT THERE SHOULD
BE FREQUENT GUSTS ABOVE 25 MPH ON SUNDAY. ON MONDAY...WINDS MAY BE
LIGHTER...ESPECIALLY OVER THE NORTHERN SECTIONS. WOULD NOT BE
SURPRISED LATER SHIFTS ISSUE FIRE WEATHER WATCHES FOR MONDAY FOR
PARTS OF THE REGION. GRIDS ONLY HAVE SILENT POPS FOR BOTH DAYS
GIVEN DRY AIRMASS OVER THE REGION.
.TUESDAY...UPPER TROUGH WILL START APPROACHING COLORADO. MID
LEVEL MOISTURE WILL MOVE INTO CENTRAL COLORADO...WITH A CHANCE FOR
SOME AFTERNOON THUNDERSTORMS OVER THE CENTRAL MOUNTAINS. DRY
SOUTHWEST FLOW MAY CONTINUE OVER THE EASTERN TWO THIRDS OF THE
CWA. SOME FIRE WEATHER HIGHLIGHTS MAY EVENTUALLY BE NEEDED FOR
PORTIONS OF THE CWA ON TUESDAY.
.WEDNESDAY THROUGH FRIDAY...EC AND GFS CONTINUE TO DISAGREE ON THE
SPEED AND TRAJECTORY OF THE STRONGER UPPER TROUGH. EC HAS
CONSISTENTLY BEEN MORE AMPLIFIED AND SLOWER WITH THE TROUGH. THE
EC SOLUTION COULD ALLOW FOR SOME LOW LEVEL MOISTURE TO ADVECT INTO
EASTERN COLORADO RESULTING IN PRECIPITATION OVER MUCH OF THE
REGION WEDNESDAY. THE GFS IS FASTER AND FURTHER NORTH...KEEPING
WESTERLY WINDS OVER MUCH OF THE REGION. THE GFS SOLUTION WOULD
ONLY PRODUCE LIGHT RAIN...IF ANY...FOR MUCH OF THE REGION. A FEW
ENSEMBLE MEMBERS SUPPORT THE EC SOLUTION...BUT A MAJORITY FOLLOW
THE OPERATIONAL GFS. GEM ALSO FOLLOWS GFS SOLUTION. WHILE MAJORITY
OF GUIDANCE FOLLOWS GFS...AM NOT DISMISSING EC SOLUTION YET GIVEN
EC PAST TRACK RECORD.
.THURSDAY AND FRIDAY...MODELS AGREE WITH UPPER LOW DEVELOPING OVER
THE NORTHERN ROCKIES...THEN MOVING EASTWARD INTO THE NORTHERN
PLAINS. THIS PATTERN WOULD CONFINE PRECIPITATION MOSTLY TO
NORTHERN AND CENTRAL COLORADO MOUNTAINS. TEMPERATURES WILL BE
COOLER DUE TO COOLER AIR ALOFT...BUT WESTERLY FLOW WOULD LIMIT ANY
PRECIPITATION TO LIGHT SHOWERS. --PGW--
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 440 AM MDT SAT MAY 25 2013
VFR CONDITIONS EXPECTED FOR THE TAF SITES NEXT 24 H. STORMS WILL BE
CONFINED TO NEAR THE KS BORDER LATE THIS AFTERNOON...BUT A COUPLE
COULD BE ON THE STRONG SIDE WITH SOME HAIL. WINDS WILL ALSO BE A BIT
GUSTY FROM THE S TO SW OVR THE ERN CO PLAINS. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ221-222-225-
227.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR COZ221-222-225-227-233-237.
&&
$$
UPDATE...KT
SHORT TERM...ROSE
LONG TERM...PGW
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS MIAMI FL
236 PM EDT SAT MAY 25 2013
.SHORT TERM (TONIGHT-MONDAY NIGHT)...
PLENTY OF DRY AIR ALONG WITH RISING UPPER HEIGHTS IN THE WAKE OF THE
FRONTAL BOUNDARY THAT PASSED THROUGH TODAY WILL LEAD TO MORE OF A
SUPPRESSED ENVIRONMENT THROUGH THE REMAINDER OF THE WEEKEND. MODEL
TIME HEIGHTS/SOUNDINGS AROUND THE LOCAL AREA REFLECT THIS AND
GENERALLY INDICATE MOST OF THE MOISTURE REMAINING CONFINED WITHIN
THE LOWER 4 KFT UNDERNEATH A STRONG SUBSIDENCE INVERSION.
PRECIPITABLE WATER VALUES ARE FORECAST TO STEADILY DROP TONIGHT AND
BOTTOM OUT JUST ABOVE HALF OF AN INCH SUNDAY BEFORE STEADILY
TRENDING BACK UP INTO THE UPCOMING WEEK. HOWEVER...MODERATE
NORTHEASTERLY WINDS AND PLENTY OF LOW-LEVEL MOISTURE MAY ALLOW FOR A
FEW SHALLOW BRIEF SHOWERS TO DEVELOP OVER THE ADJACENT ATLANTIC
WATERS AND SPREAD ASHORE THROUGH THE REMAINDER OF THE
WEEKEND...ESPECIALLY THROUGH THE OVERNIGHT AND EARLY MORNING HOURS.
THIS LINES UP WELL WITH THE LATEST WRF SOLUTIONS...WHICH INDICATE A
FEW LIGHT SHOWERS DEVELOPING AND SPREADING ASHORE OVER THE NORTHERN
AREAS LATER TONIGHT INTO SUNDAY. ON MONDAY...DEEP EASTERLY FLOW UP
TO AROUND 18 KFT ALONG WITH INCREASING MOISTURE MAY LEAD TO FEW
SHOWERS DEVELOPING INLAND AND TOWARD THE GULF COAST AREAS THROUGH
THE AFTERNOON/EVENING HOURS. HOWEVER...IN THE ABSENCE OF A GULF
COAST SEA BREEZE DUE TO THE MODERATE EASTERLY FLOW IN PLACE ALONG
WITH THE MID-LEVEL DRY AIR...MAINLY BRIEF SHOWERS WILL BE
ANTICIPATED. ALONG THE EAST COAST...TEMPERATURES WILL REMAIN
SLIGHTLY BELOW NORMAL EACH DAY. 85/AG
.LONG TERM (TUESDAY-FRIDAY)...
ADDITIONAL MOISTURE IS FORECAST TO ENTER THE REGION EARLY NEXT WEEK
AS A MID TO UPPER LEVEL TROUGH IS FORECAST TO DEEPEN IN THE EASTERN
GULF WITH A CHANCE OF SHOWERS AND THUNDERSTORMS RETURNING TO THE
REGION. THERE IS SOME CONSENSUS AMONGST THE MODEL GUIDANCE THAT
DEEPER LAYERED TROPICAL MOISTURE AND A DEEPENING OF THE MID TO UPPER
LEVEL TROUGH COULD OCCUR AROUND MID-WEEK AND PERSIST FOR A COUPLE OF
DAYS WITH MORE WIDESPREAD CONVECTION POSSIBLE. WILL HAVE TO WAIT AND
SEE IF FUTURE GUIDANCE PERSISTS WITH THESE SYNOPTIC FEATURES.
BD
&&
.AVIATION...
EASTERLY FLOW WILL PREVAIL THROUGH THE REMAINDER OF THE AFTERNOON
ACROSS THE SOUTH FLORIDA AREA WITH VFR CONDITIONS. A FEW SHOWERS
HAVE DEVELOPED THIS AFTERNOON ACROSS EXTREME SOUTHERN MAINLAND
MONROE COUNTY. THE LATEST HRRR DEPICTS A FEW MORE SHOWERS DEVELOPING
ACROSS THIS AREA AND IN COLLIER COUNTY OVER THE NEXT FEW
HOURS...POSSIBLY AFFECTING KAPF. BELIEVE THE SHOWER COVERAGE WILL BE
SPARSE AND DID NOT CARRY ANY MENTION FOR THE KAPF TAF. EASTERLY FLOW
SHOULD CONTINUE OVERNIGHT AT AROUND 10 KNOTS AT ALL TAF SITES BEFORE
BECOMING GUSTY AGAIN TOMORROW.
&&
.MARINE...
WINDS AND SEAS WILL QUICKLY INCREASE THROUGH THE REMAINDER OF THE
WEEKEND IN THE WAKE OF A WEAK FRONTAL BOUNDARY AS HIGH
PRESSURE BUILDS OVER THE REGION. ALTHOUGH ADVISORY LEVEL WINDS AND
SEAS ARE NOT ANTICIPATED AT THIS TIME...MARINERS OPERATING SMALL
CRAFT ARE ENCOURAGED TO EXERCISE CAUTION...MAINLY OVER THE ATLANTIC
WATERS THIS WEEKEND.
AT THE EAST COAST BEACHES...STRONG RIP CURRENTS WILL BE LIKELY BY
SUNDAY DUE TO MODERATE ONSHORE WINDS AND BUILDING SURF.
&&
.FIRE WEATHER...
DESPITE THE DRIER AIR THAT IS FORECAST TO SPREAD OVER THE AREA
THROUGH THE REMAINDER OF THE WEEKEND AND INTO THE UPCOMING
WEEK...RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE CRITICAL
LEVELS EACH DAY. EASTERLY WINDS WILL BECOME GUSTY THROUGH THE
AFTERNOON PERIODS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 82 73 83 / - 10 10 10
FORT LAUDERDALE 76 85 77 86 / - 10 20 10
MIAMI 75 84 75 85 / - 10 20 20
NAPLES 69 91 69 91 / - 10 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT-TERM DISCUSSION/MARINE/FIRE...85/AG
LONG-TERM DISCUSSION...BD
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
315 PM CDT SAT MAY 25 2013
.DISCUSSION...
ISSUED 253 PM CDT SAT MAY 25 2013
HIGH PRESSURE RIDGE JUST TO THE EAST NOT QUITE STRONG ENOUGH TO
DAMPEN LEFTOVER MCS ACTIVITY MOVING INTO CENTRAL ILLINOIS THIS
AFTERNOON. WIDESPREAD SHOWERS AND ISOLATED THUNDER THROUGHOUT THE
EARLY AFTERNOON HOURS SLOWLY LOSING ITS STRENGTH AND THUNDER.
CLEARING SLOWLY MOVING TO THE EAST...THOUGH PLENTY OF -RA AND
SPRINKLES LIKELY. 4KM WRF DOING A FAIR JOB...IF NOT A FEW HOURS
BEHIND SCHEDULE. EXTRAPOLATING THE ERROR WOULD GIVE A BRIEF BREAK
WITH MORE SCATTERED ACTIVITY BEFORE THE NEXT ROUND. TODAYS WEATHER
EXPECTED TO CONTINUE THROUGH MONDAY BEFORE SLOWING ON TUESDAY.
MODELS IN PRETTY DECENT AGREEMENT THROUGH MID WEEK BEFORE
DIVERGING ON THE HANDLING OF THE UPPER WAVE PATTERN WITH THE TROF
OVER THE ERN HALF OF THE CONUS...AND ITS MOVEMENT AND TILT AS IT
PUSHES THE UPPER RIDGE OUT OF THE MIDWEST. TIMING ET AL IN
COMPLETE DISAGREEMENT BEYOND FH120.
SHORT TERM...TONIGHT THROUGH MONDAY...
PERIODIC SHOWERS AND THUNDERSTORMS LIKELY THROUGH MONDAY. WARM AIR
BUILDING UNDER THE RIDGE OVER THE PLAINS...AND A FRONT
DELINEATING THE BOUNDARY BETWEEN THE WARMER AIR TO THE SW AND THE
COOLER AIR OVER THE REGION ALMOST QUASI STATIONARY ALONG THE MISS
RIVER VALLEY FOR THE REMAINDER OF THE HOLIDAY WEEKEND. A SERIES
OF SHORT WAVES TOPPING THE RIDGE AND DIVING INTO ILX WILL KEEP THE
POPS IN PLACE THROUGH THE HOLIDAY WEEKEND. TEMPS CONTINUE TO
REMAIN MILD...EVEN THOUGH WARMING A COUPLE DEGREES EACH DAY...UNTIL THE
WARM FRONT FINALLY PASSES THROUGH THE AREA MON NIGHT/TUESDAY.
LONG TERM...TUESDAY THROUGH FRIDAY...
WARM FRONT LIFTING THROUGH THE REGION MON NIGHT AS THE ERN EDGE OF
THE RIDGE BREAKS DOWN AND PLENTY OF WARM AIR MOVES IN AT
MIDLEVELS. PRECIP SLOWLY REDUCING IN COVERAGE AND MUCH WARMER INTO
THE WORK WEEK. WESTERN TROF DIGS IN...AMPLIFYING THE WAVE PATTERN
OVER THE CONUS AND LEAVING THE UPPER MIDWEST IN SWRLY FLOW...AND
MUCH OF IL IN WEAK FLOW...IF ANY...UNDER THE BUILDING RIDGE. VERY
WARM MIDLEVELS AND THE GUIDANCE STILL BEING PULLED DOWN A BIT BY
CLIMATOLOGY INFLUENCE. HAVE BOOSTED TEMPS TO COMPENSATE...STILL MAY NOT BE
ENOUGH. RETURNING POPS ON THURS NIGHT/FRI GETTING DELAYED A BIT
MORE IN THIS RUN....AND STILL VERY MUCH IN DEBATE AS THE GFS AND
ECMWF DIVERGE QUITE A BIT WITH THE PROGRESSION OF THE WAVE PATTERN
AT DAY 7/8.
HJS
&&
.AVIATION...
ISSUED 1243 PM CDT SAT MAY 25 2013
LARGE RAIN SHIELD HAS OVERSPREAD THE CENTRAL ILLINOIS TAF SITES AT
MIDDAY. THUNDER HAS BEEN ON THE WANE...AND HAVE REMOVED THUNDER AT
ALL SITES BY ABOUT 21-22Z. HAVE SEEN SOME MVFR VISIBILITIES AT
TIMES IN THE HEAVIER SHOWERS...BUT CEILINGS WILL REMAIN FAIRLY
HIGH. MAIN QUESTION LATER ON IS WITH REDEVELOPMENT OF NOCTURNAL
CONVECTION TO THE NORTHWEST. MOST MODELS FAVOR IT DEVELOPING IN
IOWA SIMILAR TO LAST NIGHT THEN MOVING SOUTHEAST...ALTHOUGH THE
LATEST RAP MODEL IS INDICATING NORTHEAST MISSOURI AND WESTERN
ILLINOIS FOR INITIATION. HAVE MADE LITTLE CHANGE TO EARLIER TAFS
IN REGARDS TO THIS...ASIDE FROM MINOR TIMING ADJUSTMENTS...FAVORING
RAIN AND VCTS MENTIONS WHILE THE POTENTIAL CONTINUES TO BE
EVALUATED OVER THE NEXT FEW HOURS. HAVE TRIED TO INDICATE A FEW
HOURS OF DRIER CONDITIONS LATE IN THE PERIOD...BUT CONFIDENCE IS
LOW AT THIS TIME DUE TO THE EARLIER QUESTION OF OVERNIGHT CONVECTION.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1243 PM CDT SAT MAY 25 2013
.DISCUSSION...
ISSUED 1011 AM CDT SAT MAY 25 2013
OVERNIGHT MCS FROM IOWA HAS BEEN SHOWING SOME WARMING CLOUD TOPS
AS IT DROPS SOUTHEAST INTO WESTERN ILLINOIS. HAVE BEEN SEEING SOME
LIGHT ECHOES ON RADAR AS FAR EAST AS THE INDIANA BORDER...BUT THE
AIR MASS OVER CENTRAL ILLINOIS IS VERY DRY AS EVIDENCED BY THE
MORNING SOUNDING AND LAPS ANALYSIS...SO A LOT OF THIS HAS BEEN
ALOFT. FINALLY SEEING SOME MEASURABLE RAIN AROUND GALESBURG
THOUGH. RAP AND HRRR MODELS DOING A REASONABLE JOB WITH THE MCS
ITSELF...AND SHOW THE RAIN MOST WIDESPREAD THROUGH EARLY AFTERNOON
BEFORE BREAKING UP. MOST OF THE THUNDERSTORMS HAVE BEEN DROPPING
SOUTHEASTWARD TOWARD WEST CENTRAL ILLINOIS...SO HAVE CUT BACK SOME
ON THE THUNDER CHANCES...ESPECIALLY NORTH OF I-74. HAVE SENT OUT
SOME UPDATES TO SIGNIFICANTLY INCREASE THE RAIN CHANCES ACROSS THE
NORTHWEST HALF OF THE CWA...WITH LESSER CHANGES NEEDED ACROSS THE
SOUTHEAST.
GEELHART
&&
.AVIATION...
ISSUED 1243 PM CDT SAT MAY 25 2013
LARGE RAIN SHIELD HAS OVERSPREAD THE CENTRAL ILLINOIS TAF SITES AT
MIDDAY. THUNDER HAS BEEN ON THE WANE...AND HAVE REMOVED THUNDER AT
ALL SITES BY ABOUT 21-22Z. HAVE SEEN SOME MVFR VISIBILITIES AT
TIMES IN THE HEAVIER SHOWERS...BUT CEILINGS WILL REMAIN FAIRLY
HIGH. MAIN QUESTION LATER ON IS WITH REDEVELOPMENT OF NOCTURNAL
CONVECTION TO THE NORTHWEST. MOST MODELS FAVOR IT DEVELOPING IN
IOWA SIMILAR TO LAST NIGHT THEN MOVING SOUTHEAST...ALTHOUGH THE
LATEST RAP MODEL IS INDICATING NORTHEAST MISSOURI AND WESTERN
ILLINOIS FOR INITIATION. HAVE MADE LITTLE CHANGE TO EARLIER TAFS
IN REGARDS TO THIS...ASIDE FROM MINOR TIMING ADJUSTMENTS...FAVORING
RAIN AND VCTS MENTIONS WHILE THE POTENTIAL CONTINUES TO BE
EVALUATED OVER THE NEXT FEW HOURS. HAVE TRIED TO INDICATE A FEW
HOURS OF DRIER CONDITIONS LATE IN THE PERIOD...BUT CONFIDENCE IS
LOW AT THIS TIME DUE TO THE EARLIER QUESTION OF OVERNIGHT CONVECTION.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 242 AM CDT SAT MAY 25 2013
UNSETTLED WEATHER THROUGH THE MEMORIAL DAY WEEKEND...FOLLOWED BY
MUCH WARMER/DRIER CONDITIONS FOR THE MIDDLE AND END OF NEXT WEEK.
SHORT TERM...TODAY THROUGH MONDAY
CONVECTION CURRENTLY DEVELOPING ALONG THE NOSE OF A 45-50KT LLJ
OVER NEBRASKA IS EXPECTED TO TRACK E/SE INTO THE AREA TODAY. MAIN
QUESTION WILL BE HOW FAR EAST THE PRECIP CAN PENETRATE INTO
SPRAWLING SURFACE RIDGE AXIS EXTENDING FROM THE GREAT LAKES TO THE
GULF COAST. 00Z KILX UPPER AIR SOUNDING SHOWED A VERY DRY PROFILE
FROM THE SURFACE UP TO ABOUT 500MB. ANY PRECIP MOVING INTO THIS
HOSTILE ENVIRONMENT WILL INITIALLY EVAPORATE UNTIL THE AIRMASS IS
SUFFICIENTLY MOISTENED. DUE TO THE CONTINUED DRY E/NE LOW-LEVEL
FLOW...HAVE REMOVED POPS ACROSS EAST-CENTRAL AND SOUTHEAST
ILLINOIS FOR THE MORNING HOURS. FURTHER WEST...HIGH-RES HRRR
SUGGESTS NEBRASKA CONVECTION WILL EVENTUALLY SPREAD INTO
WEST-CENTRAL ILLINOIS TOWARD MIDDAY. WILL THEREFORE CARRY CHANCE
POPS DURING THE MORNING...THEN LIKELY THIS AFTERNOON FOR LOCATIONS
ALONG/WEST OF I-55.
INITIAL AREA OF CONVECTION WILL DISSIPATE AS IT MOVES INTO
EAST-CENTRAL ILLINOIS LATER THIS AFTERNOON AND EVENING.
MEANWHILE...LOW-LEVEL JET WILL ONCE AGAIN STRENGTHEN AND FOCUS A
RENEWED ROUND OF SHOWERS/THUNDER UPSTREAM ACROSS IOWA TONIGHT.
THIS ACTIVITY IS THEN EXPECTED TO TRACK E/SE INTO CENTRAL ILLINOIS
LATE TONIGHT INTO SUNDAY. WITH AIRMASS MOISTENED FROM INITIAL
PRECIP TODAY...THINK RAIN CHANCES WILL BE HIGHER ACROSS THE BOARD
TONIGHT/SUNDAY. WILL THEREFORE CARRY LIKELY POPS EVERYWHERE EXCEPT
THE FAR SE CWA.
ADDITIONAL SHOWERS/STORMS WILL FIRE ON MONDAY...AS PERSISTENT
FRONTAL BOUNDARY FINALLY BEGINS TO SHIFT SLOWLY NORTHWARD ACROSS
THE AREA. WILL CONTINUE TO HIT POPS HARD...ESPECIALLY ACROSS THE
CENTRAL AND NORTHERN ZONES. TOTAL RAINFALL FROM THIS MULTI-DAY
EVENT WILL BE LIGHTEST ALONG THE ILLINOIS/INDIANA BORDER WHERE
AMOUNTS OF ONE HALF TO ONE INCH WILL BE COMMON. HIGHER RAIN TOTALS
WILL BE FOCUSED FURTHER WEST...ESPECIALLY WEST OF I-55 WHERE ONE
AND A HALF TO TWO INCHES WILL BE LIKELY.
LONG TERM...TUESDAY THROUGH FRIDAY
AS UPPER TROUGH DIGS OVER THE WESTERN CONUS...DOWNSTREAM RIDGE
WILL BUILD ACROSS THE MIDWEST/OHIO RIVER VALLEY. THIS WILL FINALLY
GIVE THE SURFACE FRONT A GOOD PUSH NORTHWARD BY TUESDAY...RESULTING
IN LOWER POPS AND HIGHER TEMPS. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE FAR NORTHERN CWA...WHILE HIGH TEMPS CLIMB INTO THE
LOWER TO MIDDLE 80S. AFTER THAT...MODEL SOLUTIONS VARY SOMEWHAT
CONCERNING HOW QUICKLY THE UPPER RIDGE EVENTUALLY BREAKS DOWN.
GIVEN AMPLIFIED PATTERN...THINK THIS WILL BE LATER RATHER THAN
SOONER...SO HAVE GONE WITH A VERY WARM AND DRY FORECAST THROUGH
THURSDAY. WEAKENING FRONTAL BOUNDARY MAY PUSH INTO THE REGION BY
THE END OF THE WEEK...SO HAVE INCLUDED CHANCE FOR SHOWERS/THUNDER
ON FRIDAY WITH CONTINUED WARM TEMPS WELL INTO THE 80S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1011 AM CDT SAT MAY 25 2013
.DISCUSSION...
ISSUED 1011 AM CDT SAT MAY 25 2013
OVERNIGHT MCS FROM IOWA HAS BEEN SHOWING SOME WARMING CLOUD TOPS
AS IT DROPS SOUTHEAST INTO WESTERN ILLINOIS. HAVE BEEN SEEING SOME
LIGHT ECHOES ON RADAR AS FAR EAST AS THE INDIANA BORDER...BUT THE
AIR MASS OVER CENTRAL ILLINOIS IS VERY DRY AS EVIDENCED BY THE
MORNING SOUNDING AND LAPS ANALYSIS...SO A LOT OF THIS HAS BEEN
ALOFT. FINALLY SEEING SOME MEASURABLE RAIN AROUND GALESBURG
THOUGH. RAP AND HRRR MODELS DOING A REASONABLE JOB WITH THE MCS
ITSELF...AND SHOW THE RAIN MOST WIDESPREAD THROUGH EARLY AFTERNOON
BEFORE BREAKING UP. MOST OF THE THUNDERSTORMS HAVE BEEN DROPPING
SOUTHEASTWARD TOWARD WEST CENTRAL ILLINOIS...SO HAVE CUT BACK SOME
ON THE THUNDER CHANCES...ESPECIALLY NORTH OF I-74. HAVE SENT OUT
SOME UPDATES TO SIGNIFICANTLY INCREASE THE RAIN CHANCES ACROSS THE
NORTHWEST HALF OF THE CWA...WITH LESSER CHANGES NEEDED ACROSS THE
SOUTHEAST.
GEELHART
&&
.AVIATION...
ISSUED 657 AM CDT SAT MAY 25 2013...FOR THE 12Z TAFS
SHOWERS ARE ADVANCING INTO THE DRY AIR MASS ACROSS CENTRAL IL FROM
THE W-NW. RADAR IMAGES ARE A LITTLE MISLEADING WITH MOST OF THE
RETURNS BELOW 40 DBZ ASSOCIATED WITH VIRGA AT THIS POINT. THE
AIRMASS WILL EVENTUALLY SUCCUMB TO THE ISENTROPIC LIFT...MOISTURE
CONVERGENCE AND STRENGTHENING LOW LEVEL JET...AS HEAVIER RAINS AND
A FEW THUNDERSTORMS BECOME MORE PROMINENT THIS AFTERNOON AND
TONIGHT. MOST AREAS SHOULD REMAIN VFR WITH CLOUD HEIGHTS ABOVE 3K
FT. VIS MAY DIP TO MVFR 3-5SM DURING HEAVIER SHOWERS AND
STORMS...BUT ANY PERIODS OF IFR CONDITIONS DURING STORMS WILL BE
BRIEF.
FREQUENT RAINS AND ISOLATED THUNDERSTORMS WILL CONTINUE TONIGHT
DESPITE LOSING LOW LEVEL INSTABILITY. A SATURATED AIRMASS AND WEAK
INSTABILITY ABOVE AN ELEVATED MIXED LAYER WITH PROVIDE ENOUGH
SUPPORT FOR SOME STORMS AND PERSISTENT RAIN.
WINDS WILL START OUT EASTERLY...THEN VEER TO THE SOUTHEAST AND
INCREASE INTO THE 10-14KT RANGE AS THE NEXT MESO-VORTEX ARRIVES
FROM THE WEST LATER THIS MORNING AND AFTERNOON. WINDS MAY BACK TO
THE EAST AGAIN THIS EVENING AS WARM FRONTOGENESIS INCREASES
ACROSS CENTRAL IL FROM WEST TO EAST.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 242 AM CDT SAT MAY 25 2013
UNSETTLED WEATHER THROUGH THE MEMORIAL DAY WEEKEND...FOLLOWED BY
MUCH WARMER/DRIER CONDITIONS FOR THE MIDDLE AND END OF NEXT WEEK.
SHORT TERM...TODAY THROUGH MONDAY
CONVECTION CURRENTLY DEVELOPING ALONG THE NOSE OF A 45-50KT LLJ
OVER NEBRASKA IS EXPECTED TO TRACK E/SE INTO THE AREA TODAY. MAIN
QUESTION WILL BE HOW FAR EAST THE PRECIP CAN PENETRATE INTO
SPRAWLING SURFACE RIDGE AXIS EXTENDING FROM THE GREAT LAKES TO THE
GULF COAST. 00Z KILX UPPER AIR SOUNDING SHOWED A VERY DRY PROFILE
FROM THE SURFACE UP TO ABOUT 500MB. ANY PRECIP MOVING INTO THIS
HOSTILE ENVIRONMENT WILL INITIALLY EVAPORATE UNTIL THE AIRMASS IS
SUFFICIENTLY MOISTENED. DUE TO THE CONTINUED DRY E/NE LOW-LEVEL
FLOW...HAVE REMOVED POPS ACROSS EAST-CENTRAL AND SOUTHEAST
ILLINOIS FOR THE MORNING HOURS. FURTHER WEST...HIGH-RES HRRR
SUGGESTS NEBRASKA CONVECTION WILL EVENTUALLY SPREAD INTO
WEST-CENTRAL ILLINOIS TOWARD MIDDAY. WILL THEREFORE CARRY CHANCE
POPS DURING THE MORNING...THEN LIKELY THIS AFTERNOON FOR LOCATIONS
ALONG/WEST OF I-55.
INITIAL AREA OF CONVECTION WILL DISSIPATE AS IT MOVES INTO
EAST-CENTRAL ILLINOIS LATER THIS AFTERNOON AND EVENING.
MEANWHILE...LOW-LEVEL JET WILL ONCE AGAIN STRENGTHEN AND FOCUS A
RENEWED ROUND OF SHOWERS/THUNDER UPSTREAM ACROSS IOWA TONIGHT.
THIS ACTIVITY IS THEN EXPECTED TO TRACK E/SE INTO CENTRAL ILLINOIS
LATE TONIGHT INTO SUNDAY. WITH AIRMASS MOISTENED FROM INITIAL
PRECIP TODAY...THINK RAIN CHANCES WILL BE HIGHER ACROSS THE BOARD
TONIGHT/SUNDAY. WILL THEREFORE CARRY LIKELY POPS EVERYWHERE EXCEPT
THE FAR SE CWA.
ADDITIONAL SHOWERS/STORMS WILL FIRE ON MONDAY...AS PERSISTENT
FRONTAL BOUNDARY FINALLY BEGINS TO SHIFT SLOWLY NORTHWARD ACROSS
THE AREA. WILL CONTINUE TO HIT POPS HARD...ESPECIALLY ACROSS THE
CENTRAL AND NORTHERN ZONES. TOTAL RAINFALL FROM THIS MULTI-DAY
EVENT WILL BE LIGHTEST ALONG THE ILLINOIS/INDIANA BORDER WHERE
AMOUNTS OF ONE HALF TO ONE INCH WILL BE COMMON. HIGHER RAIN TOTALS
WILL BE FOCUSED FURTHER WEST...ESPECIALLY WEST OF I-55 WHERE ONE
AND A HALF TO TWO INCHES WILL BE LIKELY.
LONG TERM...TUESDAY THROUGH FRIDAY
AS UPPER TROUGH DIGS OVER THE WESTERN CONUS...DOWNSTREAM RIDGE
WILL BUILD ACROSS THE MIDWEST/OHIO RIVER VALLEY. THIS WILL FINALLY
GIVE THE SURFACE FRONT A GOOD PUSH NORTHWARD BY TUESDAY...RESULTING
IN LOWER POPS AND HIGHER TEMPS. WILL ONLY CARRY LOW CHANCE POPS
ACROSS THE FAR NORTHERN CWA...WHILE HIGH TEMPS CLIMB INTO THE
LOWER TO MIDDLE 80S. AFTER THAT...MODEL SOLUTIONS VARY SOMEWHAT
CONCERNING HOW QUICKLY THE UPPER RIDGE EVENTUALLY BREAKS DOWN.
GIVEN AMPLIFIED PATTERN...THINK THIS WILL BE LATER RATHER THAN
SOONER...SO HAVE GONE WITH A VERY WARM AND DRY FORECAST THROUGH
THURSDAY. WEAKENING FRONTAL BOUNDARY MAY PUSH INTO THE REGION BY
THE END OF THE WEEK...SO HAVE INCLUDED CHANCE FOR SHOWERS/THUNDER
ON FRIDAY WITH CONTINUED WARM TEMPS WELL INTO THE 80S.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1010 PM EDT SUN MAY 26 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 244 PM EDT SUN MAY 26 2013
CENTRAL INDIANA WILL REMAIN NORTH OF A WARM FRONT INTO MONDAY...THEN
THE FRONT WILL PUSH THROUGH THE AREA. THE THREAT FOR RAIN WILL
REMAIN ACROSS AREAS NEAR AND NORTH OF IT. BY TUESDAY NIGHT THE FRONT
WILL BE FAR ENOUGH NORTH FOR DRY WEATHER TO RETURN.
DRY AND WARM WEATHER WILL THEN RULE THROUGH FRIDAY. CHANCES FOR RAIN
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1001 PM EDT SUN MAY 26 2013
ISOLATED SHOWERS THROUGHOUT THE FORECAST AREA THIS EVENING WITH A
LARGER AREA OF RAIN SLOWLY SPREADING INTO THE NORTHERN WABASH
VALLEY. TEMPS WERE GENERALLY IN THE 60S AT 02Z.
SERIES OF UPPER LEVEL SHORTWAVES EXTENDING FROM IOWA AND MINNESOTA
SOUTHEAST INTO ILLINOIS. CURRENT RAP SHOWING DEVELOPING LOW
LEVEL JET TO THE WEST OF THE REGION...LIKELY INFLUENCING ONGOING
DEVELOPMENT ACROSS SOUTHERN IOWA AND NORTHERN MISSOURI. THE LOW
LEVEL JET WILL BRING ADDITIONAL MOISTURE INTO CENTRAL INDIANA AND
COMBINED WITH ENHANCED FORCING ALOFT AS THE SHORTWAVES DRIFT
ACROSS THE REGION OVERNIGHT...ANTICIPATE UPSTREAM CONVECTION
LIKELY TO EXPAND SOUTHEAST INTO THE FORECAST AREA AS THE NIGHT
PROGRESSES. WILL CONTINUE TO CARRY ISOLATED THUNDER LATE TONIGHT
WITH WEAK ELEVATED INSTABILITY PRESENT. WILL CARRY HIGHEST POPS
NORTH OF I-70. BUMPED LOWS UP A DEGREE OR TWO BASED AS CURRENT
TEMPS RUNNING A FEW DEGREES WARMER THAN PREVIOUSLY THOUGHT.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /MEMORIAL DAY THROUGH WEDNESDAY/...
ISSUED AT 244 PM EDT SUN MAY 26 2013
FOCUS IS ON CHANCES FOR RAIN THROUGH THE PERIOD. MODELS ARE CLOSE
ENOUGH THAT A BLEND CAN BE USED FOR MOST FEATURES.
THE WARM FRONT WILL LIFT NORTH ACROSS THE AREA ON MONDAY. THERE
REMAINS SOME UNCERTAINTY IN HOW PRECIPITATION WILL EVOLVE FROM THE
LEFTOVER CONVECTION FROM THE NIGHT INTO THE AFTERNOON CONVECTION.
MODELS HAVE BEEN STRUGGLING LATELY WITH PRECIPITATION COVERAGE AND
TIMING.
FOR NOW HAVE CHOSEN TO GO HIGHEST POPS WITH THE MORNING CONVECTION
/WITH SOME UPPER SUPPORT/...THEN GRADUALLY LOWERING THROUGH THE
AFTERNOON FROM SOUTH TO NORTH AS THE FRONT PUSHES NORTH. CONFIDENCE
IS NOT HIGH THOUGH. GENERALLY STUCK WITH A BLEND OF MOS FOR
TEMPERATURES.
WENT CHANCE POPS MONDAY NIGHT EARLY...THEN DECREASED THEM THROUGH
THE NIGHT FROM SOUTH TO NORTH. AGAIN WENT GENERALLY WITH A BLEND FOR
TEMPERATURES.
KEPT LOW POPS ACROSS THE FAR NORTH ON TUESDAY WITH THE WARM FRONT
STILL IN THE VICINITY THERE. WENT DRY ELSEWHERE. WITH THE WARM FRONT
THROUGH ON TUESDAY...WENT CLOSER TO THE WARMER OF THE MOS NUMBERS
FOR HIGHS.
DRY AND WARM CONDITIONS CAN THEN BE EXPECTED WITH AN UPPER RIDGE
BUILDING INTO THE AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 202 PM EDT SUN MAY 26 2013
MODELS IN GOOD AGREEMENT ON PERSISTENT FLOW OFF GULF AIR ACROSS
CENTRAL INDIANA THROUGH AT LEAST SATURDAY. HOWEVER...THE 12Z GFS AND
00Z GEFS ARE MUCH FASTER MOVING A PLAINS FRONT THROUGH CENTRAL
INDIANA SATURDAY NIGHT AS OPPOSED TO THE 00Z ECMWF...THAT DOES NOT
PUSH THE FRONT THROUGH UNTIL BEYOND SUNDAY. WITH UNCERTAINTY...WPC
OFFERS A REASONABLE BLEND BRINGING THE FRONT ACROSS ON SUNDAY. AT
ANY RATE...RETURN FLOW SHOULD ALLOW FOR ABOVE NORMAL TEMPERATURES IN
THE 80S THROUGH SATURDAY AND SLIGHTLY COOLER NORTHWEST BEHIND THE
FRONT ON SUNDAY.
WILL KEEP IT MOSTLY DRY THROUGH FRIDAY NIGHT AND THEN THUNDERSTORM
CHANCES BY SATURDAY AS THE FRONT GETS CLOSER.
&&
.AVIATION /DISCUSSION FOR THE 27/0300Z TAF UPDATE/...
ISSUED AT 1008 PM EDT SUN MAY 26 2013
UPDATE...
NO CHANGES.
PREVIOUS DISCUSSION...
THUNDERSTORMS HAVE BEEN VERY ISOLATED IN NATURE...SO WILL ONLY
CARRY MENTION OF VCSH THROUGH TONIGHT. CONDITIONS HAVE BEEN
HOLDING STEADY AT VFR CATEGORY /EVEN THROUGH RAIN SHOWERS/...SO
WILL CONTINUE WITH VFR AS PREVAILING FLIGHT CATEGORY. THUNDERSTORM
CHANCES WILL INCREASE AGAIN LATE IN PERIOD AS ENVIRONMENT
DESTABILIZES. WINDS WILL BE SOUTHEASTERLY AT 5 TO 10 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM....MK
AVIATION...TDUD
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1001 PM EDT SUN MAY 26 2013
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 244 PM EDT SUN MAY 26 2013
CENTRAL INDIANA WILL REMAIN NORTH OF A WARM FRONT INTO MONDAY...THEN
THE FRONT WILL PUSH THROUGH THE AREA. THE THREAT FOR RAIN WILL
REMAIN ACROSS AREAS NEAR AND NORTH OF IT. BY TUESDAY NIGHT THE FRONT
WILL BE FAR ENOUGH NORTH FOR DRY WEATHER TO RETURN.
DRY AND WARM WEATHER WILL THEN RULE THROUGH FRIDAY. CHANCES FOR RAIN
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1001 PM EDT SUN MAY 26 2013
ISOLATED SHOWERS THROUGHOUT THE FORECAST AREA THIS EVENING WITH A
LARGER AREA OF RAIN SLOWLY SPREADING INTO THE NORTHERN WABASH
VALLEY. TEMPS WERE GENERALLY IN THE 60S AT 02Z.
SERIES OF UPPER LEVEL SHORTWAVES EXTENDING FROM IOWA AND MINNESOTA
SOUTHEAST INTO ILLINOIS. CURRENT RAP SHOWING DEVELOPING LOW
LEVEL JET TO THE WEST OF THE REGION...LIKELY INFLUENCING ONGOING
DEVELOPMENT ACROSS SOUTHERN IOWA AND NORTHERN MISSOURI. THE LOW
LEVEL JET WILL BRING ADDITIONAL MOISTURE INTO CENTRAL INDIANA AND
COMBINED WITH ENHANCED FORCING ALOFT AS THE SHORTWAVES DRIFT
ACROSS THE REGION OVERNIGHT...ANTICIPATE UPSTREAM CONVECTION
LIKELY TO EXPAND SOUTHEAST INTO THE FORECAST AREA AS THE NIGHT
PROGRESSES. WILL CONTINUE TO CARRY ISOLATED THUNDER LATE TONIGHT
WITH WEAK ELEVATED INSTABILITY PRESENT. WILL CARRY HIGHEST POPS
NORTH OF I-70. BUMPED LOWS UP A DEGREE OR TWO BASED AS CURRENT
TEMPS RUNNING A FEW DEGREES WARMER THAN PREVIOUSLY THOUGHT.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /MEMORIAL DAY THROUGH WEDNESDAY/...
ISSUED AT 244 PM EDT SUN MAY 26 2013
FOCUS IS ON CHANCES FOR RAIN THROUGH THE PERIOD. MODELS ARE CLOSE
ENOUGH THAT A BLEND CAN BE USED FOR MOST FEATURES.
THE WARM FRONT WILL LIFT NORTH ACROSS THE AREA ON MONDAY. THERE
REMAINS SOME UNCERTAINTY IN HOW PRECIPITATION WILL EVOLVE FROM THE
LEFTOVER CONVECTION FROM THE NIGHT INTO THE AFTERNOON CONVECTION.
MODELS HAVE BEEN STRUGGLING LATELY WITH PRECIPITATION COVERAGE AND
TIMING.
FOR NOW HAVE CHOSEN TO GO HIGHEST POPS WITH THE MORNING CONVECTION
/WITH SOME UPPER SUPPORT/...THEN GRADUALLY LOWERING THROUGH THE
AFTERNOON FROM SOUTH TO NORTH AS THE FRONT PUSHES NORTH. CONFIDENCE
IS NOT HIGH THOUGH. GENERALLY STUCK WITH A BLEND OF MOS FOR
TEMPERATURES.
WENT CHANCE POPS MONDAY NIGHT EARLY...THEN DECREASED THEM THROUGH
THE NIGHT FROM SOUTH TO NORTH. AGAIN WENT GENERALLY WITH A BLEND FOR
TEMPERATURES.
KEPT LOW POPS ACROSS THE FAR NORTH ON TUESDAY WITH THE WARM FRONT
STILL IN THE VICINITY THERE. WENT DRY ELSEWHERE. WITH THE WARM FRONT
THROUGH ON TUESDAY...WENT CLOSER TO THE WARMER OF THE MOS NUMBERS
FOR HIGHS.
DRY AND WARM CONDITIONS CAN THEN BE EXPECTED WITH AN UPPER RIDGE
BUILDING INTO THE AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 202 PM EDT SUN MAY 26 2013
MODELS IN GOOD AGREEMENT ON PERSISTENT FLOW OFF GULF AIR ACROSS
CENTRAL INDIANA THROUGH AT LEAST SATURDAY. HOWEVER...THE 12Z GFS AND
00Z GEFS ARE MUCH FASTER MOVING A PLAINS FRONT THROUGH CENTRAL
INDIANA SATURDAY NIGHT AS OPPOSED TO THE 00Z ECMWF...THAT DOES NOT
PUSH THE FRONT THROUGH UNTIL BEYOND SUNDAY. WITH UNCERTAINTY...WPC
OFFERS A REASONABLE BLEND BRINGING THE FRONT ACROSS ON SUNDAY. AT
ANY RATE...RETURN FLOW SHOULD ALLOW FOR ABOVE NORMAL TEMPERATURES IN
THE 80S THROUGH SATURDAY AND SLIGHTLY COOLER NORTHWEST BEHIND THE
FRONT ON SUNDAY.
WILL KEEP IT MOSTLY DRY THROUGH FRIDAY NIGHT AND THEN THUNDERSTORM
CHANCES BY SATURDAY AS THE FRONT GETS CLOSER.
&&
.AVIATION /DISCUSSION FOR THE 27/0000Z TAF ISSUANCE/...
ISSUED AT 732 PM EDT SUN MAY 26 2013
THUNDERSTORMS HAVE BEEN VERY ISOLATED IN NATURE...SO WILL ONLY
CARRY MENTION OF VCSH THROUGH TONIGHT. CONDITIONS HAVE BEEN
HOLDING STEADY AT VFR CATEGORY /EVEN THROUGH RAIN SHOWERS/...SO
WILL CONTINUE WITH VFR AS PREVAILING FLIGHT CATEGORY.
THUNDERSTORM CHANCES WILL INCREASE AGAIN LATE IN PERIOD AS
ENVIRONMENT DESTABILIZES. WINDS WILL BE SOUTHEASTERLY AT 5 TO 10
KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM....MK
AVIATION...TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GRAY ME
1235 AM EDT SAT MAY 25 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE AND STALL THIS EVENING. LOW
PRESSURE WILL DEVELOP ON THE FRONT NEAR CAPE COD AND WILL SLOWLY
DRIFT NORTH THROUGH THE GULF OF MAINE SATURDAY AND SATURDAY NIGHT.
LOW PRESSURE WILL ACCELERATE NORTH INTO LABRADOR ON SUNDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST SUNDAY NIGHT THROUGH MONDAY.
HIGH PRESSURE WILL SHIFT OFFSHORE ON TUESDAY. A WARM FRONT WILL
APPROACH FROM THE SOUTHWEST TUESDAY NIGHT AND WEDNESDAY AND WILL
PUSH EAST OF THE REGION WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATE...A QUICK UPDATE TO KEEP FCST UP TO DATE WITH CURRENT OBSERVATIONS.
COLD AIR RUSHING IN ON A NORTHERLY FLOW. PRECIP WILL LIKELY CHANGE
TO A MIX IN THE HIGHER TERRAIN SAT.
PREV UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS...WITH THE COLD
FRONT NOW HAVING SLIPPED SOUTH OF THE COAST WATERS AS OF 0230Z. LOW
PRESSURE WILL CONTINUE TO TAKE SHAPE OFF THE NEW ENG COASTLINE
THEREAFTER...WITH CYCLOGENESIS OCCURRING NEAR CAPE COD THIS
EVENING.
LATEST HRRR MODEL PICKING UP WELL ON CONVECTIVE SEGMENTS CROSSING
THE FORECAST AREA AT THIS TIME. THIS MODEL DEPICTS MORE AREAS OF
RAIN MOVING THROUGH THE REGION LATE TONIGHT AND SATURDAY MORNING.
WILL CONTINUE TO MONITOR COLD AIR RUSHING INTO THE MTNS FROM
CANADA OVERNIGHT. THERE COULD BE SOME MIXED SNOW AND RAIN OVER THE
HIGHER TERRAIN FOR THIS STORM WHICH IS VERY SIMILAR TO THE MAY
26TH 1967 EVENT.
HAVE ADJUSTED WINDS AND TEMPS FOR THE HIGHER TERRAIN. WINDS WILL
BECOME RATHER GUSTY FOR ANY HIKERS OUT OF THE NORTH AND NORTH OVER
THE NEXT COUPLE OF DAYS...WITH SOME SNOW ACROSS THE HIGH TERRAIN.
PREV DISC...
COLD FRONT CURRENTLY MOVING EAST THROUGH EASTERN NEW HAMPSHIRE
AND NORTHWEST MAINE AND THIS BOUNDARY WILL CONTINUE TO PUSH OFF TO
THE EAST THROUGH THE REMAINDER OF THE AFTERNOON. FRONT WILL STALL
OFFSHORE THIS EVENING AND WILL BE THE FOCUS OF LIGHT TO MODERATE
RAINFALL IN MID COAST AND CENTRAL MAINE DURING THE REMAINDER OF
THE AFTERNOON INTO THIS EVENING. WILL SEE A BRIEF BREAK IN THE
ACTION ACROSS NEW HAMPSHIRE DURING THE REST OF THE AFTERNOON
BEFORE NEXT BATCH OF PRECIP EDGES IN FROM THE WEST. WILL TAKE SOME
TIME FOR LOW PRESSURE TO GET SPUN UP OVERNIGHT SO THIS BREAK MAY
TRANSLATE EASTWARD INTO WESTERN MAINE FOR THE EVENING HOURS BEFORE
850 OVER-RUNNING GETS GOING IN EARNEST ACROSS WESTERN MAINE AFTER
MIDNIGHT.
12Z MODELS TRENDING FARTHER WEST WITH AXIS OF HEAVIEST PRECIP AND
COMING INTO LINE WITH LAST NIGHT 00Z ECMWF. 24 HOUR QPF FOR THE
MOUNTAINS AND CONNECTICUT VALLEY DOWN TO AROUND AN INCH TO 1.5
INCHES THROUGH 00Z SUN. WITH THIS IN MIND...DOESN`T APPEAR
FLOODING WILL BE AN ISSUE CONSIDERING THE BREAK IN THE ACTION
THIS AFTERNOON AND LONG DURATION OF THE EVENT ITSELF...SO HOLDING
OFF ON ANY WATCHES AT THIS POINT IN TIME.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM SUNDAY/...
RAIN WILL CONTINUE SATURDAY THROUGH SATURDAY NIGHT AS SURFACE LOW
BECOMES TRAPPED UNDER UPPER LEVEL SYSTEM AND MEANDERS AROUND THE
GULF OF MAINE THROUGH SUNDAY MORNING. MAY SEE SOME WET SNOW OVER
THE HIGHEST TERRAIN AT SOME POINT ON SATURDAY IN FAR WESTERN ZONES BUT
ENOUGH WARM AIR WRAPS AROUND THE SYSTEM THAT THIS WOULD BE FAIRLY
BRIEF. BETTER CHANCE FOR THIS WOULD BE IN THE GREENS OF VERMONT
AND THE DACKS. WILL BE A COLD AND BLUSTERY DAY WITH TEMPS HOLDING
IN THE 40S IN MOST AREAS AND SHOWING LITTLE CHANGE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPR LVL AND SFC LOWS LIFTING NE ON SUNDAY WITH STEADIER PRCP
BECOMING MORE SCT IN NATURE AND LIGHTER IN INTENSITY. ANY LEFTOVER
SHRA ENDING SUNDAY NGT AS THE SYSTEM MOVES INTO THE MARITIMES.
MEMORIAL DAY LOOKS LIKE FAIR WX NOW WITH SYSTEM PULLING OUT FAR
ENOUGH TO THE NE. STILL SOME CYCLONIC FLOW ALOFT AND SOME LEFTOVER
MOISTURE THAT COULD PRODUCE SOME CLOUDINESS ESPECIALLY IN THE N/MT
ZONES DUE TO UPSLOPING NW SFC WINDS. MIGHT SEE AN ISOLD SHRA IN
THE N/MT ZONES OTRW NO PRCP EXPECTED ON MEMORIAL DAY.
HIGH PRES AND UPR LVL RIDGE BUILD IN FOR TUESDAY INTO WEDNESDAY.
THE UPR LVL RIDGE HOLDS 0N OVER THE ERN U.S. BUT A SERIES OF WEAK
UPR LVL SHORT WAVE TROFS DRIVE THRU THE RIDGE FOR LATE WEDNESDAY
AND THURSDAY. THIS FORMS A WRM FRONTAL BOUNDARY TO OUR S THAT
LIFTS N AND WILL PROVIDE SOME CLOUDINESS AND ISOLD TO SCT SHRA
FROM LATE WEDNESDAY THRU THURSDAY. THE UPR LVL RIDGE BECOMES
BETTER ESTABLISHED OVER THE E COAST THURSDAY NGT AND FRIDAY AS THE
SHORT WAVES EXIT THE COAST. THIS SHOULD ALLOW WRM AIR TO CONT
MOVING IN FROM THE SW. STILL CAN`T RULE OUT PSBL SHRA DUE TO WRM
FNT MOVING THRU.
GENERALLY USED BLEND OF GFS40/NAM/MET/MAV/HPC QPF FOR PERIODS 4
AND 5 THEN GFS40, GMOS, HPC QPF, MEX MOS AND WNA4 FOR THE REST OF
THE LONG TERM FCST.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...IFR/LIFR CEILINGS TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...MVFR TO PSBL IFR IN SHRA
THAT WILL BE TAPERING OFF SUNDAY INTO SUNDAY NGT. MAINLY VFR
MONDAY THRU TUESDAY AND MOST OF WEDNESDAY.
&&
.MARINE...
SHORT TERM...HAVE EXTENDED SCA TO GO RIGHT THROUGH SATURDAY.
ALTHOUGH WINDS DROP OFF AT SOME POINT...WAVES WILL REMAIN AT LEAST
IN THE 3 TO 5 FOOT RANGE...WITH GREATER SEAS OUT OVER THE OPEN WATERS.
COASTAL FLOOD ADVISORY FOR MINOR SPLASH-OVER AROUND THE TIME OF
HIGH TIDE.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...SCA WIND GUSTS AND SEAS
PSBL SUNDAY THRU MOST OF SUNDAY NGT THEN HIGH PRES DROPS
CONDITIONS BELOW SCA LEVELS MONDAY THRU WEDNESDAY.
&&
.FIRE WEATHER...
NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ150>154.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
125 PM EDT SAT MAY 25 2013
.AVIATION...
//DISCUSSION...
DRY AND STABLE CONDITIONS WILL EXIST THROUGH THE TAF PERIOD AS HIGH
PRESSURE REMAINS CONTROL. RIDGE POSITIONING WILL FAVOR A LIGHT
NORTHERLY WIND COMPONENT. FEW DIURNAL CU WILL QUICKLY DISSIPATE
WITH THE LOSS OF HEATING. SE MICHIGAN WILL REMAIN ALONG THE
EASTERN FRINGE OF A THICKER MID LEVEL CLOUD DECK WITH A BRIEF PERIOD
OF BKN CIRRUS POSSIBLE THROUGH THE LATTER HALF OF THE DAY.
//DTW THRESHOLD THREATS...
* NONE.
&&
.PREV DISCUSSION...ISSUED 325 AM EDT SAT MAY 25 2013
SHORT TERM...TODAY AND TONIGHT
EARLY MORNING MSAS ANALYSIS IS SHOWING A SURFACE RIDGE EXTENDING
SOUTHWARD THROUGH THE LAKE SUPERIOR/MICHIGAN/HURON BASINS. THE BEST
SURFACE RIDGING COMPONENT INSIDE OF THE CWA IS ACROSS THE NORTHERN
THUMB DOWN INTO PORT HURON. PERUSING THROUGH THE SURFACE
OBSERVATIONS...FEELING IS THE BEST POTENTIAL FOR ANY FROST FORMATION
WILL BE IN THE THUMB AND LOW LYING AREAS OF THE GLACIAL TERRAIN WITH
THE LOCAL OFFICE TEMPERATURE AT 33 DEGREES AS OF 230 AM LDT. WILL
MAINTAIN THE FROST ADVISORY AS IS FOR SIMPLICITY.
THERE HAS BEEN A DECENT RADAR PRESENTATION OVERNIGHT ACROSS PORTIONS
OF MN/WI/IA TIED TO THE AGEOSTROPHIC RESPONSE OF MERGING AND
SHEARING OF SHORTWAVE ENERGY. ONE HR PRECIPITATION AMOUNTS HAVE BEEN
LESSENING AS THE PRECIPITATION/VIRGA PUSHES FARTHER TO THE SOUTHEAST.
THIS IS LIKELY IN RESPONSE TO INCREASING CONFLUENCE ALOFT AS THE
ENTRANCE REGION LIES DIRECTLY OVER LOWER MICHIGAN. THE BEST UPPER
LEVEL FORCING IN THE FORM OF 700-500MB FRONTOGENESIS WILL BRUSH FAR
SOUTHWESTERN SECTIONS OF THE STATE BETWEEN 12-15Z...BEFORE PASSING
HARMLESSLY TO THE SOUTH. THE AMOUNT OF AMBIENT DRY AIR IN THE LOWEST
12 KFT AGL SUPPORTS VIRTUALLY NO PRECIPITATION POTENTIAL TODAY. THE
PREFERENCE REGARDING HIGH CLOUD PROG LIES WITH THE 25.05Z RUC WHICH
BRINGS HIGH CLOUDS INTO THE SOUTHWESTERN 2/3RDS OF THE CWA BETWEEN
9-16Z THIS MORNING. INCREASED INSOLATION WITH SOME MODERATION OF THE
AIRMASS WILL SUPPORT A SOLID 3-8F DEGREE UPTICK IN HIGH TEMPERATURES.
EXPECT READINGS TO RANGE FROM THE MIDDLE 50S IN THE FAR NORTHERN
THUMB/LAKE HURON SHORELINE TO THE MIDDLE 60S DETROIT SOUTHWARD.
SURFACE HIGH PRESSURE WILL EXPAND ACROSS THE CENTRAL GREAT LAKES
TONIGHT...BRINGING THE PROSPECTS OF ANOTHER COOL TO COLD NIGHT.
DIFFERENTIAL AIRMASS RECOVERY SHOULD BE GOOD FOR A FEW DEGREES OFF
THIS MORNINGS MINS. WORKED WITH A BLEND OF UNDERCUT GUIDANCE WITH
SOME PERSISTENCE. EXPECTED LOWS TONIGHT SHOULD RANGE FROM THE LOWER
TO MIDDLE 30S IN THE THUMB TO LOWER 40S SOUTHEAST OF THE TERRAIN.
LONG TERM...SUNDAY THROUGH FRIDAY
LOWER MICHIGAN WILL RESIDE BETWEEN A HIGH AMPLITUDE RIDGE ACROSS THE
UPPER MIDWEST AND A DEEP UPPER LOW LIFTING FROM NEW ENGLAND INTO THE
CANADIAN MARITIMES DURING THE LATER HALF OF THE WEEKEND...SUSTAINING
A CONFLUENT FLOW ALOFT. AT THE SFC...THIS WILL TRANSLATE TO HIGH
PRESSURE BUILDING FROM THE UPPER GREAT LAKES ON SUNDAY TO THE
EASTERN GREAT LAKES ON MONDAY. OTHER THAN THE POTENTIAL FOR SOME
HIGH CLOUDS...SKIES SHOULD REMAIN MAINLY CLEAR WITH VERY DRY AIR
OVERHEAD. TEMPS WILL SLOWLY MODERATE...LEADING TO AN OVERALL WARMING
TREND HEADING INTO MEMORIAL DAY. EXPECT MIXING DEPTHS MAY
OVERACHIEVE WITH PLENTY OF SUNSHINE AND SUBSTANTIAL LOW LEVEL DRY
AIR. THIS SUPPORTS LEANING TOWARD THE HIGHER END OF GUIDANCE MAX
TEMPS /MID TO UPPER 60S SUNDAY AND AROUND 70 MONDAY/. THE DRY
AIRMASS AND WEAK SFC GRADIENT WILL SUPPORT OPTIMAL RADIATIONAL
COOLING POTENTIAL...SO MINS SUN NIGHT WILL CONTINUE TO BE QUITE COLD
FOR LATE MAY /UPPER 30S TO MID 40S/.
THE MID LEVEL RIDGE IS FORECAST TO BREAK DOWN EARLY NEXT WEAK AS
NUMEROUS SHORT WAVE IMPULSES ARE EJECTED OUT OF THE LONG WAVE TROUGH
OVER THE WRN US AND ACROSS THE CNTRL/NRN PLAINS. THE BULK OF THE 00Z
MODEL SUITE SUGGEST MCS DEVELOPMENT ACROSS THE UPPER MIDWEST OR WRN
GREAT LAKES MON AFTERNOON/NIGHT AS LOW LEVEL INFLOW STRENGTHENS. THE
POTENTIAL FOR REMNANT MCS ACTIVITY TO ADVANCE INTO SE MI REMAINS
HIGHLY UNCERTAIN AT THIS TIME. WHILE SEVERAL MODEL SOLUTIONS ARE
QUITE BULLISH WITH QPF OVER SE MI MON NIGHT AND TUES...THERE IS
LIKELY SOME SEMBLANCE OF CONVECTIVE FEEDBACK IN THE MODELS. THERE IS
ALSO CONCERN THAT THE MODELS HAVE A POOR HANDLING OF MCS
PROPAGATION...WHICH COULD LEAD TO REMNANT CONVECTION BEING MUCH
FARTHER SOUTH. THUS PLAN TO CARRY VERY LOW CHANCE POPS TUESDAY.
PERSISTENT LOW LEVEL S-SWLY FLOW SHOULD HOWEVER LIFT A WARMER AND
MORE HUMID AIRMASS INTO SRN LOWER MI BY MID WEEK...MARKED BY THE
PASSAGE OF A SFC WARM FRONT. THIS WILL JUSTIFY A CHANCE OF
SHOWERS/THUNDERSTORMS LATE TUES THROUGH WED.
THE ECMWF REMAINS STEADFAST IN DEVELOPING A MORE AMPLIFIED UPPER
TROUGH OVER THE WRN US BY MIDWEEK AS ENERGY EJECTS OUT OF THE GULF
OF ALASKA AND INTO THE WEST COAST. A SEASONALLY STRONG UPPER JET
WITHIN THE BASE OF THE DEEP GULF OF ALASKA UPPER LOW AND CURRENT
AMPLIFIED NATURE OF THE FLOW LENDS SUPPORT TO THE ECMWF. THIS
SOLUTION BUILDS THE SUBTROPICAL RIDGE FARTHER NORTH INTO THE ERN US
LATE IN THE WEEK AND SUGGESTS SE MI MAY BE CAPPED. EVEN THE LESS
AMPLIFIED GFS BUILDS MID LEVEL HEIGHTS SUBSTANTIALLY ACROSS SE MI.
THUS THE FORECAST FOR THE LATER HALF OF NEXT WEEK WILL HAVE VERY LOW
POPS WITH MAX TEMPS WELL INTO THE 80S.
MARINE...
A STABLE ANTICYCLONE WILL EXPAND ACROSS THE GREAT LAKES THROUGH THE
HOLIDAY WEEKEND. THIS WEATHER FEATURE WILL BE RESPONSIBLE FOR MORE
TYPICAL MARINE CONDITIONS FOR LATE MAY. WAVE HEIGHTS ARE ONLY
EXPECTED TO RANGE IN THE 1 TO 2 FOOT RANGE IN MANY AREAS THROUGHOUT
THE WEEKEND.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
701 AM EDT SAT MAY 25 2013
.AVIATION...
//DISCUSSION...
AMBIENT DRY AIR THROUGH AN IMPRESSIVE DEPTH WILL KEEP THE DOOR SHUT
ON PRECIPITATION CHANCES AS MIDLEVEL ENERGY PASSES THE STATE TO THE
SOUTH. THE ONLY IMPACT ON AVIATION CONDITIONS WILL BE SOME BKN-OVC
CEILINGS AT UPWARDS OF 25 KFT THIS MORNING. SURFACE WINDS TODAY ARE
EXPECTED TO EMERGE LIGHT NORTHERLY COMMENCING ON BOUNDARY LAYER
GROWTH. MODELS ARE HINTING AT SOME CUMULUS DEVELOPMENT THIS
AFTERNOON BUT THAT SEEMS SUSPECT ATTM.
//DTW THRESHOLD THREATS...
* NONE.
&&
.PREV DISCUSSION...ISSUED 325 AM EDT SAT MAY 25 2013
SHORT TERM...TODAY AND TONIGHT
EARLY MORNING MSAS ANALYSIS IS SHOWING A SURFACE RIDGE EXTENDING
SOUTHWARD THROUGH THE LAKE SUPERIOR/MICHIGAN/HURON BASINS. THE BEST
SURFACE RIDGING COMPONENT INSIDE OF THE CWA IS ACROSS THE NORTHERN
THUMB DOWN INTO PORT HURON. PERUSING THROUGH THE SURFACE
OBSERVATIONS...FEELING IS THE BEST POTENTIAL FOR ANY FROST FORMATION
WILL BE IN THE THUMB AND LOW LYING AREAS OF THE GLACIAL TERRAIN WITH
THE LOCAL OFFICE TEMPERATURE AT 33 DEGREES AS OF 230 AM LDT. WILL
MAINTAIN THE FROST ADVISORY AS IS FOR SIMPLICITY.
THERE HAS BEEN A DECENT RADAR PRESENTATION OVERNIGHT ACROSS PORTIONS
OF MN/WI/IA TIED TO THE AGEOSTROPHIC RESPONSE OF MERGING AND
SHEARING OF SHORTWAVE ENERGY. ONE HR PRECIPITATION AMOUNTS HAVE BEEN
LESSENING AS THE PRECIPITATION/VIRGA PUSHES FARTHER TO THE SOUTHEAST.
THIS IS LIKELY IN RESPONSE TO INCREASING CONFLUENCE ALOFT AS THE
ENTRANCE REGION LIES DIRECTLY OVER LOWER MICHIGAN. THE BEST UPPER
LEVEL FORCING IN THE FORM OF 700-500MB FRONTOGENESIS WILL BRUSH FAR
SOUTHWESTERN SECTIONS OF THE STATE BETWEEN 12-15Z...BEFORE PASSING
HARMLESSLY TO THE SOUTH. THE AMOUNT OF AMBIENT DRY AIR IN THE LOWEST
12 KFT AGL SUPPORTS VIRTUALLY NO PRECIPITATION POTENTIAL TODAY. THE
PREFERENCE REGARDING HIGH CLOUD PROG LIES WITH THE 25.05Z RUC WHICH
BRINGS HIGH CLOUDS INTO THE SOUTHWESTERN 2/3RDS OF THE CWA BETWEEN
9-16Z THIS MORNING. INCREASED INSOLATION WITH SOME MODERATION OF THE
AIRMASS WILL SUPPORT A SOLID 3-8F DEGREE UPTICK IN HIGH TEMPERATURES.
EXPECT READINGS TO RANGE FROM THE MIDDLE 50S IN THE FAR NORTHERN
THUMB/LAKE HURON SHORELINE TO THE MIDDLE 60S DETROIT SOUTHWARD.
SURFACE HIGH PRESSURE WILL EXPAND ACROSS THE CENTRAL GREAT LAKES
TONIGHT...BRINGING THE PROSPECTS OF ANOTHER COOL TO COLD NIGHT.
DIFFERENTIAL AIRMASS RECOVERY SHOULD BE GOOD FOR A FEW DEGREES OFF
THIS MORNINGS MINS. WORKED WITH A BLEND OF UNDERCUT GUIDANCE WITH
SOME PERSISTENCE. EXPECTED LOWS TONIGHT SHOULD RANGE FROM THE LOWER
TO MIDDLE 30S IN THE THUMB TO LOWER 40S SOUTHEAST OF THE TERRAIN.
LONG TERM...SUNDAY THROUGH FRIDAY
LOWER MICHIGAN WILL RESIDE BETWEEN A HIGH AMPLITUDE RIDGE ACROSS THE
UPPER MIDWEST AND A DEEP UPPER LOW LIFTING FROM NEW ENGLAND INTO THE
CANADIAN MARITIMES DURING THE LATER HALF OF THE WEEKEND...SUSTAINING
A CONFLUENT FLOW ALOFT. AT THE SFC...THIS WILL TRANSLATE TO HIGH
PRESSURE BUILDING FROM THE UPPER GREAT LAKES ON SUNDAY TO THE
EASTERN GREAT LAKES ON MONDAY. OTHER THAN THE POTENTIAL FOR SOME
HIGH CLOUDS...SKIES SHOULD REMAIN MAINLY CLEAR WITH VERY DRY AIR
OVERHEAD. TEMPS WILL SLOWLY MODERATE...LEADING TO AN OVERALL WARMING
TREND HEADING INTO MEMORIAL DAY. EXPECT MIXING DEPTHS MAY
OVERACHIEVE WITH PLENTY OF SUNSHINE AND SUBSTANTIAL LOW LEVEL DRY
AIR. THIS SUPPORTS LEANING TOWARD THE HIGHER END OF GUIDANCE MAX
TEMPS /MID TO UPPER 60S SUNDAY AND AROUND 70 MONDAY/. THE DRY
AIRMASS AND WEAK SFC GRADIENT WILL SUPPORT OPTIMAL RADIATIONAL
COOLING POTENTIAL...SO MINS SUN NIGHT WILL CONTINUE TO BE QUITE COLD
FOR LATE MAY /UPPER 30S TO MID 40S/.
THE MID LEVEL RIDGE IS FORECAST TO BREAK DOWN EARLY NEXT WEAK AS
NUMEROUS SHORT WAVE IMPULSES ARE EJECTED OUT OF THE LONG WAVE TROUGH
OVER THE WRN US AND ACROSS THE CNTRL/NRN PLAINS. THE BULK OF THE 00Z
MODEL SUITE SUGGEST MCS DEVELOPMENT ACROSS THE UPPER MIDWEST OR WRN
GREAT LAKES MON AFTERNOON/NIGHT AS LOW LEVEL INFLOW STRENGTHENS. THE
POTENTIAL FOR REMNANT MCS ACTIVITY TO ADVANCE INTO SE MI REMAINS
HIGHLY UNCERTAIN AT THIS TIME. WHILE SEVERAL MODEL SOLUTIONS ARE
QUITE BULLISH WITH QPF OVER SE MI MON NIGHT AND TUES...THERE IS
LIKELY SOME SEMBLANCE OF CONVECTIVE FEEDBACK IN THE MODELS. THERE IS
ALSO CONCERN THAT THE MODELS HAVE A POOR HANDLING OF MCS
PROPAGATION...WHICH COULD LEAD TO REMNANT CONVECTION BEING MUCH
FARTHER SOUTH. THUS PLAN TO CARRY VERY LOW CHANCE POPS TUESDAY.
PERSISTENT LOW LEVEL S-SWLY FLOW SHOULD HOWEVER LIFT A WARMER AND
MORE HUMID AIRMASS INTO SRN LOWER MI BY MID WEEK...MARKED BY THE
PASSAGE OF A SFC WARM FRONT. THIS WILL JUSTIFY A CHANCE OF
SHOWERS/THUNDERSTORMS LATE TUES THROUGH WED.
THE ECMWF REMAINS STEADFAST IN DEVELOPING A MORE AMPLIFIED UPPER
TROUGH OVER THE WRN US BY MIDWEEK AS ENERGY EJECTS OUT OF THE GULF
OF ALASKA AND INTO THE WEST COAST. A SEASONALLY STRONG UPPER JET
WITHIN THE BASE OF THE DEEP GULF OF ALASKA UPPER LOW AND CURRENT
AMPLIFIED NATURE OF THE FLOW LENDS SUPPORT TO THE ECMWF. THIS
SOLUTION BUILDS THE SUBTROPICAL RIDGE FARTHER NORTH INTO THE ERN US
LATE IN THE WEEK AND SUGGESTS SE MI MAY BE CAPPED. EVEN THE LESS
AMPLIFIED GFS BUILDS MID LEVEL HEIGHTS SUBSTANTIALLY ACROSS SE MI.
THUS THE FORECAST FOR THE LATER HALF OF NEXT WEEK WILL HAVE VERY LOW
POPS WITH MAX TEMPS WELL INTO THE 80S.
MARINE...
A STABLE ANTICYCLONE WILL EXPAND ACROSS THE GREAT LAKES THROUGH THE
HOLIDAY WEEKEND. THIS WEATHER FEATURE WILL BE RESPONSIBLE FOR MORE
TYPICAL MARINE CONDITIONS FOR LATE MAY. WAVE HEIGHTS ARE ONLY
EXPECTED TO RANGE IN THE 1 TO 2 FOOT RANGE IN MANY AREAS THROUGHOUT
THE WEEKEND.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-MIZ060-
MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-
MIZ083...UNTIL 8 AM SATURDAY.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
325 AM EDT SAT MAY 25 2013
.SHORT TERM...TODAY AND TONIGHT
EARLY MORNING MSAS ANALYSIS IS SHOWING A SURFACE RIDGE EXTENDING
SOUTHWARD THROUGH THE LAKE SUPERIOR/MICHIGAN/HURON BASINS. THE BEST
SURFACE RIDGING COMPONENT INSIDE OF THE CWA IS ACROSS THE NORTHERN
THUMB DOWN INTO PORT HURON. PERUSING THROUGH THE SURFACE
OBSERVATIONS...FEELING IS THE BEST POTENTIAL FOR ANY FROST FORMATION
WILL BE IN THE THUMB AND LOW LYING AREAS OF THE GLACIAL TERRAIN WITH
THE LOCAL OFFICE TEMPERATURE AT 33 DEGREES AS OF 230 AM LDT. WILL
MAINTAIN THE FROST ADVISORY AS IS FOR SIMPLICITY.
THERE HAS BEEN A DECENT RADAR PRESENTATION OVERNIGHT ACROSS PORTIONS
OF MN/WI/IA TIED TO THE AGEOSTROPHIC RESPONSE OF MERGING AND
SHEARING OF SHORTWAVE ENERGY. ONE HR PRECIPITATION AMOUNTS HAVE BEEN
LESSENING AS THE PRECIPITATION/VIRGA PUSHES FARTHER TO THE SOUTHEAST.
THIS IS LIKELY IN RESPONSE TO INCREASING CONFLUENCE ALOFT AS THE
ENTRANCE REGION LIES DIRECTLY OVER LOWER MICHIGAN. THE BEST UPPER
LEVEL FORCING IN THE FORM OF 700-500MB FRONTOGENESIS WILL BRUSH FAR
SOUTHWESTERN SECTIONS OF THE STATE BETWEEN 12-15Z...BEFORE PASSING
HARMLESSLY TO THE SOUTH. THE AMOUNT OF AMBIENT DRY AIR IN THE LOWEST
12 KFT AGL SUPPORTS VIRTUALLY NO PRECIPITATION POTENTIAL TODAY. THE
PREFERENCE REGARDING HIGH CLOUD PROG LIES WITH THE 25.05Z RUC WHICH
BRINGS HIGH CLOUDS INTO THE SOUTHWESTERN 2/3RDS OF THE CWA BETWEEN
9-16Z THIS MORNING. INCREASED INSOLATION WITH SOME MODERATION OF THE
AIRMASS WILL SUPPORT A SOLID 3-8F DEGREE UPTICK IN HIGH TEMPERATURES.
EXPECT READINGS TO RANGE FROM THE MIDDLE 50S IN THE FAR NORTHERN
THUMB/LAKE HURON SHORELINE TO THE MIDDLE 60S DETROIT SOUTHWARD.
SURFACE HIGH PRESSURE WILL EXPAND ACROSS THE CENTRAL GREAT LAKES
TONIGHT...BRINGING THE PROSPECTS OF ANOTHER COOL TO COLD NIGHT.
DIFFERENTIAL AIRMASS RECOVERY SHOULD BE GOOD FOR A FEW DEGREES OFF
THIS MORNINGS MINS. WORKED WITH A BLEND OF UNDERCUT GUIDANCE WITH
SOME PERSISTENCE. EXPECTED LOWS TONIGHT SHOULD RANGE FROM THE LOWER
TO MIDDLE 30S IN THE THUMB TO LOWER 40S SOUTHEAST OF THE TERRAIN.
&&
.LONG TERM...SUNDAY THROUGH FRIDAY
LOWER MICHIGAN WILL RESIDE BETWEEN A HIGH AMPLITUDE RIDGE ACROSS THE
UPPER MIDWEST AND A DEEP UPPER LOW LIFTING FROM NEW ENGLAND INTO THE
CANADIAN MARITIMES DURING THE LATER HALF OF THE WEEKEND...SUSTAINING
A CONFLUENT FLOW ALOFT. AT THE SFC...THIS WILL TRANSLATE TO HIGH
PRESSURE BUILDING FROM THE UPPER GREAT LAKES ON SUNDAY TO THE
EASTERN GREAT LAKES ON MONDAY. OTHER THAN THE POTENTIAL FOR SOME
HIGH CLOUDS...SKIES SHOULD REMAIN MAINLY CLEAR WITH VERY DRY AIR
OVERHEAD. TEMPS WILL SLOWLY MODERATE...LEADING TO AN OVERALL WARMING
TREND HEADING INTO MEMORIAL DAY. EXPECT MIXING DEPTHS MAY
OVERACHIEVE WITH PLENTY OF SUNSHINE AND SUBSTANTIAL LOW LEVEL DRY
AIR. THIS SUPPORTS LEANING TOWARD THE HIGHER END OF GUIDANCE MAX
TEMPS /MID TO UPPER 60S SUNDAY AND AROUND 70 MONDAY/. THE DRY
AIRMASS AND WEAK SFC GRADIENT WILL SUPPORT OPTIMAL RADIATIONAL
COOLING POTENTIAL...SO MINS SUN NIGHT WILL CONTINUE TO BE QUITE COLD
FOR LATE MAY /UPPER 30S TO MID 40S/.
THE MID LEVEL RIDGE IS FORECAST TO BREAK DOWN EARLY NEXT WEAK AS
NUMEROUS SHORT WAVE IMPULSES ARE EJECTED OUT OF THE LONG WAVE TROUGH
OVER THE WRN US AND ACROSS THE CNTRL/NRN PLAINS. THE BULK OF THE 00Z
MODEL SUITE SUGGEST MCS DEVELOPMENT ACROSS THE UPPER MIDWEST OR WRN
GREAT LAKES MON AFTERNOON/NIGHT AS LOW LEVEL INFLOW STRENGTHENS. THE
POTENTIAL FOR REMNANT MCS ACTIVITY TO ADVANCE INTO SE MI REMAINS
HIGHLY UNCERTAIN AT THIS TIME. WHILE SEVERAL MODEL SOLUTIONS ARE
QUITE BULLISH WITH QPF OVER SE MI MON NIGHT AND TUES...THERE IS
LIKELY SOME SEMBLANCE OF CONVECTIVE FEEDBACK IN THE MODELS. THERE IS
ALSO CONCERN THAT THE MODELS HAVE A POOR HANDLING OF MCS
PROPAGATION...WHICH COULD LEAD TO REMNANT CONVECTION BEING MUCH
FARTHER SOUTH. THUS PLAN TO CARRY VERY LOW CHANCE POPS TUESDAY.
PERSISTENT LOW LEVEL S-SWLY FLOW SHOULD HOWEVER LIFT A WARMER AND
MORE HUMID AIRMASS INTO SRN LOWER MI BY MID WEEK...MARKED BY THE
PASSAGE OF A SFC WARM FRONT. THIS WILL JUSTIFY A CHANCE OF
SHOWERS/THUNDERSTORMS LATE TUES THROUGH WED.
THE ECMWF REMAINS STEADFAST IN DEVELOPING A MORE AMPLIFIED UPPER
TROUGH OVER THE WRN US BY MIDWEEK AS ENERGY EJECTS OUT OF THE GULF
OF ALASKA AND INTO THE WEST COAST. A SEASONALLY STRONG UPPER JET
WITHIN THE BASE OF THE DEEP GULF OF ALASKA UPPER LOW AND CURRENT
AMPLIFIED NATURE OF THE FLOW LENDS SUPPORT TO THE ECMWF. THIS
SOLUTION BUILDS THE SUBTROPICAL RIDGE FARTHER NORTH INTO THE ERN US
LATE IN THE WEEK AND SUGGESTS SE MI MAY BE CAPPED. EVEN THE LESS
AMPLIFIED GFS BUILDS MID LEVEL HEIGHTS SUBSTANTIALLY ACROSS SE MI.
THUS THE FORECAST FOR THE LATER HALF OF NEXT WEEK WILL HAVE VERY LOW
POPS WITH MAX TEMPS WELL INTO THE 80S.
&&
.MARINE...
A STABLE ANTICYCLONE WILL EXPAND ACROSS THE GREAT LAKES THROUGH THE
HOLIDAY WEEKEND. THIS WEATHER FEATURE WILL BE RESPONSIBLE FOR MORE
TYPICAL MARINE CONDITIONS FOR LATE MAY. WAVE HEIGHTS ARE ONLY
EXPECTED TO RANGE IN THE 1 TO 2 FOOT RANGE IN MANY AREAS THROUGHOUT
THE WEEKEND.
&&
.AVIATION...ISSUED 1148 PM EDT FRI MAY 24 2013
//DISCUSSION...
HIGH PRESSURE WILL DOMINATE THE TAF PERIOD WITH NOTHING MORE THAN
MID/HIGH CLOUDS SPREADING ACROSS SOUTHEAST MICHIGAN OVERNIGHT. HIGH
PRESSURE WILL ALSO MAINTAIN A LIGHT NORTHEAST GRADIENT WELL INTO
SATURDAY NIGHT. SCATTERED COVERAGE OF DIURNAL CU AROUND 5-6KFT IS
LIKELY DURING PEAK HEATING ON SATURDAY.
//DTW THRESHOLD THREATS...
* NONE.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-MIZ060-
MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082-
MIZ083...UNTIL 8 AM SATURDAY.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
AVIATION.....JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DULUTH MN
924 PM CDT SUN MAY 26 2013
.UPDATE...
PERSISTENT BAND OF LIGHT RAIN STRETCHED ACROSS OUR SOUTHWEST CWA
THIS EVENING...AND SEEMS TO BE IN RESPONSE TO SOME MID LEVEL WAA
AND A SHORTWAVE. WE`VE UPDATED THE FORECAST AND GRIDS THIS
EVENING...BUT MAY NEED TO EXPAND THE POPS FURTHER NORTH AND EAST
AND INCREASE THEM. WE`LL MONITOR A BIT LONGER BEFORE MAKING ANY
FURTHER CHANGES.
&&
.PREV DISCUSSION... /ISSUED 642 PM CDT SUN MAY 26 2013/
UPDATE...
A FEW LIGHT SHOWERS WERE OCCURRING OVER OUR SOUTHWEST CWA...AND WE
UPDATED TO ADD SOME EARLY EVENING POPS TO ACCOUNT FOR THAT. WE
THINK THESE WILL DIMINISH WITH LOSS OF HEATING.
AVIATION...00Z TAFS
VFR CONDITIONS WILL PREVAIL THIS EVENING...BUT LOW LEVEL MOISTURE
WILL BE INCREASING AND WE EXPECT MVFR CEILINGS TO MOVE INTO KBRD
AFTER MIDNIGHT...WITH THESE CEILINGS PROGRESSING NORTH OVERNIGHT
INTO MONDAY AFFECTING MOST TAF SITES. WE FOLLOWED THE RAP 925MB
COND PRESSURE DEFICITS FOR TIMING OF THE CEILINGS.
SOME SHOWERS WILL ALSO BE POSSIBLE...BUT TIMING THEM WILL BE MORE
DIFFICULT AND WE LEFT THE MENTION OUT OF MOST TAFS DUE TO THE
UNCERTAINTY.
PREV DISCUSSION... /ISSUED 335 PM CDT SUN MAY 26 2013/
CURRENT...MID LVL AND SFC RIDGE HAS KEPT QUIET WX PATTERN IN PLACE
TODAY. GUSTY WINDS HAVE INCREASED THIS AFTERNOON AS MIXING LAYER
DEEPENS WITHIN UNIDIRECTIONAL BDRY LYR. PATCHES OF MID LVL CLOUDS
ARE MAKING THEIR WAY THROUGH RIDGE AXIS HOWEVER A DECENT AMOUNT OF
SUNSHINE HAS PREVAILED TODAY. SFC TEMPS RANGE FROM THE 40S NEAR
LAKE SUPERIOR TO THE 60S/70S INLAND.
TONIGHT...AS WAS THE CASE YESTERDAY...THE OVERALL TREND IS SLOWER
WITH REGARD TO APPROACHING PRECIPITATION. 85H MOISTURE TRANSPORT
AXIS SHIFTS FROM NRN PLAINS INTO SWRN EDGE OF CWA BY 06Z. SHOULD SEE
RW PUSH INTO THE AREA BY MIDNIGHT. CONVECTIVE PARAMETERS INCLUDING
SREF CPTP SUGGEST HIGHEST CHANCE OF ANY THUNDER WILL BE LIMITED TO
SWRN COUNTIES THROUGH THE EARLY MORNING. FCST POSITIONING OF
NOCTURNAL LLJ... AND ITS IMPINGEMENT ACROSS EAST/WEST LOW LVL
THERMAL GRADIENT... INDICATES A POTENTIAL MCS DEVELOPMENT FROM ERN
SODAK INTO SWRN MN.
TOMORROW...EJECTING MID LVL SHORTWAVE TROF WILL MOVE FROM ERN SODAK
TOWARDS BRD LAKES REGION BY MONDAY EVENING. THIS WILL ASSIST IN
INCREASING 85H MSTR TRANSPORT CONCURRENT WITH ADVECTION OF 85/30H
LAYER OMEGA. RESULT SHOULD BE AN INCREASE IN AMOUNT OF RW/TRW
DEVELOPMENT HOWEVER PRESENCE OF EARLY MORNING MCS SOUTH OF CWA MAY
AFFECT DISTRIBUTION OF PRECIP. MAJORITY OF MDL QPF LEAN TOWARDS A
CONVECTIVE MAXIMUM SOUTH OF REGION EXCEPT ECMWF SO CONFIDENCE IS
LOW ON AREAL DISTRIBUTION OF POPS TOMORROW.
LONG TERM...MONDAY NIGHT THROUGH SUNDAY.
THE EXTENDED TIME PERIOD WILL BE QUITE UNSETTLED AND WET. TIMING OF
VARIOUS FEATURES WILL BE TOUGH IN THIS NOTORIOUSLY DIFFICULT
FORECAST PATTERN. BROAD LOW PRESSURE WILL GRADUALLY MIGRATE TOWARD
THE UPPER MIDWEST...ALONG WITH ABUNDANT MOISTURE. THE FIRST SUCH
SYSTEM WILL MOVE IN MONDAY NIGHT AND TUESDAY...WITH PERHAPS A BIT OF
A LET UP OR BREAK FOR PORTIONS OF THE AREA TUESDAY NIGHT AND
WEDNESDAY. IT LOOKS LIKE THERE WILL BE POTENTIALLY A FEW MCS ACROSS
THE AREA MONDAY NIGHT AND TUESDAY. THE NEXT LOW PRESSURE SYSTEM IN
SW FLOW WILL ARRIVE WEDNESDAY NIGHT...AND LINGERING INTO THE
WEEKEND. COULD BE SEVERAL INCHES OF RAIN DEPENDING ON HOW THE MCS
DEVELOPMENT UNFOLDS. THE LOW PRESSURE SYSTEM WILL BE VERY SLOW
MOVING AS IT LIFTS INTO THE GREAT LAKES. TEMPERATURES WILL LARGELY
BE IN THE 70S DURING THE EXTENDED BUT SOME DAYS WILL LIKELY ONLY BE
IN THE 60S DUE TO CLOUDS AND RAIN.
&&
.POINT TEMPS/POPS...
DLH 43 60 51 71 / 10 50 70 60
INL 46 71 53 72 / 10 20 50 40
BRD 50 64 57 76 / 50 60 60 40
HYR 47 66 57 75 / 20 60 70 60
ASX 40 66 52 70 / 10 20 70 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR LSZ143>147.
&&
$$
SHORT TERM...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
642 PM CDT SUN MAY 26 2013
.UPDATE...
A FEW LIGHT SHOWERS WERE OCCURRING OVER OUR SOUTHWEST CWA...AND WE
UPDATED TO ADD SOME EARLY EVENING POPS TO ACCOUNT FOR THAT. WE
THINK THESE WILL DIMINISH WITH LOSS OF HEATING.
&&
.AVIATION...00Z TAFS
VFR CONDITIONS WILL PREVAIL THIS EVENING...BUT LOW LEVEL MOISTURE
WILL BE INCREASING AND WE EXPECT MVFR CEILINGS TO MOVE INTO KBRD
AFTER MIDNIGHT...WITH THESE CEILINGS PROGRESSING NORTH OVERNIGHT
INTO MONDAY AFFECTING MOST TAF SITES. WE FOLLOWED THE RAP 925MB
COND PRESSURE DEFICITS FOR TIMING OF THE CEILINGS.
SOME SHOWERS WILL ALSO BE POSSIBLE...BUT TIMING THEM WILL BE MORE
DIFFICULT AND WE LEFT THE MENTION OUT OF MOST TAFS DUE TO THE
UNCERTAINTY.
&&
.PREV DISCUSSION... /ISSUED 335 PM CDT SUN MAY 26 2013/
CURRENT...MID LVL AND SFC RIDGE HAS KEPT QUIET WX PATTERN IN PLACE
TODAY. GUSTY WINDS HAVE INCREASED THIS AFTERNOON AS MIXING LAYER
DEEPENS WITHIN UNIDIRECTIONAL BDRY LYR. PATCHES OF MID LVL CLOUDS
ARE MAKING THEIR WAY THROUGH RIDGE AXIS HOWEVER A DECENT AMOUNT OF
SUNSHINE HAS PREVAILED TODAY. SFC TEMPS RANGE FROM THE 40S NEAR
LAKE SUPERIOR TO THE 60S/70S INLAND.
TONIGHT...AS WAS THE CASE YESTERDAY...THE OVERALL TREND IS SLOWER
WITH REGARD TO APPROACHING PRECIPITATION. 85H MOISTURE TRANSPORT
AXIS SHIFTS FROM NRN PLAINS INTO SWRN EDGE OF CWA BY 06Z. SHOULD SEE
RW PUSH INTO THE AREA BY MIDNIGHT. CONVECTIVE PARAMETERS INCLUDING
SREF CPTP SUGGEST HIGHEST CHANCE OF ANY THUNDER WILL BE LIMITED TO
SWRN COUNTIES THROUGH THE EARLY MORNING. FCST POSITIONING OF
NOCTURNAL LLJ... AND ITS IMPINGEMENT ACROSS EAST/WEST LOW LVL
THERMAL GRADIENT... INDICATES A POTENTIAL MCS DEVELOPMENT FROM ERN
SODAK INTO SWRN MN.
TOMORROW...EJECTING MID LVL SHORTWAVE TROF WILL MOVE FROM ERN SODAK
TOWARDS BRD LAKES REGION BY MONDAY EVENING. THIS WILL ASSIST IN
INCREASING 85H MSTR TRANSPORT CONCURRENT WITH ADVECTION OF 85/30H
LAYER OMEGA. RESULT SHOULD BE AN INCREASE IN AMOUNT OF RW/TRW
DEVELOPMENT HOWEVER PRESENCE OF EARLY MORNING MCS SOUTH OF CWA MAY
AFFECT DISTRIBUTION OF PRECIP. MAJORITY OF MDL QPF LEAN TOWARDS A
CONVECTIVE MAXIMUM SOUTH OF REGION EXCEPT ECMWF SO CONFIDENCE IS
LOW ON AREAL DISTRIBUTION OF POPS TOMORROW.
LONG TERM...MONDAY NIGHT THROUGH SUNDAY.
THE EXTENDED TIME PERIOD WILL BE QUITE UNSETTLED AND WET. TIMING OF
VARIOUS FEATURES WILL BE TOUGH IN THIS NOTORIOUSLY DIFFICULT
FORECAST PATTERN. BROAD LOW PRESSURE WILL GRADUALLY MIGRATE TOWARD
THE UPPER MIDWEST...ALONG WITH ABUNDANT MOISTURE. THE FIRST SUCH
SYSTEM WILL MOVE IN MONDAY NIGHT AND TUESDAY...WITH PERHAPS A BIT OF
A LET UP OR BREAK FOR PORTIONS OF THE AREA TUESDAY NIGHT AND
WEDNESDAY. IT LOOKS LIKE THERE WILL BE POTENTIALLY A FEW MCS ACROSS
THE AREA MONDAY NIGHT AND TUESDAY. THE NEXT LOW PRESSURE SYSTEM IN
SW FLOW WILL ARRIVE WEDNESDAY NIGHT...AND LINGERING INTO THE
WEEKEND. COULD BE SEVERAL INCHES OF RAIN DEPENDING ON HOW THE MCS
DEVELOPMENT UNFOLDS. THE LOW PRESSURE SYSTEM WILL BE VERY SLOW
MOVING AS IT LIFTS INTO THE GREAT LAKES. TEMPERATURES WILL LARGELY
BE IN THE 70S DURING THE EXTENDED BUT SOME DAYS WILL LIKELY ONLY BE
IN THE 60S DUE TO CLOUDS AND RAIN.
&&
.POINT TEMPS/POPS...
DLH 43 60 51 71 / 10 50 70 60
INL 46 71 53 72 / 10 20 50 40
BRD 50 64 57 76 / 50 60 60 40
HYR 47 66 57 75 / 20 60 70 60
ASX 40 66 52 70 / 10 20 70 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR LSZ143>147.
&&
$$
SHORT TERM...MELDE
LONG TERM....DAP
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
600 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT SAT MAY 25 2013
INITIAL SHIELD OF WAA SHOWERS THAT WAS DEPICTED WELL ON 310K
ISENTROPIC SFC ON THE NAM/GFS IS FADING AWAY ACROSS WRN WI AS THIS
BATCH OF FORCING WEAKENS AND DIVES SOUTHEAST. IN ITS WAKE...WE HAVE
WAA AT H85...BUT THE DEEPER MOISTURE HAS PUSHED EAST...SO PRECIP HAS
CUT OFF PRETTY QUICK. WITH THE WAA AND WEAK MOISTURE
TRANSPORT...SHOULD BE ABLE TO GET SOME LIGHT SHOWERS/SPRINKLES
ACROSS MN THIS MORNING...BUT NOT MUCH MORE THAN THAT.
BEST CHANCE FOR RAIN TODAY WILL BE ACROSS SRN MN. WARM FRONT NOW CAN
BE FOUND ACROSS SOUTH CENTRAL NEB INTO NE KAN...WITH A STRONG LLJ
OVERRUNNING IT. THIS HAS GENERATED AN MCS OVER ERN NEB THIS MORNING.
THUNDER STARTING TO INCREASE ACROSS IA AS WELL AS THE LLJ HAS SLOWLY
WORKED EAST. MOST OF THIS THUNDERSTORM ACTIVITY WILL REMAIN SOUTH OF
MN THROUGH THE DAY...BUT ALL HI-RES MODELS SHOW SOME OF THIS
MOISTURE FROM IA SNEAKING UP INTO SOUTH CENTRAL MN THROUGH
MORNING...WHERE SOME HIGH CHANCE/LIKELY POPS ARE CONTINUED THROUGH
THE MORNING HOURS. FOR THE AFTERNOON...PRECIP LOOKS TO SHUT
OFF...BUT WE WILL BE STUCK WITH FAIRLY BROAD CLOUD COVER...WITH THE
ONLY HOPE FOR SOME BREAKS ACROSS THE NE MPX CWA THANKS TO THE
INFLUENCE OF A DRY SFC HIGH THAT WILL BE SPLAYED OUT ACROSS THE
GREAT LAKES. GIVEN THE CLOUD COVER WILL BE A COOL DAY...WITH
TEMPERATURES IN SOUTH CENTRAL MN LIKELY STAYING IN THE 50S THANKS TO
BETTER RAIN CHANCES AND THICKER CLOUD COVER.
FOR TONIGHT...ALL MODELS SHOW ANOTHER ROUND OF CONVECTION RIDING
ALONG NORTH OF THE WARM FRONT...KIND OF LIKE WHAT WE HAVE SEEN
OVERNIGHT TO OUR SOUTHWEST. QUESTION BECOMES HOW FAR NORTH DOES THE
ACTIVITY MAKE IT. CONSENSUS PLACEMENT FROM THE WARM FRONT PLACES IT
BY 12Z SUNDAY MORNING FROM THE BLACK HILLS...DOWN THROUGH
YANKTON...SD AND THEN DOWN TO THE CENTRAL IA/MO BORDER. ONCE
AGAIN...WILL SEE A LLJ OVERRUNNING THIS FRONTAL FEATURE...WHICH
SHOULD GENERATE YET ANOTHER MCS. GIVEN THE FRONTS PLACEMENT TO OUR
SOUTHWEST...BEST CHANCES FOR THUNDERSTORMS TONIGHT WILL BE SOUTH OF
THE UPPER MN RIVER IN SW MN INTO SC MN. FOR TIMING...FAVORED HIGHEST
POPS TO AFTER 6Z...AS CONVECTION SHOULD FIRE THIS EVENING OVER SE
SODAK INTO NE NEB...THEN HEAD TOWARD SW/SC MN. ALL OF THIS ACTIVITY
WOULD BE ELEVATED...SO SEVERE THREAT LOOKS MINIMAL...WITH THE MAIN
IMPACT BEING THE POTENTIAL FOR HEAVY RAIN...AS WE HAVE SEEN THIS
EVENING IN NEB.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 344 AM CDT SAT MAY 25 2013
THE LONG TERM PERIOD CONTINUES TO LOOK INCREASINGLY WET AND
STORMY. THIS IS DUE TO THE REGION BEING SANDWICHED BETWEEN A
BUILDING UPPER HIGH ALONG THE EASTERN SEABOARD... WHILE A VERY
DEEP TROUGH PUSHES INTO THE WESTERN HALF OF THE UNITED STATES.
THERE SHOULD BE A ROUND OF CONVECTION PASS ACROSS SOUTHERN MN
SUNDAY MORNING...VERY SIMILAR TO WHAT HAS BEEN ONGOING OVERNIGHT
ACROSS NE/IA. THE STORMS TO OUR SOUTH CURRENTLY HAVE BEEN BASICALLY
SUB SEVERE... BUT VERY EFFICIENT RAIN PRODUCERS... WITH UPWARDS OF
1.75 INCHES OF RAIN IN THREE HOURS. THIS IS THE TREND EXPECTED
SUNDAY MORNING ACROSS SOUTHERN MN... ESPECIALLY THE I-90
CORRIDOR. THEREAFTER... A SIGNIFICANT DIMINISHING TREND IN THE
PRECIPITATION FOR SUNDAY AFTERNOON AND EVENING WITH THE NMM/ARW
WRF/S IN AGREEMENT.
MEMORIAL DAY IS LOOKING A LITTLE WORSE NOW WITH EVEN THE ECMWF
DRIVING A WAVE OF CONVECTION ACROSS THE FA DURING THE DAY AND
EVENING. JUST GENERAL THUNDER INDICATED ON SWODY2 WHICH SEEMS
REASONABLE WITH THE MAIN WARM FRONTAL BOUNDARY MEANDERING FROM THE
CENTRAL PLAINS TO THE LOWER OHIO VALLEY. AGAIN... THE CONCERN WILL
BE LOCALIZED HEAVY RAINFALL. THE DETERMINISTIC RUNS WOULD ALSO
SUGGEST ANOTHER ROUND OF CONVECTION FOR US LATE MONDAY NIGHT AND
TUESDAY MORNING... ESPECIALLY ACROSS SOUTHERN MN.
THIS REPEATING ROUNDS OF POTENTIAL CONVECTION IS DISTURBING WITH
AREAS OF SOUTHERN AND ESPECIALLY SOUTHEAST MN RUNNING WELL ABOVE
NORMAL ON RAINFALL FOR THE MONTH OF MAY. THE THREAT FOR FLASH
FLOODING WILL BE ON THE INCREASE. IT WAS POINTED OUT ON FRIDAY
IN THE WEATHERTALK FROM DR SEELY AT THE UMN THAT SINCE MARCH
1ST...(METEOROLOGICAL SPRING) IT HAS BEEN ONE OF THE WETTEST IN
HISTORY FOR MANY AREAS OF MN. ADD THIS TO THE CIPS ANALOGS
FOR 5 DAYS FROM NOW AND ONE SEES A VERY WET PATTERN ACROSS ALL OF
THE REGION WITH 2 INCHES OF RAINFALL EXCEEDING 30 PERCENT
PROBABILITY WITH EVEN WIDESPREAD 3 INCHES HAVING A 10 PERCENT
PROBABILITY. THIS IS IN ADDITION TO THE RAINS SUNDAY THROUGH
TUESDAY. NOT SURPRISING THEN ARE THE RUN TOTALS FROM THE GFS AND
ECMWF THROUGH NEXT FRIDAY WHICH PAINT THE LANDSCAPE WITH 2 TO 4
INCHES OF RAIN... WITH 4 INCHES OR MORE SOUTH OF US. DIGRESSING
FOR A MOMENT... ONE OF THE MONTHS/YEARS THAT HAS SHOWN UP IN THE
CIPS ANALOGS RECENTLY IS JULY 1993... WITH RECORD FLOODING IN THIS
PART OF THE COUNTRY. A REVIEW FROM NCDC SHOWED LOW PRESSURE ALOFT
OVER THE WESTERN HIGH PLAINS WITH A STRONG SW JET AT 250 MB ACROSS
OUR AREA. THE BERMUDA HIGH HAD PUSHED INTO THE SOUTHEAST UNITED
STATES WITH ORGANIZED 850 MB WINDS FROM THE WESTERN GULF OF MEXICO
TO THE WESTERN GREAT LAKES. HENCE... THE FLOODING POTENTIAL IS A
BIG CONCERN FOR THE WEEK AHEAD AS THE PATTERN IN THE SUMMER OF
1993 MIMICS OUR WEEK AHEAD QUITE WELL.
FINALLY... AND JUST AS IMPORTANT... WILL BE THE THREAT FOR SEVERE
WEATHER NEXT WEEK AS THE WARM FRONT LIFTS NORTH INTO OUR AREA
BEGINNING ON TUESDAY. NOT TOO CONCERN ABOUT SEVERE ON SUNDAY. THE
CHANCE INCREASES SOME ON MONDAY (ISOLATED)...ESPECIALLY IF
AFTERNOON CONVECTION DEVELOPS AS DEEP LAYER SHEAR RISES. THEN FROM
TUESDAY ONWARD THERE IS SEVERE POTENTIAL EACH DAY. THE CIPS
ANALOGS CONTAIN MANY SEVERE REPORTS FOR US FOR THE MIDDLE OF NEXT
WEEK WITH SEVERE PROBABILITIES FROM 15 TO 30 PERCENT FOR THE
ENTIRE FA USING THE TOP 8 ANALOGS. A COLD FRONT MAY MOVE ACROSS
THE FA FROM FRIDAY INTO SATURDAY...DIMINISHING THE SEVERE WEATHER
THREAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT MAY 25 2013
LOTS OF CONVECTION ON THE RADAR...BUT IT IS ALL WELL TO THE SOUTH.
MAY SEE A FEW SPRINKLES/LIGHT SHOWERS ACROSS MN THROUGH THE
MORNING...WITH ANYTHING MORE SUBSTANTIAL STAYING CONFINED TO THE
I-90 CORRIDOR. FOR THE REST OF THE DAY...WILL HAVE TO TRACK MVFR
CIGS EMANATING FROM THE TSRA ACTIVITY IN IOWA. CONTINUED TO FAVOR A
HRRR/RAP DEPICTION FOR THE HANDLING OF THESE LOW CLOUDS...KEEPING
MVFR CIGS DURING THE DAY CONFINED TO RWF. WITH SE FLOW...NAM ALONG
WITH THE RAP SHOW MVFR CIGS WORKING NW INTO NODAK...WHICH SHOULD
BRING MVFR CIGS TO AXN THIS AFTERNOON OR EVENING. MSP/STC LOOK TO BE
SITTING ON THE EDGE OF THE MVFR CIGS BY THE END OF THE TAF PERIOD
AND AT THIS POINT...STUCK WITH VFR CONDITIONS AT BOTH LOCATIONS
THROUGHOUT...THOUGH CERTAINLY SOME MVFR CIGS COULD BE SEEN AFTER
06Z. EXPECT ANOTHER ROUND OF THUNDERSTORMS TONIGHT...THOUGH WITH
WARM FRONT DRIFTING NORTH...STORMS SATURDAY NIGHT SHOULD BE A BIT
FARTHER NORTH OF WHERE THEY ARE NOW. BEST CHANCE FOR THUNDER LOOKS
TO BE ALONG/SOUTH OF THE MN RIVER...SO INTRODUCED SOME VCTS TO THE
END OF THE RWF TAF. FOR WINDS...THEY WILL BE REMARKABLY PERSISTENT
THIS PERIOD OUT OF THE SOUTHEAST...WITH WINDS TODAY EXPECTED TO
INCREASE TO NEAR WHAT WAS SEEN FRIDAY ACROSS MN.
KMSP...CONFIDENCE HIGH IN TAF THROUGH 06Z. AFTER 06Z...MVFR CIGS
THAT WILL BE SOUTHWEST OF THE FIELD WILL START TO PUSH NORTHEAST AND
COULD BEGIN TO IMPACT THE FIELD. HOWEVER...STICKING WITH THE THEME
OF THE GFS...WITH CIGS REMAINING ABOVE 4K FT. WILL ALSO HAVE TO
WATCH HOW ACTIVITY EVOLVES TO THE SOUTHWEST LATE TONIGHT...AS THERE
ARE INDICATIONS FROM THE GFS/ECMWF THAT SOME LIGHT ACTIVITY COULD
APPROACH THE FIELD SUNDAY MORNING. HOWEVER...AT THIS TIME...WITH THE
WARM FRONT EXPECTED DOWN ACROSS CENTRAL IOWA...FEEL BETTER SHRA/TSRA
CHANCES SUNDAY MORNING WILL BE DOWN ACROSS SOUTH CENTRAL MN...SO
KEPT ANY SORT OF PRECIP MENTION OUT OF THE TAF.
/OUTLOOK FOR KMSP/
SUN...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
MON...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10 KTS.
TUE...CHC MVFR OR LOWER CIGS. TSRA LIKELY. WINDS SSE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
344 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT SAT MAY 25 2013
INITIAL SHIELD OF WAA SHOWERS THAT WAS DEPICTED WELL ON 310K
ISENTROPIC SFC ON THE NAM/GFS IS FADING AWAY ACROSS WRN WI AS THIS
BATCH OF FORCING WEAKENS AND DIVES SOUTHEAST. IN ITS WAKE...WE HAVE
WAA AT H85...BUT THE DEEPER MOISTURE HAS PUSHED EAST...SO PRECIP HAS
CUT OFF PRETTY QUICK. WITH THE WAA AND WEAK MOISTURE
TRANSPORT...SHOULD BE ABLE TO GET SOME LIGHT SHOWERS/SPRINKLES
ACROSS MN THIS MORNING...BUT NOT MUCH MORE THAN THAT.
BEST CHANCE FOR RAIN TODAY WILL BE ACROSS SRN MN. WARM FRONT NOW CAN
BE FOUND ACROSS SOUTH CENTRAL NEB INTO NE KAN...WITH A STRONG LLJ
OVERRUNNING IT. THIS HAS GENERATED AN MCS OVER ERN NEB THIS MORNING.
THUNDER STARTING TO INCREASE ACROSS IA AS WELL AS THE LLJ HAS SLOWLY
WORKED EAST. MOST OF THIS THUNDERSTORM ACTIVITY WILL REMAIN SOUTH OF
MN THROUGH THE DAY...BUT ALL HI-RES MODELS SHOW SOME OF THIS
MOISTURE FROM IA SNEAKING UP INTO SOUTH CENTRAL MN THROUGH
MORNING...WHERE SOME HIGH CHANCE/LIKELY POPS ARE CONTINUED THROUGH
THE MORNING HOURS. FOR THE AFTERNOON...PRECIP LOOKS TO SHUT
OFF...BUT WE WILL BE STUCK WITH FAIRLY BROAD CLOUD COVER...WITH THE
ONLY HOPE FOR SOME BREAKS ACROSS THE NE MPX CWA THANKS TO THE
INFLUENCE OF A DRY SFC HIGH THAT WILL BE SPLAYED OUT ACROSS THE
GREAT LAKES. GIVEN THE CLOUD COVER WILL BE A COOL DAY...WITH
TEMPERATURES IN SOUTH CENTRAL MN LIKELY STAYING IN THE 50S THANKS TO
BETTER RAIN CHANCES AND THICKER CLOUD COVER.
FOR TONIGHT...ALL MODELS SHOW ANOTHER ROUND OF CONVECTION RIDING
ALONG NORTH OF THE WARM FRONT...KIND OF LIKE WHAT WE HAVE SEEN
OVERNIGHT TO OUR SOUTHWEST. QUESTION BECOMES HOW FAR NORTH DOES THE
ACTIVITY MAKE IT. CONSENSUS PLACEMENT FROM THE WARM FRONT PLACES IT
BY 12Z SUNDAY MORNING FROM THE BLACK HILLS...DOWN THROUGH
YANKTON...SD AND THEN DOWN TO THE CENTRAL IA/MO BORDER. ONCE
AGAIN...WILL SEE A LLJ OVERRUNNING THIS FRONTAL FEATURE...WHICH
SHOULD GENERATE YET ANOTHER MCS. GIVEN THE FRONTS PLACEMENT TO OUR
SOUTHWEST...BEST CHANCES FOR THUNDERSTORMS TONIGHT WILL BE SOUTH OF
THE UPPER MN RIVER IN SW MN INTO SC MN. FOR TIMING...FAVORED HIGHEST
POPS TO AFTER 6Z...AS CONVECTION SHOULD FIRE THIS EVENING OVER SE
SODAK INTO NE NEB...THEN HEAD TOWARD SW/SC MN. ALL OF THIS ACTIVITY
WOULD BE ELEVATED...SO SEVERE THREAT LOOKS MINIMAL...WITH THE MAIN
IMPACT BEING THE POTENTIAL FOR HEAVY RAIN...AS WE HAVE SEEN THIS
EVENING IN NEB.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 344 AM CDT SAT MAY 25 2013
THE LONG TERM PERIOD CONTINUES TO LOOK INCREASINGLY WET AND
STORMY. THIS IS DUE TO THE REGION BEING SANDWICHED BETWEEN A
BUILDING UPPER HIGH ALONG THE EASTERN SEABOARD... WHILE A VERY
DEEP TROUGH PUSHES INTO THE WESTERN HALF OF THE UNITED STATES.
THERE SHOULD BE A ROUND OF CONVECTION PASS ACROSS SOUTHERN MN
SUNDAY MORNING...VERY SIMILAR TO WHAT HAS BEEN ONGOING OVERNIGHT
ACROSS NE/IA. THE STORMS TO OUR SOUTH CURRENTLY HAVE BEEN BASICALLY
SUB SEVERE... BUT VERY EFFICIENT RAIN PRODUCERS... WITH UPWARDS OF
1.75 INCHES OF RAIN IN THREE HOURS. THIS IS THE TREND EXPECTED
SUNDAY MORNING ACROSS SOUTHERN MN... ESPECIALLY THE I-90
CORRIDOR. THEREAFTER... A SIGNIFICANT DIMINISHING TREND IN THE
PRECIPITATION FOR SUNDAY AFTERNOON AND EVENING WITH THE NMM/ARW
WRF/S IN AGREEMENT.
MEMORIAL DAY IS LOOKING A LITTLE WORSE NOW WITH EVEN THE ECMWF
DRIVING A WAVE OF CONVECTION ACROSS THE FA DURING THE DAY AND
EVENING. JUST GENERAL THUNDER INDICATED ON SWODY2 WHICH SEEMS
REASONABLE WITH THE MAIN WARM FRONTAL BOUNDARY MEANDERING FROM THE
CENTRAL PLAINS TO THE LOWER OHIO VALLEY. AGAIN... THE CONCERN WILL
BE LOCALIZED HEAVY RAINFALL. THE DETERMINISTIC RUNS WOULD ALSO
SUGGEST ANOTHER ROUND OF CONVECTION FOR US LATE MONDAY NIGHT AND
TUESDAY MORNING... ESPECIALLY ACROSS SOUTHERN MN.
THIS REPEATING ROUNDS OF POTENTIAL CONVECTION IS DISTURBING WITH
AREAS OF SOUTHERN AND ESPECIALLY SOUTHEAST MN RUNNING WELL ABOVE
NORMAL ON RAINFALL FOR THE MONTH OF MAY. THE THREAT FOR FLASH
FLOODING WILL BE ON THE INCREASE. IT WAS POINTED OUT ON FRIDAY
IN THE WEATHERTALK FROM DR SEELY AT THE UMN THAT SINCE MARCH
1ST...(METEOROLOGICAL SPRING) IT HAS BEEN ONE OF THE WETTEST IN
HISTORY FOR MANY AREAS OF MN. ADD THIS TO THE CIPS ANALOGS
FOR 5 DAYS FROM NOW AND ONE SEES A VERY WET PATTERN ACROSS ALL OF
THE REGION WITH 2 INCHES OF RAINFALL EXCEEDING 30 PERCENT
PROBABILITY WITH EVEN WIDESPREAD 3 INCHES HAVING A 10 PERCENT
PROBABILITY. THIS IS IN ADDITION TO THE RAINS SUNDAY THROUGH
TUESDAY. NOT SURPRISING THEN ARE THE RUN TOTALS FROM THE GFS AND
ECMWF THROUGH NEXT FRIDAY WHICH PAINT THE LANDSCAPE WITH 2 TO 4
INCHES OF RAIN... WITH 4 INCHES OR MORE SOUTH OF US. DIGRESSING
FOR A MOMENT... ONE OF THE MONTHS/YEARS THAT HAS SHOWN UP IN THE
CIPS ANALOGS RECENTLY IS JULY 1993... WITH RECORD FLOODING IN THIS
PART OF THE COUNTRY. A REVIEW FROM NCDC SHOWED LOW PRESSURE ALOFT
OVER THE WESTERN HIGH PLAINS WITH A STRONG SW JET AT 250 MB ACROSS
OUR AREA. THE BERMUDA HIGH HAD PUSHED INTO THE SOUTHEAST UNITED
STATES WITH ORGANIZED 850 MB WINDS FROM THE WESTERN GULF OF MEXICO
TO THE WESTERN GREAT LAKES. HENCE... THE FLOODING POTENTIAL IS A
BIG CONCERN FOR THE WEEK AHEAD AS THE PATTERN IN THE SUMMER OF
1993 MIMICS OUR WEEK AHEAD QUITE WELL.
FINALLY... AND JUST AS IMPORTANT... WILL BE THE THREAT FOR SEVERE
WEATHER NEXT WEEK AS THE WARM FRONT LIFTS NORTH INTO OUR AREA
BEGINNING ON TUESDAY. NOT TOO CONCERN ABOUT SEVERE ON SUNDAY. THE
CHANCE INCREASES SOME ON MONDAY (ISOLATED)...ESPECIALLY IF
AFTERNOON CONVECTION DEVELOPS AS DEEP LAYER SHEAR RISES. THEN FROM
TUESDAY ONWARD THERE IS SEVERE POTENTIAL EACH DAY. THE CIPS
ANALOGS CONTAIN MANY SEVERE REPORTS FOR US FOR THE MIDDLE OF NEXT
WEEK WITH SEVERE PROBABILITIES FROM 15 TO 30 PERCENT FOR THE
ENTIRE FA USING THE TOP 8 ANALOGS. A COLD FRONT MAY MOVE ACROSS
THE FA FROM FRIDAY INTO SATURDAY...DIMINISHING THE SEVERE WEATHER
THREAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1259 AM CDT SAT MAY 25 2013
BATCH OF WARM ADVECTIVE SHOWERS WORKING INTO WI TO START THE
TAF...BUT DRY AIR IS STARTING TO TAKE ITS TOLL...WITH PRECIP
COVERAGE BEGINNING TO DIMINISH. LLJ STARTING TO ORGANIZE INTO ERN
NEB AT THE MOMENT...AND WILL LAY INTO IOWA OVERNIGHT. FOLLOWED
IDEA OF HRRR AND OTHER HI-RES MODELS WITH SHOWERS CURRENTLY OVER
THE MN/WI BORDER SLOWLY DIMINISHING THROUGH 10Z...WITH ANY
SIGNIFICANT TSRA ACTIVITY STAYING SOUTH OF MN THE REST OF THE
NIGHT. HOWEVER...WILL HAVE PLENTY OF CLOUD COVER AND WEAK MOISTURE
TRANSPORT REMAINING INTO THE MORNING...WITH BOUTS OF SPRINKLES/LIGHT
RAIN EXPECTED ACROSS MN...SO DID KEEP SOME VCSH MENTION GOING.
OTHER CHANGE TO THESE TAFS WAS TO START SLOWING DOWN ARRIVAL OF
MVFR CIGS LATER TODAY. BASED TIMING ON THE RAP/HRRR/NAM...WHICH
SHOW MVFR CIGS CURRENTLY DEVELOPING OVER SE NEB NOT ARRIVING INTO
THE RWF AREA UNTIL CLOSE TO 18Z. WITH WARM FRONT EXPECTED TO STAY
DOWN ALONG THE IA/MO BORDER TODAY...EXPECT MAJORITY OF MVFR CIGS
TO STAY DOWN IN IOWA THROUGH THE DAY...WITH A MORE SIGNIFICANT
PUSH OF MVFR CIGS NORTH NOT EXPECTED UNTIL TONIGHT AS THE FRONT
BEGINS A SLOW CRAWL NORTH ACROSS IOWA...BRINGING MVFR CIGS FURTHER
NORTH AS WELL. AS RESULT...DELAYED ARRIVAL OF MVFR CIGS UNTIL
AFTER 00Z FOR ALL MN TERMINALS EXCEPT RWF.
KMSP...GIVEN HOW CIGS WITH RAIN ONLY DROPPED TO 6K FT AT
BEST...FEEL CONFIDENT IN VFR CIGS REMAIN THROUGH THE COURSE OF THE
DAY TODAY. SHOWER COVERAGE WILL BE DIMINISHING THROUGH 8Z...WITH
NOT MUCH MORE THAN SPRINKLES EXPECTED THE REST OF THIS TAF
PERIOD...AS LLJ FORCING REMAINS WELL SOUTH/WEST OF THE FIELD. HAVE
MODERATE CONFIDENCE IN MVFR CIGS DEVELOPING SAT NIGHT...BUT WITH THE
WARM FRONT ONLY MAKING IT INTO CENTRAL IA...MSP MAY REMAIN NE OF THE
MAIN MVFR CIG SHIELD THROUGH THE 30 HRS OF THE TAF.
/OUTLOOK FOR KMSP/
SUN...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
MON...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10 KTS.
TUE...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SSE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
327 AM CDT SAT MAY 25 2013
.SHORT TERM...TODAY THROUGH SUNDAY...
AXIS OF WEAK WARM ADVECTION AND FRONTOGENESIS MAXED OUT IN THE
700-600MB LAYER CONTINUES TO TRANSLATE SLOWLY EASTWARD ACROSS
EASTERN MINNESOTA EARLY THIS MORNING WHILE SLOWLY WEAKENING. NW-SE
ORIENTED BAND OF SHOWERS HAS SLOWLY DIMINISHED IN BOTH COVERAGE
AND INTENSITY OVER THE PAST COUPLE OF HOURS..AND SHOULD CONTINUE
TO DO SO THROUGH MID MORNING TODAY. HOWEVER..UNTIL LOW-MID LEVEL
FLOW BACKS AS IT STARTS TO FEEL THE INFLUENCE OF THE NEXT WAVE
MOVING FROM THE ROCKIES INTO THE NRN PLAINS THERE WILL BE AT LEAST
SOME MODEST FORCING FOR ASCENT..AND A FEW SHOWERS COULD PERSIST
INTO LATE MORNING.
BY THIS AFTERNOON..MAIN THREAT FOR ADDITIONAL SHOWERS/TSTORMS IS
EXPECTED TO CONSOLIDATE TO AREAS MOSTLY SOUTH AND WEST OF THE
DULUTH CWA IN CLOSER PROXIMITY TO LOW LEVEL BAROCLINIC ZONE FROM
THE DAKOTAS INTO THE MID MISSOURI VALLEY. AS A RESULT..WE HAVE
CONTINUED THE PREVIOUS TREND OF A DRY FORECAST FOR THIS AFTERNOON
IN MOST AREAS AS EAST/SOUTHEAST LOW LEVEL FLOW BRINGS A FLUX OF
DRIER AIR INTO THE REGION. THE FAR SOUTHWEST CWA WILL REMAIN CLOSE
ENOUGH TO THE LOW LEVEL THERMAL/MOISTURE GRADIENT TO WARRANT AT
LEAST A MENTION OF A FEW SHOWERS TONIGHT. CHANCES FOR SHOWERS THEN
EXPAND A BIT FARTHER EASTWARD ON SUNDAY AS NEXT WAVE BRUSHES
NORTHEASTWARD..ALONG WITH SOME CONTRIBUTION FROM ENHANCED
WARM/MOIST ADVECTION BY THE LLJ LATE SAT NIGHT AND SUNDAY MORNING.
EASTERLY BOUNDARY LAYER FLOW WILL ALSO KEEP AREAS NEAR LAKE
SUPERIOR COOLER TODAY AND SUNDAY..ALONG WITH LOCALLY GUSTY WINDS
IN SOME OF THE FAVORED LOCATIONS NEAR THE TWIN PORTS AND ASHLAND.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY NIGHT...
A PERIOD OF ACTIVE WEATHER WILL DEVELOP THIS WEEK WITH MULTIPLE
DISTURBANCES MOVING ACROSS THE UPPER MIDWEST...PRODUCING RAIN
SHOWERS AND THUNDERSTORMS MONDAY THROUGH SATURDAY. UPPER LEVEL
RIDGE AXIS ACROSS THE REGION LATE THIS WEEKEND WILL SHIFT EWD ON
MONDAY AS A 500MB S/W PUSHES INTO THE RIDGE ACROSS THE NRN PLAINS
ON THE LEADING EDGE OF A LONG WAVE TROUGH OVER THE WRN CONUS. THIS
S/W IS EXPECTED TO HAVE AN ASSOCIATED SFC INVERTED TROUGH/WARM
FRONT LIFT NWD THROUGH CNTRL MN ON MONDAY. RAIN SHOWER CHANCES
WILL INCREASE DURING THE DAY MONDAY...ALONG WITH A SLIGHT CHC OF
T-STORMS. A LLJ WILL DEVELOP MON NIGHT/TUE MORNING AND USHER IN A
MOIST UNSTABLE AIR MASS ACROSS THE REGION. THE INTERACTION OF THIS
S/W AND INCREASED INSTABILITY/MOISTURE WILL ALLOW FOR THE
POTENTIAL OF MDT/HVY RAIN SHOWERS AND EVEN A FEW STRONG STORMS
THROUGH TUE MORNING. THE ACTIVE PATTERN CONTINUES THROUGH THE
MIDDLE AND LATTER PART OF THE WEEK AS THE LONG WAVE TROUGH OVER
THE WEST TRANSITIONS EASTWARD AND CONTINUES TO DRAW UP A ROBUST
AMT OF WARM MOIST AIR FROM THE SOUTH AND PRODUCES RAIN SHOWERS AND
SCATTERED T-STORMS ACROSS THE NORTHLAND INTO THE EARLY PART OF THE
WEEKEND. THERE ARE NOTABLE DIFFERENCES IN THE SYNOPTIC PATTERNS OF
THE ECMWF AND GFS DURING THIS WEEK...WHICH LEAD TO UNRESOLVABLE
CONVECTIVE MODES. AT THIS TIME...WILL CONTINUE WITH HIGH CHC
POPS...LOW LIKELY POPS. IT WILL BE DIFFICULT TO NAIL DOWN SPECIFIC
TIMES/LOCATIONS OF THE BEST/HEAVIEST PRECIP AND ANY T-STORM
CHANCES UNTIL WELL INTO THE WEEK.
TEMPERATURES WILL CONTINUE ON THE WARMING TREND THROUGH THE WEEK
WITH HIGHS ON MONDAY IN THE 60S...AND OVERNIGHT LOWS IN THE 40S. BY
WEDNESDAY...HIGHS WILL BE TOPPING OUT IN THE 70S AND LOWER
80S...WITH NIGHT TIME LOWS IN THE 50S AND 60S.
&&
.AVIATION...06Z TAF ISSUANCE...
VFR CONDITIONS PREVAILED ACROSS THE NORTHLAND LATE THIS EVENING.
AN AREA OF SHOWERS STRETCHED FROM NORTHWEST MINNESOTA INTO
SOUTHEAST MINNESOTA. AN AREA OF MID LEVEL FGEN WAS HELPING TO
DRIVE THESE SHOWERS...AND THIS MOVES EAST THEN DIMINISHES
OVERNIGHT. MVFR CONDITIONS WILL BE POSSIBLE IN THE HEAVIER
SHOWERS...BUT THE OVERALL CHANCE OF THAT IS LOW AND MOST LIKELY
TOWARD KBRD. AN AREA OF MVFR CEILINGS EXISTS OVER PORTIONS OF
CENTRAL NEBRASKA LATE THIS EVENING...AND THE RAP SHOWS THOSE
MOVING QUICKLY NORTH INTO SOUTHWEST MINNESOTA TONIGHT BUT DOES NOT
BRING THEM INTO KBRD ON SATURDAY. WE`LL HAVE TO MONITOR THE
PROGRESSION OF THESE CLOUDS...AS WE WENT VFR FOR PREVAILING
CONDITIONS AT KBRD THROUGH THE PERIOD.
&&
.POINT TEMPS/POPS...
DLH 57 42 60 45 / 20 10 10 10
INL 64 44 68 47 / 10 10 10 20
BRD 61 46 62 50 / 40 20 30 40
HYR 63 42 67 47 / 20 10 10 20
ASX 60 40 61 43 / 10 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM....TENTINGER
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
100 AM CDT SAT MAY 25 2013
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 355 PM CDT FRI MAY 24 2013
SURFACE CYCLONE AND ASSOCIATED TROUGH NOTED ON IR SATELLITE IMAGERY
FROM SOUTHERN ALBERTA INTO EASTERN WYOMING. WARM FRONT ASSOCIATED
WITH THIS SYSTEM CURRENTLY FIRING UP SHIELD OF MAINLY LIGHT
SHOWERS AND ISOLATED THUNDERSTORMS OVER FAR EASTERN SODAK AND
WESTERN QUARTER OF OUR CWA. USED A COMBO OF HRRR...GFS40 305K
SFC...AND THETA E ADVECTION TO PAINT PICTURE OF FORWARD
PROGRESSION ACROSS REMAINDER OF CWA DURING THE OVERNIGHT. FAIRLY
DRY COLUMN TO CONTEND WITH OVER MUCH OF THE FA THIS AFTERNOON AND
EVENING...THUS AM EXPECTING MAINLY LIGHT PCPN FOR THIS FIRST WAVE
OF ACTIVITY. ALTHOUGH K INDICES AND 850 LI`S INDICATING LITTLE
CHANCE OF THUNDER ATTM...DECIDED TO INCLUDE ISOLATED CHANCE MOST
AREAS INTO TOMORROW AFTN DUE TO FAIR AMOUNT OF LIGHTNING NOTED ON
CURRENT 0.5 REFLECTIVITY. AS PREVIOUSLY ADVERTISED CHANCES FOR
WIDESPREAD CONVECTIVE ACTIVITY DECREASE MARKEDLY AFTER ABOUT
25/15Z TIME FRAME...AS WARM FRONTAL BOUNDARY STALLS OVER NE
MINNESOTA BY LATE SATURDAY MORNING. DECIDED TO INCREASE SATURDAY`S
HIGHS BY ONE CATEGORY CONSIDERING LIMITED PCPN POTENTIAL AND
POSSIBILITY OF MUCH LESS CLOUD COVER THEN CURRENTLY FORECAST.
FOCUS FOR ANY CONVECTIVE ACTIVITY ON SATURDAY AFTERNOON DEFINITELY
NOTED OVER FAR SOUTHERN MINNESOTA...WITH BEST UPPER LEVEL SUPPORT
VIA 250MB WEAK TO MODERATE DIVERGENCE OVER THIS REGION. LEFT SLGT
POPS OVER REMAINDER OF CWA TOMORROW AFTN DUE TO FAIRLY ROBUST
850-500MB LAPSE RATES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 355 PM CDT FRI MAY 24 2013
THETA E ADVECTION BLOSSOMS FROM SOUTHWEST INTO CENTRAL MN ON
SATURDAY NIGHT INTO SUNDAY...WHEN BOTH GFS AND NAM MODELS FORECAST A
SHORTWAVE TO CARVE THROUGH THE MID LEVEL RIDGE. EXPECT TO SEE
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING...WITH THE HIGHEST
COVERAGE OVER SOUTHWEST MN WHERE 850 MB MOISTURE TRANSPORT IS
SLIGHTLY ENHANCED. HIGH TEMPERATURES ON SUNDAY WILL LIKELY MAX
OUT IN THE UPPER 50S AND LOWER 60S...AS THE WARM FRONT REMAINS TO
THE SOUTH OF THE AREA AND EXTENSIVE CLOUD COVER AND SHOWERS
PERSIST.
YET MORE WEAK SHORTWAVES RIDE NORTH OF THE WARM FRONT ON MEMORIAL
DAY...AND CONTINUE THE POSSIBILITY OF SCATTERED SHOWERS AND
THUNDERSTORMS. SHOULD SEE TEMPS MODERATE SLIGHTLY FOR THE
HOLIDAY...ALTHOUGH IT WILL STILL BE ON THE COOL SIDE WITH UPPER
60S TO MID 70S.
ON TUESDAY...THE AFOREMENTIONED WARM FRONT WILL BEGIN TO LIFT
NORTH...AND ENTER THE FORECAST AREA FROM WEDNESDAY THROUGH
THURSDAY. THIS WILL SIGNAL THE ARRIVAL OF SLIGHTLY WARMER
TEMPERATURES AND AN INCREASE IN HUMIDITY...WITH HIGHS IN THE 75 TO
80 DEGREE RANGE. THE ARRIVAL OF THE FRONT WILL ALSO YIELD AN
INCREASING THREAT FOR SEVERE WEATHER AND EXCESSIVE RAINFALL FOR
THURSDAY AND FRIDAY. FORECAST PRECIPITABLE WATER VALUES INCREASE TO
OVER 1.5 INCHES...WHICH ILLUSTRATES THE POTENTIAL FOR A DOUSING
RAINFALL EVENT. THE SEVERE WEATHER POTENTIAL IS SOMEWHAT UNCERTAIN
DUE TO THE DIFFERENCES IN THE MODELS WITH THE EVOLUTION OF THE
WESTERN TROUGH...AND THE DEGREE OF SURFACE CYCLOGENESIS THAT
ENSUES OVER THE NORTHERN PLAINS TOWARD THE END OF NEXT WEEK.
HOWEVER...IF THE 24.12Z GFS SHEAR AND INSTABILITY PROGS WERE TO
PAN OUT...THERE WOULD BE A FAIRLY HIGH THREAT FOR SEVERE WEATHER
AND TORNADOES ACROSS CENTRAL AND SOUTHERN MN ON THURSDAY
AFTERNOON/EVE. WILL CONTINUE TO MONITOR AND REFINE OVER THE NEXT
FEW MODEL RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1259 AM CDT SAT MAY 25 2013
BATCH OF WARM ADVECTIVE SHOWERS WORKING INTO WI TO START THE
TAF...BUT DRY AIR IS STARTING TO TAKE ITS TOLL...WITH PRECIP
COVERAGE BEGINNING TO DIMINISH. LLJ STARTING TO ORGANIZE INTO ERN
NEB AT THE MOMENT...AND WILL LAY INTO IOWA OVERNIGHT. FOLLOWED
IDEA OF HRRR AND OTHER HI-RES MODELS WITH SHOWERS CURRENTLY OVER
THE MN/WI BORDER SLOWLY DIMINISHING THROUGH 10Z...WITH ANY
SIGNIFICANT TSRA ACTIVITY STAYING SOUTH OF MN THE REST OF THE
NIGHT. HOWEVER...WILL HAVE PLENTY OF CLOUD COVER AND WEAK MOISTURE
TRANSPORT REMAINING INTO THE MORNING...WITH BOUTS OF SPRINKLES/LIGHT
RAIN EXPECTED ACROSS MN...SO DID KEEP SOME VCSH MENTION GOING.
OTHER CHANGE TO THESE TAFS WAS TO START SLOWING DOWN ARRIVAL OF
MVFR CIGS LATER TODAY. BASED TIMING ON THE RAP/HRRR/NAM...WHICH
SHOW MVFR CIGS CURRENTLY DEVELOPING OVER SE NEB NOT ARRIVING INTO
THE RWF AREA UNTIL CLOSE TO 18Z. WITH WARM FRONT EXPECTED TO STAY
DOWN ALONG THE IA/MO BORDER TODAY...EXPECT MAJORITY OF MVFR CIGS
TO STAY DOWN IN IOWA THROUGH THE DAY...WITH A MORE SIGNIFICANT
PUSH OF MVFR CIGS NORTH NOT EXPECTED UNTIL TONIGHT AS THE FRONT
BEGINS A SLOW CRAWL NORTH ACROSS IOWA...BRINGING MVFR CIGS FURTHER
NORTH AS WELL. AS RESULT...DELAYED ARRIVAL OF MVFR CIGS UNTIL
AFTER 00Z FOR ALL MN TERMINALS EXCEPT RWF.
KMSP...GIVEN HOW CIGS WITH RAIN ONLY DROPPED TO 6K FT AT
BEST...FEEL CONFIDENT IN VFR CIGS REMAIN THROUGH THE COURSE OF THE
DAY TODAY. SHOWER COVERAGE WILL BE DIMINISHING THROUGH 8Z...WITH
NOT MUCH MORE THAN SPRINKLES EXPECTED THE REST OF THIS TAF
PERIOD...AS LLJ FORCING REMAINS WELL SOUTH/WEST OF THE FIELD. HAVE
MODERATE CONFIDENCE IN MVFR CIGS DEVELOPING SAT NIGHT...BUT WITH THE
WARM FRONT ONLY MAKING IT INTO CENTRAL IA...MSP MAY REMAIN NE OF THE
MAIN MVFR CIG SHIELD THROUGH THE 30 HRS OF THE TAF.
/OUTLOOK FOR KMSP/
SUN...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
MON...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10 KTS.
TUE...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SSE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1237 AM CDT SAT MAY 25 2013
.AVIATION...06Z TAFS
VFR CONDITIONS PREVAILED ACROSS THE NORTHLAND LATE THIS EVENING. AN
AREA OF SHOWERS STRETCHED FROM NORTHWEST MINNESOTA INTO SOUTHEAST
MINNESOTA. AN AREA OF MID LEVEL FGEN WAS HELPING TO DRIVE THESE
SHOWERS...AND THIS MOVES EAST THEN DIMINISHES OVERNIGHT. MVFR
CONDITIONS WILL BE POSSIBLE IN THE HEAVIER SHOWERS...BUT THE OVERALL
CHANCE OF THAT IS LOW AND MOST LIKELY TOWARD KBRD. AN AREA OF MVFR
CEILINGS EXISTS OVER PORTIONS OF CENTRAL NEBRASKA LATE THIS
EVENING...AND THE RAP SHOWS THOSE MOVING QUICKLY NORTH INTO
SOUTHWEST MINNESOTA TONIGHT BUT DOES NOT BRING THEM INTO KBRD ON
SATURDAY. WE`LL HAVE TO MONITOR THE PROGRESSION OF THESE CLOUDS...AS
WE WENT VFR FOR PREVAILING CONDITIONS AT KBRD THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 646 PM CDT FRI MAY 24 2013/
UPDATE...
AREA RADARS SHOW AN AREA OF RAIN...WITH A FEW THUNDERSTORMS...FROM
FAR NORTHWEST MINNESOTA INTO SOUTH CENTRAL MINNESOTA AS OF EARLY
EVENING. THIS IS TIED CLOSELY WITH AN AREA OF 700MB FGEN. THE FGEN
WILL MOVE A BIT TO THE EAST TONIGHT...THEN DIMINISH BY 12Z. WE
WILL UPDATE IN A BIT TO ADJUST POPS AND WE`LL USE THE 700MB FGEN
AS A GUIDE TO WHERE TO PUT THE HIGHER POPS.
AVIATION...00Z TAFS
VFR CONDITIONS COVERED THE NORTHLAND AS OF EARLY EVENING...BUT AN
AREA OF SHOWERS WERE MOVING EAST TOWARD KBRD/KXVG. WE EXPECT THIS
AREA OF SHOWERS...AND POSSIBLY SOME THUNDERSTORMS...TO MOVE EAST
THIS EVENING. IT SHOULD NOT OVERTAKE ALL AREAS AS DRIER AIR
EXISTS OVER THE EAST...AND THE FORCING RESPONSIBLE DOES NOT MOVE
THROUGH THE NORTHLAND EITHER. KBRD WILL HAVE THE BEST CHANCE AT
SEEING RAIN TONIGHT. MVFR CONDITIONS WILL DEVELOP OVER PORTIONS OF
THE WEST...WITH CEILINGS LOWERING OVER OTHER LOCATIONS THROUGH THE
PERIOD.
PREV DISCUSSION... /ISSUED 405 PM CDT FRI MAY 24 2013/
SHORT TERM...TONIGHT AND SATURDAY...
AN AREA OF SHOWERS AND THUNDERSTORMS FROM THE EASTERN DAKOTAS AND
WESTERN MN WILL SLOWLY SPREAD EAST THIS EVENING. THIS AREA IS AN
AREA OF LOW LEVEL WARM AIR ADVECTION AND AN ASSOCIATED UPPER LEVEL
VORT MAX ROUNDING OUT THE TOP OF UPPER RIDGE. MOST OF THE LIFT
ASSOCIATE WITH THE SYSTEMS WILL SLIDE ACROSS THE SOUTHWEST SECTIONS
OF THE CWA...WHERE THERE ARE THE HIGHER POPS. PUT SOME POPS IN
FARTHER NORTH ALONG THE HIGHWAY 2 CORRIDOR IN MN AND NORTHWEST
WI...BUT WITH DEW POINTS IN THE 20S...IT WILL TAKE AWHILE TO
MOISTEN UP FOR RAIN.
THE SHORT TERM MODELS...LOCAL AND THE SREF...ARE CONSISTENT IN
SHOWING THE BAND OF SHOWERS OUT TO THE WEST WITH MORE SPOTTY
SHOWERS OVER THE EAST LATE TONIGHT AND TOMORROW MORNING. BY
AFTERNOON THE MAJOR AREA OF PRECIPITATION WILL MOSTLY BE ACROSS
WESTERN AND SOUTHERN MINNESOTA...LEAVING MOST OF THE NORTHLAND
UNDER CLOUDY SKIES.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
HIGH PRESSURE OVER EASTERN CANADA AND THE EASTERN UNITED STATES WILL
HELP TO SUPPRESS RAIN CHANCES ACROSS THE NORTHLAND SATURDAY NIGHT
AND SUNDAY. THE NORTHLAND WILL BE HEADING INTO A POTENTIALLY
WARM...WET...AND ACTIVE PERIOD NEXT WEEK. A MID/UPPER LEVEL RIDGE
OVER THE CENTRAL UNITED STATES WILL BEGIN TO SHIFT EAST AS A
MID/UPPER LEVEL TROUGH MOVES INTO THE WEST. THE MODELS INDICATE ONE
OR MORE WARM FRONTS MAY MOVE THROUGH OR NEAR THE NORTHLAND DURING
THE MID TO LATE WEEK PERIOD...WHICH COULD BE A STORMY PERIOD FOR THE
NORTHLAND.
&&
.POINT TEMPS/POPS...
DLH 57 41 61 43 / 20 0 10 10
INL 62 43 67 45 / 20 10 0 10
BRD 58 46 63 50 / 50 10 30 30
HYR 61 41 67 47 / 30 0 10 20
ASX 60 39 63 44 / 20 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
901 PM CDT SUN MAY 26 2013
.UPDATE...
ISSUED AT 900 PM CDT SUN MAY 26 2013
THUNDERSTORMS THAT PRODUCED 2-4 INCHES NORTH OF COLUMBIA EARLIER THIS
EVENING HAVE PROGRESSED EASTWARD INTO A LINE NOW MOVING TOWARD THE ST.
LOUIS METRO. ADDITIONAL STORMS HAVE DEVELOPED IN THE LAST TWO HOURS
OVER IOWA THAT MOVING SOUTHWARD. PROPAGATION VECTORS FROM THE RAP SUGGEST
THAT THAT THIS IOWA ACTIVITY WILL MOVE SOUTH INTO THE CWA INTO THE NEXT
FEW HOURS. THE RAP HAS BEEN CONSISTENT IN SHOWING THAT LOW LEVEL MOISTURE
CONVERGENCE WILL STRENGTHEN OVER THE NORTHERN/CENTRAL CWA THROUGH 06-09Z
BEFORE IT LIFTS NORTHEAST OF THE CWA BY 12Z. WILL UP POPS TO LIKELY/
CATEGORICAL IN AREAS ALONG AND NORTH OF I-70 IN MISSOURI/I-64 IN
ILLINOIS. WHILE EFFECTIVE SHEAR REMAINS MARGINAL FOR STORM ORGANIZATION...
MUCAPES OF 1000-2000 J/KG SUGGEST THAT A FEW STRONG TO SEVER THUNDERSTORMS
ARE POSSIBLE TONIGHT. IN ADDITION....PWATS IN THE 1.5-1.8 INCH
RANGE SUGGEST THAT THERE WILL CONTINUE TO BE THE POTENTIAL FOR
SOME LOCALLY HEAVY RAINFALL TONIGHT.
BRITT
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 319 PM CDT SUN MAY 26 2013
SCT AFTN THUNDERSTORMS INVOF A SFC WMFNT WILL PERSIST INTO THE EARLY
EVENING HOURS BEFORE GRADUALLY DISSIPATING WITH THE LOSS OF DAYTIME
HEATING. STRONG CONVERGENCE ALONG THE SFC WMFNT IN SERN NEB AND SWRN
IA MIGHT PRODUCE A THUNDERSTORM COMPLEX THAT PROPAGATES SEWD WITH
TIME. IF THIS COMPLEX DEVELOPS AND IF IT HOLDS TOGETHER THEN IT
MIGHT AFFECT PARTS OF THE CWA LATER TONIGHT.
KANOFSKY
.LONG TERM...(MONDAY THROUGH NEXT SUNDAY)
ISSUED AT 319 PM CDT SUN MAY 26 2013
(MONDAY-WEDNESDAY)
WITH LATEST GUIDANCE STILL VERY MURKY REGARDING CONVECTIVE TRENDS SO
WILL MAINTAIN A FAIRLY BROAD BRUSH APPROACH TO FORECAST FOR THE NEXT
48 HOURS...AND LEAVE THE FINER DETAILS TO THE SHORT TERM WHEN TRENDS
ARE A BIT MORE DEFINABLE. OVERALL...GOING FORECAST TRENDS ARE
STILL LOOKING QUITE REASONABLE SO CHANGES ARE GENERALLY MINOR.
SYNOPTICALLY...THERE ISN`T MUCH CHANGE EXPECTED THROUGH MONDAY
NIGHT...WITH DIFFUSE AND BROAD LOW LEVEL WAA PROGGED ACROSS AREA
WHILE SEVERAL WEAK SHORTWAVES DRIFT THROUGH WEAK UPPER RIDGE PARKED
ACROSS AREA. MOST OF THE 12Z RUNS DO DEPICT A MORE ACTIVE DAY ON
MONDAY THAN WHAT OCCURRED TODAY...AND THIS DOES SEEM LIKE A
REASONABLE TREND AS IT APPEARS THAT THE WEAK SHORTWAVES DO MAKE MORE
OF AN IMPACT ON THE EVER WEAKENING RIDGE. HIGHEST POPS...IN THE
LIKELY RANGE...WILL CONTINUE OVER N HALF OF THE CWA...WITH CHANCE
POPS S OF I-70.
IT STILL APPEARS THAT POPS WILL BE WINDING DOWN FROM S TO N ACROSS
THE AREA MONDAY NIGHT AND TUESDAY. SW FLOW IS FORECAST TO BECOME
ESTABISHED OVER THE REGION IN RESPONSE TO SYSTEM DIGGING INTO THE
WEST...WHICH SHOULD IN TURN CAUSE THE LOW LEVEL THERMAL
GRADIENT/ISENTROPIC LIFT THAT HAS BEEN PARKED OVER THE AREA TO SHIFT
N AND EAST OF THE REGION. THERE IS SOME CONCERN ABOUT A MEAGER
INCREASE IN DYNAMICS OVER OUR NW COUNTIES DURING THIS PATTERN SHIFT
THAT COULD ALLOW THE STORM THREAT TO LINGER A BIT LONGER...BUT THIS
IS QUITE SUBTLE SO FOR NOW WILL KEEP POPS BELOW CHANCE CATEGORY IN
THE TUE-WED TIME FRAME.
RAIN AND CONVECTIVE CLOUD DEBRIS MAY TEND TO HOLD TEMPS ON
MONDAY....HOWEVER BY MIDWEEK CWA SHOULD BE WELL INTO THE WARM
SECTOR WITH LITTLE IN THE WAYOF SIGNIFICANT CLOUDINESS. TEMPS AND
HUMIDITY LEVELS WILL BE TAKING ON A BIT OF AN EARLY SUMMER
FEEL...WITH HIGHS IN THE 85-90 DEGREE RANGE BY WEDNESDAY.
(THURSDAY-SUNDAY)
THE END OF THE WEEK AND NEXT WEEKEND MAY BE ANOTHER PERIOD OF
UNSETTLED WEATHER FOR THE CWA. SW FLOW ALOFT WILL BRING A SERIES
OF DISTURBANCES OUT OF THE WESTERN U.S...AND INTERACT WITH WHAT
SHOULD BE A WARM AND MODERATELY UNSTABLE AIRMASS. THUNDERSTORM
THREAT WILL RETURN TO THE FORECAST THURSDAY THROUGH
FRIDAY...WITH THE HIGHEST POPS SHOULD BE OVER NW HALF OF THE CWA
WHERE DYNAMICS WILL BE MOST ROBUST. HOWEVER...IT MAY BE THAT
STORMS WILL HAVE A TOUGH TIME PUSHING INTO SE MO AND S IL AS DUE
TO RIDGING OVER THE SE CONUS SUPPRESSING EWD PROGRESSION OF
DYNAMICS AND STORMS. EWD SHIFT OF UPPER TROF SHOULD MEAN SHOWERS
AND THUNDERSTORMS FOR MOST OF THE AREA NEXT WEEKEND.
TEMPERATURES SHOULD REMAIN AT OR ABOVE NORMAL FOR MUCH OF THE
MEDIUM RANGE.
TRUETT
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 647 PM CDT SUN MAY 26 2013
THUNDERSTORMS ARE AGAIN THE PRIMARY WEATHER CONCERN TO NIGHT.
EXPECT ONGOING STORMS OVER CENTRAL MISSOURI TO WEAKEN A BIT AND
MOVE NORTH LATER THIS EVENING AS THE LOW LEVEL JET PICKS UP SPEED.
ANOTHER LINE OF STORMS HAS JUST FIRED UP OVER SOUTHERN IOWA AND
THIS IS EXPECTED TO MAKE ITS WAY SOUTHEAST TONIGHT. IT`S UNCLEAR
HOW WIDESPREAD THE COMPLEX OF THUNDERSTORMS WILL BE LATER
TONIGHT...BUT IT COULD AFFECT A LARGE PART OF THE AREA...PRIMARILY
ALONG AND WEST OF THE MISSISSIPPI RIVER. ELSEWHERE AND
OTHERWISE...EXPECT VFR FLIGHT CONDITIONS AND SOUTH-SOUTHEAST FLOW
OUTSIDE OF THUNDERSTORMS TONIGHT.
EXPECT ANOTHER ROUND OF THUNDERSTORMS TOMORROW AFTERNOON...THOUGH
TIMING AND LOCATION IS VERY UNCERTAIN AND HIGHLY DEPENDENT ON WHAT
HAPPENS TONIGHT.
SPECIFICS FOR KSTL...
THUNDERSTORMS ARE AGAIN THE PRIMARY WEATHER CONCERN TO NIGHT.
EXPECT VFR FLIGHT CONDITIONS AND LIGHT SOUTH-SOUTHEAST FLOW TO
PREVAIL THIS EVENING...BUT THE LINE OF STORMS WHICH JUST FIRED UP
OVER SOUTHERN IOWA IS EXPECTED TO MAKE ITS WAY SOUTHEAST TONIGHT.
IT`S UNCLEAR HOW WIDESPREAD THE COMPLEX OF THUNDERSTORMS WILL BE
LATER TONIGHT...BUT CURRENT INDICATIONS ARE THAT IT COULD AFFECT
THE TERMINAL DURING THE PRE-DAWN HOURS OF MONDAY MORNING.
EXPECT ANOTHER ROUND OF THUNDERSTORMS TOMORROW AFTERNOON...THOUGH
TIMING AND LOCATION IS VERY UNCERTAIN AND HIGHLY DEPENDENT ON WHAT
HAPPENS TONIGHT.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
603 PM CDT Sat May 25 2013
.SHORT TERM...(This Evening through Sunday)
Issued at 345 PM CDT SAT MAY 25 2013
Very few changes were needed to the forecast through tomorrow. Based
on latest high res models, radar, and satellite trends it appears,
other than a stray shower across the MO/IA border, the CWA should
remain dry this evening. Later tonight a small cluster of storms is
progged to work in from the west, but the latest HRRR depicts a
weaker system than what much of the NRN third of the CWA experienced
early this morning. At this time I have an overnight precip forecast
that favors the northern half of the CWA with higher chance pops
compared to lower chances to the south. As for tomorrow, more of
the same with lingering scattered morning showers and weak
thunderstorms with perhaps redevelopment in the afternoon.
Temperature wise the CWA will remain mild and rather muggy as
compared to the past several days under partly to mostly cloudy
skies.
.LONG TERM...(Sunday Night through Saturday)
Issued at 345 PM CDT SAT MAY 25 2013
The potential for wet weather looks to bracket either end of the
work week, though there will be plenty of dry days in between.
Shortwave ridge will be dominating the Central Plains as Memorial
Day dawns, with nocturnal thunderstorm activity likely lingering
through the morning hours. In general, operational and ensemble
models continue to advertise that this modest ridge will stay in
place across the Plains States through Tuesday, when the west CONUS
trough will finally begin to shift east. As the trough begins to
move into the Plains the storm track will shift farther north which
should give most locations in our forecast areas a break from the
rain chances. However, given the negative tilt to the trough as it
shifts into the Plains, and the general synoptic pattern, thoughts
are that storms will not only return tot he forecast, but severe
weather may plague the region by the end of the work week.
Currently, the best potential for storms looks to be Thursday night
and Friday night as the nocturnal jet cranks up ahead of the west
CONUS trough.
Otherwise, with the prevailing storm track, and by extension the
prevailing westerlies, remaining to the north of Kansas and Missouri
through the work week we expect temperatures to rise to a category
or two above normal through the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 603 PM CDT SAT MAY 25 2013
Convection has blossomed across western Kansas however models seem to
be evaporating this convection as it moves eastward tonight. With
temperature/dewpoint spreads of 15-20 degrees across the area, that
seems reasonable so have left TAFs dry overnight. It appears better chance for
convection may come tomorrow afternoon but no confidence in timing or
placement to include in the TAF at the moment. GFS MOS/LAMP as well
as NAM BUFR soundings are hinting at MVFR cigs tomorrow morning but
continue to think boundary layer is too moist so have held off on
inclusion in the TAF. Winds will be out of the south between 10-15kts
through tomorrow afternoon when they will become gusty around
20-25kts.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Pietrycha
LONG TERM...Cutter
AVIATION...73
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
347 PM CDT Sat May 25 2013
.SHORT TERM...(This Evening through Sunday)
Issued at 345 PM CDT SAT MAY 25 2013
Very few changes were needed to the forecast through tomorrow. Based
on latest high res models, radar, and satellite trends it appears,
other than a stray shower across the MO/IA border, the CWA should
remain dry this evening. Later tonight a small cluster of storms is
progged to work in from the west, but the latest HRRR depicts a
weaker system than what much of the NRN third of the CWA experienced
early this morning. At this time I have an overnight precip forecast
that favors the northern half of the CWA with higher chance pops
compared to lower chances to the south. As for tomorrow, more of
the same with lingering scattered morning showers and weak
thunderstorms with perhaps redevelopment in the afternoon.
Temperature wise the CWA will remain mild and rather muggy as
compared to the past several days under partly to mostly cloudy
skies.
.LONG TERM...(Sunday Night through Saturday)
Issued at 345 PM CDT SAT MAY 25 2013
The potential for wet weather looks to bracket either end of the
work week, though there will be plenty of dry days in between.
Shortwave ridge will be dominating the Central Plains as Memorial
Day dawns, with nocturnal thunderstorm activity likely lingering
through the morning hours. In general, operational and ensemble
models continue to advertise that this modest ridge will stay in
place across the Plains States through Tuesday, when the west CONUS
trough will finally begin to shift east. As the trough begins to
move into the Plains the storm track will shift farther north which
should give most locations in our forecast areas a break from the
rain chances. However, given the negative tilt to the trough as it
shifts into the Plains, and the general synoptic pattern, thoughts
are that storms will not only return tot he forecast, but severe
weather may plague the region by the end of the work week.
Currently, the best potential for storms looks to be Thursday night
and Friday night as the nocturnal jet cranks up ahead of the west
CONUS trough.
Otherwise, with the prevailing storm track, and by extension the
prevailing westerlies, remaining to the north of Kansas and Missouri
through the work week we expect temperatures to rise to a category
or two above normal through the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1232 PM CDT SAT MAY 25 2013
For this afternoon, I am expecting VFR cigs and vis along with south
to southwest winds under 10 kts with brief gusts to 15 kts. Later
tonight the possibility exists for the development of scattered SHRA
and TSRA. Forecast confidence is low as to whether the three
terminals will see any of the activity. For that reason have placed
VCTS in the TAFS beginning late tonight. The scattered SHRA/TSRA are expected
to persist through the remainder of the TAF period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Pietrycha
LONG TERM...Cutter
AVIATION...Pietrycha
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
744 PM CDT SUN MAY 26 2013
.SYNOPSIS...
ISSUED AT 315 PM CDT SUN MAY 26 2013
A DEEP UPPER LEVEL LOW...CURRENTLY ACROSS THE NORTH PACIFIC...WILL
MIGRATE SLOWLY EAST THROUGH THE PACIFIC NORTHWEST AND INTO THE NRN
PLAINS THIS WEEK. A STRONG PACIFIC COLD FRONT WILL MOVE THROUGH
THE FCST AREA WEDNESDAY NIGHT OR THURSDAY. SEVERE WEATHER IS
POSSIBLE TODAY THROUGH WEDNESDAY AS LOW PRESSURE REMAINS QUASI
STATIONARY ACROSS ERN COLORADO AND FOCUSES...MOSITURE...WARM AIR
ADVECTION AND DRY.
&&
.UPDATE...
ISSUED AT 743 PM CDT SUN MAY 26 2013
UPDATED FORECAST TO INCLUDE TORNADO WATCH FOR NORTH CENTRAL NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 315 PM CDT SUN MAY 26 2013
TONIGHT AND MONDAY...CONVECTION LATE THIS AFTERNOON INTO THE
EVENING TONIGHT...THEN LOW CLOUDS FOG DEVELOPMENT TOWARD MORNING
REMAIN FORECAST ISSUES FOR THE SHORT TERM. WEAK COLD FRONT
ANALYZED FROM SOUTHWEST NEBRASKA SOUTHWARD INTO NW KS AND ERN CO.
WARM FRONT EXTENDS FROM SW INTO SC NEBRASKA WITH INVERTED TROUGH
NORTHWARD INTO SD. NUMEROUS OUTFLOW BOUNDARIES SHOW IN THE HAND
ANALYSIS AS WELL.
QUITE A VARIED RANGE OF SHORT TERM MODEL SOLUTIONS FOR THIS EVENING
AS HRRR AND HIRES ARW SUGGEST NOTHING ORGANIZED WILL DEVELOP SOUTH
OF I80 CORRIDOR...BUT DEVELOP A MCS ACROSS THE SANDHILLS IN THE
HIGHWAY 2 VCNTY AND MOVE IT EASTWARD OVERNIGHT. THE NAM /AND HIRES
NMM/ AS WELL AS GFS SUGGEST TWO AREAS OF DEVELOPMENT...THE FIRST IN
SIMILAR AREAS TO THE PREVIOUSLY MENTIONED MODELS /SANDHILLS/ AND A
SECOND IN THE VCNTY OF THE WARM FRONT WHICH ORGANIZES INTO A MCS AND
MOVES SOUTHEAST. FCST WILL GO WITH THE IDEA THAT TO SOME DEGREE BOTH
GROUPS OF SOLUTIONS HAVE REALISTIC POSSIBILITIES BASED ON BETTER DEEP
LAYER SHEAR ACROSS THE NORTH WHICH SHOULD ALLOW FOR A BETTER
ORGANIZATION ONCE DEVELOPMENT OCCURS IN THE SANDHILLS BY EVENING.
LOW LEVEL LAPSE RATES IN THIS AREA HOWEVER ARE NOT THE BEST AS WOULD
BE EXPECTED NORTH OF THE WARM FRONT...AND ALSO BELIEVE AIR MASS IS
STILL SOMEWHAT INFLUENCED IN THE LOW LAYERS AS A RESULT OF THE
OUTFLOW THAT WAS EVIDENT EARLIER THIS MORNING. LARGE HAIL STILL A
POSSIBILITY HERE THOUGH WITH VERY STEEP MID LEVEL LAPSE RATES...EVEN
IF STORMS ARE ELEVATED WHICH SEEMS LIKELY IN THIS AREA.
FURTHER SOUTH...LOW LEVEL LAPSE RATES ARE STEEPEST ACROSS ERN CO AND
NW KS AND HAVE SURGED EWD AHEAD OF LEE SFC LOW IN NW KS. GOOD
THETA-E ADVECTION NORTHEAST OF THIS AREA SHOULD ALLOW DEVELOPMENT IN
THIS AREAS AS WELL...THOUGH COVERAGE REMAINS IN QUESTION. SPC
MESOANALYSIS INDICATES SOME CAP STILL PRESENT HERE AND SINCE LARGE
SCALE FORCING IS BEST FURTHER NORTH THE EXTENT OF CAP EROSION IS
ALSO IN QUESTION. WOULD LIKE TO SEE BETTER SFC CONVERGENCE IN THESE
LOCATIONS TO BE MORE CERTAIN ABOUT INITIATION. IF SFC BASED
DEVELOPMENT DOES OCCUR SVR POTENTIAL WILL BE HIGH AS VERY GOOD ML
CAPE IS IN PLACE. THEREFORE...FCST INCLUDES POPS IN THESE AREAS BASED ON
PREVIOUS THINKING.
THE LAST FEW NIGHTS HAS SEEN A TENDENCY TO DEVELOP LOW CLOUD BEHIND
OUTFLOW BOUNDARIES TWD DAYBREAK AND BELIEVE THAT SHOULD BE THE CASE
ONCE AGAIN MONDAY MORNING. DEPICTING LOCATIONS IS DIFFICULT BUT
FAVORED AREAS EAST OF HIGHWAY 61 SEEM MOST LIKELY AND HAVE TRENDED
THE FCST THAT WAY. EVENTUAL HIGH TEMPS WILL BE HIGHLY DEPENDENT ON
THESE LOW CLOUD DEVELOPMENT AS WELL...BUT AS WITH THE LAST FEW DAYS
AFTERNOON MIXING SHOULD ALLOW 80S MOST PLACES.
CONVECTION AGAIN POSSIBLE MONDAY AFTERNOON. MODELS SUGGESTING UPPER
TROUGH WILL CONTINUE TO MOVE EASTWARD AND SHOULD ALLOW FOR A MORE
SOUTHERN LOCATION OF SFC FEATURES ONCE CONVECTIVE DEBRIS GIVES WAY.
SOMEWHAT BETTER UPPER PV ANOMALY LOOKS TO SWING OUT ONTO THE PLAINS
BY LATE AFTERNOON MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 315 PM CDT SUN MAY 26 2013
SFC LOW PRESSURE WILL REMAIN TUCKED ACROSS ERN COLO FOCUSING
MOISTURE...DRY AIR AND WARM AIR ADVECTION ACROSS WRN AND NCNTL NEB.
THE SFC LOW WILL GRADUALLY DEEPEN TO AROUND 992 MB BY TUESDAY AND
CONTINUING NEAR 992 MB THROUGH WEDNESDAY. A PACIFIC FRONT SHOULD
MOVE INTO WRN NEB LATE WEDNESDAY. THROUGH WEDNESDAY...500 MB HEIGHTS
WILL GRADUALLY FALL WHILE H700 MB TEMPS REMAIN NEAR STEADY AT
10C-12C. WIND SHEAR APPEARS TO GRADUALLY INCREASE SUPPORTING A
SLIGHT INCREASE IN BULK SHEAR. NEARLY ALL OF THE FCST AREA HAS BEEN
OUTLOOKED FOR SEVERE WEATHER BY SPC THROUGH WEDNESDAY. ALL
CONVECTION WHICH DEVELOPS TONIGHT THROUGH WEDNESDAY WILL HAVE A
LARGE IMPACT ON SUBSEQUENT STORM DEVELOPMENT AS RAIN COOLED OUTFLOW
DEVELOPS AND SETS UP FOCUS FOR SUCCEEDING STORM DEVELOPMENT. THUS THE
LOCATION OF HIGHEST POPS IS HIGHLY CONDITIONAL. A MULTI MODEL BLEND
WAS USED FOR POPS AND CAPPED AT 40 PERCENT. A SIMILAR STRATEGY WAS
USED FOR QPF. IN GENERAL NRN AND WRN NEB APPEAR MORE FAVORABLE FOR
STORM DEVELOPMENT THAT THE SOUTHWEST WHERE 700 MB WARM AIR ADVECTION
WILL OFTEN CAP THE ATMOSPHERE.
A SERIES OF PERTURBATIONS WILL CONTINUE TO EJECT FROM THE UPPER LOW
ACROSS THE NRN PACIFIC. THESE DISTURBANCES WILL MOVE THROUGH SD AND
NEB TRIGGERING STORM DEVELOPMENT. IN TIME THE UPPER LEVEL WILL BUILD
SOUTHEAST THROUGH PACIFIC NORTHWEST AND NRN ROCKIES. FALLING HEIGHTS
SHOULD MAINTAIN STEEP LAPSE RATES AND AN EML CONDUCIVE FOR STORM
DEVELOPMENT. AS LONG AS THE PACIFIC FRONT REMAINS WEST OF THE FCST
AREA...MOISTURE AND WARM AIR ADVECTION SHOULD CONTINUE PROVIDING
FUEL FOR STORM DEVELOPMENT.
WITH THE PERSISTENT MOISTURE ADVECTION...K INDICES INCREASE TO 40C
OR GREATER IN THE NAM AND GFS MODELS. THIS ALONG WITH THE FACT THAT
VERY HEAVY RAINFALL TOTALS HAVE OCCURRED FROM STORMS THIS LAST TWO
DAYS...SUGGEST SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL.
WEDNESDAY NIGHT THROUGH MONDAY MORNING...
THE PACIFIC FRONT WILL LIKELY CROSS THE FCST AREA WEDNESDAY
NIGHT...EARLY THURSDAY AT THE LATEST. THIS WILL SHUNT LOW LEVEL
MOISTURE EAST OF THE FCST AREA. H500 MB TEMPS FALL TO AROUND -18C
WHICH WOULD CONTINUE TO SUPPORT SHOWERS AND THUNDERSTORMS. THE
MODELS ARE IN GOOD AGREEMENT THAT AN UPPER LEVEL LOW WILL CIRCULATE
THROUGH THE NRN AND CNTL PLAINS. ALTHOUGH THE COLD CORE WILL LIKELY
CENTER ACROSS ND/SD...THERE SHOULD BE ENOUGH COLD AIR ALOFT ACROSS
THE FCST AREA TO DESTABILIZE THE ATMOSPHERE THURSDAY AND
FRIDAY...PERHAPS EVEN SATURDAY.
FCST MAX TEMPS WILL RISE INTO THE 60S AND 70S BEHIND THE FRONT
THURSDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 659 PM CDT SUN MAY 26 2013
THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER WESTERN NEBRASKA THIS
EVENING. STRONG CAP IN PLACE AND NOT A GOOD TRIGGER MECHANISM. VFR
CEILINGS AND VISIBILITIES EXPECTED. HAVE INCLUDED A TEMPO GROUP
FOR THUNDERSTORMS AT BOTH KVTN AND KLBF. CONFIDENCE NOT HIGH THAT
THESE WILL DEVELOP. EAST WINDS OVER NIGHT WITH STRATUS AND MVFR
CEILINGS DEVELOPING AFTER 2706Z. THESE STRATUS WILL HOLD ON
THROUGH THE MORNING BEFORE LIFTING INTO VFR THROUGH THE AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...POWER
SYNOPSIS...CDC
SHORT TERM...JWS
LONG TERM...CDC
AVIATION...POWER
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
701 PM CDT SUN MAY 26 2013
.SYNOPSIS...
ISSUED AT 315 PM CDT SUN MAY 26 2013
A DEEP UPPER LEVEL LOW...CURRENTLY ACROSS THE NORTH PACIFIC...WILL
MIGRATE SLOWLY EAST THROUGH THE PACIFIC NORTHWEST AND INTO THE NRN
PLAINS THIS WEEK. A STRONG PACIFIC COLD FRONT WILL MOVE THROUGH
THE FCST AREA WEDNESDAY NIGHT OR THURSDAY. SEVERE WEATHER IS
POSSIBLE TODAY THROUGH WEDNESDAY AS LOW PRESSURE REMAINS QUASI
STATIONARY ACROSS ERN COLORADO AND FOCUSES...MOSITURE...WARM AIR
ADVECTION AND DRY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 315 PM CDT SUN MAY 26 2013
TONIGHT AND MONDAY...CONVECTION LATE THIS AFTERNOON INTO THE
EVENING TONIGHT...THEN LOW CLOUDS FOG DEVELOPMENT TOWARD MORNING
REMAIN FORECAST ISSUES FOR THE SHORT TERM. WEAK COLD FRONT
ANALYZED FROM SOUTHWEST NEBRASKA SOUTHWARD INTO NW KS AND ERN CO.
WARM FRONT EXTENDS FROM SW INTO SC NEBRASKA WITH INVERTED TROUGH
NORTHWARD INTO SD. NUMEROUS OUTFLOW BOUNDARIES SHOW IN THE HAND
ANALYSIS AS WELL.
QUITE A VARIED RANGE OF SHORT TERM MODEL SOLUTIONS FOR THIS EVENING
AS HRRR AND HIRES ARW SUGGEST NOTHING ORGANIZED WILL DEVELOP SOUTH
OF I80 CORRIDOR...BUT DEVELOP A MCS ACROSS THE SANDHILLS IN THE
HIGHWAY 2 VCNTY AND MOVE IT EASTWARD OVERNIGHT. THE NAM /AND HIRES
NMM/ AS WELL AS GFS SUGGEST TWO AREAS OF DEVELOPMENT...THE FIRST IN
SIMILAR AREAS TO THE PREVIOUSLY MENTIONED MODELS /SANDHILLS/ AND A
SECOND IN THE VCNTY OF THE WARM FRONT WHICH ORGANIZES INTO A MCS AND
MOVES SOUTHEAST. FCST WILL GO WITH THE IDEA THAT TO SOME DEGREE BOTH
GROUPS OF SOLUTIONS HAVE REALISTIC POSSIBILITIES BASED ON BETTER DEEP
LAYER SHEAR ACROSS THE NORTH WHICH SHOULD ALLOW FOR A BETTER
ORGANIZATION ONCE DEVELOPMENT OCCURS IN THE SANDHILLS BY EVENING.
LOW LEVEL LAPSE RATES IN THIS AREA HOWEVER ARE NOT THE BEST AS WOULD
BE EXPECTED NORTH OF THE WARM FRONT...AND ALSO BELIEVE AIR MASS IS
STILL SOMEWHAT INFLUENCED IN THE LOW LAYERS AS A RESULT OF THE
OUTFLOW THAT WAS EVIDENT EARLIER THIS MORNING. LARGE HAIL STILL A
POSSIBILITY HERE THOUGH WITH VERY STEEP MID LEVEL LAPSE RATES...EVEN
IF STORMS ARE ELEVATED WHICH SEEMS LIKELY IN THIS AREA.
FURTHER SOUTH...LOW LEVEL LAPSE RATES ARE STEEPEST ACROSS ERN CO AND
NW KS AND HAVE SURGED EWD AHEAD OF LEE SFC LOW IN NW KS. GOOD
THETA-E ADVECTION NORTHEAST OF THIS AREA SHOULD ALLOW DEVELOPMENT IN
THIS AREAS AS WELL...THOUGH COVERAGE REMAINS IN QUESTION. SPC
MESOANALYSIS INDICATES SOME CAP STILL PRESENT HERE AND SINCE LARGE
SCALE FORCING IS BEST FURTHER NORTH THE EXTENT OF CAP EROSION IS
ALSO IN QUESTION. WOULD LIKE TO SEE BETTER SFC CONVERGENCE IN THESE
LOCATIONS TO BE MORE CERTAIN ABOUT INITIATION. IF SFC BASED
DEVELOPMENT DOES OCCUR SVR POTENTIAL WILL BE HIGH AS VERY GOOD ML
CAPE IS IN PLACE. THEREFORE...FCST INCLUDES POPS IN THESE AREAS BASED ON
PREVIOUS THINKING.
THE LAST FEW NIGHTS HAS SEEN A TENDENCY TO DEVELOP LOW CLOUD BEHIND
OUTFLOW BOUNDARIES TWD DAYBREAK AND BELIEVE THAT SHOULD BE THE CASE
ONCE AGAIN MONDAY MORNING. DEPICTING LOCATIONS IS DIFFICULT BUT
FAVORED AREAS EAST OF HIGHWAY 61 SEEM MOST LIKELY AND HAVE TRENDED
THE FCST THAT WAY. EVENTUAL HIGH TEMPS WILL BE HIGHLY DEPENDENT ON
THESE LOW CLOUD DEVELOPMENT AS WELL...BUT AS WITH THE LAST FEW DAYS
AFTERNOON MIXING SHOULD ALLOW 80S MOST PLACES.
CONVECTION AGAIN POSSIBLE MONDAY AFTERNOON. MODELS SUGGESTING UPPER
TROUGH WILL CONTINUE TO MOVE EASTWARD AND SHOULD ALLOW FOR A MORE
SOUTHERN LOCATION OF SFC FEATURES ONCE CONVECTIVE DEBRIS GIVES WAY.
SOMEWHAT BETTER UPPER PV ANOMALY LOOKS TO SWING OUT ONTO THE PLAINS
BY LATE AFTERNOON MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 315 PM CDT SUN MAY 26 2013
SFC LOW PRESSURE WILL REMAIN TUCKED ACROSS ERN COLO FOCUSING
MOISTURE...DRY AIR AND WARM AIR ADVECTION ACROSS WRN AND NCNTL NEB.
THE SFC LOW WILL GRADUALLY DEEPEN TO AROUND 992 MB BY TUESDAY AND
CONTINUING NEAR 992 MB THROUGH WEDNESDAY. A PACIFIC FRONT SHOULD
MOVE INTO WRN NEB LATE WEDNESDAY. THROUGH WEDNESDAY...500 MB HEIGHTS
WILL GRADUALLY FALL WHILE H700 MB TEMPS REMAIN NEAR STEADY AT
10C-12C. WIND SHEAR APPEARS TO GRADUALLY INCREASE SUPPORTING A
SLIGHT INCREASE IN BULK SHEAR. NEARLY ALL OF THE FCST AREA HAS BEEN
OUTLOOKED FOR SEVERE WEATHER BY SPC THROUGH WEDNESDAY. ALL
CONVECTION WHICH DEVELOPS TONIGHT THROUGH WEDNESDAY WILL HAVE A
LARGE IMPACT ON SUBSEQUENT STORM DEVELOPMENT AS RAIN COOLED OUTFLOW
DEVELOPS AND SETS UP FOCUS FOR SUCCEEDING STORM DEVELOPMENT. THUS THE
LOCATION OF HIGHEST POPS IS HIGHLY CONDITIONAL. A MULTI MODEL BLEND
WAS USED FOR POPS AND CAPPED AT 40 PERCENT. A SIMILAR STRATEGY WAS
USED FOR QPF. IN GENERAL NRN AND WRN NEB APPEAR MORE FAVORABLE FOR
STORM DEVELOPMENT THAT THE SOUTHWEST WHERE 700 MB WARM AIR ADVECTION
WILL OFTEN CAP THE ATMOSPHERE.
A SERIES OF PERTURBATIONS WILL CONTINUE TO EJECT FROM THE UPPER LOW
ACROSS THE NRN PACIFIC. THESE DISTURBANCES WILL MOVE THROUGH SD AND
NEB TRIGGERING STORM DEVELOPMENT. IN TIME THE UPPER LEVEL WILL BUILD
SOUTHEAST THROUGH PACIFIC NORTHWEST AND NRN ROCKIES. FALLING HEIGHTS
SHOULD MAINTAIN STEEP LAPSE RATES AND AN EML CONDUCIVE FOR STORM
DEVELOPMENT. AS LONG AS THE PACIFIC FRONT REMAINS WEST OF THE FCST
AREA...MOISTURE AND WARM AIR ADVECTION SHOULD CONTINUE PROVIDING
FUEL FOR STORM DEVELOPMENT.
WITH THE PERSISTENT MOISTURE ADVECTION...K INDICES INCREASE TO 40C
OR GREATER IN THE NAM AND GFS MODELS. THIS ALONG WITH THE FACT THAT
VERY HEAVY RAINFALL TOTALS HAVE OCCURRED FROM STORMS THIS LAST TWO
DAYS...SUGGEST SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL.
WEDNESDAY NIGHT THROUGH MONDAY MORNING...
THE PACIFIC FRONT WILL LIKELY CROSS THE FCST AREA WEDNESDAY
NIGHT...EARLY THURSDAY AT THE LATEST. THIS WILL SHUNT LOW LEVEL
MOISTURE EAST OF THE FCST AREA. H500 MB TEMPS FALL TO AROUND -18C
WHICH WOULD CONTINUE TO SUPPORT SHOWERS AND THUNDERSTORMS. THE
MODELS ARE IN GOOD AGREEMENT THAT AN UPPER LEVEL LOW WILL CIRCULATE
THROUGH THE NRN AND CNTL PLAINS. ALTHOUGH THE COLD CORE WILL LIKELY
CENTER ACROSS ND/SD...THERE SHOULD BE ENOUGH COLD AIR ALOFT ACROSS
THE FCST AREA TO DESTABILIZE THE ATMOSPHERE THURSDAY AND
FRIDAY...PERHAPS EVEN SATURDAY.
FCST MAX TEMPS WILL RISE INTO THE 60S AND 70S BEHIND THE FRONT
THURSDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 659 PM CDT SUN MAY 26 2013
THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER WESTERN NEBRASKA THIS
EVENING. STRONG CAP IN PLACE AND NOT A GOOD TRIGGER MECHANISM. VFR
CEILINGS AND VISIBILITIES EXPECTED. HAVE INCLUDED A TEMPO GROUP
FOR THUNDERSTORMS AT BOTH KVTN AND KLBF. CONFIDENCE NOT HIGH THAT
THESE WILL DEVELOP. EAST WINDS OVER NIGHT WITH STRATUS AND MVFR
CEILINGS DEVELOPING AFTER 2706Z. THESE STRATUS WILL HOLD ON
THROUGH THE MORNING BEFORE LIFTING INTO VFR THROUGH THE AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CDC
SHORT TERM...JWS
LONG TERM...CDC
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
311 PM CDT SAT MAY 25 2013
.DISCUSSION...
ALTHOUGH TIMING OF HIGHEST CONCENTRATION OF ANY CONVECTION IS THE
MAIN CHALLENGE FOR ANY GIVEN PERIOD WELL INTO NEXT WEEK...PATTERN
LOOKS TO REMAIN ACTIVE WITH PRECIP CHANCES GOOD IF NOT LIKELY MOST
AREAS MOST EVENINGS/OVERNIGHT PDS.
AT 19Z SURFACE BOUNDARY EXTENDED FROM JUST N OF FNB TO JUST SW OF
OLU/BVN WITH RESIDUAL COOL OUTFLOW FROM MORNING CONVECTION
REINFORCING FRONT. CONVERGENCE NEAR BOUNDARY HAD INCREASED CU
FIELD WCNTRL ZONES AND LATEST RAP MESO ANALYSIS PLACED AXIS OF
2000-3000 J/KG ML CAPE ACROSS THAT AREA WITH LITTLE/NO CIN. SO
THERE REMAINS SOME POSSIBILITY OF CONVECTION DEVELOPING NEAR/N OF
THIS BOUNDARY EARLY THIS EVENING...ESPECIALLY AS ANY SUBSIDENCE
EFFECTS OF DEPARTING MCV FROM EARLIER CONVECTION GETS FARTHER
REMOVED. LATER THIS EVENING/OVERNIGHT HIGH PLAINS CONVECTION WILL
PROBABLY MAKE A RUN TOWARD/INTO FA...POSSIBLY CONSOLIDATING MORE
ACROSS NRN ZONES AIDED BY RR ENTRANCE REGION OF WEAK UPPER JET
SEGMENT. HOWEVER...CAN/T RULE OUT ACTIVITY FARTHER S AS WELL SINCE
BOUNDARY MAY NOT MOVE MUCH TONIGHT. LOW LEVEL JET DOES STRENGTHEN
SOME INTO FRONT OVERNIGHT...BUT STRONGEST/MORE CONVERGENT AREA NOT
NECESSARILY FOCUSED ACROSS THE FORECAST AREA...SO CONFIDENCE ON
WIDESPREAD HEAVY RAINFALL NOT VERY GOOD. THAT SAID...SMALL AREA OF
NRN IA ZONES DID PICK UP 1-2+ INCHES OF RAIN LAST NIGHT AND THAT
AREA APPEARS TO HAVE THE HIGHEST CHANCE OF SIGNIFICANT RAINS
TONIGHT AS MOISTURE REMAINS PLENTIFUL WITH PWATS AROUND 1.5
INCHES. THUS ISSUED A SMALL FLASH FLOOD WATCH NE OF OMAHA TO MATCH
UP WITH DMX WHERE HEAVIER RAIN WAS MORE WIDESPREAD.
DECREASED POPS DIURNALLY ON SUNDAY LIKE TODAY ALTHOUGH IT WAS
NOTED THAT FOR SEVERAL RUNS NOW NAM HAD DEVELOPED A SMALL MCS AND
DROPPED IT SE ACROSS FA DURING THE AFTERNOON. FORECAST WAS NOT
BASED ON THAT SCENARIO. ALSO MODELS HINTING AT MORE LOW LEVEL
MOISTURE WITH LOW CLOUDS POSSIBLY LINGERING INTO THE AFTERNOON.
THUS INCREASED SKY COVER. IF CLOUDS HOLD ALL DAY CONVECTIVE
DEVELOPMENT COULD BE ALTERED AS WELL AS HIGH TEMPERATURES.
OTHERWISE...LIKELY POPS MANY AREAS AGAIN WERE MENTIONED SUN NIGHT.
MONDAY POSSIBLY A VERY SIMILAR SCENARIO...ALTHOUGH FINER DETAILS
PROBABLY IMPACTED BY PREVIOUS PERIODS CONVECTION BOTH DAYS.
SOME INDICATION BY MODELS THAT A FRONT...POSSIBLY AIDED BY
OVERNIGHT CONVECTION...WILL PUSH S INTO NRN ZONES ON TUESDAY AS A
STRONGER WAVE EJECTS ACROSS CANADIAN PRAIRIE. COOLING AT H85
MINIMAL FOR THAT AREA...BUT NE WINDS AND POSSIBLE LOW CLOUDS
COULD KEEP MAX TEMPS COOLER AND THIS COULD NEED ATTENTION IN LATER
FORECASTS. OTHERWISE...THIS BOUNDARY AND UPPER TROUGH BEGINNING TO
APPROACH AREA WILL KEEP AREA ACTIVE TUESDAY/TUE NGT. WEDNESDAY
COULD POSSIBLY BE MORE OF A LULL WITH WARMER TEMPERATURES BEFORE
STRONGER ENERGY PUNCHES ACROSS CNTRL PLAINS WED NGT/THURSDAY
INCREASING COVERAGE/CHCS AGAIN. ALTHOUGH SEVERE POTENTIAL WILL
EXIST INTO TUESDAY...THIS STRONGER TROUGH COULD BRING A HEIGHTENED
RISK OF SVR WEATHER TO AREA LATE NEXT WEEK.
CHERMOK
&&
.AVIATION...
18Z TAFS FOR KOMA...KLNK AND KOFK.
A WARM FRONT SLOWLY LIFTING OVER THE CNTRL PLAINS WILL BE THE
FOCUS FOR TSRA ACTIVITY OVER ERN NEB LATER TONIGHT. LLVL MOISTURE
WILL CONTINUE STREAMING NWD INTO THE REGION THROUGH THIS EVENING.
THIS ALONG WITH A STRENGTHENING LLVL JET...TSRA ACTIVITY SHOULD
INCREASE SOMEWHAT IN AREAL COVERAGE...MAINLY OVER NERN NEB. DUE
TO SOME UNCERTAINTY THOUGH HOW FAST THE SFC BNDRY WILL
LIFT...HAVE DECIDED TO JUST COVER ALL SITES WITH PROB30 GROUPS
BTWN 26/03Z- 12Z. MEANWHILE...WITH PERSISTENT MOISTURE ADVECTION
EXPECTED...CONDITIONS SHOULD BEGIN DETERIORATING FROM VFR TO IFR
BY OR SHORTLY AFT 26/06Z. GOOD INDICATION FROM MODEL GUIDANCE THAT
MVFR CONDITIONS THEN WILL PREVAIL THE REST OF THE FCST PD.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...FLASH FLOOD WATCH FROM MIDNIGHT CDT TONIGHT THROUGH SUNDAY
MORNING FOR IAZ043-055-056.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1245 PM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1131 AM CDT SAT MAY 25 2013
THIS WILL SERVE AS THE NOON ESTF UPDATE.
TEMPS OVER OUR KS COUNTIES ARE RAPIDLY APPROACHING 80F. SO HIGH
TEMPS HAVE BEEN RAISED ALL AREAS FOR THIS AFTN.
THE FLOOD WARNING FOR SHERMAN/HOWARD COUNTIES WAS ALLOWED TO
EXPIRE AT 1030AM. CALLS TO REGIONAL DISPATCH INDICATE WATERS WERE
RECEDING. HOWEVER...COORDINATED WITH THE RFC AND WE WILL BE
CLOSELY MONITORING AREA RIVERS PARTICULARLY N OF I-80 AFTER THE
VERY HVY RAINS LAST NGT. HIGHEST TOTAL SO FAR IS 4.28" 2 W OF LOUP
CITY.
THANK YOU VERY MUCH TO ALL COOP/SPOTTER/NE-RAIN/COCORAHS OBSERVERS.
THE BOUNDARY LEFT BY LAST NGT`S MCS WILL PLAY AN IMPORTANT ROLE IN
TSTM DEVELOPMENT THIS AFTN-EVE. MEAN S LOW-LVL FLOW WILL BE
MAINTAINED JUST E OF THE LEE TROF WHICH WILL RESULT IN CONVERGENCE
AND ASCENT ALONG THIS BOUNDARY. WE/VE NOTED A PLUME OF VERY WARM
MID-LVL TEMPS ON THE DDC SOUNDING WHICH WILL ADVECT OVER THE FCST
AREA TODAY. THIS WILL DELAY TSTM DEVELOP UNTIL LATE...AND COULD
KEEP IT FROM OCCURRING AT ALL S OF THE BOUNDARY.
RADAR AND VIS SATELLITE SHOWS AN MCV JUST SW OF THE FCST AREA NEAR
HYS. THIS WILL BE A WILDCARD AS IT COULD TRIGGER TSTMS IN THE WARM
SECTOR...BUT DOES IT OCCUR DURING THE DAYLGT HRS? IT/S HEADING NE
AND WILL MOVE ACROSS OUR SE COUNTIES. IF IT HOLDS OFF UNTIL TNGT
THEN IT COULD BE E OF THE FCST AREA.
WITH VERY LITTLE CLOUD COVER N OF THE BOUNDARY...DIABATIC HEATING
WILL DESTABILIZE THE ATMS. TEMPS IN THE 80S...DWPTS IN THE 60S AND
MID-LVL LAPSE RATES OF 8 DEG C/KM WILL RESULT IN MLCAPE OF
2000-3000 J/KG. MID-LVL SHEAR WILL BE AROUND 30 KTS...SUPPORTIVE
OF SUPERCELLS DUE TO BACKED LOW-LVL SE WINDS.
0-1 KM EHI WILL BE IN EXCESS OF 1 WHERE WINDS ARE BACKED. THIS
COMBINED WITH LOWEST LCL HGTS SUGGESTS TORNADO POTENTIAL WILL BE
ALONG AND N OF A LINE FROM LXN-HJH.
SATELLITE-DERIVED PW SHOWS A PLUME OF SUBTROPICAL MSTR EXTENDING N
FROM THE CARIBBEAN INTO THE CNTRL PLAINS. LBF/OAX/TOP 12Z SOUNDINGS
ARE ALL 150-170% OF NORMAL. ANY CLUSTERING OF TSTMS WILL THREATEN
FLASH FLOODING...ESPECIALLY HERE HVY RAIN OCCURRED LAST NGT.
ORDINARY STORM MVMT WILL BE 05025 KTS. SUPERCELL MVMT: E 10-15 KTS
WHICH COULD ALSO BE TROUBLE FOR EXCESSIVE RAINFALL.
HWO AND EHWO HAVE BEEN UPDATED WITH OUR LATEST THINKING.
UPDATE ISSUED AT 920 AM CDT SAT MAY 25 2013
MCS HAS BASICALLY EXITED. RADAR IS SHOWING SOME SHWRS STILL
PERCOLATING FROM HLC-PHG AND DRIFTING NE TOWARD THE STATE LINE.
THESE SHWRS /WITH AN OCCASIONAL RUMBLE OF THUNDER/ WERE DEVELOPING
AS THE REMAINS OF THE LLJ ARE STILL LARGELY PERPENDICULAR TO THE
CONVECTIVELY-REINFORCED WARM FRONT THAT EXTENDS W-E ACROSS NRN KS.
EXPECT THESE SHWRS TO EVENTUALLY END. SO SHORT-TERM ADJUSTMENTS
THRU NOON HAVE ADJUSTED POPS AND SKYCOVER ACCORDINGLY.
12Z LBF/OAX/TOP SOUNDINGS SUPPORT HIGH TEMPS IN THE LOW-MID 80S E
OF HWY 281 AND MID-UPR 80S TO THE W.
WE WILL CONT TO EVALUATE TSTM AND SVR WX POTENTIAL FOR THIS AFTN-
EVE. CERTAINLY THE BOUNDARY LAID DOWN FROM THIS MCS WILL BE
WATCHED CLOSELY.
PLEASE FOLLOW OUR LSR/RTP/LCO PRODUCTS FOR THE IMPRESSIVE RAINFALL
TOTALS OVERNGT. MANY REPORTS OF 2-3" IN A SWATH FROM SHERMAN-HALL-
HAMILTON-CLAY-THAYER COUNTIES. THIS MAY SET THE STAGE FOR SOME
FLOODING WITH MULTIPLE THREATS OF TSTMS THE NEXT SVRL DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM CDT SAT MAY 25 2013
UNCERTAINTY IS ABOVE AVERAGE DUE TO TSTM POTENTIAL.
THIS AFTN: VFR WITH A SLGT CHC OF AN IFR TSTM AFTER 21Z. SSE WINDS
WILL GUST TO AROUND 22 KTS.
TNGT: VFR MUCH OF THE NGT BUT THERE IS A SLGT CHC OF A TSTM. JUST
CANNOT PINPOINT IT ATTM. GUSTINESS OF SSE WINDS WILL DIMINISH
AROUND SUNSET...BUT THERE COULD BE SOME OCCASIONAL GUSTS TO NEAR
20 KTS.
SUN THRU 18Z: VFR. SSE WINDS GUST UP TO 25 KTS.
CIG CONFIDENCE: MEDIUM
VSBY CONFIDENCE: MEDIUM
WIND CONFIDENCE: HIGH EXCEPT NEAR TSTMS
WX CONFIDENCE: LOW DUE TO TSTM POTENTIAL
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
1138 AM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1131 AM CDT SAT MAY 25 2013
THIS WILL SERVE AS THE NOON ESTF UPDATE.
TEMPS OVER OUR KS COUNTIES ARE RAPIDLY APPROACHING 80F. SO HIGH
TEMPS HAVE BEEN RAISED ALL AREAS FOR THIS AFTN.
THE FLOOD WARNING FOR SHERMAN/HOWARD COUNTIES WAS ALLOWED TO
EXPIRE AT 1030AM. CALLS TO REGIONAL DISPATCH INDICATE WATERS WERE
RECEDING. HOWEVER...COORDINATED WITH THE RFC AND WE WILL BE
CLOSELY MONITORING AREA RIVERS PARTICULARLY N OF I-80 AFTER THE
VERY HVY RAINS LAST NGT. HIGHEST TOTAL SO FAR IS 4.28" 2 W OF LOUP
CITY.
THANK YOU VERY MUCH TO ALL COOP/SPOTTER/NE-RAIN/COCORAHS OBSERVERS.
THE BOUNDARY LEFT BY LAST NGT`S MCS WILL PLAY AN IMPORTANT ROLE IN
TSTM DEVELOPMENT THIS AFTN-EVE. MEAN S LOW-LVL FLOW WILL BE
MAINTAINED JUST E OF THE LEE TROF WHICH WILL RESULT IN CONVERGENCE
AND ASCENT ALONG THIS BOUNDARY. WE/VE NOTED A PLUME OF VERY WARM
MID-LVL TEMPS ON THE DDC SOUNDING WHICH WILL ADVECT OVER THE FCST
AREA TODAY. THIS WILL DELAY TSTM DEVELOP UNTIL LATE...AND COULD
KEEP IT FROM OCCURRING AT ALL S OF THE BOUNDARY.
RADAR AND VIS SATELLITE SHOWS AN MCV JUST SW OF THE FCST AREA NEAR
HYS. THIS WILL BE A WILDCARD AS IT COULD TRIGGER TSTMS IN THE WARM
SECTOR...BUT DOES IT OCCUR DURING THE DAYLGT HRS? IT/S HEADING NE
AND WILL MOVE ACROSS OUR SE COUNTIES. IF IT HOLDS OFF UNTIL TNGT
THEN IT COULD BE E OF THE FCST AREA.
WITH VERY LITTLE CLOUD COVER N OF THE BOUNDARY...DIABATIC HEATING
WILL DESTABILIZE THE ATMS. TEMPS IN THE 80S...DWPTS IN THE 60S AND
MID-LVL LAPSE RATES OF 8 DEG C/KM WILL RESULT IN MLCAPE OF
2000-3000 J/KG. MID-LVL SHEAR WILL BE AROUND 30 KTS...SUPPORTIVE
OF SUPERCELLS DUE TO BACKED LOW-LVL SE WINDS.
0-1 KM EHI WILL BE IN EXCESS OF 1 WHERE WINDS ARE BACKED. THIS
COMBINED WITH LOWEST LCL HGTS SUGGESTS TORNADO POTENTIAL WILL BE
ALONG AND N OF A LINE FROM LXN-HJH.
SATELLITE-DERIVED PW SHOWS A PLUME OF SUBTROPICAL MSTR EXTENDING N
FROM THE CARIBBEAN INTO THE CNTRL PLAINS. LBF/OAX/TOP 12Z SOUNDINGS
ARE ALL 150-170% OF NORMAL. ANY CLUSTERING OF TSTMS WILL THREATEN
FLASH FLOODING...ESPECIALLY HERE HVY RAIN OCCURRED LAST NGT.
ORDINARY STORM MVMT WILL BE 05025 KTS. SUPERCELL MVMT: E 10-15 KTS
WHICH COULD ALSO BE TROUBLE FOR EXCESSIVE RAINFALL.
HWO AND EHWO HAVE BEEN UPDATED WITH OUR LATEST THINKING.
UPDATE ISSUED AT 920 AM CDT SAT MAY 25 2013
MCS HAS BASICALLY EXITED. RADAR IS SHOWING SOME SHWRS STILL
PERCOLATING FROM HLC-PHG AND DRIFTING NE TOWARD THE STATE LINE.
THESE SHWRS /WITH AN OCCASIONAL RUMBLE OF THUNDER/ WERE DEVELOPING
AS THE REMAINS OF THE LLJ ARE STILL LARGELY PERPENDICULAR TO THE
CONVECTIVELY-REINFORCED WARM FRONT THAT EXTENDS W-E ACROSS NRN KS.
EXPECT THESE SHWRS TO EVENTUALLY END. SO SHORT-TERM ADJUSTMENTS
THRU NOON HAVE ADJUSTED POPS AND SKYCOVER ACCORDINGLY.
12Z LBF/OAX/TOP SOUNDINGS SUPPORT HIGH TEMPS IN THE LOW-MID 80S E
OF HWY 281 AND MID-UPR 80S TO THE W.
WE WILL CONT TO EVALUATE TSTM AND SVR WX POTENTIAL FOR THIS AFTN-
EVE. CERTAINLY THE BOUNDARY LAID DOWN FROM THIS MCS WILL BE
WATCHED CLOSELY.
PLEASE FOLLOW OUR LSR/RTP/LCO PRODUCTS FOR THE IMPRESSIVE RAINFALL
TOTALS OVERNGT. MANY REPORTS OF 2-3" IN A SWATH FROM SHERMAN-HALL-
HAMILTON-CLAY-THAYER COUNTIES. THIS MAY SET THE STAGE FOR SOME
FLOODING WITH MULTIPLE THREATS OF TSTMS THE NEXT SVRL DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 540 AM CDT SAT MAY 25 2013
TSTMS CONTINUE IN THE VICINITY OF KGRI EARLY THIS MORNING. THIS
INITIAL ROUND OF CONVECTION WILL END THIS MORNING WITH
REDEVELOPMENT OF STORMS FORECAST THIS AFTN AND EVENING. LOOK FOR
VARIABLE WINDS TO TRANSITIION SOUTHERLY TODAY...BUT WILL BE
VARIABLE/GUSTY IN VCNTY OF STORMS. CIGS/VSBYS WILL MAINLY BE VFR BUT
WILL DROP TO MVFR AND POTENTIALLY NEAR IFR DURING TSTM ACTIVITY.
SEVERE STORMS ARE POSSIBLE LATER TODAY/TONIGHT WITH LARGE
HAIL/DAMAGING WINDS/HEAVY RAINFALL THE MAIN HAZARDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1132 AM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1131 AM CDT SAT MAY 25 2013
THIS WILL SERVE AS THE NOON ESTF UPDATE.
TEMPS OVER OUR KS COUNTIES ARE RAPIDLY APPROACHING 80F. SO HIGH
TEMPS HAVE BEEN RAISED ALL AREAS FOR THIS AFTN.
THE FLOOD WARNING FOR SHERMAN/HOWARD COUNTIES WAS ALLOWED TO
EXPIRE AT 1030AM. CALLS TO REGIONAL DISPATCH INDICATE WATERS WERE
RECEDING. HOWEVER...COORDINATED WITH THE RFC AND WE WILL BE
CLOSELY MONITORING AREA RIVERS PARTICULARLY N OF I-80 AFTER THE
VERY HVY RAINS LAST NGT. HIGHEST TOTAL SO FAR IS 4.28" 2 W OF LOUP
CITY.
THANK YOU VERY MUCH TO ALL COOP/SPOTTER/NE-RAIN/COCORAHS OBSERVERS.
WE BOUNDARY LEFT BY LAST NGT`S MCS WILL PLAY AN IMPORTANT ROLE IN
TSTM DEVELOPMENT THIS AFTN-EVE. MEAN S LOW-LVL FLOW WILL BE
MAINTAINED JUST E OF THE LEE TROF WHICH WILL RESULT IN CONVERGENCE
AND ASCENT ALONG THIS BOUNDARY. WE/VE NOTED A PLUME OF VERY WARM
MID-LVL TEMPS ON THE DDC SOUNDING WHICH WILL ADVECT OVER THE FCST
AREA TODAY. THIS WILL DELAY TSTM DEVELOP UNTIL LATE...AND COULD
KEEP IT FROM OCCURRING AT ALL S OF THE BOUNDARY.
RADAR AND VIS SATELLITE SHOWS AN MCV JUST SW OF THE FCST AREA NEAR
HYS. THIS WILL BE A WILDCARD AS IT COULD TRIGGER TSTMS IN THE WARM
SECTOR...BUT DOES IT OCCUR DURING THE DAYLGT HRS? IT/S HEADING NE
AND WILL MOVE ACROSS OUR SE COUNTIES. IF IT HOLDS OFF UNTIL TNGT
THEN IT COULD BE E OF THE FCST AREA.
WITH VERY LITTLE CLOUD COVER N OF THE BOUNDARY...DIABATIC HEATING
WILL DESTABILIZE THE ATMS. TEMPS IN THE 80S...DWPTS IN THE 60S AND
MID-LVL LAPSE RATES OF 8 DEG C/KM WILL RESULT IN MLCAPE OF
2000-3000 J/KG. MID-LVL SHEAR WILL BE AROUND 30 KTS...SUPPORTIVE
OF SUPERCELLS DUE TO BACKED LOW-LVL SE WINDS.
0-1 KM EHI WILL BE IN EXCESS OF 1 WHERE WINDS ARE BACKED. THIS
COMBINED WITH LOWEST LCL HGTS SUGGESTS TORNADO POTENTIAL WILL BE
ALONG AND N OF A LINE FROM LXN-HJH.
SATELLITE-DERIVED PW SHOWS A PLUME OF SUBTROPICAL MSTR EXTENDING N
FROM THE CARIBBEAN INTO THE CNTRL PLAINS. LBF/OAX/TOP 12Z SOUNDINGS
ARE ALL 150-170% OF NORMAL. ANY CLUSTERING OF TSTMS WILL THREATEN
FLASH FLOODING...ESPECIALLY HERE HVY RAIN OCCURRED LAST NGT.
ORDINARY STORM MVMT WILL BE 05025 KTS. SUPERCELL MVMT: E 10-15 KTS
WHICH COULD ALSO BE TROUBLE FOR EXCESSIVE RAINFALL.
HWO AND EHWO HAVE BEEN UPDATED WITH OUR LATEST THINKING.
UPDATE ISSUED AT 920 AM CDT SAT MAY 25 2013
MCS HAS BASICALLY EXITED. RADAR IS SHOWING SOME SHWRS STILL
PERCOLATING FROM HLC-PHG AND DRIFTING NE TOWARD THE STATE LINE.
THESE SHWRS /WITH AN OCCASIONAL RUMBLE OF THUNDER/ WERE DEVELOPING
AS THE REMAINS OF THE LLJ ARE STILL LARGELY PERPENDICULAR TO THE
CONVECTIVELY-REINFORCED WARM FRONT THAT EXTENDS W-E ACROSS NRN KS.
EXPECT THESE SHWRS TO EVENTUALLY END. SO SHORT-TERM ADJUSTMENTS
THRU NOON HAVE ADJUSTED POPS AND SKYCOVER ACCORDINGLY.
12Z LBF/OAX/TOP SOUNDINGS SUPPORT HIGH TEMPS IN THE LOW-MID 80S E
OF HWY 281 AND MID-UPR 80S TO THE W.
WE WILL CONT TO EVALUATE TSTM AND SVR WX POTENTIAL FOR THIS AFTN-
EVE. CERTAINLY THE BOUNDARY LAID DOWN FROM THIS MCS WILL BE
WATCHED CLOSELY.
PLEASE FOLLOW OUR LSR/RTP/LCO PRODUCTS FOR THE IMPRESSIVE RAINFALL
TOTALS OVERNGT. MANY REPORTS OF 2-3" IN A SWATH FROM SHERMAN-HALL-
HAMILTON-CLAY-THAYER COUNTIES. THIS MAY SET THE STAGE FOR SOME
FLOODING WITH MULTIPLE THREATS OF TSTMS THE NEXT SVRL DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 540 AM CDT SAT MAY 25 2013
TSTMS CONTINUE IN THE VICINITY OF KGRI EARLY THIS MORNING. THIS
INITIAL ROUND OF CONVECTION WILL END THIS MORNING WITH
REDEVELOPMENT OF STORMS FORECAST THIS AFTN AND EVENING. LOOK FOR
VARIABLE WINDS TO TRANSITIION SOUTHERLY TODAY...BUT WILL BE
VARIABLE/GUSTY IN VCNTY OF STORMS. CIGS/VSBYS WILL MAINLY BE VFR BUT
WILL DROP TO MVFR AND POTENTIALLY NEAR IFR DURING TSTM ACTIVITY.
SEVERE STORMS ARE POSSIBLE LATER TODAY/TONIGHT WITH LARGE
HAIL/DAMAGING WINDS/HEAVY RAINFALL THE MAIN HAZARDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
920 AM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 920 AM CDT SAT MAY 25 2013
MCS HAS BASICALLY EXITED. RADAR IS SHOWING SOME SHWRS STILL
PERCOLATING FROM HLC-PHG AND DRIFTING NE TOWARD THE STATE LINE.
THESE SHWRS /WITH AN OCCASIONAL RUMBLE OF THUNDER/ WERE DEVELOPING
AS THE REMAINS OF THE LLJ ARE STILL LARGELY PERPENDICULAR TO THE
CONVECTIVELY-REINFORCED WARM FRONT THAT EXTENDS W-E ACROSS NRN KS.
EXPECT THESE SHWRS TO EVENTUALLY END. SO SHORT-TERM ADJUSTMENTS
THRU NOON HAVE ADJUSTED POPS AND SKYCOVER ACCORDINGLY.
12Z LBF/OAX/TOP SOUNDINGS SUPPORT HIGH TEMPS IN THE LOW-MID 80S E
OF HWY 281 AND MID-UPR 80S TO THE W.
WE WILL CONT TO EVALUATE TSTM AND SVR WX POTENTIAL FOR THIS AFTN-
EVE. CERTAINLY THE BOUNDARY LAID DOWN FROM THIS MCS WILL BE
WATCHED CLOSELY.
PLEASE FOLLOW OUR LSR/RTP/LCO PRODUCTS FOR THE IMPRESSIVE RAINFALL
TOTALS OVERNGT. MANY REPORTS OF 2-3" IN A SWATH FROM SHERMAN-HALL-
HAMILTON-CLAY-THAYER COUNTIES. THIS MAY SET THE STAGE FOR SOME
FLOODING WITH MULTIPLE THREATS OF TSTMS THE NEXT SVRL DAYS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 540 AM CDT SAT MAY 25 2013
TSTMS CONTINUE IN THE VICINITY OF KGRI EARLY THIS MORNING. THIS
INITIAL ROUND OF CONVECTION WILL END THIS MORNING WITH
REDEVELOPMENT OF STORMS FORECAST THIS AFTN AND EVENING. LOOK FOR
VARIABLE WINDS TO TRANSITIION SOUTHERLY TODAY...BUT WILL BE
VARIABLE/GUSTY IN VCNTY OF STORMS. CIGS/VSBYS WILL MAINLY BE VFR BUT
WILL DROP TO MVFR AND POTENTIALLY NEAR IFR DURING TSTM ACTIVITY.
SEVERE STORMS ARE POSSIBLE LATER TODAY/TONIGHT WITH LARGE
HAIL/DAMAGING WINDS/HEAVY RAINFALL THE MAIN HAZARDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
543 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 540 AM CDT SAT MAY 25 2013
TSTMS CONTINUE IN THE VICINITY OF KGRI EARLY THIS MORNING. THIS
INITIAL ROUND OF CONVECTION WILL END THIS MORNING WITH
REDEVELOPMENT OF STORMS FORECAST THIS AFTN AND EVENING. LOOK FOR
VARIABLE WINDS TO TRANSITIION SOUTHERLY TODAY...BUT WILL BE
VARIABLE/GUSTY IN VCNTY OF STORMS. CIGS/VSBYS WILL MAINLY BE VFR BUT
WILL DROP TO MVFR AND POTENTIALLY NEAR IFR DURING TSTM ACTIVITY.
SEVERE STORMS ARE POSSIBLE LATER TODAY/TONIGHT WITH LARGE
HAIL/DAMAGING WINDS/HEAVY RAINFALL THE MAIN HAZARDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
428 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM CDT SAT MAY 25 2013
FOCUS REMAINS ON TSTM POTENTIAL.
TSTMS CONTINUE EARLY THIS MORNING WITH MCS ROLLING EAST ACROSS
CENTRAL/EASTERN NEBRASKA. MAIN IMPACT CURRENTLY FM CONVECTION IS HEAVY
RAINFALL...WITH MANY LOCATIONS NORTH OF INTERSTATE 80 PICKING UP
AT LEAST AN INCH OF RAIN. WE HAVE HAD ONE REPORT OF 3.13 INCHES SO
FAR AT LOUP CITY WITH RAIN STILL FALLING.
THIS INITIAL ROUND OF CONVECTION WILL CONTINUE TO MOVE EAST/END THIS
MORNING THEN ATTENTION TURNS TO ADDITIONAL CHANCES FOR CONVECTION
THIS AFTN. SFC BOUNDARY HAS SETTLED NEAR THE NEB/KS STATELINE AND
FRONT IS PROGGED TO LIFT NORTHWARD THIS AFTN INTO SC NEB...WITH SFC
LOW ORIENTED IN EASTERN COLORADO AND DRY LINE ALONG THE HIGH PLAINS
REGION. FRONTAL BOUNDARY AND ANY RESIDUAL OUTFLOW BOUNDARIES WILL BE
FOCUS FOR CONVECTION AGAIN THIS AFTN/EVE AND BOUNDARY PLACEMENT
WILL NEED TO BE MONITORED CLOSELY. CAP LOOKS TO HOLD INITIALLY
HOWEVER MODELS ARE INDICATING DEVELOPMENT ALONG THE DRY LINE AND
ALONG/NORTH OF WARM FRONTAL BOUNDARY...AND HAVE FOLLOWED CLOSER TO
RAP MODEL FOR POTENTIAL DEVELOPMENT THIS AFTN. STORMS FOR
TODAY/TONIGHT HAVE THE POTENTIAL TO BE MORE VOLATILE WITH SEVERE
PARAMETERS INDICATING POTENTIAL FOR SUPERCELLS. INSTABILITY IS
PROGGED AROUND 4000 J/KG WITH SHEAR OF 40KTS OR SO AND STORMS WILL
BE CAPABLE OF PRODUCING VERY LARGE HAIL...DAMAGING WINDS AND EVEN
TORNADOES IN VCNTY OF BOUNDARIES. HEAVY RAINFALL/FLOODING ALSO
REMAINS A CONCERN DUE TO THE HEAVY OVERNIGHT/EARLY THIS MORNING
AND PRECIPITABLE WATER VALUES ARE ON THE ORDER OF AN INCH TO INCH
AND A HALF AND ARE A 100 TO 150 PERCENT OF NORMAL. ALL OF THIS
BEING SAID...MODELS ARE NOT CONSISTENT IN FRONTAL POSITION WHICH
IS KEY TO DEVELOPMENT THIS AFTN. AGAIN FEEL RAP AND LATEST SREF
RUN HAS A BETTER HANDLE ON THE FARTHER SOUTH WARM FRONTAL POSITION
ACROSS OUR AREA TODAY...AND WILL NEED TO MONITOR CLOSELY.
OTHERWISE...LOOK FOR SOME WARMER TEMPS THIS AFTN AND STEADY/GUSTY
WINDS WITH THE HIGHEST WIND SPEEDS EXPECTED ACROSS NC KANSAS/SOUTH
OF WARM FRONT...WHERE WINDY CONDITIONS ARE POSSIBLE WITH GUSTS OF
30+ MPH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 423 AM CDT SAT MAY 25 2013
SUNDAY THROUGH FRIDAY. MAIN FORECAST CONCERNS WILL BE
CHANCES FOR THUNDERSTORMS MOST EVERY DAY AND TEMPERATURES THROUGH
THE PERIOD.
A VERY ACTIVE WEATHER PATTERN WILL AFFECT THE FORECAST AREA THROUGH
THE PERIOD. AN UPPER LEVEL LOW DEVELOPS IN THE WESTERN CONUS AND
GRADUALLY MOVES THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS BY FRIDAY. THIS UPPER LOW WILL SEND WAVES INTO THE FORECAST
AREA THROUGH THE PERIOD. THE MODELS ARE SIMILAR IN THE MAIN
FEATURES...BUT THE ECMWF HAS A LITTLE STRONGER AMPLITUDE MID WEEK.
EACH OF THE WAVES WILL HAVE A CHANCE FOR SOME THUNDERSTORMS WHEN
THEY MOVE THROUGH. IT CERTAINLY WILL NOT BE A RAIN OUT...IT WILL NOT
RAIN ALL OF THE TIME...BUT THERE WILL BE CHANCES FOR SOME SHOWERS
AND THUNDERSTORMS AT VARIOUS TIMES DURING THE PERIOD.
THE BEST CHANCES FOR THUNDERSTORMS WILL BE SUNDAY AFTERNOON AND
SUNDAY NIGHT...DURING WHICH TIME THE CAPE APPROACHES 5000 J/KG.
ANOTHER GOOD CHANCE WILL BE MONDAY AFTERNOON AND MONDAY NIGHT WITH
CAPES OVER 5000 J/KG AGAIN. BEYOND MONDAY THE MODELS HAVE A FEW
TIMING DIFFERENCES WITH THE UPPER LEVEL WAVES THAT MOVE THROUGH THE
AREA AND THEREFORE TIMING THUNDERSTORMS IS MORE OF A CHALLENGE.
TEMPERATURES WILL BE THE WARMEST SUNDAY THROUGH TUESDAY THEN SLOWLY
COOL OFF TOWARD THE END OF THE WEEK. TEMPERATURES SHOULD STILL
REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 1217 AM CDT SAT MAY 25 2013
TSTMS WILL IMPACT THE TERMINAL INTO THE OVERNIGHT HOURS...WITH
POTENTIAL FOR SEVERE WEATHER WITH DAMAGING WINDS...LARGE HAIL AND
HEAVY RAINFALL. CHCS FOR TSTMS AND SEVERE WEATHER RETURN SATURDAY
EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...JCB
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1004 PM CDT SUN MAY 26 2013
.UPDATE...
ISSUED AT 958 PM CDT SUN MAY 26 2013
UPDATE TO DELAY THUNDERSTORMS EVEN MORE FROM THE EARLY EVENING
UPDATE...BASED ON EVENING HIGH RESOLUTION MODEL TRENDS. STORMS
STILL EXPECTED TO SPREAD INTO WESTERN COUNTIES OVERNIGHT. THERE
MAY BE A FEW STRONG TO MARGINALLY SEVERE STORMS...BUT RELATIVELY
WEAK DEEP LAYER SHEAR IS EXPECTED TO LIMIT POTENTIAL FOR MORE
SIGNIFICANT SEVERE WEATHER. RELATIVELY SLOW STORM MOTIONS WOULD
FAVOR POTENTIAL FOR ISOLATED HEAVY RAINFALL AMOUNTS. STILL SOME
UNCERTAINTY AS TO HOW FAR EAST STORMS WILL SPREAD TOWARD DAYBREAK
AND INTO THE MORNING HOURS MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 320 PM CDT SUN MAY 26 2013
FORECAST PROBLEM IN THE SHORT TERM WILL BE THUNDERSTORM CHANCES
THROUGH THE PERIOD. OVERALL MODEL TREND HAS BEEN TO LESSEN OR PUSH
BACK PRECIPITATION CHANCES ESPECIALLY LATE THIS AFTERNOON AND THIS
EVENING. BEYOND THIS THERE IS LITTLE FORECAST CONFIDENCE REGARDING
PRECIPITATION TIMING AND PLACEMENT AS MODELS ARE HAVING A HARD TIME
RESOLVING THIS IN THE BROAD SOUTHWEST UPPER FLOW.
CURRENTLY...MVFR-IFR STRATUS REMAIN ACROSS THE SOURIS TO JAMES
RIVER BASINS...WHILE STRATUS HAS DISSIPATED BUT WELL DEVELOPED CU
FIELD HAS BROKEN OUT OVER THE WEST AND SOUTH CENTRAL. THIS HAS
RESULTED IN TEMPERATURES PUSHING INTO THE LOW TO MID 70S WITH MID
50S DEWPOINT TEMPERATURES FROM WESTERN NORTH DAKOTA INTO EASTERN
MONTANA AND NORTHWEST SOUTH DAKOTA. CURRENT SPC ANALYSIS IS
SHOWING CAPES OF 1000-1500 J/KG WITH DIMINISHING CIHN OVER THE
MONDAK REGION WITH INCREASING LAPSE RATES. CONVECTION HAS RECENTLY
INITIATED OVER THE BIGHORNS AND BLACK HILLS. GGW 18Z SOUNDING AND
CURRENT LAPS SOUNDING NEAR KOLF INDICATE A NEAR COMPLETE ERODED
CAP OVER EASTERN MONTANA. LATEST WATER VAPOR SATELLITE IMAGERY
SHOW AN APPROACHING SHORTWAVE TROUGH LIFTING NORTHEAST THROUGH
WYOMING WHICH SHOULD HELP TO INITIATE CONVECTION AWAY FROM THE
MOUNTAINS. WITH THIS SAID...MODELS ARE NOT POINTING TO STRONG
CONVECTION OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON
AND EARLY EVENING. GFS/ECMWF BRING BEST CHANCES INTO THE FAR WEST
LATE TONIGHT WITH CONVECTION CONTINUING EAST ACROSS THE AREA ON
MONDAY. 12 UTC NAM AND 17 UTC HRRR BRING CONVECTION FIRING OFF THE
BIGHORNS INTO SOUTHEAST MONTANA BUT THEN SUPPRESS REFLECTIVITIES
AS THEY MOVE INTO WESTERN NORTH DAKOTA. 12 UTC HIRES ARW/NMM EAST
BOTH POINT MORE TOWARD LATE NIGHT CONVECTION MOVING INTO THE WEST
AND LINGERING INTO MONDAY...WITH YET ANOTHER ROUND OF CONVECTION
ON MONDAY.
FOR NOW WILL LEAN TOWARD SLIGHT CHANCE POPS EAST TO CHANCE POPS
WEST THIS EVENING...THEN INCREASING AFTER MIDNIGHT WITH HIGHEST
POPS REMAINING IN THE WEST. THEN BASICALLY A BROAD BRUSH OF HIGH
CHANCE POPS ON MONDAY DUE TO SO MUCH UNCERTAINTY ON
TIMING/PLACEMENT. WITH AFOREMENTIONED SEVERE WEATHER INGREDIENTS
WILL KEEP A MENTION OF SEVERE LATE THIS AFTERNOON AND THIS
EVENING. IF CONVECTION WOULD DEVELOP AND MOVE INTO WESTERN NORTH
DAKOTA...THE GREATEST THREAT WOULD LIKELY BE LARGE HAIL AND VERY
HEAVY RAIN CAUSING LOCALIZED FLOODING PROBLEMS.
ALTHOUGH SPC SLIGHT RISK DOES INCLUDE A PORTION OF THE FAR
SOUTHWEST ON MONDAY...WILL HOLD OFF ON MENTIONING THIS IN THE
FORECAST FOR NOW. WILL LET LATER SHIFTS RE-EVALUATE.
MODELS DO INDICATE INCREASING 925MB MOISTURE TONIGHT. CONSIDERED
ADDING A MENTION OF FOG...BUT THINK THE BIGGEST ISSUE WILL BE LOW
STRATUS AND LIFR CEILINGS. COULD SEE SOME MVFR VISIBILITIES BUT
WILL HOLD OFF ON ADDING FOG FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 PM CDT SUN MAY 26 2013
A VERY ACTIVE WEATHER PATTERN WILL PERSIST ACROSS THE NORTHERN
PLAINS THROUGH MUCH IF NOT ALL OF THE EXTENDED PERIOD.
LONG WAVE TROUGH WEST AND RIDGING EAST WILL MAINTAIN SOUTHWESTERLY
FLOW ALOFT ACROSS THE DAKOTAS MONDAY NIGHT. SHOWERS AND POSSIBLY
SEVERE THUNDERSTORMS WILL BE ONGOING AT THE START OF THE PERIOD
MONDAY EVENING AS A STRONG S/WV LIFTS NORTHEAST THROUGH THE REGION.
SCALED BACK PRECIPITATION CHANCES TUESDAY/TUESDAY EVENING AS A S/WV
RIDGE ADVANCES NORTHEAST THROUGH THE STATE ALONG WITH DRIER AIR INTO
MY WEST. SHOWER/THUNDERSTORM CHANCES INCREASE TUESDAY NIGHT AS THE
RIDGE CONTINUES OFF TO OUR NORTH AND EAST RESULTING IN FLOW ALOFT
TRANSITIONING TO SOUTHWEST ONCE AGAIN...WITH A LEAD IMPULSE MOVING
NORTH THROUGH THE WESTERN DAKOTAS.
BY WEDNESDAY MORNING THE BASE OF THE WESTERN CONUS TROUGH WILL BE
OVER THE SOUTHERN ROCKIES...WHICH IS DEPICTED BY BOTH THE 12Z
GFS/ECMWF TO SWING NORTH THROUGH THE CENTRAL PLAINS INTO THE DAKOTAS
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. FOR THURSDAY...THE BASE OF
THE TROUGH MORPHS INTO A CUTOFF LOW WHICH MAY LINGER ACROSS THE
NORTHERN PLAINS INTO SATURDAY IF THE 12Z ECMWF VERIFIES. THE 12Z GFS
IS MORE PROGRESSIVE...WITH THE LOW BECOMING AN OPEN WAVE AND MOVING
OVER THE WESTERN GREAT LAKES REGION BY SATURDAY MORNING. BOTH MODEL
SOLUTIONS RESULT IN HIGH CHANCES FOR SHOWERS AND THUNDERSTORMS
WEDNESDAY-WEDNESDAY NIGHT-THURSDAY...WITH A CHANCE OF STRONG TO
SEVERE STORMS AS WELL. FORECAST UNCERTAINTY INCREASES AFTERWARDS FOR
FRIDAY THROUGH THE WEEKEND WITH THE ABOVE MENTIONED DIFFERENCES
BETWEEN THE GFS/ECMWF.
TEMPERATURES WILL AVERAGE NEAR TO SLIGHTLY ABOVE NORMAL EARLY NEXT
WEEK...THEN WILL AVERAGE NEAR TO SLIGHTLY BELOW NORMAL FOR THE END
OF THE WORK WEEK THROUGH NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 658 PM CDT SUN MAY 26 2013
SOUTHEAST FLOW WILL CONTINUE THROUGH THE FORECAST PERIOD. THIS WILL
KEEP A THREAT OF MVFR-IFR CEILINGS IN THE FORECAST AT ALL TAF SITES.
THE PRESENCE OF ABUNDANT LOW LEVEL MOISTURE TONIGHT WILL ALLOW FOR
LOWERED CEILINGS DOWN TO IFR-LIFR IN STRATUS AROUND 06-10Z AT ALL
SITES...WITH SOME MVFR FOG. BROUGHT A MENTION OF LIGHT RAIN FOR ALL
SITES EXCEPT FOR KJMS AFTER 18 UTC..WHERE VCSH WAS MORE APPROPRIATE
SINCE THREAT FOR RAIN WILL BE LATER THERE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RP KINNEY
SHORT TERM...TWH
LONG TERM...NH
AVIATION...LTH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
708 PM CDT SUN MAY 26 2013
.UPDATE...
ISSUED AT 658 PM CDT SUN MAY 26 2013
UPDATE MAINLY TO REFINE POPS OVERNIGHT...KEEPING THE HIGHER POPS
CONFINED MAINLY TO THE WEST AND EVENTUALLY THE CENTRAL COUNTIES
LATE. RADAR/VISIBLE SATELLITE IMAGERY INDICATING SOME SHOWERS AND
ENHANCED CUMULUS DEVELOPING AROUND HETTINGER AND MOTT. ML CAPES IN
THAT AREA ARE AROUND 1500 J/KG...ALTHOUGH DEEP LAYER SHEAR IS
RELATIVELY WEAK. STRONG TO SEVERE STORMS ARE CURRENTLY LOCATED WELL
WEST OF THE FORECAST AREA IN MONTANA AND WYOMING. SHORT WAVE
ENERGY IS EXPECTED TO MOVE INTO THE SOUTHWEST THIS EVENING...AND
THE 22Z RUN OF THE HRRR BRINGS STORMS INTO THE SOUTHWEST BETWEEN
02Z-03Z. NOT ANTICIPATING WIDESPREAD SIGNIFICANT SEVERE
WEATHER...BUT WILL LIKELY HAVE A FEW STRONGER STORMS TO MONITOR
LATER ON.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 320 PM CDT SUN MAY 26 2013
FORECAST PROBLEM IN THE SHORT TERM WILL BE THUNDERSTORM CHANCES
THROUGH THE PERIOD. OVERALL MODEL TREND HAS BEEN TO LESSEN OR PUSH
BACK PRECIPITATION CHANCES ESPECIALLY LATE THIS AFTERNOON AND THIS
EVENING. BEYOND THIS THERE IS LITTLE FORECAST CONFIDENCE REGARDING
PRECIPITATION TIMING AND PLACEMENT AS MODELS ARE HAVING A HARD TIME
RESOLVING THIS IN THE BROAD SOUTHWEST UPPER FLOW.
CURRENTLY...MVFR-IFR STRATUS REMAIN ACROSS THE SOURIS TO JAMES
RIVER BASINS...WHILE STRATUS HAS DISSIPATED BUT WELL DEVELOPED CU
FIELD HAS BROKEN OUT OVER THE WEST AND SOUTH CENTRAL. THIS HAS
RESULTED IN TEMPERATURES PUSHING INTO THE LOW TO MID 70S WITH MID
50S DEWPOINT TEMPERATURES FROM WESTERN NORTH DAKOTA INTO EASTERN
MONTANA AND NORTHWEST SOUTH DAKOTA. CURRENT SPC ANALYSIS IS
SHOWING CAPES OF 1000-1500 J/KG WITH DIMINISHING CIHN OVER THE
MONDAK REGION WITH INCREASING LAPSE RATES. CONVECTION HAS RECENTLY
INITIATED OVER THE BIGHORNS AND BLACK HILLS. GGW 18Z SOUNDING AND
CURRENT LAPS SOUNDING NEAR KOLF INDICATE A NEAR COMPLETE ERODED
CAP OVER EASTERN MONTANA. LATEST WATER VAPOR SATELLITE IMAGERY
SHOW AN APPROACHING SHORTWAVE TROUGH LIFTING NORTHEAST THROUGH
WYOMING WHICH SHOULD HELP TO INITIATE CONVECTION AWAY FROM THE
MOUNTAINS. WITH THIS SAID...MODELS ARE NOT POINTING TO STRONG
CONVECTION OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON
AND EARLY EVENING. GFS/ECMWF BRING BEST CHANCES INTO THE FAR WEST
LATE TONIGHT WITH CONVECTION CONTINUING EAST ACROSS THE AREA ON
MONDAY. 12 UTC NAM AND 17 UTC HRRR BRING CONVECTION FIRING OFF THE
BIGHORNS INTO SOUTHEAST MONTANA BUT THEN SUPPRESS REFLECTIVITIES
AS THEY MOVE INTO WESTERN NORTH DAKOTA. 12 UTC HIRES ARW/NMM EAST
BOTH POINT MORE TOWARD LATE NIGHT CONVECTION MOVING INTO THE WEST
AND LINGERING INTO MONDAY...WITH YET ANOTHER ROUND OF CONVECTION
ON MONDAY.
FOR NOW WILL LEAN TOWARD SLIGHT CHANCE POPS EAST TO CHANCE POPS
WEST THIS EVENING...THEN INCREASING AFTER MIDNIGHT WITH HIGHEST
POPS REMAINING IN THE WEST. THEN BASICALLY A BROAD BRUSH OF HIGH
CHANCE POPS ON MONDAY DUE TO SO MUCH UNCERTAINTY ON
TIMING/PLACEMENT. WITH AFOREMENTIONED SEVERE WEATHER INGREDIENTS
WILL KEEP A MENTION OF SEVERE LATE THIS AFTERNOON AND THIS
EVENING. IF CONVECTION WOULD DEVELOP AND MOVE INTO WESTERN NORTH
DAKOTA...THE GREATEST THREAT WOULD LIKELY BE LARGE HAIL AND VERY
HEAVY RAIN CAUSING LOCALIZED FLOODING PROBLEMS.
ALTHOUGH SPC SLIGHT RISK DOES INCLUDE A PORTION OF THE FAR
SOUTHWEST ON MONDAY...WILL HOLD OFF ON MENTIONING THIS IN THE
FORECAST FOR NOW. WILL LET LATER SHIFTS RE-EVALUATE.
MODELS DO INDICATE INCREASING 925MB MOISTURE TONIGHT. CONSIDERED
ADDING A MENTION OF FOG...BUT THINK THE BIGGEST ISSUE WILL BE LOW
STRATUS AND LIFR CEILINGS. COULD SEE SOME MVFR VISIBILITIES BUT
WILL HOLD OFF ON ADDING FOG FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 PM CDT SUN MAY 26 2013
A VERY ACTIVE WEATHER PATTERN WILL PERSIST ACROSS THE NORTHERN
PLAINS THROUGH MUCH IF NOT ALL OF THE EXTENDED PERIOD.
LONG WAVE TROUGH WEST AND RIDGING EAST WILL MAINTAIN SOUTHWESTERLY
FLOW ALOFT ACROSS THE DAKOTAS MONDAY NIGHT. SHOWERS AND POSSIBLY
SEVERE THUNDERSTORMS WILL BE ONGOING AT THE START OF THE PERIOD
MONDAY EVENING AS A STRONG S/WV LIFTS NORTHEAST THROUGH THE REGION.
SCALED BACK PRECIPITATION CHANCES TUESDAY/TUESDAY EVENING AS A S/WV
RIDGE ADVANCES NORTHEAST THROUGH THE STATE ALONG WITH DRIER AIR INTO
MY WEST. SHOWER/THUNDERSTORM CHANCES INCREASE TUESDAY NIGHT AS THE
RIDGE CONTINUES OFF TO OUR NORTH AND EAST RESULTING IN FLOW ALOFT
TRANSITIONING TO SOUTHWEST ONCE AGAIN...WITH A LEAD IMPULSE MOVING
NORTH THROUGH THE WESTERN DAKOTAS.
BY WEDNESDAY MORNING THE BASE OF THE WESTERN CONUS TROUGH WILL BE
OVER THE SOUTHERN ROCKIES...WHICH IS DEPICTED BY BOTH THE 12Z
GFS/ECMWF TO SWING NORTH THROUGH THE CENTRAL PLAINS INTO THE DAKOTAS
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. FOR THURSDAY...THE BASE OF
THE TROUGH MORPHS INTO A CUTOFF LOW WHICH MAY LINGER ACROSS THE
NORTHERN PLAINS INTO SATURDAY IF THE 12Z ECMWF VERIFIES. THE 12Z GFS
IS MORE PROGRESSIVE...WITH THE LOW BECOMING AN OPEN WAVE AND MOVING
OVER THE WESTERN GREAT LAKES REGION BY SATURDAY MORNING. BOTH MODEL
SOLUTIONS RESULT IN HIGH CHANCES FOR SHOWERS AND THUNDERSTORMS
WEDNESDAY-WEDNESDAY NIGHT-THURSDAY...WITH A CHANCE OF STRONG TO
SEVERE STORMS AS WELL. FORECAST UNCERTAINTY INCREASES AFTERWARDS FOR
FRIDAY THROUGH THE WEEKEND WITH THE ABOVE MENTIONED DIFFERENCES
BETWEEN THE GFS/ECMWF.
TEMPERATURES WILL AVERAGE NEAR TO SLIGHTLY ABOVE NORMAL EARLY NEXT
WEEK...THEN WILL AVERAGE NEAR TO SLIGHTLY BELOW NORMAL FOR THE END
OF THE WORK WEEK THROUGH NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 658 PM CDT SUN MAY 26 2013
SOUTHEAST FLOW WILL CONTINUE THROUGH THE FORECAST PERIOD. THIS WILL
KEEP A THREAT OF MVFR-IFR CEILINGS IN THE FORECAST AT ALL TAF SITES.
THE PRESENCE OF ABUNDANT LOW LEVEL MOISTURE TONIGHT WILL ALLOW FOR
LOWERED CEILINGS DOWN TO IFR-LIFR IN STRATUS AROUND 06-10Z AT ALL
SITES...WITH SOME MVFR FOG. BROUGHT A MENTION OF LIGHT RAIN FOR ALL
SITES EXCEPT FOR KJMS AFTER 18 UTC..WHERE VCSH WAS MORE APPROPRIATE
SINCE THREAT FOR RAIN WILL BE LATER THERE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RP KINNEY
SHORT TERM...TWH
LONG TERM...NH
AVIATION...LTH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
109 AM EDT SAT MAY 25 2013
.SYNOPSIS...
CHILLY HIGH PRESSURE TAKES CHARGE TONIGHT INTO SATURDAY. WARM
FRONT LIFT NORTH INTO THE OHIO VALLEY AND WEST VIRGINIA EARLY
TUESDAY. A WARMING TREND EXPECTED MEMORIAL DAY THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
9 PM UPDATE. STILL GOING WITH A FROST SCENARIO FOR THE LOW LANDS
UNDER A FROST ADVISORY. DEWPOINTS ACROSS THE NORTH ARE NOW IN THE
LOW TO MID 30S ON A DECREASING NORTH WIND. WHILE THE MAJOR CITIES
MAY ESCAPE FROST...THE OUTLYING AREAS AND FAVORED LOW SPOTS ARE
INCREASINGLY LIKELY FOR SOME FROST. WILL MAKE NO CHANGE TO HEADLINES
NOR CURRENT FORECAST.
PREVIOUS DISCUSSION...
VERY TOUGH FCST TONIGHT REGARDING FROST/FREEZE POTENTIAL. DWPTS
CURRENTLY STRADDLING THE MARGINAL THRESHOLD FOR FROST TONIGHT
GIVEN AFTN MIXING. NOT SURE IF THESE GO LWR NEXT FEW HRS BEFORE
RECOVERING THIS EVE. GUIDANCE FOR METRO AREAS IN THE LOWLANDS RUN
32 TO 40F FROM KHTS TO KCRW. H925 WINDS STAY UP ARND 20 KTS
OVERNIGHT AS SFC HIGH BUILDS IN TO ALLOW WINDS AT THE GROUND TO
TRY TO GO CALM. ALL OF THIS COMPLICATES MATTERS FOR EXPANDING
FROST ADV. HOWEVER...GIVEN TIME OF YEAR AND FACT THAT MOST FOLKS
HAVE SOME OF THEIR VEGGIES IN THE GROUND ALONG WITH ANNUAL PLANT
INVESTMENTS...FELT PRUDENT TO LEAN A LITTLE LIBERAL AND EXPAND TO
ENCOMPASS REST OF CWA SAVE FOR S COAL FIELDS TO SW VA. OUTLYING
AREAS WILL SEE BEST SHOT OF FROST. HEADLINE SHOULD GARNER MORE
ATTENTION FOR FOLKS TO TAKE PRECAUTIONS TO BE ON SAFE SIDE. ALSO
EXPANDED FRZ WARNING TO RALEIGH BASED ON GUIDANCE RANGING FROM 28F
TO 33F. THEY WILL HAVE GET UNDER INVERSION THOUGH GIVEN H925 WINDS
OFF MDLS OVERNIGHT. OTHER CONCERN IS STRATUS OVERNIGHT ACROSS THE
N. NAM HAS BEEN WAY TOO FAST IN ERADICATING THE LLVL MOISTURE VS
RUC WHICH HAS BEEN PRETTY STEADY. RUC SHOWS CLDS LIFTING AND SCT
THIS EVE ACROSS THE N BEFORE REDEVELOPING IN N MTNS BY 06Z. NAM
KEEPS ENTIRE COLUMN DRY BUT HAS NOT HANDLED TDY WELL AT ALL. SO
WILL LEAN TOWARD RUC AND REDEVELOP SOME STRATUS IN N MTNS LATE
TONIGHT. THIS MAY KEEP TEMPS UP TONIGHT ESPECIALLY IN
VALLEYS...BUT STILL FEEL AOB FRZ TEMPS WILL BE REALIZED.
UPR TROF AXIS SHIFTS TO E COAST ON SAT WITH SOME RECOVERY IN TEMPS
COMPARED TO TDY. INHERITED TEMPS LOOKED GOOD AND ONLY NEEDED
TWEAKING SOME...MAINLY ACROSS THE N.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
MADE MODIFICATIONS TO THE SHORT TERM FORECAST AS FOLLOWS:
HIGH PRESSURE WILL BE IN CONTROL THROUGH THE WEEKEND...KEEPING DRY
CONDITIONS AREAWIDE. MODELS SHOW A MID LEVEL SHORTWAVE...EVIDENT
IN H5 CHARTS...UNDER NORTHWEST FLOW ALOFT...MOVING ACROSS SOUTHERN
OH...SOUTHEAST INTO NORTHWEST KY. REMOVED ANY POPS FOR THE WEEKEND
AS MOISTURE LOOKS VERY LIMITED OVER WV. IN FACT...THERE COULD BE
SOME CLEARING SATURDAY NIGHT INTO SUNDAY MORNING...KEEPING
TEMPERATURES AT OR JUST BELOW FREEZING OVER POCAHONTAS AND
RANDOLPH COUNTIES. INCLUDED PATCHY FROST OVER NORTHEAST MOUNTAINS.
HIGH PRESSURE MOVES EAST OVER THE MID ATLANTIC STATES KEEPING
INFLUENCE OVER WV FOR A DRY SUNDAY THROUGH MONDAY NIGHT.
MINOR CHANGES TO TEMPERATURES THROUGH THE PERIOD...PERHAPS A
COUPLE DEGREES LOWER CLOSER TO THE COOLER MET.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANOTHER SHORTWAVE UNDER NORTHWEST FLOW ALOFT PASSES ACROSS
SOUTHEAST OH AND WV MONDAY AND TUESDAY. AT THE SAME TIME...A WARM
FRONT LIFTS NORTH INTO SOUTHERN OH...ACROSS WV AND VA ORIENTED
WEST TO EAST BY 12Z TUESDAY. THESE TWO FEATURES WILL BE CAPABLE TO
PRODUCE SHOWERS AND STORMS LATE MONDAY INTO TUESDAY AS THE WARM
FRONT MOVES NORTH OF THE AREA BY EARLY WEDNESDAY. INCREASED POPS
TO CHANCE INCLUDING THUNDER IN WEATHER GRIDS ACCORDINGLY.
HIGH PRESSURE TAKES CONTROL BY EARLY WEDNESDAY PROVIDING DRY
WEATHER WITH A SLOW WARMING TREND THROUGH THE REST OF THE WEEK.
TWEAKED COUPLE OF DEGREES DOWN FROM HPC GUIDANCE IN THE EXTENDED
PERIODS.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED ACROSS THE FORECAST AREA THROUGH THE TAF
PERIOD. ONE EXCEPTION IS SOME MVFR CEILINGS CURRENTLY IN
EKN...AND COULD ALSO GET SOME MVFR VISIBILITY THERE BEFORE THE SUN
COMES UP. EKN SHOULD RETURN TO VFR BY 13Z-14Z. VFR CU FIELD WILL
DEVELOP TODAY...GENERALLY 6-9KFT. UPPER LEVEL DISTURBANCE BRINGS
CLOUDS TO THE SOUTH TONIGHT...BUT AGAIN REMAINING VFR.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG AT EKN 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 SAT 05/25/13
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M M M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H M M M H H H H H H H
AFTER 06Z SUNDAY...
NO WIDESPREAD IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR WVZ005>011-
013>020-026>032-039-040.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR WVZ035>038-046-
047.
OH...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR OHZ066-067-075-
076-083>087.
KY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...JMV/30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1239 PM CDT SAT MAY 25 2013
.UPDATE...
ISSUED AT 1239 PM CDT SAT MAY 25 2013
BASED ON LATEST MESOANALYSIS...ADDED A SLIGHT CHANCE THIS
AFTERNOON FOR WESTERN CWA IN SOUTH CENTRAL SOUTH DAKOTA. LATEST
SURFACE PLOT SHOWS THE NORTHWARD MOVING WARM FRONT NOW LOCATED
FROM NORTH OF RAPID CITY...TO NORTH OF ALLIANCE/O`NEILL
NEBRASKA...AND SOUTHEAST THROUGH SE NEBRASKA. CU ALSO DEVELOPING
BETWEEN KIEN/KVTN WITH SURFACE HEATING. LATEST SPC MESOANALYSIS
SHOWS AXIS OF LITTLE CIN AND SBCAPE OF 1500+ J/KG STRETCHED ACROSS
SOUTH CENTRAL SOUTH DAKOTA. WITH DAYTIME HEATING AND WEAK VORT
MAX IN FLOW ALOFT APPROACHING...ISOLATED CELL INITIATION IS
POSSIBLE THIS AFTERNOON...ALTHOUGH MUCH OF THE INITIATION IS
EXPECTED OUT IN WESTERN SODAK WITH STRONGER SHORT WAVE AND HIGHER
INSTABILITY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 25 2013
THUNDERSTORM COMPLEX OVER NEBRASKA OVERNIGHT CONTINUES EARLY THIS
MORNING. SEEING SHOWERS AND STORMS BEGINNING TO EXPAND ACROSS
NORTHWEST IOWA AS WELL AS LOW LEVEL THETAE ADVECTION INCREASES. HIGH
RES MODEL SUITE LOOK TO HAVE A PRETTY GOOD HANDLE ON THIS ACTIVITY.
EXPECT IT TO CONTINUE THIS MORNING AND POSSIBLY EXPAND A BIT FURTHER
NORTH INTO PORTIONS OF SOUTHWEST MINNESOTA. LOWERED POPS ACROSS
SOUTHEAST SOUTH DAKOTA...AS ALL INDICATIONS ARE THAT THESE STORMS
WILL NOT DEVELOP NORTHWEST OF THEIR CURRENT LOCATION. MOST OF THE
STORMS SHOULD BE EAST OF THE CWA BY 16Z. MAIN IMPACTS WILL BE
BRIEFLY HEAVY RAIN AND POSSIBLY SMALL HAIL WITH THESE CELLS...AS
EFFECTIVE SHEAR AND CAPE ARE TOO LOW FOR ANY SEVERE THREAT. MUCH OF
THE AFTERNOON SHOULD THEN BE DRY ACROSS THE CWA WITH AN AREA OF
SUBSIDENCE LIKELY BEHIND THIS MORNINGS SHORTWAVE. WARM FRONTAL
BOUNDARY WILL POSITION ITSELF SOUTH OF THE MISSOURI RIVER THIS
AFTERNOON. HRRR AND RAP TRY TO BREAK THE CAP THEIR THIS
AFTERNOON...BUT BOTH THESE MODELS SEEM A BIT OVERDONE WITH DEWPOINTS
AND INSTABILITY. FEEL MORE LIKELY SCENARIO IS ACTIVITY WAITS FOR THE
LOW LEVEL JET TO KICK IN AFTER 0Z BEFORE IT GETS GOING.
OTHER ISSUE TODAY IS CLOUD COVER AND HIGH TEMPERATURES.
INTERESTINGLY THE HRRR AND RAP ARE COMPLETE OPPOSITE OF EACH
OTHER...GIVING AROUND A 20 DEGREE DIFFERENCE IN HIGHS...WITH THE RAP
HAVING MORE STRATUS AND COOLER TEMPERATURES. THE GEM AND ECMWF SIDE
CLOSER TO THE RAP...WITH THE NAM IN BETWEEN. SINCE THE AREAL
COVERAGE OF LOW STRATUS IS CURRENTLY LESS THAN EXPECTED...DID GO
AHEAD AND RAISE HIGHS SEVERAL DEGREES FOR TODAY IN OUR CENTRAL AND
WEST. ALSO THE HRRR HAS A GOOD HANDLE ON THE CURRENT SITUATION...SO
ONE WOULD THINK ITS SHORT RANGE FORECAST SHOULD BE SOMEWHAT
RELIABLE...AND IT HAS CONSISTENTLY BEEN WARM FOR TODAY. LOWERED
HIGHS A FEW IN THE EAST WHERE IT IS RAINING...AND WHERE STRATUS
SHOULD INDEED HOLD IN FOR MUCH OF THE DAY. AGAIN THIS IS A PRETTY
LOW CONFIDENCE TEMPERATURE FORECAST FOR ANYWHERE EAST OF THE JAMES
RIVER. BUT FEEL GOING FORECAST IS A DECENT STARTING POINT...WITH THE
DAY SHIFT LIKELY HAVING TO ADJUST UP OR DOWN DEPENDING ON CLOUD
COVER TRENDS.
QUIET SHORT TERM CONDITIONS FROM THE AFTERNOON HOURS SHOULD TURN
QUICKLY TO MORE STORMY CONDITIONS OVERNIGHT. GAVE A FAIR AMOUNT
OF CREDIT TO THE CONSISTENCY OF THE 00Z HIGH RESOLUTION NAMDNG5
AND WRF-ARW SOLUTIONS...WHICH FIT THE OVERALL CONCEPTUAL MODEL FOR
CONVECTIVE INITIATION TONIGHT. BOUNDARY FROM CURRENT NIGHT MCS
WILL BE FESTERING AND DRIFTING NORTHWARD...WITH LIKELY 1000 TO
1500 J/KG ELEVATED CAPE LIFTED FROM 1 TO 1.5 KM AGL. AS 35 TO 40
KNOT LOW LEVEL JET DEVELOPS TONIGHT THROUGH THE CENTRAL PLAINS...
SHOULD BECOME ENOUGH TO INITIATE ELEVATED THUNDERSTORMS NEAR/NORTH
OF THE BOUNDARY WHICH WILL BE DRIFTING NORTHWARD OF INTERSTATE 80
DURING THE EVENING HOURS. EFFECTIVE SHEAR IN AREAS NORTH OF THE
BOUNDARY WILL BE VERY CONCENTRATED IN THE 1-3KM LAYER WITH STRONGEST
WINDS IN LOW LEVELS AND WEAKENING MID LEVEL WINDS ROUGHLY 20-30
KNOTS...WITH LESSER DEEP LAYER SHEAR CONTRIBUTIONS FROM ABOVE. ALL
SUGGEST AT LEAST A MINIMAL THREAT FOR ISOLATED LARGER HAIL OR
DAMAGING WINDS THROUGH THE MISSOURI RIVER CORRIDOR AND LIFTING
SOMEWHAT NORTHWARD THROUGH 066-08Z. OTHER SIGNIFICANT CONVECTIVE
INITIATION IS LIKELY TO OCCUR BACK THROUGH THE WESTERN HIGH PLAINS
WHERE STRONGER SHEAR EXISTS WITH A BIT STRONGER MID LEVEL WINDS
TO AROUND 25 KNOTS...AS WELL AS THE DEEP UPSLOPE TRANSPORT OF MOISTURE
TO RESULT IN STRONGER INSTABILITY. EVENTUALLY...WHEN SUPERCELL MOTIONS
WHICH WILL TAKE ACTION MORE SOUTHWARD THAN EAST START TO EASE...AND
LOW LEVEL JET VEERS EASTWARD...WILL FIND A MORE LINEAR MCS LIKELY
TAKING SHAPE. MANY HI RES MODELS SUGGEST THIS MCS WILL ZIPPER DOWN
THE LOCATION OF THE WARM ADVECTION WING SPREADING NORTHWARD...MOVING
TOWARD EAST CENTRAL SD AND SOUTHWEST MN LATE NIGHT. SEVERE THREAT
WITH THIS FEATURE WOULD SEEM TO BE SOMEWHAT LOWER...BUT LIKELY TO
GET SOME GUSTY WINDS AND AREAS OF HEAVY RAINFALL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 25 2013
MCS EXPECTED TO WEAKEN AND SHIFT EAST ON SUNDAY...AND WITH MID
LEVEL FORCING SHOWING TENDENCY TO FORCE SUBSIDENCE AROUND
MIDDAY...AGAIN EXPECT THAT MUCH OF THE DAYTIME PERIOD WILL
PROBABLY END UP PRECIPITATION FREE. HOWEVER...CLOUDS LIKELY TO
PERSIST WITH STRATUS DEVELOPING IN WAKE OF SYSTEM. MOST LIKELY TO
GET BREAKS THROUGH THE WESTERN AND SOUTHERN CWA DURING THE
AFTERNOON...AND HAVE PUSHED EXPECTED TEMPS TO NEAR 80 THERE...
WHILE MORE MID TO UPPER 60S LINGER IN THE FAR EAST. RESULT OF THIS
WILL BE GENERATION OF DECENT POTENTIAL INSTABILITY OF 1500-2000
J/KG ACROSS THE AREA...WITH WEAKEST OF THE CAPPING INVERSION NEAR
THE MISSOURI RIVER CORRIDOR. SHEAR BECOMES A BIT MORE DISTRIBUTED
THROUGH THE EFFECTIVE LAYER...AND FAIRLY CLOSE TO THOSE VALUES
FROM THIS EVENING FROM 30 TO 35 KNOTS. A FEW MORE SEVERE STORMS
WOULD BE POSSIBLE MAINLY THROUGH THE SOUTHWEST HALF OF THE AREA
DURING THE LATER AFTERNOON AND EVENING HOURS...AS INITIATION
LIKELY TO BE A RESULT OF WEAK IMPULSE SLIDING UP BACK SIDE OF
RIDGE IN THE LATER AFTERNOON AND EARLY EVENING.
THE FURTHER ONE GOES INTO THE FORECAST...THE LESS RELIABLE ANY
GUIDANCE BECOMES GIVEN THE ABUNDANCE OF CONVECTION...AND THE
INCREASINGLY GREAT UNCERTAINTY AS TO WHERE CRITICAL BOUNDARIES MAY
LIE. ONE THING FOR SURE...GIVEN THE CLOSED LOW ACROSS THE WESTERN
U.S. AND THE SOUTHWEST FLOW ALOFT...DIFFICULT TO PINPOINT ANY TIME
FROM MONDAY ON THAT ONE COULD SAY THERE WAS ABSOLUTELY NO CHANCE
FOR PRECIPITATION...BUT ON THE SAME FRONT IT CERTAINLY WILL NOT BE
AN ALL TIME WASHOUT WITH MANY BREAKS DEFINED ON THE MESOSCALE.
MEMORIAL DAY AND MONDAY NIGHT WILL PLACE THE AREA ON THE SOUTHERN
FLANK OF A COUPLE OF WAVES MOVING OVER THE RIDGE...SO LIKELY TO
HAVE ENHANCEMENT OF PRECIPITATION IN THE NOCTURNALLY FAVORED
PERIODS. WHILE A FEW SEVERE STORMS ARE AGAIN WELL WITHIN
REASON...HIGH PRECIPITABLE WATER AND FAIRLY SLOW MOVING WIND
PROFILES BRING THE CONCERN OF AREAS OF HEAVY RAINFALL...AT THIS
RANGE HARD TO DEFINE. AT THE MOMENT...THE PROSPECT FOR MORE
SIGNIFICANT CONVECTION AND SEVERE WEATHER WOULD APPEAR TO BE LATE
DAY WEDNESDAY INTO THURSDAY...AS DEEP WESTERN CLOSED LOW KICKS
STRONGER JET ENERGY INTO THE PLAINS. MOISTURE THROUGH LOWER LEVELS
/THUS INSTABILITY/ WILL CONTINUE TO BENEFIT FROM PERSISTENT
SOUTHERLY FLOW. TEMPERATURES WILL LIKELY GRAVITATE TO SOMEWHAT
ABOVE NORMAL READINGS THROUGH THE UPCOMING WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CDT SAT MAY 25 2013
MVFR CIGS ACROSS SW MN AND NW IA DID ADVECT INTO THE FSD/SUX TAF
SITES THIS MORNING WITH ESE LOW LEVEL FLOW IN PLACE. EXPECT MVFR
CIGS TO CONTINUE THROUGH THIS AFTERNOON WITH THE EDGE RIGHT AT FSD
POSSIBLY WAVERING...ALTHOUGH ADDITIONAL EXPANSION OF THIS STRATUS
IS NOT EXPECTED TOWARD HON UNTIL LATER THIS EVENING. EXPECTING
CONVECTION TO DEVELOP THIS EVENING ALONG THE WARM FRONT EXTENDING
ACROSS SW SD AND NE NEBRASKA THEN PUSH EAST AND NORTHEAST ACROSS
THE AREA LATE EVENING AND OVERNIGHT. IN ADDITION...LOW LEVEL
MOISTURE WILL CONTINUE TO INCREASE WITH ...RESULTING IN IFR CIGS
WITH SOME AREAS OF HAZE LIKELY. BY EARLY MORNING /2Z/ CONVECTION
SHOULD BE EXITING THE AREA...ALTHOUGH IFR/MVFR CIGS ARE EXPECTED
TO PERSIST THROUGH MID MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...CHAPMAN/CHENARD
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
639 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 25 2013
THUNDERSTORM COMPLEX OVER NEBRASKA OVERNIGHT CONTINUES EARLY THIS
MORNING. SEEING SHOWERS AND STORMS BEGINNING TO EXPAND ACROSS
NORTHWEST IOWA AS WELL AS LOW LEVEL THETAE ADVECTION INCREASES. HIGH
RES MODEL SUITE LOOK TO HAVE A PRETTY GOOD HANDLE ON THIS ACTIVITY.
EXPECT IT TO CONTINUE THIS MORNING AND POSSIBLY EXPAND A BIT FURTHER
NORTH INTO PORTIONS OF SOUTHWEST MINNESOTA. LOWERED POPS ACROSS
SOUTHEAST SOUTH DAKOTA...AS ALL INDICATIONS ARE THAT THESE STORMS
WILL NOT DEVELOP NORTHWEST OF THEIR CURRENT LOCATION. MOST OF THE
STORMS SHOULD BE EAST OF THE CWA BY 16Z. MAIN IMPACTS WILL BE
BRIEFLY HEAVY RAIN AND POSSIBLY SMALL HAIL WITH THESE CELLS...AS
EFFECTIVE SHEAR AND CAPE ARE TOO LOW FOR ANY SEVERE THREAT. MUCH OF
THE AFTERNOON SHOULD THEN BE DRY ACROSS THE CWA WITH AN AREA OF
SUBSIDENCE LIKELY BEHIND THIS MORNINGS SHORTWAVE. WARM FRONTAL
BOUNDARY WILL POSITION ITSELF SOUTH OF THE MISSOURI RIVER THIS
AFTERNOON. HRRR AND RAP TRY TO BREAK THE CAP THEIR THIS
AFTERNOON...BUT BOTH THESE MODELS SEEM A BIT OVERDONE WITH DEWPOINTS
AND INSTABILITY. FEEL MORE LIKELY SCENARIO IS ACTIVITY WAITS FOR THE
LOW LEVEL JET TO KICK IN AFTER 0Z BEFORE IT GETS GOING.
OTHER ISSUE TODAY IS CLOUD COVER AND HIGH TEMPERATURES.
INTERESTINGLY THE HRRR AND RAP ARE COMPLETE OPPOSITE OF EACH
OTHER...GIVING AROUND A 20 DEGREE DIFFERENCE IN HIGHS...WITH THE RAP
HAVING MORE STRATUS AND COOLER TEMPERATURES. THE GEM AND ECMWF SIDE
CLOSER TO THE RAP...WITH THE NAM IN BETWEEN. SINCE THE AREAL
COVERAGE OF LOW STRATUS IS CURRENTLY LESS THAN EXPECTED...DID GO
AHEAD AND RAISE HIGHS SEVERAL DEGREES FOR TODAY IN OUR CENTRAL AND
WEST. ALSO THE HRRR HAS A GOOD HANDLE ON THE CURRENT SITUATION...SO
ONE WOULD THINK ITS SHORT RANGE FORECAST SHOULD BE SOMEWHAT
RELIABLE...AND IT HAS CONSISTENTLY BEEN WARM FOR TODAY. LOWERED
HIGHS A FEW IN THE EAST WHERE IT IS RAINING...AND WHERE STRATUS
SHOULD INDEED HOLD IN FOR MUCH OF THE DAY. AGAIN THIS IS A PRETTY
LOW CONFIDENCE TEMPERATURE FORECAST FOR ANYWHERE EAST OF THE JAMES
RIVER. BUT FEEL GOING FORECAST IS A DECENT STARTING POINT...WITH THE
DAY SHIFT LIKELY HAVING TO ADJUST UP OR DOWN DEPENDING ON CLOUD
COVER TRENDS.
QUIET SHORT TERM CONDITIONS FROM THE AFTERNOON HOURS SHOULD TURN
QUICKLY TO MORE STORMY CONDITIONS OVERNIGHT. GAVE A FAIR AMOUNT
OF CREDIT TO THE CONSISTENCY OF THE 00Z HIGH RESOLUTION NAMDNG5
AND WRF-ARW SOLUTIONS...WHICH FIT THE OVERALL CONCEPTUAL MODEL FOR
CONVECTIVE INITIATION TONIGHT. BOUNDARY FROM CURRENT NIGHT MCS
WILL BE FESTERING AND DRIFTING NORTHWARD...WITH LIKELY 1000 TO
1500 J/KG ELEVATED CAPE LIFTED FROM 1 TO 1.5 KM AGL. AS 35 TO 40
KNOT LOW LEVEL JET DEVELOPS TONIGHT THROUGH THE CENTRAL PLAINS...
SHOULD BECOME ENOUGH TO INITIATE ELEVATED THUNDERSTORMS NEAR/NORTH
OF THE BOUNDARY WHICH WILL BE DRIFTING NORTHWARD OF INTERSTATE 80
DURING THE EVENING HOURS. EFFECTIVE SHEAR IN AREAS NORTH OF THE
BOUNDARY WILL BE VERY CONCENTRATED IN THE 1-3KM LAYER WITH STRONGEST
WINDS IN LOW LEVELS AND WEAKENING MID LEVEL WINDS ROUGHLY 20-30
KNOTS...WITH LESSER DEEP LAYER SHEAR CONTRIBUTIONS FROM ABOVE. ALL
SUGGEST AT LEAST A MINIMAL THREAT FOR ISOLATED LARGER HAIL OR
DAMAGING WINDS THROUGH THE MISSOURI RIVER CORRIDOR AND LIFTING
SOMEWHAT NORTHWARD THROUGH 066-08Z. OTHER SIGNIFICANT CONVECTIVE
INITIATION IS LIKELY TO OCCUR BACK THROUGH THE WESTERN HIGH PLAINS
WHERE STRONGER SHEAR EXISTS WITH A BIT STRONGER MID LEVEL WINDS
TO AROUND 25 KNOTS...AS WELL AS THE DEEP UPSLOPE TRANSPORT OF MOISTURE
TO RESULT IN STRONGER INSTABILITY. EVENTUALLY...WHEN SUPERCELL MOTIONS
WHICH WILL TAKE ACTION MORE SOUTHWARD THAN EAST START TO EASE...AND
LOW LEVEL JET VEERS EASTWARD...WILL FIND A MORE LINEAR MCS LIKELY
TAKING SHAPE. MANY HI RES MODELS SUGGEST THIS MCS WILL ZIPPER DOWN
THE LOCATION OF THE WARM ADVECTION WING SPREADING NORTHWARD...MOVING
TOWARD EAST CENTRAL SD AND SOUTHWEST MN LATE NIGHT. SEVERE THREAT
WITH THIS FEATURE WOULD SEEM TO BE SOMEWHAT LOWER...BUT LIKELY TO
GET SOME GUSTY WINDS AND AREAS OF HEAVY RAINFALL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 25 2013
MCS EXPECTED TO WEAKEN AND SHIFT EAST ON SUNDAY...AND WITH MID
LEVEL FORCING SHOWING TENDENCY TO FORCE SUBSIDENCE AROUND
MIDDAY...AGAIN EXPECT THAT MUCH OF THE DAYTIME PERIOD WILL
PROBABLY END UP PRECIPITATION FREE. HOWEVER...CLOUDS LIKELY TO
PERSIST WITH STRATUS DEVELOPING IN WAKE OF SYSTEM. MOST LIKELY TO
GET BREAKS THROUGH THE WESTERN AND SOUTHERN CWA DURING THE
AFTERNOON...AND HAVE PUSHED EXPECTED TEMPS TO NEAR 80 THERE...
WHILE MORE MID TO UPPER 60S LINGER IN THE FAR EAST. RESULT OF THIS
WILL BE GENERATION OF DECENT POTENTIAL INSTABILITY OF 1500-2000
J/KG ACROSS THE AREA...WITH WEAKEST OF THE CAPPING INVERSION NEAR
THE MISSOURI RIVER CORRIDOR. SHEAR BECOMES A BIT MORE DISTRIBUTED
THROUGH THE EFFECTIVE LAYER...AND FAIRLY CLOSE TO THOSE VALUES
FROM THIS EVENING FROM 30 TO 35 KNOTS. A FEW MORE SEVERE STORMS
WOULD BE POSSIBLE MAINLY THROUGH THE SOUTHWEST HALF OF THE AREA
DURING THE LATER AFTERNOON AND EVENING HOURS...AS INITIATION
LIKELY TO BE A RESULT OF WEAK IMPULSE SLIDING UP BACK SIDE OF
RIDGE IN THE LATER AFTERNOON AND EARLY EVENING.
THE FURTHER ONE GOES INTO THE FORECAST...THE LESS RELIABLE ANY
GUIDANCE BECOMES GIVEN THE ABUNDANCE OF CONVECTION...AND THE
INCREASINGLY GREAT UNCERTAINTY AS TO WHERE CRITICAL BOUNDARIES MAY
LIE. ONE THING FOR SURE...GIVEN THE CLOSED LOW ACROSS THE WESTERN
U.S. AND THE SOUTHWEST FLOW ALOFT...DIFFICULT TO PINPOINT ANY TIME
FROM MONDAY ON THAT ONE COULD SAY THERE WAS ABSOLUTELY NO CHANCE
FOR PRECIPITATION...BUT ON THE SAME FRONT IT CERTAINLY WILL NOT BE
AN ALL TIME WASHOUT WITH MANY BREAKS DEFINED ON THE MESOSCALE.
MEMORIAL DAY AND MONDAY NIGHT WILL PLACE THE AREA ON THE SOUTHERN
FLANK OF A COUPLE OF WAVES MOVING OVER THE RIDGE...SO LIKELY TO
HAVE ENHANCEMENT OF PRECIPITATION IN THE NOCTURNALLY FAVORED
PERIODS. WHILE A FEW SEVERE STORMS ARE AGAIN WELL WITHIN
REASON...HIGH PRECIPITABLE WATER AND FAIRLY SLOW MOVING WIND
PROFILES BRING THE CONCERN OF AREAS OF HEAVY RAINFALL...AT THIS
RANGE HARD TO DEFINE. AT THE MOMENT...THE PROSPECT FOR MORE
SIGNIFICANT CONVECTION AND SEVERE WEATHER WOULD APPEAR TO BE LATE
DAY WEDNESDAY INTO THURSDAY...AS DEEP WESTERN CLOSED LOW KICKS
STRONGER JET ENERGY INTO THE PLAINS. MOISTURE THROUGH LOWER LEVELS
/THUS INSTABILITY/ WILL CONTINUE TO BENEFIT FROM PERSISTENT
SOUTHERLY FLOW. TEMPERATURES WILL LIKELY GRAVITATE TO SOMEWHAT
ABOVE NORMAL READINGS THROUGH THE UPCOMING WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 619 AM CDT SAT MAY 25 2013
LOW CONFIDENCE TAF FORECAST. MANY GUIDANCE SOLUTIONS SHOWING IFR TO
MVFR STRATUS THIS MORNING. THESE SOLUTIONS SHOW IT DEVELOPING OVER
NEBRASKA AND IOWA AND ADVECTING INTO OUR AREA. WINDS ARE
SOUTHEASTERLY FROM 1500 FEET AND BELOW AND SOUTHWESTERLY ABOVE THAT.
THAT SOUTHWESTERLY WIND IS ADVECTING IN DRY AIR...THUS ONLY STRATUS
BELOW 1500 FEET WOULD BE ABLE TO ADVECT INTO THE AREA. CURRENTLY NOT
SEEING MUCH OF THAT OUT THERE. THUS CUT BACK ON THE LOW CIGS AND KEPT
MOST OF OUR AREA VFR. HOWEVER WILL HAVE TO MONITOR THINGS THROUGH THE
MORNING. NOT OUT OF THE QUESTION THAT LOW STRATUS STILL FORMS...OR
THAT WE GET SOME MVFR STRATOCU AFTER SUNRISE. NEXT PROBLEM IS
CONVECTION. THIS MORNINGS ACTIVITY SHOULD REMAIN EAST OF THE TAF
SITES AND EXIT THE CWA BY MID TO LATE MORNING. TONIGHT...EXPECT
ACTIVITY TO GET GOING IN THE VICINITY OF A LOW LEVEL WARM FRONT AFTER
03Z. WHERE THIS EXACTLY HAPPENS REMAINS UNCERTAIN. AT THIS POINT IT
APPEAR THAT AREAS NEAR THE MISSOURI RIVER HAVE THE BEST SHOT. ALSO
EXPECT A THUNDERSTORM COMPLEX TO FORM TO OUR NORTHWEST...AND DIVE
THROUGH THE AREA AFTER 7Z INTO THE MORNING HOURS. MAIN THREATS WILL
BE REDUCTIONS TO IFR VIS/CIG IN THE HEAVIER RAIN...BUT SOME HAIL AND
GUSTY WINDS ARE ALSO POSSIBLE. STRATUS MAY ALSO TRY TO FORM
TONIGHT...BUT THAT WILL BE DEPENDENT ON HOW WELL WE MIX OUT THE LOW
LEVEL MOISTURE TODAY. DID PUT MVFR CIGS IN THE TAFS STARTING THIS
EVENING...BUT THIS IS ALSO UNFORTUNATELY UNCERTAIN.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN/CHENARD
LONG TERM...CHAPMAN
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
431 AM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SAT MAY 25 2013
THUNDERSTORM COMPLEX OVER NEBRASKA OVERNIGHT CONTINUES EARLY THIS
MORNING. SEEING SHOWERS AND STORMS BEGINNING TO EXPAND ACROSS
NORTHWEST IOWA AS WELL AS LOW LEVEL THETAE ADVECTION INCREASES. HIGH
RES MODEL SUITE LOOK TO HAVE A PRETTY GOOD HANDLE ON THIS ACTIVITY.
EXPECT IT TO CONTINUE THIS MORNING AND POSSIBLY EXPAND A BIT FURTHER
NORTH INTO PORTIONS OF SOUTHWEST MINNESOTA. LOWERED POPS ACROSS
SOUTHEAST SOUTH DAKOTA...AS ALL INDICATIONS ARE THAT THESE STORMS
WILL NOT DEVELOP NORTHWEST OF THEIR CURRENT LOCATION. MOST OF THE
STORMS SHOULD BE EAST OF THE CWA BY 16Z. MAIN IMPACTS WILL BE
BRIEFLY HEAVY RAIN AND POSSIBLY SMALL HAIL WITH THESE CELLS...AS
EFFECTIVE SHEAR AND CAPE ARE TOO LOW FOR ANY SEVERE THREAT. MUCH OF
THE AFTERNOON SHOULD THEN BE DRY ACROSS THE CWA WITH AN AREA OF
SUBSIDENCE LIKELY BEHIND THIS MORNINGS SHORTWAVE. WARM FRONTAL
BOUNDARY WILL POSITION ITSELF SOUTH OF THE MISSOURI RIVER THIS
AFTERNOON. HRRR AND RAP TRY TO BREAK THE CAP THEIR THIS
AFTERNOON...BUT BOTH THESE MODELS SEEM A BIT OVERDONE WITH DEWPOINTS
AND INSTABILITY. FEEL MORE LIKELY SCENARIO IS ACTIVITY WAITS FOR THE
LOW LEVEL JET TO KICK IN AFTER 0Z BEFORE IT GETS GOING.
OTHER ISSUE TODAY IS CLOUD COVER AND HIGH TEMPERATURES.
INTERESTINGLY THE HRRR AND RAP ARE COMPLETE OPPOSITE OF EACH
OTHER...GIVING AROUND A 20 DEGREE DIFFERENCE IN HIGHS...WITH THE RAP
HAVING MORE STRATUS AND COOLER TEMPERATURES. THE GEM AND ECMWF SIDE
CLOSER TO THE RAP...WITH THE NAM IN BETWEEN. SINCE THE AREAL
COVERAGE OF LOW STRATUS IS CURRENTLY LESS THAN EXPECTED...DID GO
AHEAD AND RAISE HIGHS SEVERAL DEGREES FOR TODAY IN OUR CENTRAL AND
WEST. ALSO THE HRRR HAS A GOOD HANDLE ON THE CURRENT SITUATION...SO
ONE WOULD THINK ITS SHORT RANGE FORECAST SHOULD BE SOMEWHAT
RELIABLE...AND IT HAS CONSISTENTLY BEEN WARM FOR TODAY. LOWERED
HIGHS A FEW IN THE EAST WHERE IT IS RAINING...AND WHERE STRATUS
SHOULD INDEED HOLD IN FOR MUCH OF THE DAY. AGAIN THIS IS A PRETTY
LOW CONFIDENCE TEMPERATURE FORECAST FOR ANYWHERE EAST OF THE JAMES
RIVER. BUT FEEL GOING FORECAST IS A DECENT STARTING POINT...WITH THE
DAY SHIFT LIKELY HAVING TO ADJUST UP OR DOWN DEPENDING ON CLOUD
COVER TRENDS.
QUIET SHORT TERM CONDITIONS FROM THE AFTERNOON HOURS SHOULD TURN
QUICKLY TO MORE STORMY CONDITIONS OVERNIGHT. GAVE A FAIR AMOUNT
OF CREDIT TO THE CONSISTENCY OF THE 00Z HIGH RESOLUTION NAMDNG5
AND WRF-ARW SOLUTIONS...WHICH FIT THE OVERALL CONCEPTUAL MODEL FOR
CONVECTIVE INITIATION TONIGHT. BOUNDARY FROM CURRENT NIGHT MCS
WILL BE FESTERING AND DRIFTING NORTHWARD...WITH LIKELY 1000 TO
1500 J/KG ELEVATED CAPE LIFTED FROM 1 TO 1.5 KM AGL. AS 35 TO 40
KNOT LOW LEVEL JET DEVELOPS TONIGHT THROUGH THE CENTRAL PLAINS...
SHOULD BECOME ENOUGH TO INITIATE ELEVATED THUNDERSTORMS NEAR/NORTH
OF THE BOUNDARY WHICH WILL BE DRIFTING NORTHWARD OF INTERSTATE 80
DURING THE EVENING HOURS. EFFECTIVE SHEAR IN AREAS NORTH OF THE
BOUNDARY WILL BE VERY CONCENTRATED IN THE 1-3KM LAYER WITH STRONGEST
WINDS IN LOW LEVELS AND WEAKENING MID LEVEL WINDS ROUGHLY 20-30
KNOTS...WITH LESSER DEEP LAYER SHEAR CONTRIBUTIONS FROM ABOVE. ALL
SUGGEST AT LEAST A MINIMAL THREAT FOR ISOLATED LARGER HAIL OR
DAMAGING WINDS THROUGH THE MISSOURI RIVER CORRIDOR AND LIFTING
SOMEWHAT NORTHWARD THROUGH 066-08Z. OTHER SIGNIFICANT CONVECTIVE
INITIATION IS LIKELY TO OCCUR BACK THROUGH THE WESTERN HIGH PLAINS
WHERE STRONGER SHEAR EXISTS WITH A BIT STRONGER MID LEVEL WINDS
TO AROUND 25 KNOTS...AS WELL AS THE DEEP UPSLOPE TRANSPORT OF MOISTURE
TO RESULT IN STRONGER INSTABILITY. EVENTUALLY...WHEN SUPERCELL MOTIONS
WHICH WILL TAKE ACTION MORE SOUTHWARD THAN EAST START TO EASE...AND
LOW LEVEL JET VEERS EASTWARD...WILL FIND A MORE LINEAR MCS LIKELY
TAKING SHAPE. MANY HI RES MODELS SUGGEST THIS MCS WILL ZIPPER DOWN
THE LOCATION OF THE WARM ADVECTION WING SPREADING NORTHWARD...MOVING
TOWARD EAST CENTRAL SD AND SOUTHWEST MN LATE NIGHT. SEVERE THREAT
WITH THIS FEATURE WOULD SEEM TO BE SOMEWHAT LOWER...BUT LIKELY TO
GET SOME GUSTY WINDS AND AREAS OF HEAVY RAINFALL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 AM CDT SAT MAY 25 2013
MCS EXPECTED TO WEAKEN AND SHIFT EAST ON SUNDAY...AND WITH MID
LEVEL FORCING SHOWING TENDENCY TO FORCE SUBSIDENCE AROUND
MIDDAY...AGAIN EXPECT THAT MUCH OF THE DAYTIME PERIOD WILL
PROBABLY END UP PRECIPITATION FREE. HOWEVER...CLOUDS LIKELY TO
PERSIST WITH STRATUS DEVELOPING IN WAKE OF SYSTEM. MOST LIKELY TO
GET BREAKS THROUGH THE WESTERN AND SOUTHERN CWA DURING THE
AFTERNOON...AND HAVE PUSHED EXPECTED TEMPS TO NEAR 80 THERE...
WHILE MORE MID TO UPPER 60S LINGER IN THE FAR EAST. RESULT OF THIS
WILL BE GENERATION OF DECENT POTENTIAL INSTABILITY OF 1500-2000
J/KG ACROSS THE AREA...WITH WEAKEST OF THE CAPPING INVERSION NEAR
THE MISSOURI RIVER CORRIDOR. SHEAR BECOMES A BIT MORE DISTRIBUTED
THROUGH THE EFFECTIVE LAYER...AND FAIRLY CLOSE TO THOSE VALUES
FROM THIS EVENING FROM 30 TO 35 KNOTS. A FEW MORE SEVERE STORMS
WOULD BE POSSIBLE MAINLY THROUGH THE SOUTHWEST HALF OF THE AREA
DURING THE LATER AFTERNOON AND EVENING HOURS...AS INITIATION
LIKELY TO BE A RESULT OF WEAK IMPULSE SLIDING UP BACK SIDE OF
RIDGE IN THE LATER AFTERNOON AND EARLY EVENING.
THE FURTHER ONE GOES INTO THE FORECAST...THE LESS RELIABLE ANY
GUIDANCE BECOMES GIVEN THE ABUNDANCE OF CONVECTION...AND THE
INCREASINGLY GREAT UNCERTAINTY AS TO WHERE CRITICAL BOUNDARIES MAY
LIE. ONE THING FOR SURE...GIVEN THE CLOSED LOW ACROSS THE WESTERN
U.S. AND THE SOUTHWEST FLOW ALOFT...DIFFICULT TO PINPOINT ANY TIME
FROM MONDAY ON THAT ONE COULD SAY THERE WAS ABSOLUTELY NO CHANCE
FOR PRECIPITATION...BUT ON THE SAME FRONT IT CERTAINLY WILL NOT BE
AN ALL TIME WASHOUT WITH MANY BREAKS DEFINED ON THE MESOSCALE.
MEMORIAL DAY AND MONDAY NIGHT WILL PLACE THE AREA ON THE SOUTHERN
FLANK OF A COUPLE OF WAVES MOVING OVER THE RIDGE...SO LIKELY TO
HAVE ENHANCEMENT OF PRECIPITATION IN THE NOCTURNALLY FAVORED
PERIODS. WHILE A FEW SEVERE STORMS ARE AGAIN WELL WITHIN
REASON...HIGH PRECIPITABLE WATER AND FAIRLY SLOW MOVING WIND
PROFILES BRING THE CONCERN OF AREAS OF HEAVY RAINFALL...AT THIS
RANGE HARD TO DEFINE. AT THE MOMENT...THE PROSPECT FOR MORE
SIGNIFICANT CONVECTION AND SEVERE WEATHER WOULD APPEAR TO BE LATE
DAY WEDNESDAY INTO THURSDAY...AS DEEP WESTERN CLOSED LOW KICKS
STRONGER JET ENERGY INTO THE PLAINS. MOISTURE THROUGH LOWER LEVELS
/THUS INSTABILITY/ WILL CONTINUE TO BENEFIT FROM PERSISTENT
SOUTHERLY FLOW. TEMPERATURES WILL LIKELY GRAVITATE TO SOMEWHAT
ABOVE NORMAL READINGS THROUGH THE UPCOMING WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1103 PM CDT FRI MAY 24 2013
MODELS CONTINUE TO SHOW CEILINGS DETERIORATING INTO MVFR-IFR RANGE
LATER TONIGHT AT ALL TAF SITES. STARTING TO SEE HINTS OF MVFR CLOUDS
IN EASTERN NEBRASKA AS OF 04Z...SO WILL CONTINUE THIS DOWNWARD TREND
IN CEILINGS THROUGH THE FIRST 4-6 HOURS OF TAF PERIOD...WITH NEXT
CHANCE OF RAIN EXPANDING INTO SOUTHERN PARTS OF THE AREA ALONG WITH
THE LOWER CEILINGS. SOME MID LEVEL INSTABILITY PRESENT AS THE RAIN
MOVES INTO SOUTHWEST PARTS OF THE FORECAST AREA...BUT PRECIP MOVES
INTO MORE STABLE AIRMASS AS IT PROGRESSES EASTWARD...LEADING TO MORE
ISOLATED THUNDER THREAT ALONG AND EAST OF I-29 CORRIDOR. THUS HAVE
LEFT MENTION OF THUNDER OUT OF KFSD/KSUX TAFS AT THIS TIME...THOUGH
CANNOT COMPLETELY BE RULED OUT 08Z-15Z...ESPECIALLY AT KSUX. BULK OF
MVFR CEILINGS EXPECTED TO BECOME MORE SCATTERED THROUGH THE LATE
MORNING/EARLY AFTERNOON SATURDAY...THOUGH WITH MORE ABUNDANT LOW
LEVEL MOISTURE...POTENTIAL FOR MVFR CUMULUS AT TIMES THROUGH THE
AFTERNOON. GREATER CHANCE OF MVFR-IFR REDEVELOPMENT SATURDAY EVENING
WITH NEXT CHANCE OF CONVECTION SPREADING INTO THE AREA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN/CHENARD
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1040 PM CDT SUN MAY 26 2013
.UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...NOW LIMITING SCATTERED EVENING
THUNDERSTORMS TO COLLINGSWORTH COUNTY IN SOUTHEAST CORNER OF TEXAS
PANHANDLE ONLY. UPDATED TEXT PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 856 PM CDT SUN MAY 26 2013/
UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...REDUCING COVERAGE/POPS FOR EVENING
THUNDERSTORMS. HAVE CONFINED SCATTERED THUNDERSTORMS TO SOUTHEAST
TEXAS PANHANDLE...AND HAVE TRIMMED ISOLATED TO A SMALLER PORTION OF
EASTERN PARTS OF FORECAST AREA.
WILL ALLOW RED FLAG WARNING TO EXPIRE AT 9 PM.
UPDATED TEXT PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
PREV DISCUSSION... /ISSUED 700 PM CDT SUN MAY 26 2013/
UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...CALLING FOR SCATTERED TO ISOLATED
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST TEXAS PANHANDLE THROUGH
THE EVENING. EXPECT CONVECTION TO BE MAINLY CONTAINED SOUTHEAST
TEXAS PANHANDLE...WHERE NEWLY DEVELOPED CELLS WILL BE
PROPAGATING...DUE TO SUPPORT OF WEAK SHORTWAVE TROF. UPDATED TEXT
PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
PREV DISCUSSION... /ISSUED 626 PM CDT SUN MAY 26 2013/
AVIATION...
00Z TAF CYCLE
A DRYLINE JUST EAST OF THE GUYMON AND AMARILLO TAF SITES ALONG WITH
AN UPPER TROUGH MOVING ACROSS THE PANHANDLES EARLY TONIGHT WILL
PRODUCE ISOLATED TO SCATTERED CONVECTION. THIS CONVECTION IS EXPECTED
TO REMAIN EAST OF THE THREE TAF SITES. VFR CONDITIONS ALONG WITH
SOUTHWESTERLY WINDS 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 15Z
MONDAY...AND 10 TO 20 KNOTS BEFORE 15Z MONDAY WILL PREVAIL.
SCHNEIDER
PREV DISCUSSION... /ISSUED 405 PM CDT SUN MAY 26 2013/
DISCUSSION...
THERE REMAINS A LARGE AMOUNT OF POTENTIAL FOR WEATHER ACROSS THE
PANHANDLES FOR THE NEXT SEVERAL DAYS BUT THE QUESTION WILL BE CAN WE
TURN THAT POTENTIAL INTO REALITY.
ACROSS THE NORTHWEST TEXAS AND WESTERN OKLAHOMA PANHANDLE REMAIN A
PRIME AREA FOR CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP THIS
AFTERNOON AS THE DRYLINE SNEAKS INTO THE PANHANDLES. AS A RESULT
WILL LEAVE THE RED FLAG IN PLACE AND UNMODIFIED. FOR THE EASTERN
PANHANDLES THERE REMAINS A STRONG TO SEVERE STORM POTENTIAL THIS
AFTERNOON INTO THE OVERNIGHT HOURS. TTU WRF AND RUC HRRR SOLUTIONS
SHOW ISOLATED CONVECTION INITIATING ALONG AND EAST OF A VEGA TO
GUYMON LINE. RUC BUFR SOUNDINGS SHOW A WEAK CAP INHIBITING
INITIATION OF THESE STORMS UNTIL 6-7PM THIS EVENING. SHOULD THESE
STORMS FORM THEY WOULD BE ABLE TO TAP INTO ELEVATED INSTABILITY IN
THE RANGE OF 1000-1500 J/KG. DEEP LAYER SHEAR IN THE AREA OF LIKELY
INITIATION IS 25 TO 35 KT WITH A SLIGHT VEERING PATTERN. GIVEN
THE DEEP DRY LAYER BENEATH THE EXPECTED STORM BASES DAMAGING WINDS
OF 65 TO 70 MPH WOULD BE THE PRIMARY HAZARD BUT A HAIL THREAT CAN
NOT BE RULED OUT. ALL OF THIS IS ASSUMING THE WEAK CAP CAN BE
OVERCOME TO ALLOW STORMS TO DEVELOP. ANY STORMS THAT MAY DEVELOP
SHOULD DIMINISH BY 2 AM MONDAY MORNING.
DURING THE DAY MONDAY...THE DRYLINE WILL RACE ACROSS THE PANHANDLES
AND INTO WESTERN OKLAHOMA. THIS WILL PLACE THE VAST MAJORITY OF THE
PANHANDLES UNDER EXTREMELY DRY CONDITIONS WHICH COULD LEAD TO THE
RAPID SPREAD OF FIRE. WITH THAT BEING SAID RECENT RAINS PLUS ANY
ADDITIONAL RAIN WE GET TONIGHT WILL HELP TO MITIGATE SOME OF THIS
POTENTIAL. HAVE DECIDED TO NOT CARRY HEADLINES FOR MONDAY DUE TO THE
UNCERTAINTY OF PRECIP AMOUNTS AND COVERAGE FROM ANY STORMS
TONIGHT...BUT IF NO PRECIPITATION OCCURS A RED FLAG WARNING MAY BE
NEEDED FOR THE SIZABLE CHUNK OF THE AREA.
MODELS HAVE COME INTO A DECENT AGREEMENT FOR THE MID WEEK SYSTEM
WITH THE ECMWF LAGGING BEHIND THE OTHER MODELS SLIGHTLY. ALSO OF
NOTE HAS BEEN A SLIGHT INCREASE IN SPEED OF THE SYSTEM PLACING
BETTER PRECIP CHANCES ON TUESDAY AND CAUSING PRECIP CHANCES TO OCCUR
EARLIER IN THE DAY ON WEDNESDAY.
TUESDAY WILL BE A MIX OF FIRE WEATHER CONCERNS ACROSS THE WEST AND
ISOLATED SEVERE WEATHER CONCERNS ACROSS THE SOUTHEAST. THE POSITION
OF THE DRYLINE WILL BE THE MAJOR DETERMINING FACTOR AS TO WHO GETS
WHAT. FOR NOW HAVE GONE WITH A SPLIT OF THE GFS AND NAM ON DRYLINE
PLACEMENT WHICH ENDS UP BEING ROUGHLY ALONG A GUYMON TO CLAUDE LINE.
LOCATIONS WEST OF THIS LINE WILL HAVE A BETTER CHANCE FOR SEEING
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS...AND LOCATION
EAST OF THIS LINE WILL HAVE THE BETTER CHANCE OF SEEING
PRECIPITATION. LOOKING AT THE SYNOPTIC SCALE...A SHORTWAVE IS PROGGED TO
ROTATE AROUND THE BASE OF THE MAIN UPPER LEVEL TROUGH. THIS SYNOPTIC
LIFT COUPLED WITH CONVERGENCE ALONG THE DRYLINE COULD BE ENOUGH TO
INITIATE STORMS DURING THE AFTERNOON HOURS OF TUESDAY. DEEP LAYER
SHEAR FOR THIS TIME RANGES FROM 20 TO 35 KT AND INSTABILITY VALUES
RANGE FROM 1500 TO 2500 J/KG. STRONG TO SEVERE STORMS CAN NOT BE
RULED OUT AT THIS TIME WITH LARGE HAIL AND DAMAGING WINDS BEING THE
PRIMARY THREATS.
WEDNESDAY THE MAIN UPPER LEVEL TROUGH LOOKS TO TAKE A NEUTRAL TO
SLIGHTLY NEGATIVE TILT AS IT APPROACHES THE PANHANDLES. INSTABILITY
VALUES LOOK TO HAVE LOWERED SLIGHT WHICH COULD ALSO MEAN THAT THE
SEVERE THREAT MAY ALSO HAVE DIMINISHED SLIGHTLY. WITH THAT BEING
SAID CAPE VALUES OF 1000 TO 2000 J/KG AND DEEP LAYER SHEAR OF 35 TO
45 KT WILL KEEP AT LEAST THE CHANCE FOR STRONG STORMS AND A POSSIBLE
ISOLATED SEVERE STORM POSSIBLE. LARGE HAIL AND DAMAGING WINDS WILL
BE THE PRIMARY HAZARD.
THURSDAY THE UPPER FLOW BECOMES MORE ZONAL TO KEEP THAT AREA DRY AND
A WEAK COLD FRONT WILL DROP INTO THE PANHANDLES FRIDAY. CONDITIONS
LOOK TO REMAIN DRY GOING INTO THE WEEKEND.
FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS ARE STILL EXPECTED TO DEVELOP
ACROSS THE NORTHWESTERN TEXAS PANHANDLE AND WESTERN OKLAHOMA
PANHANDLE THIS AFTERNOON. OVERNIGHT THE DRYLINE WILL RETREAT AND
ALLOW RELATIVE HUMIDITIES TO RECOVER. HOWEVER...THE NORTHWESTERN
TEXAS AND WESTERN OKLAHOMA PANHANDLE MAY ONLY RECOVER SLIGHTLY WITH
MAXIMUM RELATIVE HUMIDITIES OF 30 TO 40 PERCENT.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE LIKELY ON
MONDAY FOR MUCH OF THE PANHANDLES AS RELATIVE HUMIDITIES DROP INTO
THE TEENS AND SINGLE DIGITS WITH SOUTHWEST 20 FOOT WINDS OF 20 TO 25
MPH WITH HIGHER GUSTS. THE RECENT RAINFALL ACROSS THE SOUTHERN TEXAS
PANHANDLE AND ANY ADDITIONAL RAINFALL TONIGHT WILL PROVIDE SOME
LIMITATIONS ON FIRE POTENTIAL...TO GO ALONG WITH LOW FUEL LOADING
DUE TO THE ONGOING DROUGHT. FOR NOW WILL KEEP HEADLINES SILENT FOR
THIS TIME PERIOD.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY DEVELOP ACROSS
THE WESTERN PANHANDLES TUESDAY AFTERNOON AS RELATIVE HUMIDITIES DROP
INTO THE SINGLE DIGITS ONCE AGAIN BEHIND THE DRYLINE AND 20 FOOT
SOUTHERLY WINDS OF 15 TO 25 MPH WINDS. HOWEVER PRECIP CHANCES WILL
BEGIN TO ENTER THE PANHANDLES DURING THE LATE AFTERNOON AND EVENING
HOURS WHICH COULD BRING AN EARLY END TO FIRE WEATHER CONDITIONS.
FIRE WEATHER CONDITIONS FROM WEDNESDAY THROUGH THE REST OF THE WORK
WEEK WILL BE HIGHLY DEPENDENT ON PRECIPITATION EXPECTED TUESDAY AND
WEDNESDAY. SHOULD THE WESTERN PANHANDLES GET LITTLE TO NO
PRECIPITATION TUESDAY AND WEDNESDAY...THEN ELEVATED TO NEAR CRITICAL
FIRE WEATHER CONDITIONS COULD BE POSSIBLE TUESDAY AFTERNOON...AND
ELEVATED FIRE WEATHER CONDITIONS THURSDAY AND FRIDAY.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/03
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
900 PM CDT SUN MAY 26 2013
.UPDATE...
FORECAST IS BEING UPDATED MAINLY FOR POPS AND SKY CONDITION...SEE
DISCUSSION.
&&
.DISCUSSION...
ISOLATED THUNDERSTORMS HAVE DEVELOPED THIS EVENING IN THE TEXAS
PANHANDLE SOUTHEAST OF AMARILLO...AND NEAR FORT STOCKTON. WITH
THE ABSENCE OF OTHER CONVECTIVE DEVELOPMENT TO OUR WEST...NOT
EXPECTING SHOWERS AND STORMS TO ENTER OUR AREA TONIGHT. HAVE
REMOVED THE POPS AND DECREASED THE CLOUD COVERAGE PER RECENT TRENDS
IN SATELLITE IMAGERY. WITH MOISTENING SOUTHEASTERLY BOUNDARY LAYER
FLOW OVERNIGHT...EXPECT LOW CLOUD DEVELOPMENT ACROSS OUR
SOUTHEASTERN COUNTIES TOWARD MORNING. THE LOW CLOUD FIELD SHOULD
ERODE MID TO LATE MORNING ON MONDAY...WITH A DIURNAL CUMULUS FIELD
IN THE AFTERNOON. MINOR ADJUSTMENTS WERE ALSO MADE TO TEMPERATURE
AND DEWPOINT GRIDS TO BRING IN LINE WITH SURFACE OBSERVATIONS THIS
EVENING. UPDATED FORECAST PRODUCTS WILL BE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 631 PM CDT SUN MAY 26 2013/
DISCUSSION...
LOOK FOR STRATUS TO BRING MVFR CEILINGS BACK TO MUCH OF WEST
CENTRAL TEXAS LATER TONIGHT. PLEASE SEE THE BELOW AVIATION
SECTION FOR MORE INFORMATION.
AVIATION...
THE LATEST RUC 925 MB RELATIVE HUMIDITY FIELD INDICATES STRATUS
WILL DOMINATE MUCH OF WEST CENTRAL TEXAS SOUTH OF INTERSTATE 20 BY
06Z TONIGHT. FOR NOW...I DECIDED TO CONTINUE WITH VFR CONDITIONS
AT SAN ANGELO...AS WELL AS ABILENE...FOR THE NEXT 24 HOURS. BY 18Z
TOMORROW...EXPECT VFR CONDITIONS TO AGAIN DOMINATE WEST CENTRAL TEXAS.
AS FOR SURFACE WINDS TOMORROW...MODELS INDICATE A SURFACE TROUGH
ACROSS WEST TEXAS WILL CREATE A MODERATE SURFACE PRESSURE GRADIENT
ACROSS WEST CENTRAL TEXAS. THUS...WATCH FOR GUSTY SOUTHERLY
SURFACE WINDS TO DOMINATE WEST CENTRAL TEXAS TOMORROW...ESPECIALLY
DURING THE AFTERNOON HOURS.
HUBER
PREV DISCUSSION... /ISSUED 327 PM CDT SUN MAY 26 2013/
SHORT TERM...
SIMILAR SCENARIO IN OUR WESTERN COUNTIES EXPECTED THIS EVENING AS
OCCURRED LAST EVENING WITH 0-6KM SHEAR OF 25-30KT AND MLCAPES OF
1500-2000 J/KG. DRYLINE WILL STRETCH FROM THE BIG BEND THROUGH THE
PERMIAN BASIN LATE THIS AFTERNOON WITH THUNDERSTORMS EXPECTED TO
DEVELOP ONCE AGAIN ALONG THE DRYLINE DURING TIME OF MAX HEATING.
ANY STORMS THAT DO DEVELOP MAY ONCE AGAIN IMPACT OUR WESTERN
COUNTIES BUT SHOULD BE IN A WEAKENING PHASE DUE TO THE LOSS OF
DIURNAL HEATING BY THE TIME THEY ENTER OUR COUNTIES. AT THIS TIME
DO NOT EXPECT ANY STORMS TO ENDURE PAST MIDNIGHT...SO SHOULD NOT
HAVE ANY STORMS PROPAGATING THROUGH THE CWA AS WE HAD LAST NIGHT.
LOOKING FOR CONTINUED WARMING WITH AFTERNOON HIGHS TOMORROW A FEW
DEGREES WARMER THAN TODAY...LOW TO MID 90S. MORNING LOWS SHOULD
ALSO BE A LITTLE WARMER...IN THE UPPER 60S TO AROUND 70.
15
LONG TERM...
THE WEST COAST TROUGH WILL DEEPEN EARLY NEXT WEEK AS A STRONG WAVE
MOVES INTO THE PACNW...AMPLIFYING THE SYNOPTIC PATTERN AS THE
MID LEVEL RIDGE BUILDS OVER THE EAST CONUS. PRONOUNCED SOUTHWEST
FLOW ALOFT WILL MAINTAIN/INTENSIFY THE MID LEVEL CAPPING INVERSION
THROUGH TUESDAY. THE MONDAY/TUESDAY DAYTIME PERIODS LOOK TO BE
BREEZY...WARM AND DRY /FOR THE MOST PART/ WITH TEMPERATURES
WARMING INTO THE LOWER 90S. A FEW DIURNAL THUNDERSTORMS ARE
EXPECTED TO FIRE EACH AFTERNOON IN THE VICINITY OF THE DRYLINE TO
THE WEST AND MAY MAKE A RUN FOR OUR WESTERN COUNTIES. THE CAP IS
STRONG BUT IF THE STRONG INSTABILITY IS TAPPED...SOME STORMS MAY
HAVE THE POTENTIAL TO BECOME SEVERE. HOWEVER...MOST AREAS WILL
REMAIN DRY.
ON WEDNESDAY...THE MODELS APPEAR TO BE CONVERGING ON A SOLUTION
THAT IS A COMPROMISE BETWEEN THE PREVIOUS RUNS OF THE GFS AND
ECMWF. THIS NEW SOLUTION DEPICTS A NEGATIVELY TILTED SHORTWAVE
TROUGH EJECTING INTO THE PLAINS BY PEAK HEATING ON WEDNESDAY.
SYNOPTIC SCALE ASCENT WILL WORK ON THE CAPPING INVERSION
THROUGHOUT THE DAY AND IS EXPECTED TO COOL MID LEVEL TEMPS
SUFFICIENTLY FOR THE CAP TO BREAK BY THURSDAY AFTERNOON. THERE IS
SOME HINT THAT WE COULD SEE ONGOING CONVECTION EARLY WEDNESDAY BUT
THIS SHOULD WEAKEN THROUGHOUT THE DAY AS MID LEVEL WARM ADVECTION
WANES. SLIGHTLY COOLER TEMPS ARE EXPECTED WITH HIGHS GENERALLY IN
THE MID/UPPER 80S. FORMIDABLE DEEP LAYER SHEAR /0-6KM BULK SHEAR
OF 35-40 KTS/ AND STRONG SURFACE BASED INSTABILITY WILL HEIGHTEN
THE POTENTIAL FOR SEVERE CONVECTION...WITH LARGE HAIL AND DAMAGING
WINDS BEING THE PRIMARY THREATS. ANY STORMS THAT DEVELOP WILL
PERSIST INTO THE EVENING HOURS.
BY THURSDAY...THIS WAVE WILL BE EAST OF THE AREA WITH A MORE
SUBSIDENT REGIME ANTICIPATED DURING THE DAY. IF ANY STORMS DO
DEVELOP...I THINK COVERAGE WILL BE VERY LIMITED. THUS...NO
MENTIONABLE POPS WERE CARRIED FOR THURSDAY AND THURSDAY NIGHT.
TEMPS WILL REBOUND TO NEAR NORMAL VALUES WITH HIGHS GENERALLY IN
THE UPPER 80S TO LOWER 90S. THIS TREND WILL CONTINUE ON FRIDAY
WITH TEMPS AT OR ABOVE 90 DEGREES IN MOST LOCATIONS WITH THE BEST
CHANCE FOR AFTERNOON AND EVENING STORMS FOUND TO THE NORTH AND
WEST OF THE CWA.
THE MODELS DISAGREE WITH THE PATTERN FOR THIS WEEKEND. THE GFS
CONTINUES TO SHOW A WEAK COLD FRONT MOVING SOUTH INTO WEST CENTRAL
TX WITH INCREASING RAIN CHANCES WHILE THE ECMWF KEEPS THIS FRONT
TO THE NORTH OF THE AREA. GIVEN THE LACK OF CONFIDENCE IN EITHER
SOLUTION...I USED A GFS/ECMWF BLEND FOR THE WEEKEND. I DID INCLUDE
A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS THE BIG COUNTRY ON
SATURDAY AFTERNOON BUT THIS IS CONDITIONAL ON THE GFS SOLUTION OF
A COLD FRONT IN THE VICINITY COMING TO FRUITION.
JOHNSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 70 92 68 90 70 / 10 10 10 5 20
SAN ANGELO 70 92 71 92 71 / 10 5 10 5 20
JUNCTION 69 91 71 90 72 / 10 5 5 5 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
856 PM CDT SUN MAY 26 2013
.UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...REDUCING COVERAGE/POPS FOR EVENING
THUNDERSTORMS. HAVE CONFINED SCATTERED THUNDERSTORMS TO SOUTHEAST
TEXAS PANHANDLE...AND HAVE TRIMMED ISOLATED TO A SMALLER PORTION OF
EASTERN PARTS OF FORECAST AREA.
WILL ALLOW RED FLAG WARNING TO EXPIRE AT 9 PM.
UPDATED TEXT PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 700 PM CDT SUN MAY 26 2013/
UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...CALLING FOR SCATTERED TO ISOLATED
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST TEXAS PANHANDLE THROUGH
THE EVENING. EXPECT CONVECTION TO BE MAINLY CONTAINED SOUTHEAST
TEXAS PANHANDLE...WHERE NEWLY DEVELOPED CELLS WILL BE
PROPAGATING...DUE TO SUPPORT OF WEAK SHORTWAVE TROF. UPDATED TEXT
PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
PREV DISCUSSION... /ISSUED 626 PM CDT SUN MAY 26 2013/
AVIATION...
00Z TAF CYCLE
A DRYLINE JUST EAST OF THE GUYMON AND AMARILLO TAF SITES ALONG WITH
AN UPPER TROUGH MOVING ACROSS THE PANHANDLES EARLY TONIGHT WILL
PRODUCE ISOLATED TO SCATTERED CONVECTION. THIS CONVECTION IS EXPECTED
TO REMAIN EAST OF THE THREE TAF SITES. VFR CONDITIONS ALONG WITH
SOUTHWESTERLY WINDS 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 15Z
MONDAY...AND 10 TO 20 KNOTS BEFORE 15Z MONDAY WILL PREVAIL.
SCHNEIDER
PREV DISCUSSION... /ISSUED 405 PM CDT SUN MAY 26 2013/
DISCUSSION...
THERE REMAINS A LARGE AMOUNT OF POTENTIAL FOR WEATHER ACROSS THE
PANHANDLES FOR THE NEXT SEVERAL DAYS BUT THE QUESTION WILL BE CAN WE
TURN THAT POTENTIAL INTO REALITY.
ACROSS THE NORTHWEST TEXAS AND WESTERN OKLAHOMA PANHANDLE REMAIN A
PRIME AREA FOR CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP THIS
AFTERNOON AS THE DRYLINE SNEAKS INTO THE PANHANDLES. AS A RESULT
WILL LEAVE THE RED FLAG IN PLACE AND UNMODIFIED. FOR THE EASTERN
PANHANDLES THERE REMAINS A STRONG TO SEVERE STORM POTENTIAL THIS
AFTERNOON INTO THE OVERNIGHT HOURS. TTU WRF AND RUC HRRR SOLUTIONS
SHOW ISOLATED CONVECTION INITIATING ALONG AND EAST OF A VEGA TO
GUYMON LINE. RUC BUFR SOUNDINGS SHOW A WEAK CAP INHIBITING
INITIATION OF THESE STORMS UNTIL 6-7PM THIS EVENING. SHOULD THESE
STORMS FORM THEY WOULD BE ABLE TO TAP INTO ELEVATED INSTABILITY IN
THE RANGE OF 1000-1500 J/KG. DEEP LAYER SHEAR IN THE AREA OF LIKELY
INITIATION IS 25 TO 35 KT WITH A SLIGHT VEERING PATTERN. GIVEN
THE DEEP DRY LAYER BENEATH THE EXPECTED STORM BASES DAMAGING WINDS
OF 65 TO 70 MPH WOULD BE THE PRIMARY HAZARD BUT A HAIL THREAT CAN
NOT BE RULED OUT. ALL OF THIS IS ASSUMING THE WEAK CAP CAN BE
OVERCOME TO ALLOW STORMS TO DEVELOP. ANY STORMS THAT MAY DEVELOP
SHOULD DIMINISH BY 2 AM MONDAY MORNING.
DURING THE DAY MONDAY...THE DRYLINE WILL RACE ACROSS THE PANHANDLES
AND INTO WESTERN OKLAHOMA. THIS WILL PLACE THE VAST MAJORITY OF THE
PANHANDLES UNDER EXTREMELY DRY CONDITIONS WHICH COULD LEAD TO THE
RAPID SPREAD OF FIRE. WITH THAT BEING SAID RECENT RAINS PLUS ANY
ADDITIONAL RAIN WE GET TONIGHT WILL HELP TO MITIGATE SOME OF THIS
POTENTIAL. HAVE DECIDED TO NOT CARRY HEADLINES FOR MONDAY DUE TO THE
UNCERTAINTY OF PRECIP AMOUNTS AND COVERAGE FROM ANY STORMS
TONIGHT...BUT IF NO PRECIPITATION OCCURS A RED FLAG WARNING MAY BE
NEEDED FOR THE SIZABLE CHUNK OF THE AREA.
MODELS HAVE COME INTO A DECENT AGREEMENT FOR THE MID WEEK SYSTEM
WITH THE ECMWF LAGGING BEHIND THE OTHER MODELS SLIGHTLY. ALSO OF
NOTE HAS BEEN A SLIGHT INCREASE IN SPEED OF THE SYSTEM PLACING
BETTER PRECIP CHANCES ON TUESDAY AND CAUSING PRECIP CHANCES TO OCCUR
EARLIER IN THE DAY ON WEDNESDAY.
TUESDAY WILL BE A MIX OF FIRE WEATHER CONCERNS ACROSS THE WEST AND
ISOLATED SEVERE WEATHER CONCERNS ACROSS THE SOUTHEAST. THE POSITION
OF THE DRYLINE WILL BE THE MAJOR DETERMINING FACTOR AS TO WHO GETS
WHAT. FOR NOW HAVE GONE WITH A SPLIT OF THE GFS AND NAM ON DRYLINE
PLACEMENT WHICH ENDS UP BEING ROUGHLY ALONG A GUYMON TO CLAUDE LINE.
LOCATIONS WEST OF THIS LINE WILL HAVE A BETTER CHANCE FOR SEEING
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS...AND LOCATION
EAST OF THIS LINE WILL HAVE THE BETTER CHANCE OF SEEING
PRECIPITATION. LOOKING AT THE SYNOPTIC SCALE...A SHORTWAVE IS PROGGED TO
ROTATE AROUND THE BASE OF THE MAIN UPPER LEVEL TROUGH. THIS SYNOPTIC
LIFT COUPLED WITH CONVERGENCE ALONG THE DRYLINE COULD BE ENOUGH TO
INITIATE STORMS DURING THE AFTERNOON HOURS OF TUESDAY. DEEP LAYER
SHEAR FOR THIS TIME RANGES FROM 20 TO 35 KT AND INSTABILITY VALUES
RANGE FROM 1500 TO 2500 J/KG. STRONG TO SEVERE STORMS CAN NOT BE
RULED OUT AT THIS TIME WITH LARGE HAIL AND DAMAGING WINDS BEING THE
PRIMARY THREATS.
WEDNESDAY THE MAIN UPPER LEVEL TROUGH LOOKS TO TAKE A NEUTRAL TO
SLIGHTLY NEGATIVE TILT AS IT APPROACHES THE PANHANDLES. INSTABILITY
VALUES LOOK TO HAVE LOWERED SLIGHT WHICH COULD ALSO MEAN THAT THE
SEVERE THREAT MAY ALSO HAVE DIMINISHED SLIGHTLY. WITH THAT BEING
SAID CAPE VALUES OF 1000 TO 2000 J/KG AND DEEP LAYER SHEAR OF 35 TO
45 KT WILL KEEP AT LEAST THE CHANCE FOR STRONG STORMS AND A POSSIBLE
ISOLATED SEVERE STORM POSSIBLE. LARGE HAIL AND DAMAGING WINDS WILL
BE THE PRIMARY HAZARD.
THURSDAY THE UPPER FLOW BECOMES MORE ZONAL TO KEEP THAT AREA DRY AND
A WEAK COLD FRONT WILL DROP INTO THE PANHANDLES FRIDAY. CONDITIONS
LOOK TO REMAIN DRY GOING INTO THE WEEKEND.
FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS ARE STILL EXPECTED TO DEVELOP
ACROSS THE NORTHWESTERN TEXAS PANHANDLE AND WESTERN OKLAHOMA
PANHANDLE THIS AFTERNOON. OVERNIGHT THE DRYLINE WILL RETREAT AND
ALLOW RELATIVE HUMIDITIES TO RECOVER. HOWEVER...THE NORTHWESTERN
TEXAS AND WESTERN OKLAHOMA PANHANDLE MAY ONLY RECOVER SLIGHTLY WITH
MAXIMUM RELATIVE HUMIDITIES OF 30 TO 40 PERCENT.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE LIKELY ON
MONDAY FOR MUCH OF THE PANHANDLES AS RELATIVE HUMIDITIES DROP INTO
THE TEENS AND SINGLE DIGITS WITH SOUTHWEST 20 FOOT WINDS OF 20 TO 25
MPH WITH HIGHER GUSTS. THE RECENT RAINFALL ACROSS THE SOUTHERN TEXAS
PANHANDLE AND ANY ADDITIONAL RAINFALL TONIGHT WILL PROVIDE SOME
LIMITATIONS ON FIRE POTENTIAL...TO GO ALONG WITH LOW FUEL LOADING
DUE TO THE ONGOING DROUGHT. FOR NOW WILL KEEP HEADLINES SILENT FOR
THIS TIME PERIOD.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY DEVELOP ACROSS
THE WESTERN PANHANDLES TUESDAY AFTERNOON AS RELATIVE HUMIDITIES DROP
INTO THE SINGLE DIGITS ONCE AGAIN BEHIND THE DRYLINE AND 20 FOOT
SOUTHERLY WINDS OF 15 TO 25 MPH WINDS. HOWEVER PRECIP CHANCES WILL
BEGIN TO ENTER THE PANHANDLES DURING THE LATE AFTERNOON AND EVENING
HOURS WHICH COULD BRING AN EARLY END TO FIRE WEATHER CONDITIONS.
FIRE WEATHER CONDITIONS FROM WEDNESDAY THROUGH THE REST OF THE WORK
WEEK WILL BE HIGHLY DEPENDENT ON PRECIPITATION EXPECTED TUESDAY AND
WEDNESDAY. SHOULD THE WESTERN PANHANDLES GET LITTLE TO NO
PRECIPITATION TUESDAY AND WEDNESDAY...THEN ELEVATED TO NEAR CRITICAL
FIRE WEATHER CONDITIONS COULD BE POSSIBLE TUESDAY AFTERNOON...AND
ELEVATED FIRE WEATHER CONDITIONS THURSDAY AND FRIDAY.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: DALLAM...HARTLEY...MOORE...SHERMAN.
OK...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: CIMARRON...TEXAS.
&&
$$
11/03
AREA FORECAST DISCUSSION
NWS AMARILLO TX
700 PM CDT SUN MAY 26 2013
.UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...CALLING FOR SCATTERED TO ISOLATED
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST TEXAS PANHANDLE THROUGH
THE EVENING. EXPECT CONVECTION TO BE MAINLY CONTAINED SOUTHEAST
TEXAS PANHANDLE...WHERE NEWLY DEVELOPED CELLS WILL BE
PROPAGATING...DUE TO SUPPORT OF WEAK SHORTWAVE TROF. UPDATED TEXT
PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 626 PM CDT SUN MAY 26 2013/
AVIATION...
00Z TAF CYCLE
A DRYLINE JUST EAST OF THE GUYMON AND AMARILLO TAF SITES ALONG WITH
AN UPPER TROUGH MOVING ACROSS THE PANHANDLES EARLY TONIGHT WILL
PRODUCE ISOLATED TO SCATTERED CONVECTION. THIS CONVECTION IS EXPECTED
TO REMAIN EAST OF THE THREE TAF SITES. VFR CONDITIONS ALONG WITH
SOUTHWESTERLY WINDS 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 15Z
MONDAY...AND 10 TO 20 KNOTS BEFORE 15Z MONDAY WILL PREVAIL.
SCHNEIDER
PREV DISCUSSION... /ISSUED 405 PM CDT SUN MAY 26 2013/
DISCUSSION...
THERE REMAINS A LARGE AMOUNT OF POTENTIAL FOR WEATHER ACROSS THE
PANHANDLES FOR THE NEXT SEVERAL DAYS BUT THE QUESTION WILL BE CAN WE
TURN THAT POTENTIAL INTO REALITY.
ACROSS THE NORTHWEST TEXAS AND WESTERN OKLAHOMA PANHANDLE REMAIN A
PRIME AREA FOR CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP THIS
AFTERNOON AS THE DRYLINE SNEAKS INTO THE PANHANDLES. AS A RESULT
WILL LEAVE THE RED FLAG IN PLACE AND UNMODIFIED. FOR THE EASTERN
PANHANDLES THERE REMAINS A STRONG TO SEVERE STORM POTENTIAL THIS
AFTERNOON INTO THE OVERNIGHT HOURS. TTU WRF AND RUC HRRR SOLUTIONS
SHOW ISOLATED CONVECTION INITIATING ALONG AND EAST OF A VEGA TO
GUYMON LINE. RUC BUFR SOUNDINGS SHOW A WEAK CAP INHIBITING
INITIATION OF THESE STORMS UNTIL 6-7PM THIS EVENING. SHOULD THESE
STORMS FORM THEY WOULD BE ABLE TO TAP INTO ELEVATED INSTABILITY IN
THE RANGE OF 1000-1500 J/KG. DEEP LAYER SHEAR IN THE AREA OF LIKELY
INITIATION IS 25 TO 35 KT WITH A SLIGHT VEERING PATTERN. GIVEN
THE DEEP DRY LAYER BENEATH THE EXPECTED STORM BASES DAMAGING WINDS
OF 65 TO 70 MPH WOULD BE THE PRIMARY HAZARD BUT A HAIL THREAT CAN
NOT BE RULED OUT. ALL OF THIS IS ASSUMING THE WEAK CAP CAN BE
OVERCOME TO ALLOW STORMS TO DEVELOP. ANY STORMS THAT MAY DEVELOP
SHOULD DIMINISH BY 2 AM MONDAY MORNING.
DURING THE DAY MONDAY...THE DRYLINE WILL RACE ACROSS THE PANHANDLES
AND INTO WESTERN OKLAHOMA. THIS WILL PLACE THE VAST MAJORITY OF THE
PANHANDLES UNDER EXTREMELY DRY CONDITIONS WHICH COULD LEAD TO THE
RAPID SPREAD OF FIRE. WITH THAT BEING SAID RECENT RAINS PLUS ANY
ADDITIONAL RAIN WE GET TONIGHT WILL HELP TO MITIGATE SOME OF THIS
POTENTIAL. HAVE DECIDED TO NOT CARRY HEADLINES FOR MONDAY DUE TO THE
UNCERTAINTY OF PRECIP AMOUNTS AND COVERAGE FROM ANY STORMS
TONIGHT...BUT IF NO PRECIPITATION OCCURS A RED FLAG WARNING MAY BE
NEEDED FOR THE SIZABLE CHUNK OF THE AREA.
MODELS HAVE COME INTO A DECENT AGREEMENT FOR THE MID WEEK SYSTEM
WITH THE ECMWF LAGGING BEHIND THE OTHER MODELS SLIGHTLY. ALSO OF
NOTE HAS BEEN A SLIGHT INCREASE IN SPEED OF THE SYSTEM PLACING
BETTER PRECIP CHANCES ON TUESDAY AND CAUSING PRECIP CHANCES TO OCCUR
EARLIER IN THE DAY ON WEDNESDAY.
TUESDAY WILL BE A MIX OF FIRE WEATHER CONCERNS ACROSS THE WEST AND
ISOLATED SEVERE WEATHER CONCERNS ACROSS THE SOUTHEAST. THE POSITION
OF THE DRYLINE WILL BE THE MAJOR DETERMINING FACTOR AS TO WHO GETS
WHAT. FOR NOW HAVE GONE WITH A SPLIT OF THE GFS AND NAM ON DRYLINE
PLACEMENT WHICH ENDS UP BEING ROUGHLY ALONG A GUYMON TO CLAUDE LINE.
LOCATIONS WEST OF THIS LINE WILL HAVE A BETTER CHANCE FOR SEEING
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS...AND LOCATION
EAST OF THIS LINE WILL HAVE THE BETTER CHANCE OF SEEING
PRECIPITATION. LOOKING AT THE SYNOPTIC SCALE...A SHORTWAVE IS PROGGED TO
ROTATE AROUND THE BASE OF THE MAIN UPPER LEVEL TROUGH. THIS SYNOPTIC
LIFT COUPLED WITH CONVERGENCE ALONG THE DRYLINE COULD BE ENOUGH TO
INITIATE STORMS DURING THE AFTERNOON HOURS OF TUESDAY. DEEP LAYER
SHEAR FOR THIS TIME RANGES FROM 20 TO 35 KT AND INSTABILITY VALUES
RANGE FROM 1500 TO 2500 J/KG. STRONG TO SEVERE STORMS CAN NOT BE
RULED OUT AT THIS TIME WITH LARGE HAIL AND DAMAGING WINDS BEING THE
PRIMARY THREATS.
WEDNESDAY THE MAIN UPPER LEVEL TROUGH LOOKS TO TAKE A NEUTRAL TO
SLIGHTLY NEGATIVE TILT AS IT APPROACHES THE PANHANDLES. INSTABILITY
VALUES LOOK TO HAVE LOWERED SLIGHT WHICH COULD ALSO MEAN THAT THE
SEVERE THREAT MAY ALSO HAVE DIMINISHED SLIGHTLY. WITH THAT BEING
SAID CAPE VALUES OF 1000 TO 2000 J/KG AND DEEP LAYER SHEAR OF 35 TO
45 KT WILL KEEP AT LEAST THE CHANCE FOR STRONG STORMS AND A POSSIBLE
ISOLATED SEVERE STORM POSSIBLE. LARGE HAIL AND DAMAGING WINDS WILL
BE THE PRIMARY HAZARD.
THURSDAY THE UPPER FLOW BECOMES MORE ZONAL TO KEEP THAT AREA DRY AND
A WEAK COLD FRONT WILL DROP INTO THE PANHANDLES FRIDAY. CONDITIONS
LOOK TO REMAIN DRY GOING INTO THE WEEKEND.
FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS ARE STILL EXPECTED TO DEVELOP
ACROSS THE NORTHWESTERN TEXAS PANHANDLE AND WESTERN OKLAHOMA
PANHANDLE THIS AFTERNOON. OVERNIGHT THE DRYLINE WILL RETREAT AND
ALLOW RELATIVE HUMIDITIES TO RECOVER. HOWEVER...THE NORTHWESTERN
TEXAS AND WESTERN OKLAHOMA PANHANDLE MAY ONLY RECOVER SLIGHTLY WITH
MAXIMUM RELATIVE HUMIDITIES OF 30 TO 40 PERCENT.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE LIKELY ON
MONDAY FOR MUCH OF THE PANHANDLES AS RELATIVE HUMIDITIES DROP INTO
THE TEENS AND SINGLE DIGITS WITH SOUTHWEST 20 FOOT WINDS OF 20 TO 25
MPH WITH HIGHER GUSTS. THE RECENT RAINFALL ACROSS THE SOUTHERN TEXAS
PANHANDLE AND ANY ADDITIONAL RAINFALL TONIGHT WILL PROVIDE SOME
LIMITATIONS ON FIRE POTENTIAL...TO GO ALONG WITH LOW FUEL LOADING
DUE TO THE ONGOING DROUGHT. FOR NOW WILL KEEP HEADLINES SILENT FOR
THIS TIME PERIOD.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY DEVELOP ACROSS
THE WESTERN PANHANDLES TUESDAY AFTERNOON AS RELATIVE HUMIDITIES DROP
INTO THE SINGLE DIGITS ONCE AGAIN BEHIND THE DRYLINE AND 20 FOOT
SOUTHERLY WINDS OF 15 TO 25 MPH WINDS. HOWEVER PRECIP CHANCES WILL
BEGIN TO ENTER THE PANHANDLES DURING THE LATE AFTERNOON AND EVENING
HOURS WHICH COULD BRING AN EARLY END TO FIRE WEATHER CONDITIONS.
FIRE WEATHER CONDITIONS FROM WEDNESDAY THROUGH THE REST OF THE WORK
WEEK WILL BE HIGHLY DEPENDENT ON PRECIPITATION EXPECTED TUESDAY AND
WEDNESDAY. SHOULD THE WESTERN PANHANDLES GET LITTLE TO NO
PRECIPITATION TUESDAY AND WEDNESDAY...THEN ELEVATED TO NEAR CRITICAL
FIRE WEATHER CONDITIONS COULD BE POSSIBLE TUESDAY AFTERNOON...AND
ELEVATED FIRE WEATHER CONDITIONS THURSDAY AND FRIDAY.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: DALLAM...HARTLEY...MOORE...SHERMAN.
OK...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: CIMARRON...TEXAS.
&&
$$
11/03
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
631 PM CDT SUN MAY 26 2013
.DISCUSSION...
LOOK FOR STRATUS TO BRING MVFR CEILINGS BACK TO MUCH OF WEST
CENTRAL TEXAS LATER TONIGHT. PLEASE SEE THE BELOW AVIATION
SECTION FOR MORE INFORMATION.
&&
.AVIATION...
THE LATEST RUC 925 MB RELATIVE HUMIDITY FIELD INDICATES STRATUS
WILL DOMINATE MUCH OF WEST CENTRAL TEXAS SOUTH OF INTERSTATE 20 BY
06Z TONIGHT. FOR NOW...I DECIDED TO CONTINUE WITH VFR CONDITIONS
AT SAN ANGELO...AS WELL AS ABILENE...FOR THE NEXT 24 HOURS. BY 18Z
TOMORROW...EXPECT VFR CONDITIONS TO AGAIN DOMINATE WEST CENTRAL TEXAS.
AS FOR SURFACE WINDS TOMORROW...MODELS INDICATE A SURFACE TROUGH
ACROSS WEST TEXAS WILL CREATE A MODERATE SURFACE PRESSURE GRADIENT
ACROSS WEST CENTRAL TEXAS. THUS...WATCH FOR GUSTY SOUTHERLY
SURFACE WINDS TO DOMINATE WEST CENTRAL TEXAS TOMORROW...ESPECIALLY
DURING THE AFTERNOON HOURS.
HUBER
&&
.PREV DISCUSSION... /ISSUED 327 PM CDT SUN MAY 26 2013/
SHORT TERM...
SIMILAR SCENARIO IN OUR WESTERN COUNTIES EXPECTED THIS EVENING AS
OCCURRED LAST EVENING WITH 0-6KM SHEAR OF 25-30KT AND MLCAPES OF
1500-2000 J/KG. DRYLINE WILL STRETCH FROM THE BIG BEND THROUGH THE
PERMIAN BASIN LATE THIS AFTERNOON WITH THUNDERSTORMS EXPECTED TO
DEVELOP ONCE AGAIN ALONG THE DRYLINE DURING TIME OF MAX HEATING.
ANY STORMS THAT DO DEVELOP MAY ONCE AGAIN IMPACT OUR WESTERN
COUNTIES BUT SHOULD BE IN A WEAKENING PHASE DUE TO THE LOSS OF
DIURNAL HEATING BY THE TIME THEY ENTER OUR COUNTIES. AT THIS TIME
DO NOT EXPECT ANY STORMS TO ENDURE PAST MIDNIGHT...SO SHOULD NOT
HAVE ANY STORMS PROPAGATING THROUGH THE CWA AS WE HAD LAST NIGHT.
LOOKING FOR CONTINUED WARMING WITH AFTERNOON HIGHS TOMORROW A FEW
DEGREES WARMER THAN TODAY...LOW TO MID 90S. MORNING LOWS SHOULD
ALSO BE A LITTLE WARMER...IN THE UPPER 60S TO AROUND 70.
15
LONG TERM...
THE WEST COAST TROUGH WILL DEEPEN EARLY NEXT WEEK AS A STRONG WAVE
MOVES INTO THE PACNW...AMPLIFYING THE SYNOPTIC PATTERN AS THE
MID LEVEL RIDGE BUILDS OVER THE EAST CONUS. PRONOUNCED SOUTHWEST
FLOW ALOFT WILL MAINTAIN/INTENSIFY THE MID LEVEL CAPPING INVERSION
THROUGH TUESDAY. THE MONDAY/TUESDAY DAYTIME PERIODS LOOK TO BE
BREEZY...WARM AND DRY /FOR THE MOST PART/ WITH TEMPERATURES
WARMING INTO THE LOWER 90S. A FEW DIURNAL THUNDERSTORMS ARE
EXPECTED TO FIRE EACH AFTERNOON IN THE VICINITY OF THE DRYLINE TO
THE WEST AND MAY MAKE A RUN FOR OUR WESTERN COUNTIES. THE CAP IS
STRONG BUT IF THE STRONG INSTABILITY IS TAPPED...SOME STORMS MAY
HAVE THE POTENTIAL TO BECOME SEVERE. HOWEVER...MOST AREAS WILL
REMAIN DRY.
ON WEDNESDAY...THE MODELS APPEAR TO BE CONVERGING ON A SOLUTION
THAT IS A COMPROMISE BETWEEN THE PREVIOUS RUNS OF THE GFS AND
ECMWF. THIS NEW SOLUTION DEPICTS A NEGATIVELY TILTED SHORTWAVE
TROUGH EJECTING INTO THE PLAINS BY PEAK HEATING ON WEDNESDAY.
SYNOPTIC SCALE ASCENT WILL WORK ON THE CAPPING INVERSION
THROUGHOUT THE DAY AND IS EXPECTED TO COOL MID LEVEL TEMPS
SUFFICIENTLY FOR THE CAP TO BREAK BY THURSDAY AFTERNOON. THERE IS
SOME HINT THAT WE COULD SEE ONGOING CONVECTION EARLY WEDNESDAY BUT
THIS SHOULD WEAKEN THROUGHOUT THE DAY AS MID LEVEL WARM ADVECTION
WANES. SLIGHTLY COOLER TEMPS ARE EXPECTED WITH HIGHS GENERALLY IN
THE MID/UPPER 80S. FORMIDABLE DEEP LAYER SHEAR /0-6KM BULK SHEAR
OF 35-40 KTS/ AND STRONG SURFACE BASED INSTABILITY WILL HEIGHTEN
THE POTENTIAL FOR SEVERE CONVECTION...WITH LARGE HAIL AND DAMAGING
WINDS BEING THE PRIMARY THREATS. ANY STORMS THAT DEVELOP WILL
PERSIST INTO THE EVENING HOURS.
BY THURSDAY...THIS WAVE WILL BE EAST OF THE AREA WITH A MORE
SUBSIDENT REGIME ANTICIPATED DURING THE DAY. IF ANY STORMS DO
DEVELOP...I THINK COVERAGE WILL BE VERY LIMITED. THUS...NO
MENTIONABLE POPS WERE CARRIED FOR THURSDAY AND THURSDAY NIGHT.
TEMPS WILL REBOUND TO NEAR NORMAL VALUES WITH HIGHS GENERALLY IN
THE UPPER 80S TO LOWER 90S. THIS TREND WILL CONTINUE ON FRIDAY
WITH TEMPS AT OR ABOVE 90 DEGREES IN MOST LOCATIONS WITH THE BEST
CHANCE FOR AFTERNOON AND EVENING STORMS FOUND TO THE NORTH AND
WEST OF THE CWA.
THE MODELS DISAGREE WITH THE PATTERN FOR THIS WEEKEND. THE GFS
CONTINUES TO SHOW A WEAK COLD FRONT MOVING SOUTH INTO WEST CENTRAL
TX WITH INCREASING RAIN CHANCES WHILE THE ECMWF KEEPS THIS FRONT
TO THE NORTH OF THE AREA. GIVEN THE LACK OF CONFIDENCE IN EITHER
SOLUTION...I USED A GFS/ECMWF BLEND FOR THE WEEKEND. I DID INCLUDE
A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS THE BIG COUNTRY ON
SATURDAY AFTERNOON BUT THIS IS CONDITIONAL ON THE GFS SOLUTION OF
A COLD FRONT IN THE VICINITY COMING TO FRUITION.
JOHNSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 70 92 68 90 70 / 10 10 10 5 20
SAN ANGELO 71 92 71 92 71 / 20 5 10 5 20
JUNCTION 69 91 71 90 72 / 10 5 5 5 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HUBER
AREA FORECAST DISCUSSION
NWS AMARILLO TX
626 PM CDT SUN MAY 26 2013
.AVIATION...
00Z TAF CYCLE
A DRYLINE JUST EAST OF THE GUYMON AND AMARILLO TAF SITES ALONG WITH
AN UPPER TROUGH MOVING ACROSS THE PANHANDLES EARLY TONIGHT WILL
PRODUCE ISOLATED TO SCATTERED CONVECTION. THIS CONVECTION IS EXPECTED
TO REMAIN EAST OF THE THREE TAF SITES. VFR CONDITIONS ALONG WITH
SOUTHWESTERLY WINDS 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 15Z
MONDAY...AND 10 TO 20 KNOTS BEFORE 15Z MONDAY WILL PREVAIL.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 405 PM CDT SUN MAY 26 2013/
DISCUSSION...
THERE REMAINS A LARGE AMOUNT OF POTENTIAL FOR WEATHER ACROSS THE
PANHANDLES FOR THE NEXT SEVERAL DAYS BUT THE QUESTION WILL BE CAN WE
TURN THAT POTENTIAL INTO REALITY.
ACROSS THE NORTHWEST TEXAS AND WESTERN OKLAHOMA PANHANDLE REMAIN A
PRIME AREA FOR CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP THIS
AFTERNOON AS THE DRYLINE SNEAKS INTO THE PANHANDLES. AS A RESULT
WILL LEAVE THE RED FLAG IN PLACE AND UNMODIFIED. FOR THE EASTERN
PANHANDLES THERE REMAINS A STRONG TO SEVERE STORM POTENTIAL THIS
AFTERNOON INTO THE OVERNIGHT HOURS. TTU WRF AND RUC HRRR SOLUTIONS
SHOW ISOLATED CONVECTION INITIATING ALONG AND EAST OF A VEGA TO
GUYMON LINE. RUC BUFR SOUNDINGS SHOW A WEAK CAP INHIBITING
INITIATION OF THESE STORMS UNTIL 6-7PM THIS EVENING. SHOULD THESE
STORMS FORM THEY WOULD BE ABLE TO TAP INTO ELEVATED INSTABILITY IN
THE RANGE OF 1000-1500 J/KG. DEEP LAYER SHEAR IN THE AREA OF LIKELY
INITIATION IS 25 TO 35 KT WITH A SLIGHT VEERING PATTERN. GIVEN
THE DEEP DRY LAYER BENEATH THE EXPECTED STORM BASES DAMAGING WINDS
OF 65 TO 70 MPH WOULD BE THE PRIMARY HAZARD BUT A HAIL THREAT CAN
NOT BE RULED OUT. ALL OF THIS IS ASSUMING THE WEAK CAP CAN BE
OVERCOME TO ALLOW STORMS TO DEVELOP. ANY STORMS THAT MAY DEVELOP
SHOULD DIMINISH BY 2 AM MONDAY MORNING.
DURING THE DAY MONDAY...THE DRYLINE WILL RACE ACROSS THE PANHANDLES
AND INTO WESTERN OKLAHOMA. THIS WILL PLACE THE VAST MAJORITY OF THE
PANHANDLES UNDER EXTREMELY DRY CONDITIONS WHICH COULD LEAD TO THE
RAPID SPREAD OF FIRE. WITH THAT BEING SAID RECENT RAINS PLUS ANY
ADDITIONAL RAIN WE GET TONIGHT WILL HELP TO MITIGATE SOME OF THIS
POTENTIAL. HAVE DECIDED TO NOT CARRY HEADLINES FOR MONDAY DUE TO THE
UNCERTAINTY OF PRECIP AMOUNTS AND COVERAGE FROM ANY STORMS
TONIGHT...BUT IF NO PRECIPITATION OCCURS A RED FLAG WARNING MAY BE
NEEDED FOR THE SIZABLE CHUNK OF THE AREA.
MODELS HAVE COME INTO A DECENT AGREEMENT FOR THE MID WEEK SYSTEM
WITH THE ECMWF LAGGING BEHIND THE OTHER MODELS SLIGHTLY. ALSO OF
NOTE HAS BEEN A SLIGHT INCREASE IN SPEED OF THE SYSTEM PLACING
BETTER PRECIP CHANCES ON TUESDAY AND CAUSING PRECIP CHANCES TO OCCUR
EARLIER IN THE DAY ON WEDNESDAY.
TUESDAY WILL BE A MIX OF FIRE WEATHER CONCERNS ACROSS THE WEST AND
ISOLATED SEVERE WEATHER CONCERNS ACROSS THE SOUTHEAST. THE POSITION
OF THE DRYLINE WILL BE THE MAJOR DETERMINING FACTOR AS TO WHO GETS
WHAT. FOR NOW HAVE GONE WITH A SPLIT OF THE GFS AND NAM ON DRYLINE
PLACEMENT WHICH ENDS UP BEING ROUGHLY ALONG A GUYMON TO CLAUDE LINE.
LOCATIONS WEST OF THIS LINE WILL HAVE A BETTER CHANCE FOR SEEING
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS...AND LOCATION
EAST OF THIS LINE WILL HAVE THE BETTER CHANCE OF SEEING
PRECIPITATION. LOOKING AT THE SYNOPTIC SCALE...A SHORTWAVE IS PROGGED TO
ROTATE AROUND THE BASE OF THE MAIN UPPER LEVEL TROUGH. THIS SYNOPTIC
LIFT COUPLED WITH CONVERGENCE ALONG THE DRYLINE COULD BE ENOUGH TO
INITIATE STORMS DURING THE AFTERNOON HOURS OF TUESDAY. DEEP LAYER
SHEAR FOR THIS TIME RANGES FROM 20 TO 35 KT AND INSTABILITY VALUES
RANGE FROM 1500 TO 2500 J/KG. STRONG TO SEVERE STORMS CAN NOT BE
RULED OUT AT THIS TIME WITH LARGE HAIL AND DAMAGING WINDS BEING THE
PRIMARY THREATS.
WEDNESDAY THE MAIN UPPER LEVEL TROUGH LOOKS TO TAKE A NEUTRAL TO
SLIGHTLY NEGATIVE TILT AS IT APPROACHES THE PANHANDLES. INSTABILITY
VALUES LOOK TO HAVE LOWERED SLIGHT WHICH COULD ALSO MEAN THAT THE
SEVERE THREAT MAY ALSO HAVE DIMINISHED SLIGHTLY. WITH THAT BEING
SAID CAPE VALUES OF 1000 TO 2000 J/KG AND DEEP LAYER SHEAR OF 35 TO
45 KT WILL KEEP AT LEAST THE CHANCE FOR STRONG STORMS AND A POSSIBLE
ISOLATED SEVERE STORM POSSIBLE. LARGE HAIL AND DAMAGING WINDS WILL
BE THE PRIMARY HAZARD.
THURSDAY THE UPPER FLOW BECOMES MORE ZONAL TO KEEP THAT AREA DRY AND
A WEAK COLD FRONT WILL DROP INTO THE PANHANDLES FRIDAY. CONDITIONS
LOOK TO REMAIN DRY GOING INTO THE WEEKEND.
FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS ARE STILL EXPECTED TO DEVELOP
ACROSS THE NORTHWESTERN TEXAS PANHANDLE AND WESTERN OKLAHOMA
PANHANDLE THIS AFTERNOON. OVERNIGHT THE DRYLINE WILL RETREAT AND
ALLOW RELATIVE HUMIDITIES TO RECOVER. HOWEVER...THE NORTHWESTERN
TEXAS AND WESTERN OKLAHOMA PANHANDLE MAY ONLY RECOVER SLIGHTLY WITH
MAXIMUM RELATIVE HUMIDITIES OF 30 TO 40 PERCENT.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE LIKELY ON
MONDAY FOR MUCH OF THE PANHANDLES AS RELATIVE HUMIDITIES DROP INTO
THE TEENS AND SINGLE DIGITS WITH SOUTHWEST 20 FOOT WINDS OF 20 TO 25
MPH WITH HIGHER GUSTS. THE RECENT RAINFALL ACROSS THE SOUTHERN TEXAS
PANHANDLE AND ANY ADDITIONAL RAINFALL TONIGHT WILL PROVIDE SOME
LIMITATIONS ON FIRE POTENTIAL...TO GO ALONG WITH LOW FUEL LOADING
DUE TO THE ONGOING DROUGHT. FOR NOW WILL KEEP HEADLINES SILENT FOR
THIS TIME PERIOD.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY DEVELOP ACROSS
THE WESTERN PANHANDLES TUESDAY AFTERNOON AS RELATIVE HUMIDITIES DROP
INTO THE SINGLE DIGITS ONCE AGAIN BEHIND THE DRYLINE AND 20 FOOT
SOUTHERLY WINDS OF 15 TO 25 MPH WINDS. HOWEVER PRECIP CHANCES WILL
BEGIN TO ENTER THE PANHANDLES DURING THE LATE AFTERNOON AND EVENING
HOURS WHICH COULD BRING AN EARLY END TO FIRE WEATHER CONDITIONS.
FIRE WEATHER CONDITIONS FROM WEDNESDAY THROUGH THE REST OF THE WORK
WEEK WILL BE HIGHLY DEPENDENT ON PRECIPITATION EXPECTED TUESDAY AND
WEDNESDAY. SHOULD THE WESTERN PANHANDLES GET LITTLE TO NO
PRECIPITATION TUESDAY AND WEDNESDAY...THEN ELEVATED TO NEAR CRITICAL
FIRE WEATHER CONDITIONS COULD BE POSSIBLE TUESDAY AFTERNOON...AND
ELEVATED FIRE WEATHER CONDITIONS THURSDAY AND FRIDAY.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: DALLAM...HARTLEY...MOORE...SHERMAN.
OK...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: CIMARRON...TEXAS.
&&
$$
11/03
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
609 PM CDT SAT MAY 25 2013
.DISCUSSION...SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...MVFR CONDITIONS ARE EXPECTED TO DEVELOP AGAIN AFTER
SUNSET...STARTING AT KCRP AND KALI BETWEEN 03Z-04Z...THEN AT KVCT
ABT 06Z...WITH MVFR CIGS AT KLRD BFR 12Z. VFR CONDITIONS SHOULD
DEVELOP AOA 16Z AREA-WIDE. CONCERNING THUNDER/SHRA IN TAFS...ONLY
HAVE THAT IN KVCT FOR NOW ENDING BY 03Z. THINK ANY OTHER
CONVECTION TONIGHT WILL BE AWAY FROM TERMINALS...AND ANY WHICH MAY
DEVELOP OVERNIGHT WILL BE TOO ISOLATED. CONCERNING WINDS...
SOUTHEAST WINDS WILL TAPER OFF TONIGHT...WITH INCREASING WINDS
WITH GUSTS AROUND 18Z...EXCEPT AT KLRD WHERE WINDS WILL BE SE WITH
GUSTS LIMITED IF ANY.
&&
.PREV DISCUSSION... /ISSUED 420 PM CDT SAT MAY 25 2013/
SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)...ACTIVE AFTERNOON WITH A
WEAK PATTERN CONTINUES. GOOD CAPE...BUT MARGINAL LAPSE RATES AND
WEAK SHEAR...BUT CONTINUE TO HAVE STORMS DEVELOP...A FEW PRODUCING
BRIEF FUNNEL CLOUDS OR TORNADOES. FLOOD CONCERNS ARE DECREASING AS
STORMS ARE MOVING BETTER THAN EARLIER IN THE DAY...AND NOT
TRAINING.
INITIAL VORT MAX CURRENTLY INTO NORTHEAST PORTIONS OF OUR FORECAST
AREA BUT RUC GUIDANCE SHOWS ADDITIONAL VORT MAX COMING ACROSS
OVERNIGHT. HAVE INCREASE POPS TO 30 OVERNIGHT...BUT SORT OF A
HEDGE BET AT THIS POINT AS MESO MODELS ARENT SHOWING A WHOLE LOT.
IF WE GET CONVECTION TO RE FIRE WITH THIS VORT MAX COULD BECOME
ANOTHER MORE WIDE SPREAD EVENT OVERNIGHT. WILL KEEP ISOLATED
SHOWERS AND STORMS IN THE FORECAST FOR TOMORROW AS WEAK SHORTWAVES
CONTINUE TO AFFECT THE AREA. BY SUNDAY AFTERNOON THINGS SHOULD
QUIET DOWN WITH PRECIP MOVING OUT OF THE AREA. COULD EVEN SEE SOME
BREAKS IN THE CLOUDS BY THE AFTERNOON. MILD MIN TEMPS AND WARM
HIGHS CONTINUE.
LONG TERM...(MONDAY THROUGH FRIDAY)...DID NOT MAKE MANY CHANGES
TO THE EXTENDED PART OF THE FORECAST. UPPER LEVEL RIDGE WILL BUILD
IN FOR MONDAY WITH DRIER AIR ACROSS THE AREA. TEMPERATURES WILL
REBOUND FOR THE EARLY PART OF THE WEEK WITH UPPER 90S OUT WEST TO
UPPER 80S OVER THE VICTORIA CROSSROADS. RIDGE WILL BEGIN TO SHIFT
EASTWARD TUESDAY INTO WEDNESDAY. MODELS NOW INDICATE UPPER TROUGH
MOVING INTO THE FOUR CORNERS WEDNESDAY AND INTO THE PLAINS WEDNESDAY
NIGHT. MOISTURE DOES INCREASE BY WEDNESDAY OVER THE RIO GRANDE
PLAINS BUT BELIEVE ATMOSPHERE MAY BE CAPPED...SO WILL CONTINUE WITH
POPS BELOW MENTIONABLE LEVELS. LEFT INHERITED LOW END POPS IN FOR
THURSDAY FOR THE TIME BEING...BUT CAPPING COULD BE AN ISSUE THIS DAY
AS WELL. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 89 73 88 75 / 20 20 10 10 10
VICTORIA 73 89 71 88 73 / 20 20 10 10 10
LAREDO 76 93 76 97 75 / 20 20 10 10 10
ALICE 72 90 72 91 74 / 20 20 10 10 10
ROCKPORT 76 86 76 86 76 / 20 20 10 10 10
COTULLA 72 92 72 93 73 / 20 20 10 10 10
KINGSVILLE 74 90 73 90 75 / 20 20 10 10 10
NAVY CORPUS 76 85 76 86 77 / 20 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
420 PM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)...ACTIVE AFTERNOON WITH A
WEAK PATTERN CONTINUES. GOOD CAPE...BUT MARGINAL LAPSE RATES AND
WEAK SHEAR...BUT CONTINUE TO HAVE STORMS DEVELOP...A FEW PRODUCING
BRIEF FUNNEL CLOUDS OR TORNADOES. FLOOD CONCERNS ARE DECREASING AS
STORMS ARE MOVING BETTER THAN EARLIER IN THE DAY...AND NOT
TRAINING.
INITIAL VORT MAX CURRENTLY INTO NORTHEAST PORTIONS OF OUR FORECAST
AREA BUT RUC GUIDANCE SHOWS ADDITIONAL VORT MAX COMING ACROSS
OVERNIGHT. HAVE INCREASE POPS TO 30 OVERNIGHT...BUT SORT OF A
HEDGE BET AT THIS POINT AS MESO MODELS ARENT SHOWING A WHOLE LOT.
IF WE GET CONVECTION TO RE FIRE WITH THIS VORT MAX COULD BECOME
ANOTHER MORE WIDE SPREAD EVENT OVERNIGHT. WILL KEEP ISOLATED
SHOWERS AND STORMS IN THE FORECAST FOR TOMORROW AS WEAK SHORTWAVES
CONTINUE TO AFFECT THE AREA. BY SUNDAY AFTERNOON THINGS SHOULD
QUIET DOWN WITH PRECIP MOVING OUT OF THE AREA. COULD EVEN SEE SOME
BREAKS IN THE CLOUDS BY THE AFTERNOON. MILD MIN TEMPS AND WARM
HIGHS CONTINUE.
&&
.LONG TERM...(MONDAY THROUGH FRIDAY)...DID NOT MAKE MANY CHANGES
TO THE EXTENDED PART OF THE FORECAST. UPPER LEVEL RIDGE WILL BUILD
IN FOR MONDAY WITH DRIER AIR ACROSS THE AREA. TEMPERATURES WILL
REBOUND FOR THE EARLY PART OF THE WEEK WITH UPPER 90S OUT WEST TO
UPPER 80S OVER THE VICTORIA CROSSROADS. RIDGE WILL BEGIN TO SHIFT
EASTWARD TUESDAY INTO WEDNESDAY. MODELS NOW INDICATE UPPER TROUGH
MOVING INTO THE FOUR CORNERS WEDNESDAY AND INTO THE PLAINS WEDNESDAY
NIGHT. MOISTURE DOES INCREASE BY WEDNESDAY OVER THE RIO GRANDE
PLAINS BUT BELIEVE ATMOSPHERE MAY BE CAPPED...SO WILL CONTINUE WITH
POPS BELOW MENTIONABLE LEVELS. LEFT INHERITED LOW END POPS IN FOR
THURSDAY FOR THE TIME BEING...BUT CAPPING COULD BE AN ISSUE THIS DAY
AS WELL. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 89 73 88 75 / 20 20 10 10 10
VICTORIA 73 89 71 88 73 / 20 20 10 10 10
LAREDO 76 93 76 97 75 / 20 20 10 10 10
ALICE 72 90 72 91 74 / 20 20 10 10 10
ROCKPORT 76 86 76 86 76 / 20 20 10 10 10
COTULLA 72 92 72 93 73 / 20 20 10 10 10
KINGSVILLE 74 90 73 90 75 / 20 20 10 10 10
NAVY CORPUS 76 85 76 86 77 / 20 20 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...SHORT TERM
TB/78...LONG TERM
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
414 PM CDT SAT MAY 25 2013
.DISCUSSION...
THROUGH TONIGHT...LEFT THE EARLY AFTERNOON UPDATE FORECAST
DISCUSSION ATTACHED BELOW FOR REFERENCE AND MORE DETAILS ON THE
SHORT TERM FORECAST CONCERNS.
CHANGES FROM EARLIER DISCUSSION...THE MCV THAT WAS EXPECTED TO
DEVELOP NEAR SAN ANTONIO WAS APPARENT IN REGIONAL RADAR RETURNS
NEAR AUSTIN AND GONZALEZ AT THE TIME OF THIS DISCUSSION. ASSUMING
THAT THIS IS THE PRIMARY MID-LEVEL LOW/MCV PRODUCED BY THE
PERSISTENT SAN ANTONIO AREA CONVECTION THIS MORNING...ADJUSTED
RAIN CHANCES THIS EVENING AND OVERNIGHT IN LINE WITH ITS EXPECTED
TRAJECTORY. THE 19Z RUN OF THE RAP SEEMS TO HAVE A GOOD HANDLE ON
THE POSITION OF THIS MCV...SO GENERALLY USED THIS MODEL FOR
GUIDANCE OVER THE NEXT 12 TO 18 HRS.
THE MCV IS EXPECTED TO MOVE GENERALLY IN A NORTHEASTERLY DIRECTION
THROUGH TONIGHT...TAKING IT FROM ITS CURRENT LOCATION TO JUST
NORTHEAST OF TYLER BY SUNRISE SUNDAY. THE GFS INDICATES THAT THE
UPPER TROUGH THAT WAS ANALYZED IN THE 12Z RAOB ANALYSIS TO THE
WEST OF THE CWA WILL INTERACT WITH THIS MCV FAVORABLY AND RESULT
IN WIDESPREAD THUNDERSTORM ACTIVITY GENERALLY EAST OF I-35 AND
SOUTH OF I-20 AFTER MIDNIGHT...SPREADING NORTHEAST INTO THE
ARKLATEX AREA JUST AFTER SUNRISE. BOTH OF THESE FEATURES
EXIST...SO THIS SOLUTION IS VIABLE...HOWEVER THE FORCING FOR
ASCENT ADVERTISED BY THE GFS IS GREATLY ENHANCED BY CONVECTIVE
FEEDBACK. THAT IS...MODEL GENERATED STORMS COOL OFF LOCATIONS
DOWNSTREAM /NORTHEAST/ ALLOWING WARM AIR ADVECTION TO ARTIFICIALLY
RAMP UP RESULTING IN THE GENERATION OF MORE STORMS. IN SHORT...A
MODEL GENERATED FEEDBACK LOOP. THIS LOOP MAY VERIFY AND RESULT IN
A HEAVY RAINFALL EVENT EAST OF I-35 TO THE ARKLATEX AREA TONIGHT
THROUGH SUNDAY MORNING. HOWEVER THERE IS NOT REALLY ANY HIGH
RESOLUTION MODEL OUTPUT SUPPORT FOR THIS SOLUTION AT THIS
TIME...THEREFORE CONFIDENCE IS SOMEWHAT LOW IN A WIDESPREAD HEAVY
RAIN EVENT.
THAT SAID...MANY FACTORS ARE IN PLACE TO SUPPORT A LOCALIZED HEAVY
RAINFALL EVENT ANYWHERE STORMS EXIST OVER THE NEXT 12 TO 18 HRS.
PRECIPITABLE WATER VALUES ARE ABOVE THE 75TH PERCENTILE OF
HISTORICAL PRECIPITABLE WATER VALUES FOR THIS REGION IN LATE MAY.
MID-LEVEL LAPSE RATES ARE POOR BUT THE ENVIRONMENT IS
UNCAPPED...IN SHORT A FAVORABLE ENVIRONMENT FOR VERY TALL RAIN
SHOWERS WITH LITTLE LIGHTNING ACTIVITY AND ONLY WEAK GENERATION OF
OUTFLOW BOUNDARIES. WEAK OUTFLOW MEANS THAT STORMS CAN REMAIN IN
ONE PLACE FOR A LONGER PERIOD OF TIME INCREASING THE CHANCES FOR
TRAINING OF STORMS AND A LOCALIZED FLOODING THREAT. AT THIS TIME
WENT WITH A MENTION OF LOCALIZED HEAVY RAIN AND FLOODING IN THE
HAZARDOUS WEATHER OUTLOOK AND WORDED FORECAST.
WITH WEAK WIND SHEAR IN THIS THERMODYNAMIC ENVIRONMENT STORMS ARE
EXPECTED TO BEHAVE IN A NEARLY TROPICAL NATURE WITH EFFICIENT
RAINFALL PRODUCTION. THEREFORE CHANCES OF SEVERE WEATHER APPEAR TO
BE VERY SMALL TONIGHT. WE WILL HAVE TO KEEP A CLOSE EYE ON THE
EVOLUTION OF A LOCALIZED FLOODING EVENT...ESPECIALLY WITH MANY
PEOPLE LIKELY CAMPING OUTDOORS IN FLOOD PRONE AREAS THROUGH
TONIGHT.
SUNDAY...SUNDAY MORNING WE WILL LIKELY HAVE SOME REMNANT POCKETS
OF HEAVY RAIN ALONG A SULPHUR SPRINGS TO PALESTINE LINE...LIKELY
MOVING NORTHEAST TOWARDS THE ARKLATEX REGION THROUGHOUT THE
MORNING HOURS. FROM THE WEST...THE HRRR HAS CONSISTENTLY INDICATED
THAT A SQUALL LINE WILL ORGANIZE OVER THE SOUTHERN HIGH PLAINS/TX
PANHANDLE TONIGHT AND MOVE EAST TOWARDS OUR WESTERN CWA EARLY
SUNDAY MORNING. WE WILL HAVE TO KEEP AN EYE ON THIS...NOT SO MUCH
FROM A SEVERE WEATHER STAND POINT BUT FROM ANOTHER POTENTIAL
SOURCE FOR MCV PRODUCTION. WITH THE SAN ANTONIO AREA MCV AND
LARGER UPPER TROUGH MOVING EAST...SUBSIDENCE WILL LIKELY DOMINATE
ANY MCV MOVING OFF THE HIGH PLAINS AND THRU NORTH TX TOMORROW.
HOWEVER UNTIL WE GET SOME DRIER AIR IN OVER THE REGION CAPPING OFF
THE ATMOSPHERE FOR THUNDERSTORM DEVELOPMENT...WILL HOLD ON TO A
BROAD BRUSHED MENTION OF SHOWERS AND THUNDERSTORMS IN THE FORECAST
ACROSS ALL OF NORTH TX THROUGH SUNDAY.
NEXT WEEK...BEGINNING MONDAY A WESTERN CONUS TROUGH IS EXPECTED TO
ORGANIZE SENDING THE WEAK UPPER LEVEL RIDGE AND ENTRAPPED MCV
FEATURES OFF TO THE EAST OF THE REGION. THIS IS EXPECTED TO RESULT
IN SOUTHWEST FLOW ALOFT OVER NORTH TX ON MONDAY WHICH SHOULD HELP
TO ADVECT A RELATIVELY STOUT CAP IN PLACE OVER THE REGION BY
MONDAY AFTERNOON. THIS CAP IS EXPECTED TO HOLD IN PLACE THROUGH
THE WEEK UNLESS THE DRYLINE OR A STRONG SHORTWAVE TROUGH CAN LIFT
THE CAP AND RESULT IN THUNDERSTORM INITIATION DURING THE WEEK
AHEAD.
WE ARE EXPECTED TO HAVE RELATIVELY PERSISTENT...BREEZY SOUTH
WINDS IN PLACE BELOW THE CAP THROUGH THE WEEK. THIS WILL HELP KEEP
GOOD GULF MOISTURE IN PLACE UNDER THE CAP PROVIDING PLENTY OF
POSITIVE CAPE FOR THUNDERSTORM DEVELOPMENT IF ANYTHING CAN REMOVE
THE CAP. WITHOUT STORMS...WE WILL LIKELY SEE HIGHS HOLD IN THE
UPPER 80S WITH LOWS IN THE LOWER TO MID 70S EACH DAY. THE GFS AND
ECMWF BOTH INDICATE THAT A STRONG SHORTWAVE TROUGH WILL MOVE OVER
THE SOUTH PLAINS WEDNESDAY THROUGH WEDNESDAY EVENING. THE ECMWF
REMAINS FURTHER SOUTH WITH THIS TROUGH WHICH IS WHAT WE WILL NEED
TO LIFT THE CAP AND RESULT IN STORMS ACROSS THE CWA WEDNESDAY
AFTERNOON AND EVENING. THE GFS INDICATES THE BEST FORCING STAYS
NORTH OF THE CWA. WENT AHEAD WITH 20 TO 30 POPS WEST OF INTERSTATE
35...CLOSEST TO THE UPPER TROUGH WEDNESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT AS RESULT. REMOVED POPS THEREAFTER WITH ALL
GUIDANCE INDICATING SUBSIDENCE BEHIND THIS UPPER TROUGH ON
THURSDAY.
CAVANAUGH
&&
.PREV UPDATE FOR SHORT TERM FORECAST...
THE PRIMARY FORECAST CHALLENGE FOR THE NEXT 24 HRS IS DETERMINING
WHERE AND WHEN A MID-LEVEL LOW PRESSURE SYSTEM /MCV...CAUSED BY
PERSISTENT THUNDERSTORM ACTIVITY THAT HAS DISSIPATED/ WILL MOVE
OVER NORTH TX AND BRING US MORE THUNDERSTORM ACTIVITY. THE MID-
LEVEL LOW FROM YESTERDAYS THUNDERSTORM ACTIVITY WAS DIFFICULT TO
LOCATE THIS MORNING. 12Z UPPER AIR ANALYSIS INDICATED MID-LEVEL
CYCLONIC CIRCULATIONS FROM NORTHWEST TX SOUTH TO THE HILL COUNTRY.
IT IS POSSIBLE THAT THIS CYCLONIC SHEAR AXIS IS YESTERDAYS MID-
LEVEL LOW...BUT SHEARED APART IN THE LARGER SCALE UPPER LEVEL
RIDGE OVER THE REGION. JUST BEFORE NOON...THERE WAS A BAND OF RAIN
SHOWERS AND EMBEDDED STORMS EXTENDING FROM STEPHENVILLE SOUTH TO
THE AUSTIN AND SAN ANTONIO AREAS WHICH APPEARED TO BE ASSOCIATED
WITH THIS SHEAR AXIS.
THE MORE INTENSE THUNDERSTORMS AND RAIN SHOWERS WERE LOCATED AT
THE FAR SOUTHERN END OF THIS LINE...CAUSING WIDESPREAD FLOODING
AROUND THE CITY OF SAN ANTONIO AT THE TIME OF THIS DISCUSSION. DUE
TO THE PERSISTENCE OF INTENSE RAIN SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH OF THE CWA...WOULD EXPECT THAT A NEW OR
REINFORCED MID-LEVEL LOW PRESSURE SYSTEM WOULD DEVELOP AROUND SAN
ANTONIO SOMETIME TODAY. THERE HAS BEEN SOME INDICATION OF WEAK
CYCLONIC CIRCULATIONS IN THE LIGHTER RAINFALL RETURNS TO THE NORTH
OF SAN ANTONIO...IN BETWEEN TEMPLE AND AUSTIN.
MID-LEVEL LOW PRESSURE SYSTEMS ARE CREATED BY THUNDERSTORMS DUE
TO LARGE AMOUNTS OF LATENT HEAT RELEASED IN THE MIDDLE OF THE
ATMOSPHERE DUE TO WATER VAPOR CONDENSING INTO WATER DROPLETS OR
RAIN. BECAUSE THIS HAS BEEN GOING ON IN AN INTENSE FASHION NEAR
SAN ANTONIO ALL MORNING...THINK THAT A MID-LEVEL LOW PRESSURE
SYSTEM WILL LIKELY DEVELOP AROUND SAN ANTONIO /IF IT HAS NOT
ALREADY/ AND BECOME THE DOMINANT MESOSCALE FEATURE DRIVING RAIN
AND STORM CHANCES FOR NORTH TX OVER THE NEXT 24 HRS. THROUGH THIS
AFTERNOON JUST ADJUSTED POPS TO HIGHLIGHT AREAS SOUTH OF
INTERSTATE 20 AS HAVING THE HIGHEST RAIN CHANCES TODAY ASSUMING
THE SAN ANTONIO LOW MOVES SLIGHTLY EAST THROUGH 7 PM.
DID NOT REMOVE RAIN CHANCES TO THE NORTH BECAUSE THE WEAK
CYCLONIC SHEAR AXIS STILL EXISTS AS FAR NORTH AS WICHITA
FALLS...SO SOME RAIN AND THUNDERSTORM CHANCES ARE STILL WARRANTED
NORTH OF INTERSTATE 20 THIS AFTERNOON. SEVERE WEATHER CHANCES
REMAIN SMALL ACROSS ALL OF NORTH TX AS MID-LEVEL LAPSE RATES ARE
POOR DUE TO YESTERDAYS THUNDERSTORM ACTIVITY AND DEEP LAYER SHEAR
REMAINS WEAK AT THIS TIME.
CAVANAUGH
&&
.AVIATION...
/18Z TAFS/
CONCERNS...THUNDER THROUGH THE EVENING AND MVFR CIGS THROUGH THE
PERIOD.
A MESSY TAF PERIOD CONTINUES WITH LOW CONFIDENCE IN CLOUD AND
PRECIPITATION TRENDS FOR THE NEXT 18-24 HOURS. AT ALL THE TAF
AIRPORTS...SCATTERED TO BROKEN MVFR CIGS WITH BASES BETWEEN
1200-2000 FEET PERSIST. HOWEVER...IFR CIGS ARE BEING REPORTED
SOUTHWEST OF KACT WHERE LIGHT RAIN HAS PERSISTED FOR MUCH OF THE
MORNING. CEILINGS SHOULD LIFT ABOVE 2000 FEET THIS AFTERNOON AND
POSSIBLY INTO VFR CATEGORY BEFORE THE EVENING HOURS BUT THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN THE REGION MAY AFFECT
IMPROVING CLOUD TRENDS. MOST OF THE PRECIPITATION THIS MORNING HAS
REMAINED WEST OF THE AIRPORTS BUT RADAR INDICATES NEW DEVELOPMENT
CLOSER TO THE TAF TERMINALS. EXPECT ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS TO DEVELOP THROUGHOUT THE AFTERNOON. SHOWERS
AND THUNDERSTORMS COULD DIRECTLY IMPACT ANY OF THE AIRPORTS THIS
AFTERNOON BUT THINK KACT AS THE HIGHEST CHANCES OF BEING IMPACTS
BY CONVECTION AND INCLUDED A TEMPO FROM 19-23Z FOR TSRA. ONCE
AGAIN...EXPECT MOST OF THE CONVECTIVE ACTIVITY TO DECREASE THIS
AFTERNOON AND A FAIRLY QUIET AND DRY OVERNIGHT PERIOD...BUT WILL BE
MONITORING THE MOVEMENT OF AN UPPER LEVEL LOW OVER THE REGION FOR
ANY CHANGES TO RAIN/CONVECTIVE CHANCES. ALSO WILL BE MONITORING
FOR ANOTHER AREA OF WIDESPREAD RAIN/STORMS TO AFFECT ANY OF THE
AIRPORTS LATER TODAY. MVFR CIGS WILL LIKELY RETURN TO ALL TAF
AIRPORTS OVERNIGHT BETWEEN 09-11Z.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 69 87 69 87 70 / 30 10 5 0 0
WACO, TX 68 87 68 89 71 / 30 10 5 0 0
PARIS, TX 67 85 66 85 67 / 30 10 5 0 0
DENTON, TX 67 86 68 87 68 / 30 10 5 0 0
MCKINNEY, TX 67 85 68 87 69 / 30 10 5 0 0
DALLAS, TX 71 87 70 89 72 / 30 10 5 0 0
TERRELL, TX 67 86 68 88 70 / 30 10 5 0 0
CORSICANA, TX 67 88 68 89 70 / 30 10 5 0 0
TEMPLE, TX 67 87 68 88 70 / 20 10 5 0 0
MINERAL WELLS, TX 66 87 67 89 68 / 20 10 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
339 PM CDT SAT MAY 25 2013
.SHORT TERM...
MOIST UPSLOPE FLOW ACROSS EASTERN NEW MEXICO HAS ALREADY SUPPORTED
SCATTERED TSTMS FROM THE SACRAMENTOS NORTH TO SANTA ROSA. A SECOND
AREA OF INTEREST IS EVIDENT ON VIS SATELLITE ALONG THE MESCALERO
ESCARPMENT WHERE AGITATED CU HAVE RECENTLY DEVELOPED. HRRR AND
NAM-WRF BOTH PROG TSTM DEVELOPMENT ALONG THIS CU LINE BEFORE 00Z
AND CARRY IT EASTWARD TO VARIOUS DEGREES WITHIN 20 KNOTS OF
700-500MB FLOW. CONSIDERING CINH IS TRENDING NEGLIGIBLE ALONG THE
NM/TX STATE LINE AND SBCAPE IS AROUND 2K J/KG...HAVE ADDED SEVERE
MENTION TO OUR WESTERNMOST COUNTIES WHERE THIS ACTIVITY WILL LIKELY
PEAK IN INTENSITY BEFORE DIMINISHING THEREAFTER AS THE MIXING LAYER
DECOUPLES. LITTLE/NO BACKGROUND SUPPORT MAY FURTHER LIMIT THE
CHANCES OF THIS PERSISTING OVER THE REMAINDER OF THE SOUTH
PLAINS...BUT WILL KEEP SOME ISOLATED MENTION THROUGH 06Z.
SUNDAY WILL SEE IMPROVED W-SWLY FLOW OVERSPREAD THE REGION RESULTING
IN THE DRYLINE MIXING OUT OF NEW MEXICO AND STALLING SOMEWHERE OVER
THE WESTERN 1/3 OF THE CWA. ALBEIT MODEST...AN ADDITIONAL INFLUX OF
GULF MOISTURE BY EARLY SUNDAY IS PROGGED TO SECURE HIGHER SBCAPES
GENERALLY AROUND 3500 J/KG ALONG THE DRYLINE WITH EVEN EXTREME
VALUES IN THE ROLLING PLAINS...HOWEVER THE LATTER IS SHOWN TO REMAIN
CAPPED AND TOO FAR REMOVED FROM THE DRYLINE. NO DISCERNIBLE SHORT
WAVE TROUGHS ARE PROGGED...BUT AS IS THE CASE TODAY DEEP MIXING
SHOULD PROVE MORE THAN ADEQUATE FOR AT LEAST ISO TSTMS. WINDOW FOR
SUPERCELLS WILL BE OPENED 0-6KM BULK SHEAR VECTORS RISE TO NEARLY 40
KNOTS AND MAINTAIN A PERPENDICULAR ORIENTATION TO THE DRYLINE.
ROBUST CAPE IN THE HAIL GROWTH LAYER COMBINED WITH RELATIVELY HIGH
LCL VALUES WILL OPEN THE WINDOW FOR SOME VERY LARGE HAIL AND DMGG
DOWNBURSTS. MOST HIGH TEMPS WERE KEPT A FEW DEGREES ABOVE
MOS...PARTICULARLY WEST OF THE DRYLINE WHERE OUR HIGHEST ELEVATIONS
COULD END UP WITH THE HOTTEST VALUES FOR THE DAY.
&&
.LONG TERM...
HIGH AMPLITUDE RIDGE ORIENTED FROM THE BIG BEND TO THE WESTERN GREAT
LAKES THENCE WELL INTO CENTRAL CANADA WILL CONTINUE ITS SLOW
EASTWARD PROGRESSION AS A COUPLE OF STORM SYSTEMS COME ASHORE THE
PACIFIC NORTHWEST. TOWARD MID WEEK...FLOW ACROSS WEST TEXAS WILL
STRENGTHEN AS NEGATIVELY TILTED TROUGH DEEPENS FROM THE PAC NW.
THURSDAY SHOULD SEE A RETURN TO ZONAL FLOW AS UPPER LOW SETTLES
ACROSS WYOMING THOUGH ANOTHER LOBE OF ENERGY ROTATING AROUND THE WY
SYSTEM WILL APPROACH LATE THU/EARLY FRIDAY WITH SOUTHWESTERLIES
PERSISTING THROUGH DAY 7.
WILL CONTINUE MENTION OF TSRA INTO THE EVENING HOURS ON SUNDAY WITH
CONDITIONS SETTLING AFTER SUNSET. DRYLINE SHOULD PUSH INTO NEW
MEXICO OVERNIGHT THEN TIGHTEN UP AGAIN MONDAY AFTERNOON WITH
CONVECTION LOOKING MOST LIKELY EAST OF A SILVERTON TO BROWNFIELD
LINE THOUGH SOME VARIANCE WILL BE POSSIBLE GIVEN THE INFLUENCES OF
SUNDAY NIGHT/S STORMS. WEDNESDAY LOOKS TO KEEP THE DRYLINE A BIT
FURTHER WEST THUS GIVING MORE OF THE AREA A SHOT AT THE MUCH NEEDED
RAINFALL. WITH THE MORE STRONGLY DIFLUENT FLOW ON WEDNESDAY...THIS
COULD BE THE MOST PRONOUNCED OF THE SEVERE WEATHER THIS WEEK THOUGH
EACH DAY WILL HAVE SEVERE POTENTIAL. THE LONG AND SHORT OF IT IS
THAT EACH DAY OVER THE NEXT WEEK...WE WILL SEE AT LEAST SCATTERED
CONVECTION POTENTIAL EACH AFTERNOON AS THE DRYLINE SLOSHES ACROSS
THE REGION. AT PRESENT...IT WOULD APPEAR THE TORNADO THREAT THIS
WEEK WOULD BE MAXIMIZED ACROSS THE NORTHEASTERN ZONES ON WEDNESDAY.
TO THE WEST OF THE DRYLINE...ELEVATED TO LOW END CRITICAL FIRE
WEATHER CONDITIONS WILL EXIST NEARLY EVERY AFTERNOON AS MIN AFTN RH
DROPS TO THE LOWER TEENS WITH THE BREEZY WEST-OF-THE-DRYLINE WINDS.
OUR NORTHWEST HAS SEEN THE LOWEST AMOUNT OF GREEN-UP DUE TO THE LACK
OF PRECIPITATION THIS SPRING AND WHILE FUELS ARE NOT
PLENTIFUL...WHAT IS THERE WOULD BE EXPECTED TO BURN QUITE EASILY
GIVEN THE RIGHT METEOROLOGICAL CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 61 94 62 94 61 / 30 20 20 10 10
TULIA 61 94 65 94 64 / 20 20 20 20 20
PLAINVIEW 62 93 65 95 65 / 20 20 20 20 20
LEVELLAND 63 95 68 95 67 / 20 20 20 20 20
LUBBOCK 65 94 67 95 67 / 20 20 20 20 20
DENVER CITY 62 95 68 95 68 / 20 10 10 10 20
BROWNFIELD 63 95 68 96 68 / 20 20 20 20 20
CHILDRESS 68 94 67 94 67 / 10 10 10 10 20
SPUR 65 92 68 95 68 / 10 10 10 10 20
ASPERMONT 68 93 69 92 69 / 10 10 10 10 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/26
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1247 PM CDT SAT MAY 25 2013
.AVIATION...
/18Z TAFS/
CONCERNS...THUNDER THROUGH THE EVENING AND MVFR CIGS THROUGH THE
PERIOD.
A MESSY TAF PERIOD CONTINUES WITH LOW CONFIDENCE IN CLOUD AND
PRECIPITATION TRENDS FOR THE NEXT 18-24 HOURS. AT ALL THE TAF
AIRPORTS...SCATTERED TO BROKEN MVFR CIGS WITH BASES BETWEEN
1200-2000 FEET PERSIST. HOWEVER...IFR CIGS ARE BEING REPORTED
SOUTHWEST OF KACT WHERE LIGHT RAIN HAS PERSISTED FOR MUCH OF THE
MORNING. CEILINGS SHOULD LIFT ABOVE 2000 FEET THIS AFTERNOON AND
POSSIBLY INTO VFR CATEGORY BEFORE THE EVENING HOURS BUT THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN THE REGION MAY AFFECT
IMPROVING CLOUD TRENDS. MOST OF THE PRECIPITATION THIS MORNING HAS
REMAINED WEST OF THE AIRPORTS BUT RADAR INDICATES NEW DEVELOPMENT
CLOSER TO THE TAF TERMINALS. EXPECT ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS TO DEVELOP THROUGHOUT THE AFTERNOON. SHOWERS
AND THUNDERSTORMS COULD DIRECTLY IMPACT ANY OF THE AIRPORTS THIS
AFTERNOON BUT THINK KACT AS THE HIGHEST CHANCES OF BEING IMPACTS
BY CONVECTION AND INCLUDED A TEMPO FROM 19-23Z FOR TSRA. ONCE
AGAIN...EXPECT MOST OF THE CONVECTIVE ACTIVITY TO DECREASE THIS
AFTERNOON AND A FAIRLY QUIET AND DRY OVERNIGHT PERIOD...BUT WILL BE
MONITORING THE MOVEMENT OF AN UPPER LEVEL LOW OVER THE REGION FOR
ANY CHANGES TO RAIN/CONVECTIVE CHANCES. ALSO WILL BE MONITORING
FOR ANOTHER AREA OF WIDESPREAD RAIN/STORMS TO AFFECT ANY OF THE
AIRPORTS LATER TODAY. MVFR CIGS WILL LIKELY RETURN TO ALL TAF
AIRPORTS OVERNIGHT BETWEEN 09-11Z.
82/JLD
&&
.UPDATE...
THE PRIMARY FORECAST CHALLENGE FOR THE NEXT 24 HRS IS DETERMINING
WHERE AND WHEN A MID-LEVEL LOW PRESSURE SYSTEM /MCV...CAUSED BY
PERSISTENT THUNDERSTORM ACTIVITY THAT HAS DISSIPATED/ WILL MOVE
OVER NORTH TX AND BRING US MORE THUNDERSTORM ACTIVITY. THE MID-
LEVEL LOW FROM YESTERDAYS THUNDERSTORM ACTIVITY WAS DIFFICULT TO
LOCATE THIS MORNING. 12Z UPPER AIR ANALYSIS INDICATED MID-LEVEL
CYCLONIC CIRCULATIONS FROM NORTHWEST TX SOUTH TO THE HILL COUNTRY.
IT IS POSSIBLE THAT THIS CYCLONIC SHEAR AXIS IS YESTERDAYS MID-
LEVEL LOW...BUT SHEARED APART IN THE LARGER SCALE UPPER LEVEL
RIDGE OVER THE REGION. JUST BEFORE NOON...THERE WAS A BAND OF RAIN
SHOWERS AND EMBEDDED STORMS EXTENDING FROM STEPHENVILLE SOUTH TO
THE AUSTIN AND SAN ANTONIO AREAS WHICH APPEARED TO BE ASSOCIATED
WITH THIS SHEAR AXIS.
THE MORE INTENSE THUNDERSTORMS AND RAIN SHOWERS WERE LOCATED AT
THE FAR SOUTHERN END OF THIS LINE...CAUSING WIDESPREAD FLOODING
AROUND THE CITY OF SAN ANTONIO AT THE TIME OF THIS DISCUSSION. DUE
TO THE PERSISTENCE OF INTENSE RAIN SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH OF THE CWA...WOULD EXPECT THAT A NEW OR
REINFORCED MID-LEVEL LOW PRESSURE SYSTEM WOULD DEVELOP AROUND SAN
ANTONIO SOMETIME TODAY. THERE HAS BEEN SOME INDICATION OF WEAK
CYCLONIC CIRCULATIONS IN THE LIGHTER RAINFALL RETURNS TO THE NORTH
OF SAN ANTONIO...IN BETWEEN TEMPLE AND AUSTIN.
MID-LEVEL LOW PRESSURE SYSTEMS ARE CREATED BY THUNDERSTORMS DUE
TO LARGE AMOUNTS OF LATENT HEAT RELEASED IN THE MIDDLE OF THE
ATMOSPHERE DUE TO WATER VAPOR CONDENSING INTO WATER DROPLETS OR
RAIN. BECAUSE THIS HAS BEEN GOING ON IN AN INTENSE FASHION NEAR
SAN ANTONIO ALL MORNING...THINK THAT A MID-LEVEL LOW PRESSURE
SYSTEM WILL LIKELY DEVELOP AROUND SAN ANTONIO /IF IT HAS NOT
ALREADY/ AND BECOME THE DOMINANT MESOSCALE FEATURE DRIVING RAIN
AND STORM CHANCES FOR NORTH TX OVER THE NEXT 24 HRS. THROUGH THIS
AFTERNOON JUST ADJUSTED POPS TO HIGHLIGHT AREAS SOUTH OF
INTERSTATE 20 AS HAVING THE HIGHEST RAIN CHANCES TODAY ASSUMING
THE SAN ANTONIO LOW MOVES SLIGHTLY EAST THROUGH 7 PM.
DID NOT REMOVE RAIN CHANCES TO THE NORTH BECAUSE THE WEAK
CYCLONIC SHEAR AXIS STILL EXISTS AS FAR NORTH AS WICHITA
FALLS...SO SOME RAIN AND THUNDERSTORM CHANCES ARE STILL WARRANTED
NORTH OF INTERSTATE 20 THIS AFTERNOON. SEVERE WEATHER CHANCES
REMAIN SMALL ACROSS ALL OF NORTH TX AS MID-LEVEL LAPSE RATES ARE
POOR DUE TO YESTERDAYS THUNDERSTORM ACTIVITY AND DEEP LAYER SHEAR
REMAINS WEAK AT THIS TIME.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT SAT MAY 25 2013/
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.
THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.
MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 69 87 69 87 / 40 30 10 5 0
WACO, TX 83 68 87 68 89 / 50 30 10 5 0
PARIS, TX 83 67 85 66 85 / 30 30 10 5 0
DENTON, TX 84 67 86 68 87 / 40 30 10 5 0
MCKINNEY, TX 84 67 85 68 87 / 30 30 10 5 0
DALLAS, TX 85 71 87 70 89 / 40 30 10 5 0
TERRELL, TX 84 67 86 68 88 / 40 30 10 5 0
CORSICANA, TX 84 67 88 68 89 / 40 30 10 5 0
TEMPLE, TX 82 67 87 68 88 / 60 20 10 5 0
MINERAL WELLS, TX 81 66 87 67 89 / 40 20 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/69
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1213 PM CDT SAT MAY 25 2013
.UPDATE...
THE PRIMARY FORECAST CHALLENGE FOR THE NEXT 24 HRS IS DETERMINING
WHERE AND WHEN A MID-LEVEL LOW PRESSURE SYSTEM /MCV...CAUSED BY
PERSISTENT THUNDERSTORM ACTIVITY THAT HAS DISSIPATED/ WILL MOVE
OVER NORTH TX AND BRING US MORE THUNDERSTORM ACTIVITY. THE MID-
LEVEL LOW FROM YESTERDAYS THUNDERSTORM ACTIVITY WAS DIFFICULT TO
LOCATE THIS MORNING. 12Z UPPER AIR ANALYSIS INDICATED MID-LEVEL
CYCLONIC CIRCULATIONS FROM NORTHWEST TX SOUTH TO THE HILL COUNTRY.
IT IS POSSIBLE THAT THIS CYCLONIC SHEAR AXIS IS YESTERDAYS MID-
LEVEL LOW...BUT SHEARED APART IN THE LARGER SCALE UPPER LEVEL
RIDGE OVER THE REGION. JUST BEFORE NOON...THERE WAS A BAND OF RAIN
SHOWERS AND EMBEDDED STORMS EXTENDING FROM STEPHENVILLE SOUTH TO
THE AUSTIN AND SAN ANTONIO AREAS WHICH APPEARED TO BE ASSOCIATED
WITH THIS SHEAR AXIS.
THE MORE INTENSE THUNDERSTORMS AND RAIN SHOWERS WERE LOCATED AT
THE FAR SOUTHERN END OF THIS LINE...CAUSING WIDESPREAD FLOODING
AROUND THE CITY OF SAN ANTONIO AT THE TIME OF THIS DISCUSSION. DUE
TO THE PERSISTENCE OF INTENSE RAIN SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH OF THE CWA...WOULD EXPECT THAT A NEW OR
REINFORCED MID-LEVEL LOW PRESSURE SYSTEM WOULD DEVELOP AROUND SAN
ANTONIO SOMETIME TODAY. THERE HAS BEEN SOME INDICATION OF WEAK
CYCLONIC CIRCULATIONS IN THE LIGHTER RAINFALL RETURNS TO THE NORTH
OF SAN ANTONIO...IN BETWEEN TEMPLE AND AUSTIN.
MID-LEVEL LOW PRESSURE SYSTEMS ARE CREATED BY THUNDERSTORMS DUE
TO LARGE AMOUNTS OF LATENT HEAT RELEASED IN THE MIDDLE OF THE
ATMOSPHERE DUE TO WATER VAPOR CONDENSING INTO WATER DROPLETS OR
RAIN. BECAUSE THIS HAS BEEN GOING ON IN AN INTENSE FASHION NEAR
SAN ANTONIO ALL MORNING...THINK THAT A MID-LEVEL LOW PRESSURE
SYSTEM WILL LIKELY DEVELOP AROUND SAN ANTONIO /IF IT HAS NOT
ALREADY/ AND BECOME THE DOMINANT MESOSCALE FEATURE DRIVING RAIN
AND STORM CHANCES FOR NORTH TX OVER THE NEXT 24 HRS. THROUGH THIS
AFTERNOON JUST ADJUSTED POPS TO HIGHLIGHT AREAS SOUTH OF
INTERSTATE 20 AS HAVING THE HIGHEST RAIN CHANCES TODAY ASSUMING
THE SAN ANTONIO LOW MOVES SLIGHTLY EAST THROUGH 7 PM.
DID NOT REMOVE RAIN CHANCES TO THE NORTH BECAUSE THE WEAK
CYCLONIC SHEAR AXIS STILL EXISTS AS FAR NORTH AS WICHITA
FALLS...SO SOME RAIN AND THUNDERSTORM CHANCES ARE STILL WARRANTED
NORTH OF INTERSTATE 20 THIS AFTERNOON. SEVERE WEATHER CHANCES
REMAIN SMALL ACROSS ALL OF NORTH TX AS MID-LEVEL LAPSE RATES ARE
POOR DUE TO YESTERDAYS THUNDERSTORM ACTIVITY AND DEEP LAYER SHEAR
REMAINS WEAK AT THIS TIME.
CAVANAUGH
&&
.AVIATION...
THE WEAK UPPER LOW OVER THE REGION WILL AGAIN RESULT IN AREAS OF
SHRA/TSRA THROUGHOUT THE DAY. RADAR MOSAIC SHOWS THIS ACTIVITY
CURRENTLY FROM THE KAUS/KSAT AREA NORTHWARD TO THE RED RIVER. AS
THE DAY PROGRESSES EXPECT CONVECTION TO INCREASE IN COVERAGE WITH
SOME AFFECTING THE TAF SITES MAINLY THIS AFTERNOON. AS THE UPPER
LOW MOVES FARTHER NORTHEAST TONIGHT...SOME ACTIVITY WILL LINGER
OVER THE AREA BUT IT SHOULD BE MOSTLY -RA AFTER 26/03Z.
AIRPORT OPERATIONS WILL BE AFFECTED BY LIGHTNING STRIKES...WET
RUNWAYS AND REDUCTIONS IN CIGS AND VIS DURING CONVECTION. KDFW
OPERATIONS SHOULD EXPECT AN AIRPORT WEATHER WARNING TO BE ISSUED
LATER TODAY AS LIGHTNING NEARS THE AIRPORT.
FOR THIS TAF CYCLE...MVFR CIGS ARE ON GOING AT KACT BUT THEY
SHOULD ARRIVE AT THE METROPLEX AIRPORTS 13-14Z. CIGS WILL LIFT
TO VFR BY LATE MORNING. MVFR CIGS WILL RETURN TO KDFW LATE TONIGHT
AROUND 26/09Z AND SHOULD END AROUND 26/16Z. 75
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT SAT MAY 25 2013/
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.
THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.
MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 69 87 69 87 / 40 30 10 5 0
WACO, TX 83 68 87 68 89 / 50 30 10 5 0
PARIS, TX 83 67 85 66 85 / 30 30 10 5 0
DENTON, TX 84 67 86 68 87 / 40 30 10 5 0
MCKINNEY, TX 84 67 85 68 87 / 30 30 10 5 0
DALLAS, TX 85 71 87 70 89 / 40 30 10 5 0
TERRELL, TX 84 67 86 68 88 / 40 30 10 5 0
CORSICANA, TX 84 67 88 68 89 / 40 30 10 5 0
TEMPLE, TX 82 67 87 68 88 / 60 20 10 5 0
MINERAL WELLS, TX 81 66 87 67 89 / 40 20 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
631 AM CDT SAT MAY 25 2013
.AVIATION...
THE WEAK UPPER LOW OVER THE REGION WILL AGAIN RESULT IN AREAS OF
SHRA/TSRA THROUGHOUT THE DAY. RADAR MOSAIC SHOWS THIS ACTIVITY
CURRENTLY FROM THE KAUS/KSAT AREA NORTHWARD TO THE RED RIVER. AS
THE DAY PROGRESSES EXPECT CONVECTION TO INCREASE IN COVERAGE WITH
SOME AFFECTING THE TAF SITES MAINLY THIS AFTERNOON. AS THE UPPER
LOW MOVES FARTHER NORTHEAST TONIGHT...SOME ACTIVITY WILL LINGER
OVER THE AREA BUT IT SHOULD BE MOSTLY -RA AFTER 26/03Z.
AIRPORT OPERATIONS WILL BE AFFECTED BY LIGHTNING STRIKES...WET
RUNWAYS AND REDUCTIONS IN CIGS AND VIS DURING CONVECTION. KDFW
OPERATIONS SHOULD EXPECT AN AIRPORT WEATHER WARNING TO BE ISSUED
LATER TODAY AS LIGHTNING NEARS THE AIRPORT.
FOR THIS TAF CYCLE...MVFR CIGS ARE ON GOING AT KACT BUT THEY
SHOULD ARRIVE AT THE METROPLEX AIRPORTS 13-14Z. CIGS WILL LIFT
TO VFR BY LATE MORNING. MVFR CIGS WILL RETURN TO KDFW LATE TONIGHT
AROUND 26/09Z AND SHOULD END AROUND 26/16Z. 75
&&
.PREV DISCUSSION... /ISSUED 347 AM CDT SAT MAY 25 2013/
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.
THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.
MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 69 87 69 87 / 40 30 10 5 0
WACO, TX 83 68 87 68 89 / 50 30 10 5 0
PARIS, TX 83 67 85 66 85 / 30 30 10 5 0
DENTON, TX 84 67 86 68 87 / 40 30 10 5 0
MCKINNEY, TX 84 67 85 68 87 / 30 30 10 5 0
DALLAS, TX 85 71 87 70 89 / 30 30 10 5 0
TERRELL, TX 84 67 86 68 88 / 30 30 10 5 0
CORSICANA, TX 84 67 88 68 89 / 30 30 10 5 0
TEMPLE, TX 82 67 87 68 88 / 50 20 10 5 0
MINERAL WELLS, TX 81 66 87 67 89 / 40 20 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
347 AM CDT SAT MAY 25 2013
.DISCUSSION...
RADAR/SATELLITE LOOP INDICATES THAT THE WEAK MID LEVEL LOW IS
LIKELY LOCATED NEAR ABILENE AND 00Z 500MB ANALYSIS CONFIRMS IT IS
WARM-CORE IN NATURE. AS IS OFTEN THE CASE WITH WARM-CORE
LOWS...CONVECTION IS FIRING BEFORE SUNRISE ACROSS THE HILL
COUNTRY WITHIN A WEAK LOW LEVEL JET AXIS WHERE THETA-E ADVECTION
AND OROGRAPHIC LIFT ARE OCCURRING. SHORT-TERM MODELS SUCH AS THE
HRRR AND RUC SUGGEST THAT SCATTERED CONVECTION WILL CONTINUE TO
EXPAND NORTHWARD FROM CENTRAL TEXAS INTO THE WESTERN ZONES DURING
THE MORNING HOURS. THE GFS APPEARS TO BE SUFFERING FROM GRID SCALE
CONVECTIVE FEEDBACK WHICH IS RESULTING IN VERY HIGH QPF AND
CONTAMINATED MASS FIELDS...THUS THE GFS WILL NOT BE USED IN THE
SHORT-TERM. THE NAM SEEMS TO BE MATCHING CURRENT TRENDS AND SHORT-
TERM MODELS WELL AND THEREFORE IT GIVES CONFIDENCE TO RAISE POPS
TODAY. WE EXPECT THE BEST COVERAGE OF CONVECTION IN THE WESTERN
ZONES THIS MORNING. SCATTERED CONVECTION WILL BUILD/EXPAND
EASTWARD INTO THE EASTERN ZONES DURING THE MIDDAY/AFTERNOON HOURS.
THE AIRMASS OVER THE EASTERN ZONES WILL BE A BIT MORE UNSTABLE DUE
TO BETTER INSOLATION AND A COUPLE OF STRONG STORMS WITH GUSTY
WINDS WILL BE POSSIBLE...BUT DUE TO WEAK SHEAR THE SEVERE THREAT
IS LOW. HIGHS TODAY IN THE WESTERN ZONES WILL ONLY BE IN THE UPPER
70S TO LOW 80S DUE TO CLOUDS/RAIN...WITH HIGHS IN THE EASTERN
ZONES REACHING THE MID 80S. SCATTERED CONVECTION WILL CONTINUE
INTO THE EVENING HOURS BEFORE DISSIPATING WITH LOSS OF HEATING.
THE WARM CORE MID LEVEL LOW WILL BE EXITING THE REGION TO THE
NORTHEAST TONIGHT...AND THEREFORE THE RAIN CHANCES WILL COME TO AN
END. EXPECT A DRY SUNDAY WITH TEMPERATURES REBOUNDING INTO THE
MID-UPPER 80S AREA WIDE. AS AN UPPER LEVEL TROUGH DEVELOPS ACROSS
THE INTER-MOUNTAIN WEST...A SURFACE LOW WILL DEEPEN IN THE HIGH
PLAINS MONDAY. THIS WILL BRING BREEZY SOUTH WINDS TO THE REGION
MONDAY WHICH WILL LIKELY PERSIST THROUGH THE WEEK. LOW TEMPS WILL
WARM INTO THE 70S AREA WIDE BY MIDWEEK WITH HIGHS GENERALLY IN THE
MID 80S EAST TO LOW 90S WEST. THE SOUTHWEST FLOW ABOVE THE
SURFACE WILL BRING A THERMAL INVERSION INTO THE AREA. THUS THE
FORECAST LOOKS DRY UNLESS/UNTIL FORCING ARRIVES TO WEAKEN THE CAP.
MODEL GUIDANCE REMAINS IN POOR TO FAIR AGREEMENT REGARDING THE
EVOLUTION/EJECTION OF THE WEST COAST UPPER TROUGH MID-LATE WEEK.
THE ECMWF CONTINUES TO SHOW A VERY NEGATIVELY TILTED TROUGH
SWINGING THROUGH THE REGION LATE WEDNESDAY AND THURSDAY WHICH
WOULD BODE WELL FOR RAIN. BUT IT CONTINUES TO BE THE ONLY MODEL
THAT SHOWS THE TROUGH EJECTION LIKE THIS...AND FRANKLY THE 500MB
PATTERN IT PRESENTS JUST DOES NOT LOOK REALISTIC. IF IT WERE NOT
FOR THE ECMWF BEING THE BETTER OF THE LONG RANGE MODELS...I WOULD
DISCOUNT IT ALTOGETHER AND SHOW A DRY FORECAST ON THURSDAY...BUT
FOR NOW HAVE RETAINED THE SLIGHT CHANCE POPS. THE GFS/UKMET/GEM
FORECASTS SHOW THAT THE UPPER ENERGY NEEDED TO BREAK THE CAP WILL
LIKELY REMAIN WELL NORTHWEST OF THE REGION. FURTHERMORE...THE
DRYLINE ALSO LOOKS LIKE IT WILL REMAIN TOO FAR TO THE WEST...WITH
THE GFS SHOWING IT AS FAR WEST AS THE TX PANHANDLE. STORM MOTIONS
WILL GENERALLY BE NORTHEAST AND THIS MEANS STORMS WOULD NOT EVEN
HAVE A CHANCE TO PROPAGATE INTO THE CWA EITHER. SO IN SUMMARY THE
RAIN CHANCES ON THURSDAY AT THIS POINT ARE HINGING ON THE ECMWF
BEING CORRECT...AND THIS MAY BE A BIT OF A LONG SHOT.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 84 69 87 69 87 / 40 30 10 5 0
WACO, TX 83 68 87 68 89 / 50 30 10 5 0
PARIS, TX 83 67 85 66 85 / 30 30 10 5 0
DENTON, TX 85 67 86 68 87 / 40 30 10 5 0
MCKINNEY, TX 84 67 85 68 87 / 30 30 10 5 0
DALLAS, TX 85 71 87 70 89 / 30 30 10 5 0
TERRELL, TX 84 67 86 68 88 / 30 30 10 5 0
CORSICANA, TX 84 67 88 68 89 / 30 30 10 5 0
TEMPLE, TX 82 67 87 68 88 / 50 20 10 5 0
MINERAL WELLS, TX 81 66 87 67 89 / 40 20 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1038 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Update: Satellite imagery from this morning shows two closed
lows...one near the north Washington coast and another over
southern Alberta. Models show these two features moving very
little today. With no strong forcing mechanism to generate
showers...there should be less shower activity today compared to
yesterday. The 13z HRRR model shows most of the showers today
will be along the East Slopes of the Cascades and north of the
Columbia Basin over the northern mountains. This make sense given
these areas are in closest proximity to the two aforementioned
lows...and that showers are more likely to develop over the
mountainous terrain. Forecast has this part of the forecast well
handled with only change to lower mountain pops to 20 percent
through the morning with better chances holding off til afternoon
when instability increases.
Latest SREF and SPC guidance, as well as the 13z HRRR model shows
minimal thunder chances today. The better chances will be north of
the Canadian border...and over the Clearwaters. With cloud cover
this morning extensive over the Idaho Panhandle and northeast
Washington mountains...this will further lower convective
potential. Cloud cover was increased this morning over North
Idaho, and thunder was removed from the northern mountains, but a
slight chance was kept for the Camas Prairie with this area on the
edge of the best convective potential. Also lowered high
temperatures today a few degrees for Sandpoint and Kellogg. JW
&&
.AVIATION...
18Z TAFS: An upper level trough will remain over the Inland
Northwest over the next 24 hours. Today showers will increase
mainly over the mountains but instability is marginal for
thunderstorms with none expected. These showers will die off after
03z with the loss of daytime heating. Another disturbance embedded
within this trough will spreading thickening cloud cover into the
region between after 14z Sunday especially KEAT/KMWH where a few
showers may develop. The bulk of the showers should hold off til
after 18z Sunday. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 40 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 40 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 40 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 40 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 61 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 59 44 63 46 62 47 / 40 20 30 50 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
833 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Update: Satellite imagery from this morning shows two closed
lows...one near the north Washington coast and another over
southern Alberta. Models show these two features moving very
little today. With no strong forcing mechanism to generate
showers...there should be less shower activity today compared to
yesterday. The 13z HRRR model shows most of the showers today
will be along the East Slopes of the Cascades and north of the
Columbia Basin over the northern mountains. This make sense given
these areas are in closest proximity to the two aforementioned
lows...and that showers are more likely to develop over the
mountainous terrain. Forecast has this part of the forecast well
handled with only change to lower mountain pops to 20 percent
through the morning with better chances holding off til afternoon
when instability increases.
Latest SREF and SPC guidance, as well as the 13z HRRR model shows
minimal thunder chances today. The better chances will be north of
the Canadian border...and over the Clearwaters. With cloud cover
this morning extensive over the Idaho Panhandle and northeast
Washington mountains...this will further lower convective
potential. Cloud cover was increased this morning over North
Idaho, and thunder was removed from the northern mountains, but a
slight chance was kept for the Camas Prairie with this area on the
edge of the best convective potential. Also lowered high
temperatures today a few degrees for Sandpoint and Kellogg. JW
&&
.AVIATION...
12Z TAFS: General trof over Eastern Washington and Northern Idaho
continues through this interval. Some late night and early morning
valley fog primarily in northern valleys with some showers at
times...primarily in the afternoon and early evening. VFR ceilings
and visibilities are expected to prevail through the 24 hour
interval. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 40 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 40 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 40 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 40 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 61 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 59 44 63 46 62 47 / 40 20 30 50 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
427 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Today through Sunday...General trof pattern continues to influence
the sensible weather over Eastern Washington and Northern Idaho
keeping it unsettled at times along with temperatures on the cool
side of what would be considered normal this time of year. Last
few HRRR model runs hit at surface based convection over the
northern mountains after 11AM PDT today and upon further inspection
GFS runs for this interval show the cold pool aloft at 500mb
helping to keep the instability overhead extends west to overhang
parts of the cascades...thus the minor mention of afternoon and
early evening thunderstorms has been stretched westward to cover
parts of the East Slopes of the Northern cascades roughly north of
Leavenworth. Models also hint at a mesoscale shortwave or two
producing enough forcing to allow for some minor mention of
showers overnight...one near the cascades and the other passing
over the Blue Mountains up into North Idaho Panhandle. Sunday the
trof overhead is very very cluttered with synoptic and mesoscale
shortwave propagation through it which allows for the mention of
showers to persist. Forecast temps show a very slight cooling
trend as the flow turns a bit more southerly, which is a warm
trajectory most of the time, for Sunday. Additionally since the
jet stream is south of the forecast area through this time
interval resulting in a lowered tropopause (down to near 400mb)
some of these showers could produce the typical early spring
precipitation type (graupel or soft hail) for a spell along with
mixing moderate wind gusts down to the surface which is something
to keep in mind over the weekend. /Pelatti
Sunday Night through Wednesday: The cool upper level trough that
has been anchored over the Pacific Northwest since Wednesday is
expected to pivot into western Montana Sunday night into Monday
bringing scattered showers to the eastern third of Washington and
northern Idaho. Despite the displacement of this upper low, our
weather pattern isn`t expected to change much. There is good
agreement between the medium range models that the Polar Jet will
dive into southern Oregon and carve another upper level trough
over the Pacific Northwest. The best jet dynamics (Q-Vector
Divergence) Monday night into Tuesday should be over southern
Oregon into the Great Basin, but there will be enough moisture and
deep layer instability with the weakening frontal occlusion to
maintain a good chance of showers Tuesday and Tuesday night.
Depending on the timing of this system, we may need to add a
mention of thunderstorms on Tuesday. The 00z GFS, Canadian and
ECMWF are in pretty good agreement with a weak, negatively tilted
trough over central and western Washington. The GFS and ECMWF
are producing precipitation that looks convectively driven over
the north Cascades. The potential for thunderstorms over the burn
scars around Wenatchee, Ellensburg, and Chelan will be a concern
through the summer and we will continue to monitor patterns like
this one closely for mudslides and debris flows.
The axis of a west to east oriented upper trough is expected to
linger over the Pacific Northwest Wednesday and through the end of
the week. It does look like Tuesday`s frontal occlusion will bring
the most widespread shower activity to the region this week, but
afternoon and early evening showers will be in the forecast for
much of the week. /GKoch
Wednesday Night through Friday Night: Through this time frame we
continue to see an unsettled pattern that will continue to feature
the chance for precipitation across most of the Inland NW
especially for the higher terrains of the ID Panhandle along with
Cascade Crests earlier in the period. Models are in pretty good
agreement through Friday Afternoon by keeping a large scale
negatively tilted trough pattern in place allowing for moisture to
flow in behind the low center that pushes to our SE throughout the
night on Wednesday. With the increased moisture, there will be
thick cloud cover keeping temps in the lower 60s and 70s for
most correlating to below normal temps for this time of year. Low
temps will follow the same pattern of a couple degrees below
normal due to the lack of daytime heating. Towards the end of the
period models are indicating a ridge builds behind the exiting
trough which should help to diminish the precipitation
threat...lower the cloud coverage and ultimately push temperatures
closer to seasonal averages as we approach next weekend. Overall
not many changes were made to the forecast..just tinkered with the
POPs slightly to reflect most recent model data and trended the
temps in the same manner. /Fliehman
&&
.AVIATION...
12Z TAFS: General trof over Eastern Washington and Northern Idaho
continues through this interval. Some late night and early morning
valley fog primarily in northern valleys with some showers at
times...primarily in the afternoon and early evening. VFR ceilings
and visibilities are expected to pravail through the 24 hour
interval. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 50 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 50 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 50 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 50 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 63 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 61 44 63 46 62 47 / 40 20 30 60 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
246 AM PDT Sat May 25 2013
.SYNOPSIS...
Memorial Day Weekend is expected to be a little cooler than
average, and a series of weak upper level disturbances will bring
the potential for scattered showers Sunday and Monday. The moist,
showery weather pattern is expected to linger into late next week.
&&
.DISCUSSION...
Today through Sunday...General trof pattern continues to influence
the sensible weather over Eastern Washington and Northern Idaho
keeping it unsettled at times along with temperatures on the cool
side of what would be considered normal this time of year. Last
few HRRR model runs hit at surface based convection over the
northern mountains after 11AM PDT today and upon further inspection
GFS runs for this interval show the cold pool aloft at 500mb
helping to keep the instability overhead extends west to overhang
parts of the cascades...thus the minor mention of afternoon and
early evening thunderstorms has been stretched westward to cover
parts of the East Slopes of the Northern cascades roughly north of
Leavenworth. Models also hint at a mesoscale shortwave or two
producing enough forcing to allow for some minor mention of
showers overnight...one near the cascades and the other passing
over the Blue Mountains up into North Idaho Panhandle. Sunday the
trof overhead is very very cluttered with synoptic and mesoscale
shortwave propagation through it which allows for the mention of
showers to persist. Forecast temps show a very slight cooling
trend as the flow turns a bit more southerly, which is a warm
trajectory most of the time, for Sunday. Additionally since the
jet stream is south of the forecast area through this time
interval resulting in a lowered tropopause (down to near 400mb)
some of these showers could produce the typical early spring
precipitation type (graupel or soft hail) for a spell along with
mixing moderate wind gusts down to the surface which is something
to keep in mind over the weekend. /Pelatti
Sunday Night through Wednesday: The cool upper level trough that
has been anchored over the Pacific Northwest since Wednesday is
expected to pivot into western Montana Sunday night into Monday
bringing scattered showers to the eastern third of Washington and
northern Idaho. Despite the displacement of this upper low, our
weather pattern isn`t expected to change much. There is good
agreement between the medium range models that the Polar Jet will
dive into southern Oregon and carve another upper level trough
over the Pacific Northwest. The best jet dynamics (Q-Vector
Divergence) Monday night into Tuesday should be over southern
Oregon into the Great Basin, but there will be enough moisture and
deep layer instability with the weakening frontal occlusion to
maintain a good chance of showers Tuesday and Tuesday night.
Depending on the timing of this system, we may need to add a
mention of thunderstorms on Tuesday. The 00z GFS, Canadian and
ECMWF are in pretty good agreement with a weak, negatively tilted
trough over central and western Washington. The GFS and ECMWF
are producing precipitation that looks convectively driven over
the north Cascades. The potential for thunderstorms over the burn
scars around Wenatchee, Ellensburg, and Chelan will be a concern
through the summer and we will continue to monitor patterns like
this one closely for mudslides and debris flows.
The axis of a west to east oriented upper trough is expected to
linger over the Pacific Northwest Wednesday and through the end of
the week. It does look like Tuesday`s frontal occlusion will bring
the most widespread shower activity to the region this week, but
afternoon and early evening showers will be in the forecast for
much of the week. /GKoch
Wednesday Night through Friday Night: Through this time frame we
continue to see an unsettled pattern that will continue to feature
the chance for precipitation across most of the Inland NW
especially for the higher terrains of the ID Panhandle along with
Cascade Crests earlier in the period. Models are in pretty good
agreement through Friday Afternoon by keeping a large scale
negatively tilted trough pattern in place allowing for moisture to
flow in behind the low center that pushes to our SE throughout the
night on Wednesday. With the increased moisture, there will be
thick cloud cover keeping temps in the lower 60s and 70s for
most correlating to below normal temps for this time of year. Low
temps will follow the same pattern of a couple degrees below
normal due to the lack of daytime heating. Towards the end of the
period models are indicating a ridge builds behind the exiting
trough which should help to diminish the precipitation
threat...lower the cloud coverage and ultimately push temperatures
closer to seasonal averages as we approach next weekend. Overall
not many changes were made to the forecast..just tinkered with the
POPs slightly to reflect most recent model data and trended the
temps in the same manner. /Fliehman
&&
.AVIATION...
06Z TAFS: The Inland Northwest will be under a broad area of low
pressure through tonight. Mid to high level cloud cover is expected
over much of the region through Saturday morning. Some low level
moisture across the northern valleys and Panhandle valleys tonight
may result in some patchy fog by the morning hours. Another
relatively weak system for Saturday afternoon will produce mainly
mountain showers. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 44 65 46 65 47 / 20 10 30 50 30 10
Coeur d`Alene 63 42 65 45 64 44 / 20 20 30 50 40 10
Pullman 64 43 63 44 65 46 / 10 10 30 50 20 20
Lewiston 71 48 70 50 71 51 / 10 10 30 50 20 20
Colville 67 41 72 45 69 44 / 40 30 20 20 50 20
Sandpoint 63 39 66 43 63 42 / 30 20 20 40 50 20
Kellogg 61 44 63 46 62 47 / 40 20 30 60 50 20
Moses Lake 72 46 73 49 73 50 / 10 10 30 20 10 20
Wenatchee 68 47 70 49 71 51 / 10 10 30 10 10 20
Omak 68 41 71 45 70 46 / 30 20 30 10 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
913 PM CDT SUN MAY 26 2013
.UPDATE...
ISSUED AT 913 PM CDT SUN MAY 26 2013
CURRENTLY MONITORING SOME CONVECTION THAT HAS DEVELOPED ALONG THE
WESTERN MINNESOTA/IOWA BORDER ALONG THE NORTHEASTERN SIDE OF THE
850MB MOISTURE TRANSPORT. THE RAP HAS BEEN THE MOST CONSISTENT
THIS AFTERNOON/EVENING WITH SHOWING THIS MOISTURE TRANSPORT AND
0-3KM MUCAPE LIFTING NORTH-NORTHEAST OVERNIGHT WITH THIS
CONVECTION LIKELY REACHING NORTHEAST IOWA AND SOUTHEAST MINNESOTA
AFTER 6Z TONIGHT.
WITH SOIL CONDITIONS FAIRLY SATURATED ACROSS NORTHEAST IOWA AND
SOUTHEAST MINNESOTA DUE TO AN EXCESS OF 3 TO 6 INCHES OF RAINFALL
OVER THE PAST FEW WEEKS...AM INCREASINGLY CONCERNED FOR THE
POTENTIAL OF FLASH FLOODING ACROSS THIS REGION. THE MOST LIKELY
PERIOD FOR FLOODING IS EXPECTED TO COME ON MONDAY NIGHT AS A
STRONGER MID LEVEL SHORTWAVE TROUGH PROPAGATES NORTHEAST THROUGH
THE SOUTHWESTERLY FLOW ALOFT. WITH DEEP FORCING COMBINING WITH
HIGH PRECIPITABLE WATER VALUES APPROACHING 200 PERCENT OF NORM AND
INCREASING INSTABILITY...THE THREAT FOR FLASH FLOODING IS THE
HIGHEST MONDAY NIGHT INTO TUESDAY MORNING. BECAUSE OF THIS...HAVE
ISSUED A FLASH FLOOD WATCH FOR ALL OF NORTH CENTRAL AND NORTHEAST
IOWA. CONSIDERED A FLASH FLOOD WATCH FOR ALL OF SOUTHEASTERN
MINNESOTA...BUT WITH COLLABORATION FROM MPX HAVE DECIDED TO HOLD
OFF ON THAT AREA FOR NOW DUE TO CONFIDENCE IN HEAVY RAINFALL NOT
BEING AS HIGH THERE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 310 PM CDT SUN MAY 26 2013
WARM FRONT THIS AFTERNOON IS SLOWLY MOVING NORTH ACROSS MISSOURI.
THE REMAINS OF THE CONVECTIVE COMPLEX FROM LAST NIGHT AND THIS
MORNING CONTINUES TO MOVE OFF TO THE EAST AND SHOULD NEARLY BE
OUT OF THE AREA BY 00Z. SECONDARY COMPLEX HAS DEVELOPED OVER
NORTHWEST IOWA AHEAD OF A SHORT WAVE TROUGH MOVING ACROSS SOUTH
DAKOTA. MESO MODELS ARE NOT HANDLING THIS FEATURE WELL AT ALL WITH
POSSIBLY THE EXCEPTION OF THE LOCAL ARXLAPS. THE 26.18Z RUN
CONTINUES TO MOVE THIS TO THE EAST/SOUTHEAST WITH ADDITIONAL
DEVELOPMENT FORMING SOUTH OF THE AREA ON A POSSIBLE BOUNDARY LEFT
BEHIND BY THIS MORNINGS COMPLEX. EITHER WAY...EXPECT MOST OF THE
ACTIVITY TO REMAIN SOUTH OF THE AREA EXCEPT FOR POSSIBLY SOME
SHOWERS COMING ACROSS THE SOUTHERN PARTS OF THE AREA THIS EVENING.
LOOKING TO THE OVERNIGHT HOURS...ANOTHER SHORT WAVE TROUGH IS
COMING ACROSS EASTERN WYOMING AND THE 26.12Z NAM AND GFS SHOW THE
MOISTURE TRANSPORT INCREASING AHEAD OF THIS WAVE WITH ANOTHER
COMPLEX OF STORMS EXPECTED TO DEVELOP OVER SOUTH DAKOTA. MODELS
THEN SHOW VARIED SOLUTIONS ON WHERE THIS COMPLEX GOES. THE NAM
BRINGS IT EAST ON THE NOSE OF THE MOISTURE TRANSPORT AND INTO THE
AREA AFTER MIDNIGHT. THE GFS AND 26.00Z ECMWF TAKE IT OFF TO THE
NORTHEAST IN THE SYNOPTIC FLOW WITH THE SHORT WAVE TROUGH. THE
26.12Z HI-RES ARW AND NMM BOTH START THE COMPLEX MOVING TO THE
EAST LIKE THE NAM BUT THEN RAPIDLY DIVE IT SOUTH TOWARD THE FRONT
AND BETTER CAPE AND NEVER GET IT HERE. GIVEN WHAT THE COMPLEXES
HAVE DONE THE PAST COUPLE OF NIGHTS WITH LITTLE OVERALL CHANGE IN
THE GENERAL PATTERN...PLAN TO SHOW THIS COMPLEX COMING INTO THE
AREA AFTER MIDNIGHT AND THEN MOVE EAST/SOUTHEAST ACROSS THE AREA
MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM CDT SUN MAY 26 2013
STARTING TO BECOME CONCERNED THAT THE AREA COULD REALLY GET
PLASTERED WITH RAINFALL MONDAY NIGHT. THE UPPER LEVEL FLOW SHOULD
START TO BECOME A LITTLE MORE SOUTHWEST. THE NEXT SHORT WAVE
TROUGH WILL BE COMING OUT OF THE CENTRAL ROCKIES MONDAY AND MOVING
TOWARD THE AREA FOR MONDAY NIGHT. AS THIS WAVE COMES TOWARD THE
AREA...BOTH THE NAM AND GFS REALLY CRANK UP THE MOISTURE TRANSPORT
AS THE WARM FRONT STARTS TO APPROACH THE FROM THE SOUTH. THE NOSE
OF THE MOISTURE TRANSPORT IS EXPECTED TO BECOME FOCUSED ON THE
FORECAST AREA. THE ISENTROPIC UP GLIDE ON THE 300K SURFACE BECOMES
STRONG WITH THE NAM SHOWING VALUES OF 4 TO 6 UBAR/S. THE
COMBINATION OF THE FORCING FROM THE SHORT WAVE TROUGH...ISENTROPIC
UP GLIDE AND MOISTURE TRANSPORT SHOULD PRODUCE SHOWERS AND STORMS
FOR MUCH OF THE AREA WITH THE AXIS OF HEAVIEST RAIN ALONG THE I90
CORRIDOR. THE GFS FOCUSES ON THE SAME AREA BUT IS QUICKER WITH THE
DEVELOPMENT THAN THE NAM. HOWEVER...THE ECMWF KEEPS THE COMPLEX
MUCH CLOSER TO THE FRONT ACROSS THE IOWA/MISSOURI BORDER WITH
ANOTHER ONE TIED TO THE SHORT WAVE TROUGH GOING BY TO THE NORTH.
AT THIS TIME...PREFER THE SOLUTIONS OF THE NAM AND GFS BUT DID NOT
GO TO CATEGORICAL RAIN CHANCES AT THIS TIME TO HONOR THE ECMWF
SOLUTION. THAT COMPLEX IS THEN EXPECTED TO MOVE OUT TUESDAY BEFORE
THE POSSIBILITY OF ANOTHER ONE FOR TUESDAY NIGHT. BY THIS
TIME...CONFIDENCE ON WHERE THE FRONT WILL BE REALLY STARTS TO GO
DOWN BUT MOST MODELS EITHER HAVE IT OVER THE FORECAST AREA OR
EVEN TO THE NORTH AS THE FLOW BECOMES PROGRESSIVELY MORE
SOUTHWEST. BY THE MIDDLE OF THE WEEK...AN UPPER LEVEL LOW WILL BE
SLIDING TOWARD THE UPPER MIDWEST FROM THE PACIFIC NORTHWEST. THIS
IS EXPECTED TO KEEP THE SHORT WAVES ROTATING ACROSS THE REGION FOR
CONTINUED CHANCES OF SHOWERS AND THUNDERSTORMS. AT THIS TIME...IT
DOES NOT LOOK LIKE THERE WILL BE A BREAK IN THIS PATTERN UNTIL
NEXT WEEKEND AS THE LONG WAVE TROUGH AND UPPER LEVEL LOW FINALLY
START TO MOVE PAST THE REGION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 647 PM CDT SUN MAY 26 2013
SEVERAL RIPPLES IN THE FLOW PATTERN ACROSS THE CENTRAL PLAINS INTO
THE UPPER MIDWEST WILL LEAD TO PERIODIC ROUNDS OF CONVECTIVE
COMPLEXES ALONG AND NORTH OF A WARM FRONT THAT IS CURRENTLY IN
SOUTHERN IOWA. THERE REMAINS A LOT OF UNCERTAINTY IN WHERE THESE
COMPLEXES WILL TRACK...AND LACK OF A GOOD FORECAST MODEL SIGNAL IN
TIMING THEM AS WELL. SO IN GENERAL THE CONFIDENCE IS LOWER THAN
AVERAGE. AT THIS POINT...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP ACROSS THE DAKOTAS AND MOVE EAST. THE HIGHEST CHANCES FOR
THIS TO IMPACT THE TAF SITES LOOKS TO BE LATE OVERNIGHT INTO THE
FIRST PART OF MONDAY. DURING THE AFTERNOON...THE AREA COULD BE
BETWEEN SYSTEMS OR STUCK UNDER THE REMNANTS OF THE MORNING
SHOWERS. AS FOR CEILINGS...EXPECTING A GRADUAL MOISTENING AND
LOWERING TO IFR AT KRST AND MVFR AT KLSE. REMAINING NORTH OF THE
WARM FRONT SHOULD KEEP THESE LOW CEILINGS IN PLACE FOR MUCH OF THE
DAY. VISIBILITIES SHOULD REMAIN MAINLY VFR TO MVFR.
FINALLY...LOOKING AHEAD...ANOTHER CONVECTIVE COMPLEX COULD MOVE
THROUGH THE AREA MONDAY NIGHT INTO TUESDAY WITH MORE SHOWERS AND
LIKELY THUNDERSTORMS.
&&
.HYDROLOGY...
ISSUED AT 310 PM CDT SUN MAY 26 2013
WITH SEVERAL CONVECTIVE COMPLEXES EXPECTED TO IMPACT THE AREA OVER
THE NEXT FEW DAYS...THE CONCERN FOR FLOODING IS RISING. LAST NIGHTS
RAINS WERE GENERALLY AROUND A HALF INCH OR LESS AND EXPECTING
ABOUT THE SAME AMOUNTS AGAIN TONIGHT. THIS WILL FURTHER SATURATE
THE SOILS AND POSSIBLY SET THE STAGE FOR FLOODING MONDAY NIGHT AND
TUESDAY IF THAT COMPLEX DOES INDEED MOVE ACROSS THE AREA WITH
HEAVY RAIN. RAINFALL AMOUNTS THROUGH TUESDAY NIGHT COULD APPROACH
TWO INCHES WITH LOCALLY HIGHER AMOUNTS EXPECTED WITH
THUNDERSTORMS. SOILS AND RIVERS OVER SOUTHEAST MINNESOTA AND
NORTHEAST IOWA CAN NOT TAKE A LOT OF WATER BEFORE FLOODING WILL
START. WILL ISSUE AN ESF TO ADDRESS THESE CONCERNS. WILL LIKELY
NEED TO ISSUE A FLASH FLOOD WATCH WITH LATER FORECASTS IF IT
CONTINUES TO LOOK LIKE THE AREA WILL GET HIT MONDAY NIGHT AND
TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...FLASH FLOOD WATCH FROM 1 AM CDT MONDAY THROUGH TUESDAY EVENING
FOR IAZ008>011-018-019-029-030.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...ZT
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 PM CDT SAT MAY 25 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CDT SAT MAY 25 2013
AT 3 PM...A DYING MESOSCALE CONVECTIVE COMPLEX WAS LOCATED OVER
CENTRAL ILLINOIS. THIS SYSTEM PRODUCED UP TO 4 INCHES OF RAIN
ACROSS PARTS OF STORY...MARSHALL...AND JASPER COUNTIES IN CENTRAL
IOWA. MEANWHILE NORTHEAST IOWA AND MOWER COUNTY IN SOUTHEAST
MINNESOTA...RECEIVED UP TO A THIRD OF AN INCH /KARX RADAR WAS
OVERESTIMATING BY UP TO 300 PERCENT IN SOME LOCATIONS/. THE RAIN
AND CLOUDS FROM THIS SYSTEM KEPT TEMPERATURES IN THE LOWER AND MID
50S IN THESE AREAS WHICH IS VERY CLOSE TO THE RECORD COLDEST
MAXIMUM TEMPERATURES FOR THE DATE. THE RECORD COLD MAXIMUM FOR THE
DATE IS 46 IN 1992 FOR AUSTIN MN...48 IN 1943 IN CHARLES CITY
IA...AND 53 IN 1992 IN DECORAH IA. THE DECORAH RECORD IS THE ONLY
ONE THAT COULD POSSIBLY BE BROKEN OR TIED. MEANWHILE AREAS NORTH
OF INTERSTATE 94 SAW A BIT OF SUNSHINE AND THEY WERE ABLE TO WARM
INTO THE MID 60S.
FOR TONIGHT AND SUNDAY...THE MAIN CONCERN IS THE TRACK OF THE
MESOSCALE CONVECTIVE COMPLEX OVER WESTERN NORTH DAKOTA. CORFIDI
VECTORS SUGGEST THAT THIS SYSTEM WILL MOVE EAST ACROSS THE DAKOTAS
THIS EVENING...AND THEN IT WILL MOVE SOUTHEAST ACROSS THE EASTERN
THIRD OF SOUTH DAKOTA...SOUTHERN AND WESTERN MINNESOTA AND NORTHERN
IOWA TONIGHT. OVERALL...THE 25.18Z HRRR HAS THE BEST HANDLE ON THIS
SYSTEM AND IT HAS THIS SYSTEM OVER SOUTHWEST MINNESOTA BY 26.06Z.
WITH THAT SPEED...IT SHOULD MOVE INTO NORTHEAST IOWA AND PARTS OF
SOUTHEAST MINNESOTA BY 26.10Z...AND THEN LINGER ACROSS THESE AREAS
THROUGH MUCH OF SUNDAY MORNING. AHEAD OF THIS SYSTEM...THE
RAP...GFS...NAM/WRF...AND ECMWF SHOW THAT SCATTERED SHOWERS AND
THUNDERSTORMS WILL DEVELOP NORTH OF A WARM FRONT FROM NORTHWEST
IOWA TO SOUTHEAST IOWA. THIS PRECIPITATION IS ASSOCIATED WITH
MODERATE 925 TO 850 MB MOISTURE TRANSPORT AND 310K ISENTROPIC
LIFT.
LIKE TODAY...EXPECT THE LOW CLOUDS AND PRECIPITATION TO KEEP
TEMPERATURES IN THE MID AND UPPER 50S ACROSS SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN ON SUNDAY.
MEANWHILE SOME SUN NORTH OF INTERSTATE 94 WILL ALLOW TEMPERATURES
TO WARM INTO THE MID 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 341 PM CDT SAT MAY 25 2013
ON SUNDAY NIGHT AND MONDAY...THE WARM FRONT WILL MOVE INTO NORTH
SOUTHWEST IOWA. WEAK TO MODERATE 925 AND 850 MB MOISTURE TRANSPORT
WILL RESULT IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS NORTH
OF THE WARM FRONT FROM NORTH CENTRAL IOWA SOUTHEAST INTO SOUTHEAST
IOWA. THE GFS...ECMWF...AND GEM SUGGEST THAT A MESOSCALE
CONVECTIVE COMPLEX WILL DEVELOP ACROSS EASTERN SOUTH DAKOTA LATE
SUNDAY NIGHT...AND THE DYING SYSTEM MOVES EAST THROUGH OUR AREA
MONDAY.
FROM MONDAY NIGHT INTO TUESDAY...THE MODELS ARE CONTINUING TO
STRUGGLE WITH THE LOCATION OF THE WARM FRONT. THE NAM/WRF STALLS
THE WARM FRONT NEAR THE MINNESOTA AND IOWA BORDER. THIS MAKES A
LOT OF SENSE IF A LOT OF CONVECTION DEVELOPS NORTH OF THIS FRONT
AND ITS COLD POOL PREVENTS THIS WARM FRONT MOVING ANY FURTHER
NORTH. MEANWHILE THE GFS AND ECMWF WOULD SYNOPTICALLY FAVOR THAT
THE WARM FRONT WOULD MOVE NORTHWARD THROUGH THE AREA. HOWEVER THE
CAP IN THE WARM SECTOR REMAINS SOUTHWEST OF THE FORECAST
AREA...THUS THERE WOULD BE THE POTENTIAL FOR A SERIES OF MESOSCALE
CONVECTIVE SYSTEMS TO MOVE THROUGH THE AREA. SO IN EITHER
SCENARIO...IT LOOKS LIKE THE FORECAST AREA WILL REMAIN WET. WITH
PRECIPITABLE WATER VALUES AROUND 1.5 INCHES AND WARM CLOUD LAYER
DEPTHS UP TO 4KM...THERE WILL BE THE POTENTIAL FOR HEAVY RAIN FROM
ANY SHOWERS AND THUNDERSTORMS THAT DEVELOP. IN ADDITION...WILL
HAVE TO WATCH FOR THE POTENTIAL OF SEVERE WEATHER...BUT THIS IS
HIGHLY DEPENDENT UPON THE LOCATION OF THE WARM FRONT.
FROM TUESDAY NIGHT INTO SATURDAY...IT CONTINUES TO LOOK LIKE A
SERIES OF SHORT WAVE TROUGHS WILL MOVE THROUGH THE REGION. HOWEVER
THE TIMING OF THESE WAVES IS UNCERTAIN...THUS KEPT PRECIPITATION
CHANCES IN THE 40 TO 60 PERCENT RANGE THROUGH THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1208 PM CDT SAT MAY 25 2013
AREA OF MVFR CEILINGS OVER SOUTHERN INTO WESTERN MINNESOTA HAS
SLIPPED INTO KRST. THE 25.15Z RAP INDICATES THESE SHOULD REMAIN
THROUGH ABOUT THE MIDDLE OF THE AFTERNOON BEFORE THEY RISE TO A
LOW VFR LEVEL FROM THE HEATING OF THE DAY. THE CONCERN FOR THE
OVERNIGHT HOURS IS WHETHER THE NEXT CONVECTIVE COMPLEX WILL IMPACT
THE TAF SITES. THE 25.12Z NAM ALONG WITH THE 25.06Z HI-RES ARW
BOTH SUGGEST THE WARM FRONT WILL REMAIN SOUTH OF THE AREA. THE
NEXT COMPLEX IS EXPECTED TO DEVELOP OVER SOUTH DAKOTA AND THEN
RIDE SOUTHEAST ALONG THE FRONT MOVING ACROSS IOWA INTO ILLINOIS
STAYING SOUTH OF BOTH AIRPORTS. AT THIS POINT...WILL NOT EVEN
INCLUDE A VCSH BUT WILL LOWER THE CEILINGS EXPECTING THE NORTHERN
EDGE OF THE LOWER CLOUDS FROM THE CONVECTIVE COMPLEX TO IMPACT
BOTH AIRPORTS. THE NAM BUFKIT SOUNDINGS SHOWS KRST GOING DOWN TO
MVFR WITH KLSE STAYING VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1209 PM CDT SAT MAY 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 230 AM CDT SAT MAY 25 2013
LOW/MID LEVEL FRONTOGENETIC FORCING...COUPLED WITH SOME LOW LEVEL
MOISTURE TRANSPORT AND A BIT OF UPPER LEVEL ENERGY...WERE HELPING
CONTINUE AN AREA OF EAST/SOUTHEAST MOVING SHOWERS. TRENDS IN THE
LATEST HRRR/NAM12 IS TO DIMINISH THIS ACTIVITY THROUGH THE PRE DAWN
HOURS...WHILE FIRING CONVECTION OVER THE SOUTHERN PLAINS/WESTERN IA.
SATELLITE IMAGERY AND RADAR RETURNS ALREADY SHOW THIS
HAPPENING...WHERE THE NOSE OF THE LOW LEVEL JET/MOISTURE TRANSPORT
WAS LOCATED. THIS COMPLEX SHOULD MOVE EAST THROUGH THE REST OF THE
MORNING INTO THE AFTERNOON...RIDING ALONG AND NORTH OF A WARM FRONT.
THIS REGION SHOULD SERVE AS THE FOCUS FOR MORE SHOWER/STORM
DEVELOPMENT TONIGHT...WITH THE LOW LEVEL JET REASSERTING ITSELF AND
SOME UPPER LEVEL ENERGY MOVING OUT OF A WEST COAST TROUGH. EASTWARD
MOVEMENT WOULD AGAIN BE FAVORED...KEEPING THE BULK OF THE PCPN SOUTH
OF THE FORECAST AREA.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 230 AM CDT SAT MAY 25 2013
HIGH CONFIDENCE ITS GOING TO RAIN ACROSS PARTS OF THE REGION THROUGH
THE UPCOMING WORK WEEK. TIMING AND PLACEMENT IS MORE SHAKY.
THE FORECAST KEYS ON A FEW AREAS...A SFC WARM FRONT...LOW LEVEL
JET/MOISTURE TRANSPORT...AND VARIOUS MCVS. WHERE THESE ELEMENTS ALL
COME TOGETHER WILL BE WHERE THE GREATER THREAT FOR RAIN WILL LIE.
CLARITY FOR THE MESOSCALE VORTICIES/SPAWNING GROUNDS AND MOVEMENT
IS THE MAIN STICKING POINT FOR INCREASING CONFIDENCE.
THE UPPER LEVEL PATTERN IS SLOW TO PROGRESS EAST AS THERE IS LITTLE
IMPETUS VIA 250/300MB JET INTERACTION - RELATIVELY QUIET A LOFT.
SO...THE 500 MB RIDGE WILL REMAIN ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY/GREAT LAKES INTO AT LEAST THE MIDDLE PART OF THE NEW WORK
WEEK...WITH A BROAD TROUGH OVER THE WEST COAST. BITS OF ENERGY WILL
SPIN OUT OF THE TROUGH...AND THEN ENHANCE VIA CONVECTION SPAWNED BY
IT AND THE LOW LEVEL JET/MOISTURE TRANSPORT. WITH THE RIDGE OVERHEAD
THE NEXT FEW DAYS...AND THE SFC WARM FRONT HOLDING TO THE
SOUTH...THESE UPPER AIR INFLECTIONS ARE PROGGED TO RIDE ALONG AND
NORTH OF THE WARM FRONT...KEEPING THE BEST RAIN CHANCES JUST SOUTH
-BUT NOT COMPLETELY OUT- OF THE FORECAST AREA.
THE WARM FRONT WILL START TO LIFT NORTH ON TUE...A FAIRLY CONSISTENT
SIGNAL IN THE NAM/GFS/ECMWF. HOW FAR NORTH IS NOT THOUGH...WITH THE
GFS APPEARING THE MORE AGGRESSIVE IN HOW FAR NORTH AND HOW FAST.
RAIN CHANCES LOOK TO BECOME MORE WIDESPREAD FOR THE FORECAST AREA
MON-TUE AS A RESULT.
DEPENDING ON HOW QUICKLY AND HOW FAR NORTH THE WARM FRONT MAKES
IT...THE AREA COULD GET INTO THE WARM SECTOR...WHICH WOULD HELP CAP
OFF THE ATMOSPHERE TO CONVECTION - OUTSIDE OF A KICKER MOVING IN.
MODEL DIFFERENCES START TO BECOME BIGGER AS WE MOVE TOWARD NEXT
WEEKEND...WITH THE EC SUGGESTING A CLOSED LOW WILL DEVELOP IN THE
WEST COAST TROUGH...SLOWLY PUSHING EAST ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY NEXT WEEKEND. THIS COULD LAY UP A SFC TROUGH ACROSS THE
REGION FOR SEVERAL DAYS. THE GFS IS MORE PROGRESSIVE...MOVING THE
UPPER LEVEL ENERGY NORTHEAST...BUT STILL HAS A COUPLE SFC BOUNDARIES
THAT COULD ACT AS SHOWER/STORM PRODUCERS. WILL LIKELY STAY WITH THE
CONSENSUS SOLUTION FOR THE DETAILS IN THIS PART OF THE FORECAST.
AS FOR STORM CHANCES...INSTABILITY IS LIMITED THE NEXT COUPLE
DAYS...AND SO SHOULD BE THE THUNDERSTORMS. THE CHANCE FOR BOOMERS
WILL INCREASE WITH THE ENCROACHMENT OF THE WARM FRONT...AND
SUBSEQUENT INCREASE IN CAPES. DON/T SEE A SIGNIFICANT THREAT FOR
ORGANIZED SEVERE WEATHER THROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1208 PM CDT SAT MAY 25 2013
AREA OF MVFR CEILINGS OVER SOUTHERN INTO WESTERN MINNESOTA HAS
SLIPPED INTO KRST. THE 25.15Z RAP INDICATES THESE SHOULD REMAIN
THROUGH ABOUT THE MIDDLE OF THE AFTERNOON BEFORE THEY RISE TO A
LOW VFR LEVEL FROM THE HEATING OF THE DAY. THE CONCERN FOR THE
OVERNIGHT HOURS IS WHETHER THE NEXT CONVECTIVE COMPLEX WILL IMPACT
THE TAF SITES. THE 25.12Z NAM ALONG WITH THE 25.06Z HI-RES ARW
BOTH SUGGEST THE WARM FRONT WILL REMAIN SOUTH OF THE AREA. THE
NEXT COMPLEX IS EXPECTED TO DEVELOP OVER SOUTH DAKOTA AND THEN
RIDE SOUTHEAST ALONG THE FRONT MOVING ACROSS IOWA INTO ILLINOIS
STAYING SOUTH OF BOTH AIRPORTS. AT THIS POINT...WILL NOT EVEN
INCLUDE A VCSH BUT WILL LOWER THE CEILINGS EXPECTING THE NORTHERN
EDGE OF THE LOWER CLOUDS FROM THE CONVECTIVE COMPLEX TO IMPACT
BOTH AIRPORTS. THE NAM BUFKIT SOUNDINGS SHOWS KRST GOING DOWN TO
MVFR WITH KLSE STAYING VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1148 PM CDT FRI MAY 24 2013
.UPDATE...
ISSUED AT 646 PM CDT FRI MAY 24 2013
QUICK UPDATE TO REFLECT THE FASTER TIMING OF PRECIPITATION
CURRENTLY ACROSS WESTERN/CENTRAL MINNESOTA. THIS ACTIVITY IS
RIDING ALONG MID LEVEL FRONTOGENESIS AND WARM AIR
ADVECTION...AND COMBINED WITH SOME DECENT UPPER LEVEL FORCING / PV
ADVECTION. MOST OF THE MESO-MODELS AND 18Z GUIDANCE SHOWS THIS
SLIDING SOUTH/EAST MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER
THROUGH THE OVERNIGHT. SO HAVE SPED UP PRECIPITATION WORDING TO
ACCOUNT FOR THIS. OTHERWISE...FORECAST REMAINS ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 334 PM CDT FRI MAY 24 2013
AT 3 PM...A 1003 MB HIGH PRESSURE SYSTEM...CENTERED OVER LAKE
MICHIGAN...KEPT SKIES PARTLY SUNNY ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY. MEANWHILE FURTHER WEST...A SHORT WAVE WAS PRODUCING
SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN QUARTER OF THE
DAKOTAS AND WESTERN MINNESOTA. THE MESO AND DETERMINISTIC MODELS ARE
CONTINUING TO STRUGGLE WITH THE EASTWARD PROGRESS OF THIS
PRECIPITATION TONIGHT. THE ECMWF AND HRRR MOVE THIS PRECIPITATION
ACROSS MOST OF FORECAST AREA BY 25.06Z. MEANWHILE THE
NMM...ARW...GFS...GEM...RAP... AND NAM MAINLY CONFINE THE
PRECIPITATION WEST OF THE MISSISSIPPI RIVER THIS EVENING...AND
THEN MOVES IT ACROSS THE REMAINDER OF THE AREA OVERNIGHT. SINCE
THE CONVECTION ACROSS THE DAKOTAS WILL BE MOVING INTO AN AREA WITH
LESS FRONTOGENETIC FORCING...MOISTURE TRANSPORT...WEAK ISENTROPIC
LIFT...AND DRIER AIR...DECIDED TO TREND THE FORECAST TOWARD THE
LATTER MODEL SET. IN ADDITION...THE RADAR ECHOS ACROSS WESTERN
MINNESOTA ARE SHOWING A DECREASING TREND. EVEN BY DOING
THIS...THERE IS SOME VARIATIONS AMONGST THEM...SO TRIED TO GO WITH
AN ENSEMBLE APPROACH WHEN ASSIGNING THE HOURLY PRECIPITATION
CHANCES. THE HIGHEST PRECIPITATION CHANCE AND AMOUNTS /UP TO A
HALF INCH/ WILL BE FOUND ACROSS ACROSS SOUTHEAST MINNESOTA AND
NORTHEAST IOWA.
ON SATURDAY...THE SHORT WAVE WILL MOVE EAST SOUTHEAST ACROSS IOWA.
AS THIS OCCURS...THE 850 MB MOISTURE TRANSPORT AND ISENTROPIC LIFT
WILL GRADUALLY WEAKEN. AS A RESULT...WENT WITH A DECREASING TREND
IN THE PRECIPITATION TRENDS FROM LATE MORNING INTO THE AFTERNOON.
ADDITIONAL RAINFALL AMOUNTS WILL BE LESS THAN 2 TENTHS OF AN INCH.
WITH THE 24.12Z AND 24.18Z MODELS IN GOOD AGREEMENT THAT THERE
WILL BE LESS THAN 100 J/KG CAPES...JUST KEPT AN ISOLATED
THUNDERSTORM CHANCE MAINLY WEST AND SOUTH IF THE INTERSTATE 94
CORRIDOR.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM CDT FRI MAY 24 2013
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE WARM FRONT WILL
REMAIN WELL SOUTHWEST OF THE FORECAST AREA. AS A RESULT...
SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN
WILL REMAIN CLOUDY WITH PERIODIC SHOWERS AND MAYBE AN ISOLATED
THUNDERSTORM. OVER THE PAST 3 DAYS...THE CONSALL HAS CONTINUED
TO TREND TOWARD COOLER HIGH TEMPERATURES FOR SUNDAY. IT NOW HAS
HIGH TEMPERATURES AROUND 60. MEANWHILE THE ECMWF ONLY HAS HIGH
TEMPERATURES IN THE LOWER 50S FOR THESE AREAS. SINCE THE ECMWF
TYPICALLY VERIFIES THE BEST FOR THIS TIME PERIOD...WENT WITH A
BLEND OF THE CONSALL...CONSALLBC...AND ECMWF.
FROM MEMORIAL DAY INTO TUESDAY...THE MODELS ARE CONTINUING TO SHOW
THAT A WARM FRONT WILL MOVE NORTHWARD INTO THE AREA. THIS WILL
ALLOW ML CAPES TO CLIMB INTO THE 1K TO 3K J/KG RANGE. AS A
RESULT...EXPECT THE THUNDERSTORM CHANCES TO INCREASE DURING THIS
TIME PERIOD. THE 0-3KM SHEAR WOULD BE FAVORABLE FOR THE
POSSIBILITY THAT A FEW THUNDERSTORMS MAY BE CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WINDS.
FROM TUESDAY NIGHT INTO FRIDAY...THE MODELS CONTINUE TO STRUGGLE
ON WHERE THE WARM SECTOR WILL BE LOCATED. THIS GREATLY AFFECTS
THE WHERE THE PRECIPITATION MAY BE LOCATED. IN ADDITION...IT WILL
ALSO AFFECT THE SHEAR AND INSTABILITY...THUS...THERE IS A LOT OF
UNCERTAINTY ON WHETHER THERE WILL BE ANY SEVERE WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1148 PM CDT FRI MAY 24 2013
A BAND OF LIGHT TO MODERATE RAIN HAS SET UP ALONG AND JUST TO THE
WEST OF THE MISSISSIPPI RIVER AND IS EXPECTED TO PERSIST THROUGH
THE OVERNIGHT HOURS. AS THE FORCING WEAKENS LATER THIS
MORNING...EXPECT THAT THE RAIN WILL COME TO AN END THOUGH SOME
MVFR CEILINGS WILL BECOME POSSIBLE AT RST. CURRENT THINKING IS
THAT CONDITIONS SHOULD MAINLY BE DRY THROUGH THE REST OF THE DAY
WITH OVERALL FORCING BEING WEAK INTO THE NIGHT. THE MAIN QUESTION
WILL BE WHETHER THERE WILL BE ENOUGH LOW LEVEL MOISTURE TRAPPED
UNDER THE SHALLOW INVERSION AROUND 3KFT TO PRODUCE SOME MVFR
CEILINGS...PARTICULARLY AT RST. WITH CONFIDENCE NOT AS HIGH AS IT
PREVIOUSLY WAS...HAVE REMOVED IT FROM THE FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...ZT
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
950 PM PDT SUN MAY 26 2013
.SHORT TERM DISCUSSION...
AREA OF ENHANCED CLOUDS ALONG THE ORE/NRN CA COAST AHEAD OF UPPER
TROF ALONG 130W WILL BE PUSHING INLAND TONIGHT. HRRR PRECIP FORECAST
INDICATES LEADING EDGE OF THE RAIN WILL BE NEARING THE BURNEY...RED
BLUFF...STONEYFORD LINE BY AROUND 13Z MON...SO RDD AND RBL MAY HAVE
SOME LIGHT PRECIP EARLY MON MORNING. LEADING EDGE OF PRECIP THEN
FORECAST TO MOVE INTO THE I-80 CORRIDOR BY LATE MORNING...18Z OR
SO...ESPECIALLY OVER THE W SLOPE SIERNEV BUT NOT NECESSARILY IN THE
SRN SAC VLY AS THE PRECIP IS A LITTLE MORE PROBLEMATIC THERE...AND
MAY HOLD OFF UNTIL THE 00Z-06Z TUE TIME FRAME PER THE GFS VALLEY
CROSS SECTION WHEN MOISTURE AND UPWARD MOTION ARE COINCIDENT. HIGH
PWS OFF THE COAST ARE SPLITTING AS THE UPPER JET DRIVES SEWD ACROSS
THE REGION. SO THE DEEPER MOISTURE IS LIKELY TO BE N OF THE I-80
CORRIDOR.
STRATUS SCHEME HAS COME OUT NEGATIVE THIS EVENING...BUT ONSHORE
GRADS AND ONSHORE FLOW THROUGH THE DELTA MAY ALLOW FOR ANOTHER
MORNING OF STRATUS ON THE E SIDE OF THE VALLEY SIMILAR TO SUN
MORNING...AND ALSO SOMEWHAT SUGGESTED BY THE NAM BUFKIT MOISTURE
PROFILES FOR SAC AREA SITES. JHM
.PREVIOUS DISCUSSION...
SOME LINGERING CHANCES OF SHOWERS WILL PERSIST ON TUESDAY AND
MAINLY FOR THE WESTERN SLOPES...BUT FOR THE MOST PART THE SYSTEM
WILL HAVE PASSED THROUGH THE REGION WITH ONLY SOME RESIDUAL
SHOWERS IN ITS WAKE REMAINING. NOT A LOT OF RAIN IS EXPECTED FROM
THIS SYSTEM WITHIN THE VALLEY WITH AMOUNTS RANGING FROM TRACE
TO TWO TENTH OF AN INCH...WHILE THE MOUNTAINS SHOULD FAIR A
LITTLE BETTER WITH AMOUNTS RANGING FROM TWO TENTHS TO THREE
QUARTERS OF AN INCH OF RAIN. SOME LIGHT SNOW ACCUMULATIONS WILL BE
POSSIBLE MONDAY NIGHT ABOVE 8000 FEET.
ON WEDNESDAY ANOTHER SHORTWAVE WILL MOVE INTO THE PACIFIC
NORTHWEST WITH THE TAIL END PUSHING THROUGH NORTHERN CALIFORNIA.
THIS WILL BRING CONTINUED SHOWER CHANCES TO THE MOUNTAINS...MAINLY
NORTH OF I-80 AND OVER THE NORTHERN SACRAMENTO VALLEY.
TEMPERATURES WILL CONTINUE TO BE COOLER THAN NORMAL.
.EXTENDED DISCUSSION (THURSDAY THROUGH SUNDAY)
UNSETTLED WEATHER LINGERS OVER HIGHER TERRAIN ON THURSDAY AS OUR
REGION IS SANDWICHED BETWEEN A TROUGH TO THE NORTHEAST AND HIGH
PRESSURE TO THE SOUTHWEST. PRECIPITATION WILL TAPER OFF DURING
THE DAY ON THURSDAY AND DRY WEATHER WILL PERSIST THROUGH THE WEEKEND.
TEMPERATURES ON THURS WILL BE NEAR TO 5 DEGREES BELOW NORMAL BUT
THE REGION WILL UNDERGO A WARMING TREND INTO THE WEEKEND.
TEMPERATURES IN THE UPPER 80S TO LOW 90S FOR THE VALLEY ON FRIDAY
THRU SUNDAY WHILE THE MOUNTAINS WARM INTO THE UPPER 60S AND 70S.
JBB
&&
.AVIATION...
VFR CONDITIONS UNTIL 12Z-18Z MON WHEN CIGS/VSBYS MAY LOWER TO MVFR
DUE TO -RASH/RASH OVER NRN SAC VLY INCLUDING NRN MTNS...SPREADING
SEWD TOWARDS I-80 CORRIDOR FROM 18Z-00Z TUE. OVER MTNS...CIGS/VSBYS
LOWERING TO IFR IN SHRA OBSCG HYR TRRN THROUGHOUT THE DAY. CENTRAL
AND SRN SAC/NRN SJ VLY EXPECTED TO MAINTAIN VFR CONDITIONS ALTHO SCT
-SHRA POSSIBLE ESPECIALLY N OF THE I-80 CORRIDOR AFT 18Z MON.
POSSIBLE MFR CIGS BETWEEN 12Z-18Z MON FOR SRN SAC VLY/NRN SJ VLY AND
SIERNEV FOOTHILLS DUE TO MORNING STRATUS.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1235 AM EDT MON MAY 27 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 244 PM EDT SUN MAY 26 2013
CENTRAL INDIANA WILL REMAIN NORTH OF A WARM FRONT INTO MONDAY...THEN
THE FRONT WILL PUSH THROUGH THE AREA. THE THREAT FOR RAIN WILL
REMAIN ACROSS AREAS NEAR AND NORTH OF IT. BY TUESDAY NIGHT THE FRONT
WILL BE FAR ENOUGH NORTH FOR DRY WEATHER TO RETURN.
DRY AND WARM WEATHER WILL THEN RULE THROUGH FRIDAY. CHANCES FOR RAIN
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1001 PM EDT SUN MAY 26 2013
ISOLATED SHOWERS THROUGHOUT THE FORECAST AREA THIS EVENING WITH A
LARGER AREA OF RAIN SLOWLY SPREADING INTO THE NORTHERN WABASH
VALLEY. TEMPS WERE GENERALLY IN THE 60S AT 02Z.
SERIES OF UPPER LEVEL SHORTWAVES EXTENDING FROM IOWA AND MINNESOTA
SOUTHEAST INTO ILLINOIS. CURRENT RAP SHOWING DEVELOPING LOW
LEVEL JET TO THE WEST OF THE REGION...LIKELY INFLUENCING ONGOING
DEVELOPMENT ACROSS SOUTHERN IOWA AND NORTHERN MISSOURI. THE LOW
LEVEL JET WILL BRING ADDITIONAL MOISTURE INTO CENTRAL INDIANA AND
COMBINED WITH ENHANCED FORCING ALOFT AS THE SHORTWAVES DRIFT
ACROSS THE REGION OVERNIGHT...ANTICIPATE UPSTREAM CONVECTION
LIKELY TO EXPAND SOUTHEAST INTO THE FORECAST AREA AS THE NIGHT
PROGRESSES. WILL CONTINUE TO CARRY ISOLATED THUNDER LATE TONIGHT
WITH WEAK ELEVATED INSTABILITY PRESENT. WILL CARRY HIGHEST POPS
NORTH OF I-70. BUMPED LOWS UP A DEGREE OR TWO BASED AS CURRENT
TEMPS RUNNING A FEW DEGREES WARMER THAN PREVIOUSLY THOUGHT.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /MEMORIAL DAY THROUGH WEDNESDAY/...
ISSUED AT 244 PM EDT SUN MAY 26 2013
FOCUS IS ON CHANCES FOR RAIN THROUGH THE PERIOD. MODELS ARE CLOSE
ENOUGH THAT A BLEND CAN BE USED FOR MOST FEATURES.
THE WARM FRONT WILL LIFT NORTH ACROSS THE AREA ON MONDAY. THERE
REMAINS SOME UNCERTAINTY IN HOW PRECIPITATION WILL EVOLVE FROM THE
LEFTOVER CONVECTION FROM THE NIGHT INTO THE AFTERNOON CONVECTION.
MODELS HAVE BEEN STRUGGLING LATELY WITH PRECIPITATION COVERAGE AND
TIMING.
FOR NOW HAVE CHOSEN TO GO HIGHEST POPS WITH THE MORNING CONVECTION
/WITH SOME UPPER SUPPORT/...THEN GRADUALLY LOWERING THROUGH THE
AFTERNOON FROM SOUTH TO NORTH AS THE FRONT PUSHES NORTH. CONFIDENCE
IS NOT HIGH THOUGH. GENERALLY STUCK WITH A BLEND OF MOS FOR
TEMPERATURES.
WENT CHANCE POPS MONDAY NIGHT EARLY...THEN DECREASED THEM THROUGH
THE NIGHT FROM SOUTH TO NORTH. AGAIN WENT GENERALLY WITH A BLEND FOR
TEMPERATURES.
KEPT LOW POPS ACROSS THE FAR NORTH ON TUESDAY WITH THE WARM FRONT
STILL IN THE VICINITY THERE. WENT DRY ELSEWHERE. WITH THE WARM FRONT
THROUGH ON TUESDAY...WENT CLOSER TO THE WARMER OF THE MOS NUMBERS
FOR HIGHS.
DRY AND WARM CONDITIONS CAN THEN BE EXPECTED WITH AN UPPER RIDGE
BUILDING INTO THE AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 202 PM EDT SUN MAY 26 2013
MODELS IN GOOD AGREEMENT ON PERSISTENT FLOW OFF GULF AIR ACROSS
CENTRAL INDIANA THROUGH AT LEAST SATURDAY. HOWEVER...THE 12Z GFS AND
00Z GEFS ARE MUCH FASTER MOVING A PLAINS FRONT THROUGH CENTRAL
INDIANA SATURDAY NIGHT AS OPPOSED TO THE 00Z ECMWF...THAT DOES NOT
PUSH THE FRONT THROUGH UNTIL BEYOND SUNDAY. WITH UNCERTAINTY...WPC
OFFERS A REASONABLE BLEND BRINGING THE FRONT ACROSS ON SUNDAY. AT
ANY RATE...RETURN FLOW SHOULD ALLOW FOR ABOVE NORMAL TEMPERATURES IN
THE 80S THROUGH SATURDAY AND SLIGHTLY COOLER NORTHWEST BEHIND THE
FRONT ON SUNDAY.
WILL KEEP IT MOSTLY DRY THROUGH FRIDAY NIGHT AND THEN THUNDERSTORM
CHANCES BY SATURDAY AS THE FRONT GETS CLOSER.
&&
.AVIATION /DISCUSSION FOR THE 270600Z TAFS/...
ISSUED AT 1235 AM EDT MON MAY 27 2013
SCATTERED RAIN SHOWERS WILL CONTINUE TO DRIFT ACROSS TAF SITES FOR
DURATION OF TAF PERIOD AS WARM FRONT REMAINS JUST TO THE SOUTH OF
CENTRAL INDIANA. A FEW LIGHTNING STRIKES COULD OCCUR THROUGH
DAYBREAK...BUT IT STILL REMAINS TOO ISOLATED TO INCLUDE IN TAFS FOR
THAT TIME FRAME. CONVECTION CURRENTLY OVER ILLINOIS CONTAINS MUCH
MORE PERSISTENT LIGHTNING. SO...CHANCES WILL BE BETTER BY LATE
MORNING/EARLY AFTERNOON ACROSS TAF SITES AS ENVIRONMENT DESTABILIZES
AND THAT SHOWER/THUNDERSTORM ACTIVITY PUSHES INTO THE AREA. KEPT
VCTS FOR NOW IN TAFS STARTING LATE THIS MORNING/EARLY THIS AFTERNOON
UNTIL IT CAN BE BETTER PINPOINTED WITH FUTURE TAF ISSUANCES. WINDS
WILL TAKE ON MORE OF A SOUTHERLY COMPONENT THROUGH THE COURSE OF THE
TAF PERIOD...AND WILL BE SUSTAINED AT 6 TO 12 KTS. VFR CONDITIONS
WILL BE THE PREVAILING FLIGHT CATEGORY WITH PERIODS OF MVFR DUE TO
REDUCED VISIBILITIES IN ANY SHOWERS/THUNDERSTORMS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM....MK
AVIATION...TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
535 AM EDT MON MAY 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 532 AM EDT MON MAY 27 2013
WATER VAROR IMAGERY AND RUC ANALYSIS SHOW THE BEGINNINGS OF AN
ACTIVE PATTERN SHAPING UP FOR THE UPPER GREAT LAKES THIS WEEK. MEAN
TROF SETTLING INTO THE WRN CONUS THRU MIDWEEK AND THEN SLOW SHIFTING
E WILL SEND NMRS SHORTWAVES THRU THE CNTRL CONUS AND INTO THE GREAT
LAKES. MODELS WILL NO DOUBT STRUGGLE WITH THE CONVECTION ASSOCIATED
WITH THE WAVES...AND THE FCST WILL HAVE MUCH MORE THAN NORMAL
UNCERTAINTY BEYOND THE SHORT TERM. SEVERAL CLUSTERS OF SHRA/TSRA
HAVE BEEN OCCURRING FROM THE DAKOTAS TO THE OHIO VALLEY DURING THE
NIGHT...A SIGN OF THE ACTIVE PATTERN EVOLVING THIS WEEK.
MEANWHILE...DRY AIR CONTINUES TO LINGER OVER THE UPPER LAKES (NOTE
THE DRY 00Z SOUNDINGS FROM KGRB/KAPX).
THERE ARE 3 SHORTWAVES OF INTEREST FOR THE SHORT TERM. THE FIRST OF
IS OVER ERN MT/WRN ND...THE SECOND IS OVER WRN IA AND THE THIRD IS
OVER THE SRN ROCKIES. THE FIRST WAVE IS PRODUCING CONVECTION OVER
THE WRN DAKOTAS. THIS WAVE IS ON A TRACK TO LIFT NE AROUND THE RIDGE
EXTENDING N THRU THE MISSISSIPPI VALLEY TOWARD HUDSON BAY...AND WILL
NOT BE A FACTOR HERE. THE SECOND WAVE SHOULD WEAKEN AS IT CUTS THRU
THE RIDGE...AND ITS ASSOCIATED CONVECTION SHOULD ALSO WEAKEN AS IT
OUTRUNS THE INSTABILITY POOL OVER THE PLAINS. THE THIRD WAVE WILL
HELP STRENGTHEN THE LOW LEVEL JET TONIGHT AS IT MOVES OUT ACROSS THE
PLAINS. WITH FRONTAL BOUNDARY CURRENTLY WELL TO THE SW AND S AND NOT
LIKELY TO MAKE MUCH PROGRESS TODAY...DRY WEATHER WILL BE THE RULE
TODAY AND PROBABLY RIGHT INTO THE EVENING HRS. ALL MODELS WITH THE
EXCEPTION OF THE GEM HAVE TRENDED NOTABLY SLOWER ADVANCING PCPN
TOWARD UPPER MI. WILL THUS RUN WITH A DRY FCST INTO THE EVENING.
TONIGHT...STRENGTHENING LOW-LEVEL JET IN RESPONSE TO AFOREMENTIONED
SHORTWAVE WILL HELP GENERATE MORE SHRA/TSRA ACROSS THE PLAINS TOWARD
THE UPPER MISSISSIPPI VALLEY/WRN LAKES. DIFFICULT TO SAY HOW FAR N
AND E PCPN WILL ADVANCE...BUT WITH ADVANCING WARM FRONT STILL A GOOD
DISTANCE TO THE SW...WOULD EXPECT BULK OF SHRA/TSRA ACTIVITY TO
REMAIN TO THE S AND SW. HOWEVER...NRN FRINGES OF PCPN MAY STILL
SPREAD FAR ENOUGH N TO AFFECT AT LEAST SRN UPPER MI...AND WILL
INCLUDE SCHC/CHC POPS OVERNIGHT.
ALTHOUGH CI BLOWOFF FROM CONVECTION OVER ERN NEBRASKA/WRN IA IS
CURRENTLY SPREADING INTO UPPER MI...EXPECT THESE HIGH CLOUDS TO THIN
OUT SOME DURING THE DAY AS CONVECTION WEAKENS. SO...THERE SHOULD
STILL BE FAIRLY STRONG HEATING TODAY AND THUS DEEP MIXING TO BRING
DRIER AIR DOWN TO THE SFC. DWPTS SHOULD FALL TO THE LOW/MID 30S THIS
AFTN...PERHAPS LOWER OVER THE CNTRL/E BASED ON POTENTIAL MIXING
HEIGHTS. WITH HIGH TEMPS UP AROUND 70F IN THE INTERIOR...RH SHOULD
BOTTOM OUT IN THE 25-30PCT RANGE W AND 20-25PCT RANGE E. WINDS WILL
BE A LITTLE STRONGER TODAY AS SFC HIGH PRES RIDGE DRIFTS FARTHER E
OF THE AREA. WILL PROBABLY SEE AFTN GUSTS AROUND 20MPH OVER THE W
AND CNTRL AND 15MPH OVER THE E. WITH THE RECENT DRY DAYS...FIRE WX
CONCERNS WILL BE HIGHER TODAY GIVEN THE LOW RH AND A LITTLE STRONGER
WIND.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 532 AM EDT MON MAY 27 2013
TRICKY FORECAST FOR TUESDAY INTO TUESDAY NIGHT CONCERNING
PRECIPITATION CHANCES. OVERALL...SHORT WAVE ENERGY CURRENTLY MOVING
INTO THE CENTRAL PLAINS WILL MOVE INTO THE WESTERN GREAT LAKES
REGION LATER TONIGHT INTO TUESDAY. MEANWHILE...A WARM FRONTAL
BOUNDARY WILL MOVE NORTH INTO THE UPPER GREAT LAKES ON TUESDAY. THIS
WARM FRONT WILL LIKELY SERVE AS THE FOCUS FOR SHOWERS AND
THUNDERSTORMS...SIMILAR TO WHAT IT IS DOING THIS MORNING. THE
PROBLEM IS THAT THE NWP ARE HANDLING THIS WARM FRONT RATHER
POORLY...ALONG WITH THE 850MB JET THAT INTERSECTS THE FRONT. THE 12Z
ECMWF IS BY FAR THE FARTHEST WEST WITH THE LLJ AND ASSOCIATED
PCPN...PLACING THE HEAVIER PCPN ACROSS THE WESTERN LAKE AND WESTERN
UPPER MICHIGAN LATE TONIGHT INTO TUESDAY (ALTHOUGH THE 00Z ECMWF HAS
TRENDED AWAY FROM THIS SOLN). NOT SURE IF THE 12Z RUN MAKES SENSE AS
THE PCPN SEEMS TO RACE OUT AHEAD OF THE PRIMARY WARM FRONT.
MEANWHILE...THE NAM AND GFS CONTINUE TO BE SLOWER WITH PCPN MOVING
INTO THE AREA (WITH THE GFS BEING EVEN SLOWER)...BUT THEY KEEP THE
PCPN TIED TO THE FRONT...WITH THE HEAVIEST PCPN FURTHER SOUTH INTO
WISCONSIN WHERE THE LLJ IS JUSXTAPOSITIONED WITH THE BETTER
INSTABILITY. FINALLY...THE REGIONAL GEM IS SIMILAR WITH THE HEAVIEST
PCPN WELL SOUTH OF THE AREA BUT IT SPREADS PCPN INTO UPPER MICHIGAN
TOO FAST AND WELL AHEAD OF THE WARM FRONT. HAVE OPTED TO TREND
TOWARD A SLOWER NAM/GFS COMPROMISE SOLN WITH LIKELY POPS INTO
SOUTHERN UPPER MICH TUE MORNING...THEN SPREADING NORTH/EAST DURING
THE DAY AS THE WARM FRONT LIFTS NORTH. THE WESTERN AREAS WILL ALSO
TEND TO DRY OUT LATER IN THE DAY BEHIND THE SHORT WAVE. NOT TERRIBLY
IMPRESSED WITH THUNDER CHANCES ON TUESDAY. WITH THE SLOWER MOVEMENT
OF THE WARM FRONT...THE BEST INSTABILITY WILL REMAIN IN WISCONSIN.
SIMPLY DUE TO THE FORCING ALONG THE FRONT...CANNOT COMPLETELY RULE
OUT THUNDER BUT THE EXPECTATION IS THAT THE BEST THUNDER CHANCES
WOULD STAY ACROSS THE FAR SOUTH CLOSER TO THE BETTER INSTABILITY.
SHOULD END UP BEING A GENERALLY QUIET TUESDAY NIGHT AND WEDNESDAY
MORNING ACROSS THE AREA WITH UPPER AND SFC RIDGING ACROSS THE AREA.
WILL LIKELY BE A LITTLE MUGGY WITH THE AREA BEING IN THE WARM SECTOR
AND DEWPOINTS IN THE UPPER 50S. BUT GIVEN LACK OF FORCING OVERNIGHT
WILL GO WITH A DRY FORECAST AFTER ANY REMAINING SHOWERS/STORMS EXIT
EAST. ON WEDNESDAY...POPS WERE LOWERED WITH LACK OF ANY SIGNIFICANT
FOCUS FOR THUNDERSTORMS DESPITE MLCAPE VALUES OF 1000-1500 J/KG.
BETTER FOCUS FOR STORMS WITH THE NOSE OF THE 50KT LOW LEVEL JET AND
DEEP MOISTURE TRANSPORT INTO THE AREA EXPECTED WEDNESDAY NIGHT. THIS
MAY BE THE MOST LIKELY PERIOD FOR STRONG/SEVERE STORMS WITH FORWARD
PROPOGATING STORMS LIKELY MOVING INTO THE AREA FROM WISCONSIN.
FOR THE THU-SUNDAY PERIOD...THE AREA WILL BE FIRMLY IN THE WARM
SECTOR ON THURSDAY...AS THE LOW LEVEL JET BACKS TO A MORE SOUTHERLY
DIRECTION AND THE NOSE FOCUSES OVER NW WISCONSIN. EXPECT MORE
CONVECTION TO DEVELOP IN THIS AREA THURSDAY AND MOVE INTO UPPER
MICHIGAN DURING THE AFTN AND EVENING HOURS AS THE GFS AND 00Z ECMWF
ARE IN GOOD AGREEMENT IN SHOWING ANOTHER SHORT WAVE MOVING ACROSS
THE AREA. THE UPPER TROUGH AND SURFACE LOW FINALLY MOVES EAST
STARTING FRIDAY WITH THE SYSTEM MOVING ACROSS THE AREA BY SATURDAY.
WILL CONTINUE WITH CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
SATURDAY. ANOTHER WARM AND MUGGY DAY ON FRIDAY...THEN TURNING COOLER
BY SUNDAY AS 850MB TEMPS DROP TO +6C BEHIND THE SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 118 AM EDT MON MAY 27 2013
DRY LOW LEVEL AIR MASS ASSOCIATED WITH HIGH PRES OVER THE GREAT
LAKES WILL RESULT IN VFR CONDITIONS AT KIWD/KCMX/KSAW THOUGH THIS
AFTERNOON. PCPN WITH AN APPROACHING WARM FRONT MAY MOVE IN TONIGHT
BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE MENTION OF PCPN OR TSRA
IN THE TAF. SE WINDS WILL INCREASE TODAY BUT GUSTS SHOULD REMAIN BELOW
20 KT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 532 AM EDT MON MAY 27 2013
WITH GENERALLY WEAK PRES GRADIENT AND STABLE CONDITIONS OVER LAKE
SUPERIOR...EXPECT WINDS TO BE UNDER 25KT THRU THE WEEK. HOWEVER...
WITH THE POTENTIAL FOR CLUSTERS OF SHRA/TSRA TO PASS ACROSS/NEAR THE
UPPER GREAT LAKES...THERE COULD BE SHORT PERIODS OF ENHANCED WINDS
AT TIMES (STRONGER SE WINDS OVER ERN LAKE SUPERIOR AND STRONGER NE
WINDS OVER WRN LAKE SUPERIOR). ONCE SOME RAINFALL OCCURS OVER THE
LAKE...FOG WILL LIKELY DEVELOP...AND IT COULD BECOME DENSE MID TO
LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...MRD
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
353 AM CDT MON MAY 27 2013
.SHORT TERM...TODAY THROUGH TUESDAY...
STRENGTH AND PERSISTENCE OF LOW LEVEL RIDGING OVER THE CENTRAL AND
EASTERN GREAT LAKES REGION CONTINUES TO BE GREATER THAN PREVIOUS
MODEL FORECASTS THIS MORNING..WITH DRY/COOL EASTERLY FLOW
PERSISTING. THE OVERALL REASONING WITH THIS FORECAST PACKAGE HAS
NOT CHANGED A LOT FROM YESTERDAY AT THIS TIME..WITH THE ONE MAJOR
EXCEPTION THAT THE NORTHWARD THRUST OF MOISTURE AND INSTABILITY
SEEMS TO BE DELAYED 12-24 HOURS FROM PREVIOUS THINKING.
THUS..CHANCES FOR PRECIP TODAY/TONIGHT ARE SMALLER ACROSS THE
DULUTH CWA AS THE ENTIRE PATTERN SUGGESTS A SOUTHWARD SUPPRESSION
OF CONVECTIVE ACTIVITY THROUGH TONIGHT AS OUTFLOW FROM LARGE MCS
IN IOWA ACTS TO REINFORCE WARM FRONTAL BOUNDARY. AS A RESULT..WE
HAVE REDUCED POPS FOR TODAY AND TONIGHT IN MOST AREAS..ALTHOUGH
THERE WILL STILL BE SMALL CHANCES FOR SHOWERS/TSTORMS ACROSS THE
SOUTH THIS AFTERNOON AND TONIGHT.
S/W TROF IN BROAD WSW FLOW ALOFT WILL APPROACH THE AREA FROM THE
WEST LATE TONIGHT..AND SHOULD FINALLY ALLOW THE 925-850
THERMAL/MOISTURE GRADIENT TO MOVE NORTHWARD TO NEAR THE SW PART OF
THE DULUTH CWA. THIS SHOULD BRING VERY GOOD CHANCES FOR SHOWERS
AND THUNDERSTORMS TO THE SOUTHEAST HALF TO TWO THIRDS OF THE CWA
ON TUESDAY. HOWEVER..IT NOW APPEARS THAT THE BEST SEVERE THREAT
WILL REMAIN FARTHER SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
AN UPPER S/W AND ASSOCIATED SFC WARM FRONT WILL LIFT TO THE NE TUE
NIGHT/WED MORNING AS HIGH PRESSURE BUILDS IN FROM THE SW. THERE WILL
BE RAIN SHOWERS AND A FEW WEAK THUNDERSTORMS WITH THIS WAVE...AND
QUICKLY TAPER OFF FROM WEST TO EAST THROUGH THE NIGHT. ANOTHER
PERIOD OF SHOWERS AND STORMS IS EXPECTED TO DEVELOP WED AFTERNOON AS
A POTENT UPPER LOW TRACKS EWD THROUGH THE NRN ROCKIES INTO THE UPPER
MIDWEST...AND A SFC WARM FRONT LIFTS SLOWLY NWD THROUGH THE REGION.
A STRONGER SURGE OF WARM/MOIST/UNSTABLE AIR WILL ADVECT IN FROM THE
SOUTH ON THE LEADING EDGE OF A 40-50KT LLJ. THE INTERACTION OF THIS
UPPER WAVE AND UNSTABLE AIR MASS WILL ALLOW FOR THUNDERSTORMS TO
DEVELOP WED NIGHT. A FEW OF THESE STORMS COULD BECOME STRONG TO
SEVERE...AND PRODUCE LOCALLY HEAVY RAINFALL AS WELL. COULD SEE A
BRIEF BREAK IN THE SHOWERS THUR MORNING BEFORE ANOTHER ROUND OF
SHOWERS AND STORMS DEVELOP THUR AFTERNOON AND LAST THROUGH FRI
MORNING. THE ACTIVE WEATHER WILL LIKELY CONTINUE INTO THE WEEKEND.
HOWEVER...THE INSTABILITY WILL DECREASE...AND KEEP THUNDER CHANCES
AT A MINIMUM. CONDITIONS GRADUALLY DRY OUT ON SUNDAY AS HIGH
PRESSURE OVER ALBERTA/MANITOBA MOVES IN FROM THE NW.
TEMPERATURES WILL START OUT RATHER WARM...WITH RELATIVELY HIGH
HUMIDITIES...TUESDAY/WEDNESDAY. HIGHS WILL RANGE FROM THE UPPER 60S
TO MID/UPPER 70S ACROSS THE REGION. A SLIGHT COOLING TREND WILL
START UP FRIDAY AND CONTINUE THROUGH THE WEEKEND. HIGH TEMPS WILL
DROP FROM THE 70S...INTO THE 60S. OVERNIGHT LOWS THROUGH THE
EXTENDED PERIOD WILL RANGE FROM THE 50S AND 60S EARLY...TO THE 40S
AND 50S LATE.
&&
.AVIATION...06Z TAF ISSUANCE...
VFR CONDITIONS WERE OCCURRING ACROSS THE NORTHLAND AS OF LATE
EVENING...WITH MVFR CEILINGS INCHING CLOSER TO KBRD. THESE LOWER
CEILINGS WILL AFFECT KBRD FIRST...THEN SLOWLY MOVE NORTH AND WEST.
THE LATEST RAP DELAYS THESE CEILINGS OVER THE REST OF THE TAF
SITES...AND SUGGEST THEY WILL NOT AFFECT KDLH/KINL/KHIB/KHYR UNTIL
LATE MONDAY AFTERNOON OR EVENING. WE ARE GOING TO FOLLOW THIS
TREND.
A FEW LIGHT SHOWERS/SPRINKLES CONTINUED OVER PORTIONS OF THE SOUTH
AND WEST...BUT RADAR SHOWED COVERAGE AND INTENSITY DECREASING. WE
PULLED SHOWERS OUT OF MOST TAFS THROUGH THE PERIOD...AS THE MODELS
TREND OF SLOWING THINGS DOWN CONTINUES.
&&
.POINT TEMPS/POPS...
DLH 60 51 66 52 / 30 50 50 20
INL 72 52 70 53 / 10 30 20 40
BRD 65 55 71 54 / 30 60 40 10
HYR 67 56 71 56 / 40 60 60 20
ASX 67 53 64 51 / 30 50 60 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM....TENTINGER
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1237 AM CDT MON MAY 27 2013
.AVIATION...06Z TAFS
VFR CONDITIONS WERE OCCURRING ACROSS THE NORTHLAND AS OF LATE
EVENING...WITH MVFR CEILINGS INCHING CLOSER TO KBRD. THESE LOWER
CEILINGS WILL AFFECT KBRD FIRST...THEN SLOWLY MOVE NORTH AND WEST.
THE LATEST RAP DELAYS THESE CEILINGS OVER THE REST OF THE TAF
SITES...AND SUGGEST THEY WILL NOT AFFECT KDLH/KINL/KHIB/KHYR UNTIL
LATE MONDAY AFTERNOON OR EVENING. WE ARE GOING TO FOLLOW THIS TREND.
A FEW LIGHT SHOWERS/SPRINKLES CONTINUED OVER PORTIONS OF THE SOUTH
AND WEST...BUT RADAR SHOWED COVERAGE AND INTENSITY DECREASING. WE
PULLED SHOWERS OUT OF MOST TAFS THROUGH THE PERIOD...AS THE MODELS
TREND OF SLOWING THINGS DOWN CONTINUES.
&&
.PREV DISCUSSION... /ISSUED 924 PM CDT SUN MAY 26 2013/
UPDATE...
PERSISTENT BAND OF LIGHT RAIN STRETCHED ACROSS OUR SOUTHWEST CWA
THIS EVENING...AND SEEMS TO BE IN RESPONSE TO SOME MID LEVEL WAA
AND A SHORTWAVE. WE`VE UPDATED THE FORECAST AND GRIDS THIS
EVENING...BUT MAY NEED TO EXPAND THE POPS FURTHER NORTH AND EAST
AND INCREASE THEM. WE`LL MONITOR A BIT LONGER BEFORE MAKING ANY
FURTHER CHANGES.
PREV DISCUSSION... /ISSUED 642 PM CDT SUN MAY 26 2013/
UPDATE...
A FEW LIGHT SHOWERS WERE OCCURRING OVER OUR SOUTHWEST CWA...AND WE
UPDATED TO ADD SOME EARLY EVENING POPS TO ACCOUNT FOR THAT. WE
THINK THESE WILL DIMINISH WITH LOSS OF HEATING.
AVIATION...00Z TAFS
VFR CONDITIONS WILL PREVAIL THIS EVENING...BUT LOW LEVEL MOISTURE
WILL BE INCREASING AND WE EXPECT MVFR CEILINGS TO MOVE INTO KBRD
AFTER MIDNIGHT...WITH THESE CEILINGS PROGRESSING NORTH OVERNIGHT
INTO MONDAY AFFECTING MOST TAF SITES. WE FOLLOWED THE RAP 925MB
COND PRESSURE DEFICITS FOR TIMING OF THE CEILINGS.
SOME SHOWERS WILL ALSO BE POSSIBLE...BUT TIMING THEM WILL BE MORE
DIFFICULT AND WE LEFT THE MENTION OUT OF MOST TAFS DUE TO THE
UNCERTAINTY.
PREV DISCUSSION... /ISSUED 335 PM CDT SUN MAY 26 2013/
CURRENT...MID LVL AND SFC RIDGE HAS KEPT QUIET WX PATTERN IN PLACE
TODAY. GUSTY WINDS HAVE INCREASED THIS AFTERNOON AS MIXING LAYER
DEEPENS WITHIN UNIDIRECTIONAL BDRY LYR. PATCHES OF MID LVL CLOUDS
ARE MAKING THEIR WAY THROUGH RIDGE AXIS HOWEVER A DECENT AMOUNT OF
SUNSHINE HAS PREVAILED TODAY. SFC TEMPS RANGE FROM THE 40S NEAR
LAKE SUPERIOR TO THE 60S/70S INLAND.
TONIGHT...AS WAS THE CASE YESTERDAY...THE OVERALL TREND IS SLOWER
WITH REGARD TO APPROACHING PRECIPITATION. 85H MOISTURE TRANSPORT
AXIS SHIFTS FROM NRN PLAINS INTO SWRN EDGE OF CWA BY 06Z. SHOULD SEE
RW PUSH INTO THE AREA BY MIDNIGHT. CONVECTIVE PARAMETERS INCLUDING
SREF CPTP SUGGEST HIGHEST CHANCE OF ANY THUNDER WILL BE LIMITED TO
SWRN COUNTIES THROUGH THE EARLY MORNING. FCST POSITIONING OF
NOCTURNAL LLJ... AND ITS IMPINGEMENT ACROSS EAST/WEST LOW LVL
THERMAL GRADIENT... INDICATES A POTENTIAL MCS DEVELOPMENT FROM ERN
SODAK INTO SWRN MN.
TOMORROW...EJECTING MID LVL SHORTWAVE TROF WILL MOVE FROM ERN SODAK
TOWARDS BRD LAKES REGION BY MONDAY EVENING. THIS WILL ASSIST IN
INCREASING 85H MSTR TRANSPORT CONCURRENT WITH ADVECTION OF 85/30H
LAYER OMEGA. RESULT SHOULD BE AN INCREASE IN AMOUNT OF RW/TRW
DEVELOPMENT HOWEVER PRESENCE OF EARLY MORNING MCS SOUTH OF CWA MAY
AFFECT DISTRIBUTION OF PRECIP. MAJORITY OF MDL QPF LEAN TOWARDS A
CONVECTIVE MAXIMUM SOUTH OF REGION EXCEPT ECMWF SO CONFIDENCE IS
LOW ON AREAL DISTRIBUTION OF POPS TOMORROW.
LONG TERM...MONDAY NIGHT THROUGH SUNDAY.
THE EXTENDED TIME PERIOD WILL BE QUITE UNSETTLED AND WET. TIMING OF
VARIOUS FEATURES WILL BE TOUGH IN THIS NOTORIOUSLY DIFFICULT
FORECAST PATTERN. BROAD LOW PRESSURE WILL GRADUALLY MIGRATE TOWARD
THE UPPER MIDWEST...ALONG WITH ABUNDANT MOISTURE. THE FIRST SUCH
SYSTEM WILL MOVE IN MONDAY NIGHT AND TUESDAY...WITH PERHAPS A BIT OF
A LET UP OR BREAK FOR PORTIONS OF THE AREA TUESDAY NIGHT AND
WEDNESDAY. IT LOOKS LIKE THERE WILL BE POTENTIALLY A FEW MCS ACROSS
THE AREA MONDAY NIGHT AND TUESDAY. THE NEXT LOW PRESSURE SYSTEM IN
SW FLOW WILL ARRIVE WEDNESDAY NIGHT...AND LINGERING INTO THE
WEEKEND. COULD BE SEVERAL INCHES OF RAIN DEPENDING ON HOW THE MCS
DEVELOPMENT UNFOLDS. THE LOW PRESSURE SYSTEM WILL BE VERY SLOW
MOVING AS IT LIFTS INTO THE GREAT LAKES. TEMPERATURES WILL LARGELY
BE IN THE 70S DURING THE EXTENDED BUT SOME DAYS WILL LIKELY ONLY BE
IN THE 60S DUE TO CLOUDS AND RAIN.
&&
.POINT TEMPS/POPS...
DLH 60 51 71 53 / 50 70 60 30
INL 71 53 72 54 / 20 50 40 30
BRD 64 57 76 58 / 60 60 40 30
HYR 66 57 75 58 / 60 70 60 30
ASX 66 52 70 53 / 20 70 60 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
403 AM CDT MON MAY 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT MON MAY 27 2013
ONCE AGAIN DEALING WITH A COMPLEX FORECAST WITH THE SENSIBLE WEATHER
STRONGLY CONTROLLED BY MESOSCALE FACTORS...SOMETHING THE MODELS
TYPICALLY HAVE DIFFICULTY IN RESOLVING. THE CONVECTIVE SYSTEM
CURRENTLY EXTENDING THROUGH EASTERN MO HAS BEEN WEAKENING AND
SHRINKING OVER THE LAST FEW HOURS AS IT MOVES ESEWD TOWARDS THE MS
RIVER. I SEE NO REASON FOR THIS TREND NOT TO CONTINUE...WITH A
CONTINUED DECREASE IN INTENSITY AND COVERAGE AS IT OUTRUNS THE
INSTABILITY AND BETTER LOW LEVEL FORCING. ATTENTION THEN TURNS TO
THE MATURE BOW ECHO SYSTEM/MCS ACROSS WESTERN IOWA/SERN NEBRASKA.
THIS WELL-DEFINED SYSTEM IS BEING FEED BY A 40+KT SWLY LLJ WITH
MUCAPES OF 1500-2000 J/KG. VIRTUALLY ALL THE EXPLICIT CONVECTION
ALLOWING MODELS INCLUDING THE HRRR BRING THIS SYSTEM SEWD THIS
MORNING AND HAVE IT IMPACTING THE AREA ALONG AND NORTH OF
I-70...PRIMARILY THIS AFTERNOON. I`M NOT SURE ABOUT THE TIMING OR
THE EXACT STRUCTURE OF THE FINAL PRODUCT BUT THIS SCENARIO LOOKS
QUITE REASONABLE AND I HAVE LIKELY POPS OVER A MOST OF THE NRN
2/3RDS OF THE CWA. THE SYSTEM IS MOVING AT A PRETTY GOOD CLIP
RIGHT NOW AND PURE EXTRAPOLATION WOULD HAVE IT ENTERING THE NW
PORTION OF THE CWA 14Z OR SO...HOWEVER IT MAY BECOME MORE ELONGATED
WITH TIME. THE LONGER IT TAKES TO ENTER THE CWA...THE GREATER THE
OPPORTUNITY FOR THE AIR MASS AHEAD OF IT TO DESTABILIZE AND THEN FOR
THE SYSTEM AND ITS MESOSCALE BOUNDARY TO INTERACT WITH. IT COULD
POSE A LOCALLY HEAVY RAIN AND WIND THREAT DEPENDING ON ITS FINAL
INTENSITY.
NORTHERN PORTIONS OF MO INTO WEST CENTRAL IL LOOK ACTIVE AGAIN
TONIGHT. A SHORTWAVE WILL BE MOVING ENEWD FROM THE PLAINS INTO THE
MID/UPPER MS VALLEY PROVIDING LARGE SCALE ASCENT ALONG WITH
FORCING VIA A STOUT 50+ KT VEERING SWLY LLJ. THIS WILL PROVIDE
STRONG SUPPORT FOR AT LEAST ONE AND POSSIBLY SEVERAL MCSS WHICH
TRACK EASTWARD FROM THE CENTRAL PLAINS AND EFFECT PORTIONS OF NRN
MO. AGAIN THERE COULD BE A WIND AND HEAVY RAIN THREAT WITH ANY
SYSTEM.
GLASS
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 400 AM CDT MON MAY 27 2013
THE CHANCE OF SHOWERS AND THUNDERSTORMS LINGERS A BIT LONGER THAN
PREVIOUSLY FORECAST INTO TUESDAY AND TUESDAY NIGHT ACCOUNTING FOR
RESIDUAL BOUNDARIES FROM TONIGHTS ACTIVITY...HOWEVER OVERALL THE
AREA IMPACTED SHOULD BE SHRINKING AND TEMPERATURES WILL BE WARMING
TUESDAY AND WEDNESDAY AS A RIDGE BUILDS THRU THE ERN U.S. BY THE
LATER PART OF THE WEEK AND INTO THE WEEKEND WE GET BACK INTO AN
ACTIVE PATTERN AS A DEEP UPPER TROF SLOWLY PROGRESSES EASTWARD
INTO THE NATIONS MIDSECTION.
GLASS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1135 PM CDT SUN MAY 26 2013
THUNDERSTORM TRENDS CONTINUE TO BE THE PRIMARY FOCUS FOR THIS TAF
CYCLE. CURRENT THINKING IS THAT THE CLUSTER OF STORMS OVER EAST
CENTRAL MISSOURI WILL CONTINUE MOVING SLOWLY EASTWARD. IT SHOULD
PRODUCE GUSTY WINDS UP TO 20-30KTS...AND OCCASIONAL HEAVY RAIN. A
SECOND LINE OF STORMS WILL CONTINUE MOVING SOUTH-SOUTHEAST FROM
NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS DOWN TO NEAR THE MISSOURI
RIVER BY 08-09Z. IT`S UNCLEAR AT THIS TIME HOW FAR EAST THE
CLUSTER WILL STRETCH...BUT THE LOW LEVEL JET IS FORECAST TO
CONTINUE TO PUMP WARM AND UNSTABLE AIR INTO THE AREA...SO CURRENT
THINKING IS THAT MOST OF THE AREA ALONG AND WEST OF THE
MISSISSIPPI AT LEAST DOWN TO THE ST. LOUIS METRO AREA WILL SEE
SOME THUNDERSTORMS BEFORE SUNRISE. THE SECOND LINE OF STORMS WILL
ALSO PRODUCE GUSTY WINDS OF 20-30KTS FROM THE NORTH-NORTHWEST.
STILL LOOKS LIKELY THAT THE ATMOSPHERE WILL RESET MONDAY AFTERNOON
FOR ANOTHER ROUND OF AFTERNOON STORMS. TIMING AND AREAL COVERAGE
WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS OVER THE NEXT 8 TO 10
HOURS WITH THE CURRENT ROUND OF STORMS.
SPECIFICS FOR KSTL...
THUNDERSTORM TRENDS CONTINUE TO BE THE PRIMARY FOCUS FOR THIS TAF
CYCLE. CURRENT THINKING IS THAT THE CLUSTER OF STORMS NORTHWEST OF
THE TERMINAL WILL CONTINUE MOVING SLOWLY EASTWARD. IT SHOULD
PRODUCE GUSTY WINDS UP TO 20-30KTS BUT THE HEAVIEST RAIN SHOULD
REMAIN NORTH OF LAMBERT. A SECOND LINE OF STORMS WILL CONTINUE MOVING
SOUTH-SOUTHEAST FROM NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS
DOWN TO NEAR THE MISSOURI RIVER BY 08-09Z. IT`S UNCLEAR AT THIS
TIME HOW FAR EAST THE CLUSTER WILL STRETCH...BUT THE LOW LEVEL JET
IS FORECAST TO CONTINUE TO PUMP WARM AND UNSTABLE AIR INTO THE
AREA. CURRENT THINKING IS THAT LAMBERT WILL GET SOME THUNDERSTORMS
AND IFR OUT OF THIS SECOND WAVE. THE SECOND LINE OF STORMS WILL
ALSO PRODUCE GUSTY WINDS OF 20-30KTS FROM THE NORTH-NORTHWEST.
STILL LOOKS LIKELY THAT THE ATMOSPHERE WILL RESET MONDAY AFTERNOON
FOR ANOTHER ROUND OF AFTERNOON STORMS. TIMING AND AREAL COVERAGE
WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS OVER THE NEXT 8 TO 10
HOURS WITH THE CURRENT ROUND OF STORMS.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1154 PM CDT SUN MAY 26 2013
.UPDATE...
ISSUED AT 900 PM CDT SUN MAY 26 2013
THUNDERSTORMS THAT PRODUCED 2-4 INCHES NORTH OF COLUMBIA EARLIER THIS
EVENING HAVE PROGRESSED EASTWARD INTO A LINE NOW MOVING TOWARD THE ST.
LOUIS METRO. ADDITIONAL STORMS HAVE DEVELOPED IN THE LAST TWO HOURS
OVER IOWA THAT MOVING SOUTHWARD. PROPAGATION VECTORS FROM THE RAP SUGGEST
THAT THAT THIS IOWA ACTIVITY WILL MOVE SOUTH INTO THE CWA INTO THE NEXT
FEW HOURS. THE RAP HAS BEEN CONSISTENT IN SHOWING THAT LOW LEVEL MOISTURE
CONVERGENCE WILL STRENGTHEN OVER THE NORTHERN/CENTRAL CWA THROUGH 06-09Z
BEFORE IT LIFTS NORTHEAST OF THE CWA BY 12Z. WILL UP POPS TO LIKELY/
CATEGORICAL IN AREAS ALONG AND NORTH OF I-70 IN MISSOURI/I-64 IN
ILLINOIS. WHILE EFFECTIVE SHEAR REMAINS MARGINAL FOR STORM ORGANIZATION...
MUCAPES OF 1000-2000 J/KG SUGGEST THAT A FEW STRONG TO SEVER THUNDERSTORMS
ARE POSSIBLE TONIGHT. IN ADDITION....PWATS IN THE 1.5-1.8 INCH
RANGE SUGGEST THAT THERE WILL CONTINUE TO BE THE POTENTIAL FOR
SOME LOCALLY HEAVY RAINFALL TONIGHT.
BRITT
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 319 PM CDT SUN MAY 26 2013
SCT AFTN THUNDERSTORMS INVOF A SFC WMFNT WILL PERSIST INTO THE EARLY
EVENING HOURS BEFORE GRADUALLY DISSIPATING WITH THE LOSS OF DAYTIME
HEATING. STRONG CONVERGENCE ALONG THE SFC WMFNT IN SERN NEB AND SWRN
IA MIGHT PRODUCE A THUNDERSTORM COMPLEX THAT PROPAGATES SEWD WITH
TIME. IF THIS COMPLEX DEVELOPS AND IF IT HOLDS TOGETHER THEN IT
MIGHT AFFECT PARTS OF THE CWA LATER TONIGHT.
KANOFSKY
.LONG TERM...(MONDAY THROUGH NEXT SUNDAY)
ISSUED AT 319 PM CDT SUN MAY 26 2013
(MONDAY-WEDNESDAY)
WITH LATEST GUIDANCE STILL VERY MURKY REGARDING CONVECTIVE TRENDS SO
WILL MAINTAIN A FAIRLY BROAD BRUSH APPROACH TO FORECAST FOR THE NEXT
48 HOURS...AND LEAVE THE FINER DETAILS TO THE SHORT TERM WHEN TRENDS
ARE A BIT MORE DEFINABLE. OVERALL...GOING FORECAST TRENDS ARE
STILL LOOKING QUITE REASONABLE SO CHANGES ARE GENERALLY MINOR.
SYNOPTICALLY...THERE ISN`T MUCH CHANGE EXPECTED THROUGH MONDAY
NIGHT...WITH DIFFUSE AND BROAD LOW LEVEL WAA PROGGED ACROSS AREA
WHILE SEVERAL WEAK SHORTWAVES DRIFT THROUGH WEAK UPPER RIDGE PARKED
ACROSS AREA. MOST OF THE 12Z RUNS DO DEPICT A MORE ACTIVE DAY ON
MONDAY THAN WHAT OCCURRED TODAY...AND THIS DOES SEEM LIKE A
REASONABLE TREND AS IT APPEARS THAT THE WEAK SHORTWAVES DO MAKE MORE
OF AN IMPACT ON THE EVER WEAKENING RIDGE. HIGHEST POPS...IN THE
LIKELY RANGE...WILL CONTINUE OVER N HALF OF THE CWA...WITH CHANCE
POPS S OF I-70.
IT STILL APPEARS THAT POPS WILL BE WINDING DOWN FROM S TO N ACROSS
THE AREA MONDAY NIGHT AND TUESDAY. SW FLOW IS FORECAST TO BECOME
ESTABISHED OVER THE REGION IN RESPONSE TO SYSTEM DIGGING INTO THE
WEST...WHICH SHOULD IN TURN CAUSE THE LOW LEVEL THERMAL
GRADIENT/ISENTROPIC LIFT THAT HAS BEEN PARKED OVER THE AREA TO SHIFT
N AND EAST OF THE REGION. THERE IS SOME CONCERN ABOUT A MEAGER
INCREASE IN DYNAMICS OVER OUR NW COUNTIES DURING THIS PATTERN SHIFT
THAT COULD ALLOW THE STORM THREAT TO LINGER A BIT LONGER...BUT THIS
IS QUITE SUBTLE SO FOR NOW WILL KEEP POPS BELOW CHANCE CATEGORY IN
THE TUE-WED TIME FRAME.
RAIN AND CONVECTIVE CLOUD DEBRIS MAY TEND TO HOLD TEMPS ON
MONDAY....HOWEVER BY MIDWEEK CWA SHOULD BE WELL INTO THE WARM
SECTOR WITH LITTLE IN THE WAYOF SIGNIFICANT CLOUDINESS. TEMPS AND
HUMIDITY LEVELS WILL BE TAKING ON A BIT OF AN EARLY SUMMER
FEEL...WITH HIGHS IN THE 85-90 DEGREE RANGE BY WEDNESDAY.
(THURSDAY-SUNDAY)
THE END OF THE WEEK AND NEXT WEEKEND MAY BE ANOTHER PERIOD OF
UNSETTLED WEATHER FOR THE CWA. SW FLOW ALOFT WILL BRING A SERIES
OF DISTURBANCES OUT OF THE WESTERN U.S...AND INTERACT WITH WHAT
SHOULD BE A WARM AND MODERATELY UNSTABLE AIRMASS. THUNDERSTORM
THREAT WILL RETURN TO THE FORECAST THURSDAY THROUGH
FRIDAY...WITH THE HIGHEST POPS SHOULD BE OVER NW HALF OF THE CWA
WHERE DYNAMICS WILL BE MOST ROBUST. HOWEVER...IT MAY BE THAT
STORMS WILL HAVE A TOUGH TIME PUSHING INTO SE MO AND S IL AS DUE
TO RIDGING OVER THE SE CONUS SUPPRESSING EWD PROGRESSION OF
DYNAMICS AND STORMS. EWD SHIFT OF UPPER TROF SHOULD MEAN SHOWERS
AND THUNDERSTORMS FOR MOST OF THE AREA NEXT WEEKEND.
TEMPERATURES SHOULD REMAIN AT OR ABOVE NORMAL FOR MUCH OF THE
MEDIUM RANGE.
TRUETT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1135 PM CDT SUN MAY 26 2013
THUNDERSTORM TRENDS CONTINUE TO BE THE PRIMARY FOCUS FOR THIS TAF
CYCLE. CURRENT THINKING IS THAT THE CLUSTER OF STORMS OVER EAST
CENTRAL MISSOURI WILL CONTINUE MOVING SLOWLY EASTWARD. IT SHOULD
PRODUCE GUSTY WINDS UP TO 20-30KTS...AND OCCASIONAL HEAVY RAIN. A
SECOND LINE OF STORMS WILL CONTINUE MOVING SOUTH-SOUTHEAST FROM
NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS DOWN TO NEAR THE MISSOURI
RIVER BY 08-09Z. IT`S UNCLEAR AT THIS TIME HOW FAR EAST THE
CLUSTER WILL STRETCH...BUT THE LOW LEVEL JET IS FORECAST TO
CONTINUE TO PUMP WARM AND UNSTABLE AIR INTO THE AREA...SO CURRENT
THINKING IS THAT MOST OF THE AREA ALONG AND WEST OF THE
MISSISSIPPI AT LEAST DOWN TO THE ST. LOUIS METRO AREA WILL SEE
SOME THUNDERSTORMS BEFORE SUNRISE. THE SECOND LINE OF STORMS WILL
ALSO PRODUCE GUSTY WINDS OF 20-30KTS FROM THE NORTH-NORTHWEST.
STILL LOOKS LIKELY THAT THE ATMOSPHERE WILL RESET MONDAY AFTERNOON
FOR ANOTHER ROUND OF AFTERNOON STORMS. TIMING AND AREAL COVERAGE
WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS OVER THE NEXT 8 TO 10
HOURS WITH THE CURRENT ROUND OF STORMS.
SPECIFICS FOR KSTL...
THUNDERSTORM TRENDS CONTINUE TO BE THE PRIMARY FOCUS FOR THIS TAF
CYCLE. CURRENT THINKING IS THAT THE CLUSTER OF STORMS NORTHWEST OF
THE TERMINAL WILL CONTINUE MOVING SLOWLY EASTWARD. IT SHOULD
PRODUCE GUSTY WINDS UP TO 20-30KTS BUT THE HEAVIEST RAIN SHOULD
REMAIN NORTH OF LAMBERT. A SECOND LINE OF STORMS WILL CONTINUE MOVING
SOUTH-SOUTHEAST FROM NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS
DOWN TO NEAR THE MISSOURI RIVER BY 08-09Z. IT`S UNCLEAR AT THIS
TIME HOW FAR EAST THE CLUSTER WILL STRETCH...BUT THE LOW LEVEL JET
IS FORECAST TO CONTINUE TO PUMP WARM AND UNSTABLE AIR INTO THE
AREA. CURRENT THINKING IS THAT LAMBERT WILL GET SOME THUNDERSTORMS
AND IFR OUT OF THIS SECOND WAVE. THE SECOND LINE OF STORMS WILL
ALSO PRODUCE GUSTY WINDS OF 20-30KTS FROM THE NORTH-NORTHWEST.
STILL LOOKS LIKELY THAT THE ATMOSPHERE WILL RESET MONDAY AFTERNOON
FOR ANOTHER ROUND OF AFTERNOON STORMS. TIMING AND AREAL COVERAGE
WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS OVER THE NEXT 8 TO 10
HOURS WITH THE CURRENT ROUND OF STORMS.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
425 AM CDT MON MAY 27 2013
.DISCUSSION...
VERY SHORT TERM CONCERNS WILL BE SEVERE THUNDERSTORM WATCH THAT
CONTINUES UNTIL 5AM FOR PARTS OF SOUTHERN NEBRASKA AND SOUTHWEST
IOWA. THEN...FORECAST CONCERNS CONTINUE TO BE THUNDERSTORMS AND
SEVERE WEATHER POTENTIONAL/HEAVY RAIN IN ACTIVE WEATHER PATTERN
THIS WEEK.
THE 00Z OAX SOUNDING HAD CAPE OF NEARLY 4000J/KG...STEEP MID LEVEL
SHEAR...PRECIPITABLE WATER OF 1.52 INCHES (185%)...FREEZING LEVEL OF
13,500...AND SFC-2KM SRH OF 258M2/S2. THE SURFACE WARM FRONT WAS
SOUTH OF COLUMBUS TO PLATTSMOUTH INTO SOUTHWEST IOWA. AT
00Z...THUNDERSTORMS FORMED IN SOUTHWEST IOWA ALONG THE WARM
FRONT/OUTFLOW BOUNDARY AND BY 02Z...THUNDERSTORMS HAD DEVELOPED OVER
NORTH CENTRAL NEBRASKA AND WERE SPREADING SOUTHEAST ACROSS THE
FORECAST AREA AT 06Z. THE STRONGER WINDS ALOFT WERE HAVING A TOUGH
TIME MAKING IT DOWN TO THE SURFACE...HOWEVER THE STRONGER WINDS DID
START TO REACH THE GROUND AS THE STORMS APPROACHED THE FREMONT AREA
AND AS THEY MOVED THROUGH PARTS OF DOUGLAS CO. FREMONT HAD A WIND
REPORT OF 77 MPH AND WEST OF EPPLEY 67 MPH...WITH SOME WINDS 50 TO
55 MPH.
THE 00Z H5 PATTERN HAD A TROF OVER THE WESTERN U.S. +10C AIR AT
H7 HAD SPREAD INTO SOUTH CNTRL NEB AND +9 AT OAX. THE H85 DEWPOINT
WAS 17DEG C AT KOAX.
THROUGH 06Z MONDAY NIGHT...PRECIPITABLE WATER REMAINS HIGHS...FROM
AROUND 1.5 TO 1.6 INCHES...THEN RETURNS NORTHWARD BY 00Z TUESDAY
EVENING AND REMAINS HIGH THROUGH WEDNESDAY NIGHT. THE UPPER LEVEL
JET AND H5 PATTERN WILL REMAIN FAVORABLE FOR THUNDERSTORMS TO
DEVELOP OVER THE FORECAST AREA.
TODAY...THE SURFACE BOUNDARY WILL BE AFFECTED BY THE CONVECTION
THIS MORNING AND WILL MAINTAIN SOME THUNDERSTORMS OVER PARTS OF
THE AREA UNTIL THE LOW LEVEL JET WEAKENS. THE OVERALL TREND IS A
DIURNAL WEAKENING THIS MORNING...HOWEVER LOW LEVEL FLOW RETURN
THIS AFTERNOON AND EVEN MORESO OVERNIGHT AS A 50KT LOW LEVEL JET
DEVELOPS ACROSS KANSAS AND SHORTWAVE TROF ENERGY ONCE AGAIN MOVES
ACROSS THE REGION. WITH THE FRONTAL LOCATION UNCERTAIN...TRENDED
COOLER WITH THE TEMPERATURES IN THE NORTH AND LEFT HIGHS IN THE
80S SOUTH. THIS PATTERN CONTINUES THROUGH THE WEEK AND THE UPPER
LEVEL TROF SHIFTS EASTWARD INTO THE PLAINS WEDNESDAY. WE ARE STILL
IN THE SEVERE WEATHER OUTLOOK FOR DAYS 1 THRU 3 AND HEAVY RAIN
WILL BE POSSIBLE WITH THE STORMS THAT DEVELOP. ALTHOUGH WE ARE NOT
IN THE EXCESSIVE OUTLOOK. WILL NEED TO ASSESS HEAVY RAIN POTENTIAL
AND FLASH FLOOD WATCH EACH SHIFT DUE TO THE REPEATED RAINS
EXPECTED.
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
TSRA SHOULD CONTINUE IN THE KOFK AREA THE NEXT SEVERAL HOURS...
WITH THE STRONGEST ACTIVITY LIKELY BEFORE 07Z. THERE IS STILL
SOME UNCERTAINTY HOW FAR SOUTHEAST STORMS WILL REACH OVERNIGHT...
BUT HRRR MODEL DEVELOPS ACTIVITY TOWARD NORTHEAST KANSAS AND
NORTHWEST MISSOURI BY A LITTLE AFTER SUNRISE.
EXPECT A GRADUAL DECREASE IN CEILINGS THROUGH 14Z...THEN A GRADUAL
UPWARD TREND TOWARD VFR CONDITIONS AT ALL THREE SITES BY EARLY
AFTERNOON MONDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1229 AM CDT MON MAY 27 2013
.SYNOPSIS...
ISSUED AT 315 PM CDT SUN MAY 26 2013
A DEEP UPPER LEVEL LOW...CURRENTLY ACROSS THE NORTH PACIFIC...WILL
MIGRATE SLOWLY EAST THROUGH THE PACIFIC NORTHWEST AND INTO THE NRN
PLAINS THIS WEEK. A STRONG PACIFIC COLD FRONT WILL MOVE THROUGH
THE FCST AREA WEDNESDAY NIGHT OR THURSDAY. SEVERE WEATHER IS
POSSIBLE TODAY THROUGH WEDNESDAY AS LOW PRESSURE REMAINS QUASI
STATIONARY ACROSS ERN COLORADO AND FOCUSES...MOSITURE...WARM AIR
ADVECTION AND DRY.
&&
.UPDATE...
ISSUED AT 1114 PM CDT SUN MAY 26 2013
UPDATED FORECAST TO DROP TORNADO WATCH AND ISSUE SEVERE
THUNDERSTORM WATCH.
UPDATE ISSUED AT 743 PM CDT SUN MAY 26 2013
UPDATED FORECAST TO INCLUDE TORNADO WATCH FOR NORTH CENTRAL NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 315 PM CDT SUN MAY 26 2013
TONIGHT AND MONDAY...CONVECTION LATE THIS AFTERNOON INTO THE
EVENING TONIGHT...THEN LOW CLOUDS FOG DEVELOPMENT TOWARD MORNING
REMAIN FORECAST ISSUES FOR THE SHORT TERM. WEAK COLD FRONT
ANALYZED FROM SOUTHWEST NEBRASKA SOUTHWARD INTO NW KS AND ERN CO.
WARM FRONT EXTENDS FROM SW INTO SC NEBRASKA WITH INVERTED TROUGH
NORTHWARD INTO SD. NUMEROUS OUTFLOW BOUNDARIES SHOW IN THE HAND
ANALYSIS AS WELL.
QUITE A VARIED RANGE OF SHORT TERM MODEL SOLUTIONS FOR THIS EVENING
AS HRRR AND HIRES ARW SUGGEST NOTHING ORGANIZED WILL DEVELOP SOUTH
OF I80 CORRIDOR...BUT DEVELOP A MCS ACROSS THE SANDHILLS IN THE
HIGHWAY 2 VCNTY AND MOVE IT EASTWARD OVERNIGHT. THE NAM /AND HIRES
NMM/ AS WELL AS GFS SUGGEST TWO AREAS OF DEVELOPMENT...THE FIRST IN
SIMILAR AREAS TO THE PREVIOUSLY MENTIONED MODELS /SANDHILLS/ AND A
SECOND IN THE VCNTY OF THE WARM FRONT WHICH ORGANIZES INTO A MCS AND
MOVES SOUTHEAST. FCST WILL GO WITH THE IDEA THAT TO SOME DEGREE BOTH
GROUPS OF SOLUTIONS HAVE REALISTIC POSSIBILITIES BASED ON BETTER DEEP
LAYER SHEAR ACROSS THE NORTH WHICH SHOULD ALLOW FOR A BETTER
ORGANIZATION ONCE DEVELOPMENT OCCURS IN THE SANDHILLS BY EVENING.
LOW LEVEL LAPSE RATES IN THIS AREA HOWEVER ARE NOT THE BEST AS WOULD
BE EXPECTED NORTH OF THE WARM FRONT...AND ALSO BELIEVE AIR MASS IS
STILL SOMEWHAT INFLUENCED IN THE LOW LAYERS AS A RESULT OF THE
OUTFLOW THAT WAS EVIDENT EARLIER THIS MORNING. LARGE HAIL STILL A
POSSIBILITY HERE THOUGH WITH VERY STEEP MID LEVEL LAPSE RATES...EVEN
IF STORMS ARE ELEVATED WHICH SEEMS LIKELY IN THIS AREA.
FURTHER SOUTH...LOW LEVEL LAPSE RATES ARE STEEPEST ACROSS ERN CO AND
NW KS AND HAVE SURGED EWD AHEAD OF LEE SFC LOW IN NW KS. GOOD
THETA-E ADVECTION NORTHEAST OF THIS AREA SHOULD ALLOW DEVELOPMENT IN
THIS AREAS AS WELL...THOUGH COVERAGE REMAINS IN QUESTION. SPC
MESOANALYSIS INDICATES SOME CAP STILL PRESENT HERE AND SINCE LARGE
SCALE FORCING IS BEST FURTHER NORTH THE EXTENT OF CAP EROSION IS
ALSO IN QUESTION. WOULD LIKE TO SEE BETTER SFC CONVERGENCE IN THESE
LOCATIONS TO BE MORE CERTAIN ABOUT INITIATION. IF SFC BASED
DEVELOPMENT DOES OCCUR SVR POTENTIAL WILL BE HIGH AS VERY GOOD ML
CAPE IS IN PLACE. THEREFORE...FCST INCLUDES POPS IN THESE AREAS BASED ON
PREVIOUS THINKING.
THE LAST FEW NIGHTS HAS SEEN A TENDENCY TO DEVELOP LOW CLOUD BEHIND
OUTFLOW BOUNDARIES TWD DAYBREAK AND BELIEVE THAT SHOULD BE THE CASE
ONCE AGAIN MONDAY MORNING. DEPICTING LOCATIONS IS DIFFICULT BUT
FAVORED AREAS EAST OF HIGHWAY 61 SEEM MOST LIKELY AND HAVE TRENDED
THE FCST THAT WAY. EVENTUAL HIGH TEMPS WILL BE HIGHLY DEPENDENT ON
THESE LOW CLOUD DEVELOPMENT AS WELL...BUT AS WITH THE LAST FEW DAYS
AFTERNOON MIXING SHOULD ALLOW 80S MOST PLACES.
CONVECTION AGAIN POSSIBLE MONDAY AFTERNOON. MODELS SUGGESTING UPPER
TROUGH WILL CONTINUE TO MOVE EASTWARD AND SHOULD ALLOW FOR A MORE
SOUTHERN LOCATION OF SFC FEATURES ONCE CONVECTIVE DEBRIS GIVES WAY.
SOMEWHAT BETTER UPPER PV ANOMALY LOOKS TO SWING OUT ONTO THE PLAINS
BY LATE AFTERNOON MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 315 PM CDT SUN MAY 26 2013
SFC LOW PRESSURE WILL REMAIN TUCKED ACROSS ERN COLO FOCUSING
MOISTURE...DRY AIR AND WARM AIR ADVECTION ACROSS WRN AND NCNTL NEB.
THE SFC LOW WILL GRADUALLY DEEPEN TO AROUND 992 MB BY TUESDAY AND
CONTINUING NEAR 992 MB THROUGH WEDNESDAY. A PACIFIC FRONT SHOULD
MOVE INTO WRN NEB LATE WEDNESDAY. THROUGH WEDNESDAY...500 MB HEIGHTS
WILL GRADUALLY FALL WHILE H700 MB TEMPS REMAIN NEAR STEADY AT
10C-12C. WIND SHEAR APPEARS TO GRADUALLY INCREASE SUPPORTING A
SLIGHT INCREASE IN BULK SHEAR. NEARLY ALL OF THE FCST AREA HAS BEEN
OUTLOOKED FOR SEVERE WEATHER BY SPC THROUGH WEDNESDAY. ALL
CONVECTION WHICH DEVELOPS TONIGHT THROUGH WEDNESDAY WILL HAVE A
LARGE IMPACT ON SUBSEQUENT STORM DEVELOPMENT AS RAIN COOLED OUTFLOW
DEVELOPS AND SETS UP FOCUS FOR SUCCEEDING STORM DEVELOPMENT. THUS THE
LOCATION OF HIGHEST POPS IS HIGHLY CONDITIONAL. A MULTI MODEL BLEND
WAS USED FOR POPS AND CAPPED AT 40 PERCENT. A SIMILAR STRATEGY WAS
USED FOR QPF. IN GENERAL NRN AND WRN NEB APPEAR MORE FAVORABLE FOR
STORM DEVELOPMENT THAT THE SOUTHWEST WHERE 700 MB WARM AIR ADVECTION
WILL OFTEN CAP THE ATMOSPHERE.
A SERIES OF PERTURBATIONS WILL CONTINUE TO EJECT FROM THE UPPER LOW
ACROSS THE NRN PACIFIC. THESE DISTURBANCES WILL MOVE THROUGH SD AND
NEB TRIGGERING STORM DEVELOPMENT. IN TIME THE UPPER LEVEL WILL BUILD
SOUTHEAST THROUGH PACIFIC NORTHWEST AND NRN ROCKIES. FALLING HEIGHTS
SHOULD MAINTAIN STEEP LAPSE RATES AND AN EML CONDUCIVE FOR STORM
DEVELOPMENT. AS LONG AS THE PACIFIC FRONT REMAINS WEST OF THE FCST
AREA...MOISTURE AND WARM AIR ADVECTION SHOULD CONTINUE PROVIDING
FUEL FOR STORM DEVELOPMENT.
WITH THE PERSISTENT MOISTURE ADVECTION...K INDICES INCREASE TO 40C
OR GREATER IN THE NAM AND GFS MODELS. THIS ALONG WITH THE FACT THAT
VERY HEAVY RAINFALL TOTALS HAVE OCCURRED FROM STORMS THIS LAST TWO
DAYS...SUGGEST SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL.
WEDNESDAY NIGHT THROUGH MONDAY MORNING...
THE PACIFIC FRONT WILL LIKELY CROSS THE FCST AREA WEDNESDAY
NIGHT...EARLY THURSDAY AT THE LATEST. THIS WILL SHUNT LOW LEVEL
MOISTURE EAST OF THE FCST AREA. H500 MB TEMPS FALL TO AROUND -18C
WHICH WOULD CONTINUE TO SUPPORT SHOWERS AND THUNDERSTORMS. THE
MODELS ARE IN GOOD AGREEMENT THAT AN UPPER LEVEL LOW WILL CIRCULATE
THROUGH THE NRN AND CNTL PLAINS. ALTHOUGH THE COLD CORE WILL LIKELY
CENTER ACROSS ND/SD...THERE SHOULD BE ENOUGH COLD AIR ALOFT ACROSS
THE FCST AREA TO DESTABILIZE THE ATMOSPHERE THURSDAY AND
FRIDAY...PERHAPS EVEN SATURDAY.
FCST MAX TEMPS WILL RISE INTO THE 60S AND 70S BEHIND THE FRONT
THURSDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1229 AM CDT MON MAY 27 2013
ISOLATED TO SCATTERED THUNDERSTORMS WILL CONTINUE OVER WESTERN
NEBRASKA THROUGH THE EARLY MORNING HOURS. STRATUS WILL DROP SOUTH IN
THE KVTN AREA INTO THE SANDHILLS THROUGH THE EARLY MORNING. IFR
CONDITIONS EXPECTED WITH IFR STRATUS CONDITIONS TO HOLD ON AT KVTN
THROUGH THE MORNING. SKIES TO GRADUALLY CLEAR OUT OVER WESTERN
NEBRASKA THROUGH THE AFTERNOON WITH THUNDERSTORMS
REDEVELOPING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...POWER
SYNOPSIS...CDC
SHORT TERM...JWS
LONG TERM...CDC
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1206 AM CDT MON MAY 27 2013
.UPDATE...
BOW ECHO OVER NORTHEAST NEBRASKA CONTINUES TO MOVE EAST AND
SOUTHEAST...WE SHOULD CONTINUE TO SEE SOME DEVELOPMENT INTO
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA OVERNIGHT.
MILLER
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
TSRA SHOULD CONTINUE IN THE KOFK AREA THE NEXT SEVERAL HOURS...
WITH THE STRONGEST ACTIVITY LIKELY BEFORE 07Z. THERE IS STILL
SOME UNCERTAINTY HOW FAR SOUTHEAST STORMS WILL REACH OVERNIGHT...
BUT HRRR MODEL DEVELOPS ACTIVITY TOWARD NORTHEAST KANSAS AND
NORTHWEST MISSOURI BY A LITTLE AFTER SUNRISE.
EXPECT A GRADUAL DECREASE IN CEILINGS THROUGH 14Z...THEN A GRADUAL
UPWARD TREND TOWARD VFR CONDITIONS AT ALL THREE SITES BY EARLY
AFTERNOON MONDAY.
MILLER
&&
.PREV DISCUSSION... /ISSUED 249 PM CDT SUN MAY 26 2013/
DISCUSSION...
VERY ACTIVE WEEK ON TAP OVER THE CNTRL PLAINS WITH POTENTIAL SVR
ACTIVITY ALONG WITH PROLONGED/EXCESSIVE PCPN. MORNING PRECIP WATER
PLOTS WERE SHOWING AMPLE GULF MOISTURE IN PLACE WITH VALUES ROUGHLY
150% OF NORM. LATEST MESOSCALE ANALYSIS INDICATING STOUT MOISTURE
STILL STREAMING INTO THE REGION...AND MODELS ARE IN GOOD AGREEMENT
THIS INFLUX OF MOISTURE WILL CONTINUE THRU AT LEAST
MIDWEEK...GUARANTEEING ENVIRONMENTAL MOISTURE CONTENT WILL REMAIN
QUITE HIGH. AS A MATTER OF FACT...THE GFS IS SUGGESTING TOTAL PCPN
AMOUNTS REACHING 400% OF NORM OVER IA BY NEXT SUNDAY GIVEN SUSTAINED
PCPN EFFICIENCY.
MEANWHILE...MODELS ARE AGAIN IN GOOD AGREEMENT LARGE SCALE FLOW THRU
THIS WEEK WILL GRADUALLY TRANSITION FROM A LARGE CLOSED LOW
CURRENTLY SITTING OVER THE PAC NW TO A RATHER IMPRESSIVE DEEP
ELONGATED LONGWAVE TROF WITH THE AXIS EXTENDING FROM THE ALASKAN
GULF TO THE SRN TIP OF TX. HEADING INTO NEXT WEEKEND THEN...MODELS
PROG THE WRN CONUS TROF BECOMING MORE BROAD IN NATURE WITH LITTLE
MOVEMENT.
FOR TONIGHT...STOUT 310K ISENTROPIC UPGLIDE IS THE DRIVING FORCE FOR
CONVECTIVE ACTIVITY. LIFT WILL BE FURTHER ENHANCED VIA UPPER DIVG
ASSOCIATED WITH RRQ OF JET MAX. MODELS ADVERTISE ENVIRONMENTAL
INSTABILITY WILL REMAIN HIGH OVERNIGHT WITH THE AXIS FOCUSED WEST OF
THE CWA WITHIN AREA OF BEST DEEP LYR SHEAR/MUCAPES. LATEST HRRR
INITIATES CONVECTION THIS EVEN INVOF THE INSTABILITY AXIS...THEN
GRADUALLY PUSHES IT EWD OVERNIGHT. AT THIS POINT CANNOT DISCOUNT A
FEW STORMS PRODUCING HAIL AND/OR STRONG WIND GUSTS.
AS FOR SVR POTENTIAL...SPC CONVECTIVE OUTLOOK KEEPS THE CWA IN THE
SLGT RISK THRU DAY 3. LOOKING AT MONDAY AFTN/EVENING...FAVORABLE
CONDITIONS APPEAR TO BE FOCUS INVOF THE SRN CWA ALONG A WARM FRONT
EXTENDING ALONG THE NEB/KS BORDER. COMBINATION OF DEEP LYR
SHEAR/EFFECTIVE SRH/MLCAPE/ML LCL SUGGEST AN ISOLATED TORNADO OR 2
WILL BE POSSIBLE. TUES AFTN/EVENING THEN...SVR POTENTIAL REMAINS
FOCUSED OVER THE SRN CWA ALONG A SFC BNDRY ALONG THE NEB/KS BORDER.
ENVIRONMENTAL CONDITIONS WILL QUITE SIMILAR WITH THE POTENTIAL FOR
PRODUCING AN ISOLATED TORNADO OR 2.
IN REGARDS TO POPS THE REST OF THIS WEEK...AM COMPELLED TO MAINTAIN
PCPN CHANCES THRU THE MAJORITY OF THE FCST PERIOD GIVEN MODELS
ADVERTISING PERSISTENT FORCING VIA UPPER LEVEL DIVERGENCE...SERIES
OF VORT IMPULSES...ISENTROPIC UPGLIDE...MEANDERING SFC
BOUNDARIES...AS WELL AS GENEROUS MOISTURE TO TAP INTO.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1115 PM CDT SUN MAY 26 2013
.SYNOPSIS...
ISSUED AT 315 PM CDT SUN MAY 26 2013
A DEEP UPPER LEVEL LOW...CURRENTLY ACROSS THE NORTH PACIFIC...WILL
MIGRATE SLOWLY EAST THROUGH THE PACIFIC NORTHWEST AND INTO THE NRN
PLAINS THIS WEEK. A STRONG PACIFIC COLD FRONT WILL MOVE THROUGH
THE FCST AREA WEDNESDAY NIGHT OR THURSDAY. SEVERE WEATHER IS
POSSIBLE TODAY THROUGH WEDNESDAY AS LOW PRESSURE REMAINS QUASI
STATIONARY ACROSS ERN COLORADO AND FOCUSES...MOSITURE...WARM AIR
ADVECTION AND DRY.
&&
.UPDATE...
ISSUED AT 1114 PM CDT SUN MAY 26 2013
UPDATED FORECAST TO DROP TORNADO WATCH AND ISSUE SEVERE
THUNDERSTORM WATCH.
UPDATE ISSUED AT 743 PM CDT SUN MAY 26 2013
UPDATED FORECAST TO INCLUDE TORNADO WATCH FOR NORTH CENTRAL NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 315 PM CDT SUN MAY 26 2013
TONIGHT AND MONDAY...CONVECTION LATE THIS AFTERNOON INTO THE
EVENING TONIGHT...THEN LOW CLOUDS FOG DEVELOPMENT TOWARD MORNING
REMAIN FORECAST ISSUES FOR THE SHORT TERM. WEAK COLD FRONT
ANALYZED FROM SOUTHWEST NEBRASKA SOUTHWARD INTO NW KS AND ERN CO.
WARM FRONT EXTENDS FROM SW INTO SC NEBRASKA WITH INVERTED TROUGH
NORTHWARD INTO SD. NUMEROUS OUTFLOW BOUNDARIES SHOW IN THE HAND
ANALYSIS AS WELL.
QUITE A VARIED RANGE OF SHORT TERM MODEL SOLUTIONS FOR THIS EVENING
AS HRRR AND HIRES ARW SUGGEST NOTHING ORGANIZED WILL DEVELOP SOUTH
OF I80 CORRIDOR...BUT DEVELOP A MCS ACROSS THE SANDHILLS IN THE
HIGHWAY 2 VCNTY AND MOVE IT EASTWARD OVERNIGHT. THE NAM /AND HIRES
NMM/ AS WELL AS GFS SUGGEST TWO AREAS OF DEVELOPMENT...THE FIRST IN
SIMILAR AREAS TO THE PREVIOUSLY MENTIONED MODELS /SANDHILLS/ AND A
SECOND IN THE VCNTY OF THE WARM FRONT WHICH ORGANIZES INTO A MCS AND
MOVES SOUTHEAST. FCST WILL GO WITH THE IDEA THAT TO SOME DEGREE BOTH
GROUPS OF SOLUTIONS HAVE REALISTIC POSSIBILITIES BASED ON BETTER DEEP
LAYER SHEAR ACROSS THE NORTH WHICH SHOULD ALLOW FOR A BETTER
ORGANIZATION ONCE DEVELOPMENT OCCURS IN THE SANDHILLS BY EVENING.
LOW LEVEL LAPSE RATES IN THIS AREA HOWEVER ARE NOT THE BEST AS WOULD
BE EXPECTED NORTH OF THE WARM FRONT...AND ALSO BELIEVE AIR MASS IS
STILL SOMEWHAT INFLUENCED IN THE LOW LAYERS AS A RESULT OF THE
OUTFLOW THAT WAS EVIDENT EARLIER THIS MORNING. LARGE HAIL STILL A
POSSIBILITY HERE THOUGH WITH VERY STEEP MID LEVEL LAPSE RATES...EVEN
IF STORMS ARE ELEVATED WHICH SEEMS LIKELY IN THIS AREA.
FURTHER SOUTH...LOW LEVEL LAPSE RATES ARE STEEPEST ACROSS ERN CO AND
NW KS AND HAVE SURGED EWD AHEAD OF LEE SFC LOW IN NW KS. GOOD
THETA-E ADVECTION NORTHEAST OF THIS AREA SHOULD ALLOW DEVELOPMENT IN
THIS AREAS AS WELL...THOUGH COVERAGE REMAINS IN QUESTION. SPC
MESOANALYSIS INDICATES SOME CAP STILL PRESENT HERE AND SINCE LARGE
SCALE FORCING IS BEST FURTHER NORTH THE EXTENT OF CAP EROSION IS
ALSO IN QUESTION. WOULD LIKE TO SEE BETTER SFC CONVERGENCE IN THESE
LOCATIONS TO BE MORE CERTAIN ABOUT INITIATION. IF SFC BASED
DEVELOPMENT DOES OCCUR SVR POTENTIAL WILL BE HIGH AS VERY GOOD ML
CAPE IS IN PLACE. THEREFORE...FCST INCLUDES POPS IN THESE AREAS BASED ON
PREVIOUS THINKING.
THE LAST FEW NIGHTS HAS SEEN A TENDENCY TO DEVELOP LOW CLOUD BEHIND
OUTFLOW BOUNDARIES TWD DAYBREAK AND BELIEVE THAT SHOULD BE THE CASE
ONCE AGAIN MONDAY MORNING. DEPICTING LOCATIONS IS DIFFICULT BUT
FAVORED AREAS EAST OF HIGHWAY 61 SEEM MOST LIKELY AND HAVE TRENDED
THE FCST THAT WAY. EVENTUAL HIGH TEMPS WILL BE HIGHLY DEPENDENT ON
THESE LOW CLOUD DEVELOPMENT AS WELL...BUT AS WITH THE LAST FEW DAYS
AFTERNOON MIXING SHOULD ALLOW 80S MOST PLACES.
CONVECTION AGAIN POSSIBLE MONDAY AFTERNOON. MODELS SUGGESTING UPPER
TROUGH WILL CONTINUE TO MOVE EASTWARD AND SHOULD ALLOW FOR A MORE
SOUTHERN LOCATION OF SFC FEATURES ONCE CONVECTIVE DEBRIS GIVES WAY.
SOMEWHAT BETTER UPPER PV ANOMALY LOOKS TO SWING OUT ONTO THE PLAINS
BY LATE AFTERNOON MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 315 PM CDT SUN MAY 26 2013
SFC LOW PRESSURE WILL REMAIN TUCKED ACROSS ERN COLO FOCUSING
MOISTURE...DRY AIR AND WARM AIR ADVECTION ACROSS WRN AND NCNTL NEB.
THE SFC LOW WILL GRADUALLY DEEPEN TO AROUND 992 MB BY TUESDAY AND
CONTINUING NEAR 992 MB THROUGH WEDNESDAY. A PACIFIC FRONT SHOULD
MOVE INTO WRN NEB LATE WEDNESDAY. THROUGH WEDNESDAY...500 MB HEIGHTS
WILL GRADUALLY FALL WHILE H700 MB TEMPS REMAIN NEAR STEADY AT
10C-12C. WIND SHEAR APPEARS TO GRADUALLY INCREASE SUPPORTING A
SLIGHT INCREASE IN BULK SHEAR. NEARLY ALL OF THE FCST AREA HAS BEEN
OUTLOOKED FOR SEVERE WEATHER BY SPC THROUGH WEDNESDAY. ALL
CONVECTION WHICH DEVELOPS TONIGHT THROUGH WEDNESDAY WILL HAVE A
LARGE IMPACT ON SUBSEQUENT STORM DEVELOPMENT AS RAIN COOLED OUTFLOW
DEVELOPS AND SETS UP FOCUS FOR SUCCEEDING STORM DEVELOPMENT. THUS THE
LOCATION OF HIGHEST POPS IS HIGHLY CONDITIONAL. A MULTI MODEL BLEND
WAS USED FOR POPS AND CAPPED AT 40 PERCENT. A SIMILAR STRATEGY WAS
USED FOR QPF. IN GENERAL NRN AND WRN NEB APPEAR MORE FAVORABLE FOR
STORM DEVELOPMENT THAT THE SOUTHWEST WHERE 700 MB WARM AIR ADVECTION
WILL OFTEN CAP THE ATMOSPHERE.
A SERIES OF PERTURBATIONS WILL CONTINUE TO EJECT FROM THE UPPER LOW
ACROSS THE NRN PACIFIC. THESE DISTURBANCES WILL MOVE THROUGH SD AND
NEB TRIGGERING STORM DEVELOPMENT. IN TIME THE UPPER LEVEL WILL BUILD
SOUTHEAST THROUGH PACIFIC NORTHWEST AND NRN ROCKIES. FALLING HEIGHTS
SHOULD MAINTAIN STEEP LAPSE RATES AND AN EML CONDUCIVE FOR STORM
DEVELOPMENT. AS LONG AS THE PACIFIC FRONT REMAINS WEST OF THE FCST
AREA...MOISTURE AND WARM AIR ADVECTION SHOULD CONTINUE PROVIDING
FUEL FOR STORM DEVELOPMENT.
WITH THE PERSISTENT MOISTURE ADVECTION...K INDICES INCREASE TO 40C
OR GREATER IN THE NAM AND GFS MODELS. THIS ALONG WITH THE FACT THAT
VERY HEAVY RAINFALL TOTALS HAVE OCCURRED FROM STORMS THIS LAST TWO
DAYS...SUGGEST SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL.
WEDNESDAY NIGHT THROUGH MONDAY MORNING...
THE PACIFIC FRONT WILL LIKELY CROSS THE FCST AREA WEDNESDAY
NIGHT...EARLY THURSDAY AT THE LATEST. THIS WILL SHUNT LOW LEVEL
MOISTURE EAST OF THE FCST AREA. H500 MB TEMPS FALL TO AROUND -18C
WHICH WOULD CONTINUE TO SUPPORT SHOWERS AND THUNDERSTORMS. THE
MODELS ARE IN GOOD AGREEMENT THAT AN UPPER LEVEL LOW WILL CIRCULATE
THROUGH THE NRN AND CNTL PLAINS. ALTHOUGH THE COLD CORE WILL LIKELY
CENTER ACROSS ND/SD...THERE SHOULD BE ENOUGH COLD AIR ALOFT ACROSS
THE FCST AREA TO DESTABILIZE THE ATMOSPHERE THURSDAY AND
FRIDAY...PERHAPS EVEN SATURDAY.
FCST MAX TEMPS WILL RISE INTO THE 60S AND 70S BEHIND THE FRONT
THURSDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 659 PM CDT SUN MAY 26 2013
THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER WESTERN NEBRASKA THIS
EVENING. STRONG CAP IN PLACE AND NOT A GOOD TRIGGER MECHANISM. VFR
CEILINGS AND VISIBILITIES EXPECTED. HAVE INCLUDED A TEMPO GROUP
FOR THUNDERSTORMS AT BOTH KVTN AND KLBF. CONFIDENCE NOT HIGH THAT
THESE WILL DEVELOP. EAST WINDS OVER NIGHT WITH STRATUS AND MVFR
CEILINGS DEVELOPING AFTER 2706Z. THESE STRATUS WILL HOLD ON
THROUGH THE MORNING BEFORE LIFTING INTO VFR THROUGH THE AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...POWER
SYNOPSIS...CDC
SHORT TERM...JWS
LONG TERM...CDC
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
345 AM CDT MON MAY 27 2013
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT MON MAY 27 2013
THE CHALLENGE WILL BE SHOWER/THUNDER CHANCES AND TIMING/PLACEMENT
OF SHORTWAVES IN SOUTHWEST FLOW ALOFT. THE MODELS ALL INDICATE THE
SAME GENERAL SOLUTION...BUT DIFFER GREATLY WITH WHERE THEY
INITIATE AND PROPAGATE CONVECTIVE COMPLEXES. THE ECMWF...AND
ESPECIALLY THE GEM...HAVE VERIFIED THE BEST OVER THE PAST COUPLE
DAYS...AND WILL FOLLOW FOR DETAILS.
FOR TODAY...THERE ARE TWO SHORTWAVES AND ASSOCIATED CONVECTIVE
COMPLEXES THAT COULD AFFECT THE FA. ONE IS ENTERING IOWA...AND
PROPAGATING SOUTHEAST...AND WILL REMAIN WELL TO THE SOUTH. THE
SECOND IS ACROSS WESTERN NORTH DAKOTA. THE STRONGEST FORCING FROM
THIS SHORTWAVE WILL CONTINUE PROPAGATING TO THE NORTHEAST...AND
SHOULD MISS THE FA. THE AIRMASS REMAINS STABLE AS LOW LEVEL
SOUTHEAST FLOW CONTINUES...AND EXPECT ANYTHING THAT APPROACHES THE
FA TO FALL APART (MUCH LIKE YESTERDAY). SO...WENT WITH A DRY
FORECAST FOR TODAY (THERE COULD BE SPRINKLES OR AN ISOLATED
SHOWER...BUT NOT MUCH MORE THAN THAT).
CLOUDS HAVE DEVELOPED ACROSS THE ENTIRE FA AS 925MB WINDS ARE NOW
SOUTHERLY...AS OPPOSED TO SOUTHEAST. MODELS INDICATE 925MB WINDS
BECOMING MORE SOUTHEAST BY THE AFTERNOON...AND ADVECTING A DRIER
AIRMASS INTO PARTS OF THE EASTERN FA. MAX TEMPS WILL BE SIMILAR TO
YESTERDAY...LOW TO MID 60S WHERE CLOUDY...AND LOW TO MID 70S WHERE
PARTLY CLOUDY. FOLLOWED THE RAP FOR PLACEMENT OF CLOUDS AND
ASSOCIATED TEMPERATURES...WHICH WILL LIKELY NEED TO BE ADJUSTED A
BIT (VERY SIMILAR TO YESTERDAY).
TONIGHT-TUESDAY...A SIMILAR SITUATION SHOULD PLAY OUT FOR THIS
PERIOD AS TO WHAT IS OCCURRING TONIGHT. ANTICIPATE TWO CONVECTIVE
COMPLEXES TO INITIATE THIS EVENING...WITH ONE ACROSS THE WESTERN
DAKOTAS AND THE OTHER ACROSS CENTRAL/EASTERN SOUTH DAKOTA (THE
ASSOCIATED SHORTWAVES CAN EASILY BEEN SEEN UPSTREAM ON WATER VAPOR
IMAGERY). THESE COMPLEXES COULD BRUSH THE NW AND SE FA...ALTHOUGH
INSTABILITY REMAINS WEAK WITHIN THIS FA. THE ECMWF IS MUCH
FURTHER NORTH AND BULLISH WITH THE SOUTHERN COMPLEX...BUT WILL
DISCOUNT AS IT HAD A SIMILAR BIAS WITH THE CURRENT ACTIVITY. KEPT
THE CHANCE POPS ACROSS THE FAR WESTERN AND SOUTHERN FA...AND
REMOVED THE THUNDER CHANCES FOR THE REMAINDER OF THE FA (THE
AMERICAN MODELS HAVE HAD A WET BIAS AND ANY DISSIPATING SHOWERS
WILL NOT HAVE AN IMPACT). WEAK RIDING EXPECTED BY TUESDAY
AFTERNOON AND EXPECT SUNSHINE AND WARMER TEMPERATURES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON MAY 27 2013
TUESDAY NIGHT-WEDNESDAY NIGHT...
WEAK RIDING TO START THIS PERIOD WITH UPPER FLOW BECOMING MORE
SOUTHERLY BY WEDNESDAY AFTERNOON/EVENING. THIS SHOULD LEAD TO DRY
WEATHER INTO MUCH OF WEDNESDAY AFTERNOON...WITH THUNDER CHANCES
INCREASING LATER WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. SEVERE
POTENTIAL WILL DEPEND ON HOW QUICKLY THE HIGHER LOW LEVEL MOISTURE
AND THE WARM FRONT CAN ADVECT NORTHWARD. THE GEM/NAM ARE FURTHER
NORTH WITH THIS FEATURE THAN THE GFS/ECMWF BY LATE WEDNESDAY
AFTERNOON. SPC KEEPS THE HIGHER SEVERE PROBABILITIES SOUTH OF THE
FA (LINING UP WITH THE GFS/ECMWF). USUALLY...THE WARM FRONT DOES
STAY SOUTH...WE SHALL SEE. AS FORCING INCREASES WEDNESDAY
NIGHT...INSTABILITY SHOULD BE WEAKER AND THE SEVERE THREAT
DEPENDENT OF THE STRENGTH OF THE LOW LEVEL JET (ANTICIPATE A FEW
STRONGER STORMS).
THURSDAY-SUNDAY...
MODELS REMAIN FAIRLY CONSISTENT WITH CLOSING OFF AN UPPER LOW
OVER MONTANA BY THURSDAY FROM THE 500MB SOUTHWEST FLOW. AS A
RESULT STRONG WAA ON THURSDAY ACROSS THE CWFA MAY BRING A SOUTH TO
NORTH CONVECTIVE COMPLEX THROUGH THE AREA. KEPT THE LIKELY POPS
INTO THE AFTERNOON THURSDAY. BY 00Z FRI THE ECMWF AND GEM BOTH
CENTER THE UPPER LOW IN E MT OR W ND WHEREAS THE GFS BRINGS IT
FARTHER TO THE SE OVER NC SD WITH THE SFC LOW NEAR BIS. THE ECMWF
AND GEM SOLN WOULD BRING THE DRY SLOT ACROSS THE AREA FRI AND SAT
COMPARED TO THE MORE CONVECTIVE AND WETTER GFS WHICH KEEPS WARM
FRONTAL BOUNDARY DRAPED ACROSS THE CWFA. BY SUNDAY THE WAVE IS
PUSHED EAST WITH SHOWERS ENDING. HI TEMPS TO BE HIGHLY DEPENDENT
ON CLOUD COVER FRI AND SAT...WARMER IN THE DRY SLOT AND COOLER IF
GFS VERIFIES...70S VS 60S. SEASONABLY COOL ON SUNDAY IN THE WAKE
OF THE SYSTEM WITH HIGHS IN 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1130 PM CDT SUN MAY 26 2013
EXPECT A SLOW LOWERING OF CIGS INTO THE MVFR RANGE FROM WEST TO
EAST THROUGH TONIGHT. CAN/T RULE OUT SOME IFR POCKETS MAINLY ALONG
AND WEST OF THE RED RIVER VALLEY...BUT FOR NOW WILL JUST MENTION
MVFR CONDITIONS AND MONITOR CONDITIONS. SE WINDS WILL CONTINUE AND
GUST TO AROUND 20KT ON TUE AS CLOUDS CONTINUE ALTHOUGH WON/T
MENTION ANY CONVECTION AT THIS TIME...BUT CHANCES FOR SHOWERS AND
STORMS SHOULD INCREASE AT ALL AREAS NEAR THE END OF THIS TAF PERIOD.
&&
.HYDROLOGY...
ISSUED AT 118 PM CDT SUN MAY 26 2013
ALL TRIBUTARIES TO THE RED RIVER ARE FALLING ACROSS THE FORECAST
AREA. THE BUFFALO RIVER AT DILWORTH HAS APPARENTLY CRESTED AND WILL
FALL SLOWLY DURING THIS WEEK. ON THE MAIN STEM OF THE RED RIVER...
THE RIVER IS STEADY OR FALLING IN THE SOUTHERN PART OF THE VALLEY.
IT IS STILL SLOWLY RISING OVER THE NORTHERN VALLEY AT PEMBINA...AND
NEAR CREST AT DRAYTON. OSLO CRESTED EARLIER TODAY AT AROUND MINOR
FLOOD STAGE OF 26 FEET.
RIVER FLOOD WARNINGS REMAIN IN EFFECT AT JUST THREE LOCATIONS...
PEMBINA AND DRAYTON ON THE RED AND DILWORTH ON THE BUFFALO.
AREAL FLOOD WARNINGS REMAIN IN EFFECT FOR PEMBINA...WALSH...AND
EASTERN CAVALIER COUNTIES THROUGH TUESDAY. WATER LEVELS ACROSS THIS
AREA SHOULD GRADUALLY DECREASE OVER THE NEXT FEW DAYS WITH MODEST
ADDITIONAL RAINFALL ANTICIPATED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...DK
HYDROLOGY...WJB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1253 AM CDT MON MAY 27 2013
.UPDATE...
ISSUED AT 1245 AM CDT MON MAY 27 2013
IN COLLABORATION WITH NEIGHBORS HAVE DECIDED TO DROP POPS EAST AND
LOWER THEM SIGNIFICANTLY CENTRAL NORTH DAKOTA FOR THE OVERNIGHT. A
LINE OF THUNDERSTORMS THROUGH EASTERN MONTANA WAS APPROACHING THE
NORTH DAKOTA BORDER AND SO KEPT HIGH POPS THERE. THE STORMS WERE
MOVING INTO LESS UNSTABLE AIR AND SHOULD NOT BE SEVERE. WILL
LIKELY ISSUE A STATEMENT ON THEM FOR SMALL HAIL AND GUSTS WINDS AND
TIME THEM ACROSS THE STATE LINE FOR DECISION SUPPORT SERVICES.
UPDATE ISSUED AT 958 PM CDT SUN MAY 26 2013
UPDATE TO DELAY THUNDERSTORMS EVEN MORE FROM THE EARLY EVENING
UPDATE...BASED ON EVENING HIGH RESOLUTION MODEL TRENDS. STORMS
STILL EXPECTED TO SPREAD INTO WESTERN COUNTIES OVERNIGHT. THERE
MAY BE A FEW STRONG TO MARGINALLY SEVERE STORMS...BUT RELATIVELY
WEAK DEEP LAYER SHEAR IS EXPECTED TO LIMIT POTENTIAL FOR MORE
SIGNIFICANT SEVERE WEATHER. RELATIVELY SLOW STORM MOTIONS WOULD
FAVOR POTENTIAL FOR ISOLATED HEAVY RAINFALL AMOUNTS. STILL SOME
UNCERTAINTY AS TO HOW FAR EAST STORMS WILL SPREAD TOWARD DAYBREAK
AND INTO THE MORNING HOURS MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 320 PM CDT SUN MAY 26 2013
FORECAST PROBLEM IN THE SHORT TERM WILL BE THUNDERSTORM CHANCES
THROUGH THE PERIOD. OVERALL MODEL TREND HAS BEEN TO LESSEN OR PUSH
BACK PRECIPITATION CHANCES ESPECIALLY LATE THIS AFTERNOON AND THIS
EVENING. BEYOND THIS THERE IS LITTLE FORECAST CONFIDENCE REGARDING
PRECIPITATION TIMING AND PLACEMENT AS MODELS ARE HAVING A HARD TIME
RESOLVING THIS IN THE BROAD SOUTHWEST UPPER FLOW.
CURRENTLY...MVFR-IFR STRATUS REMAIN ACROSS THE SOURIS TO JAMES
RIVER BASINS...WHILE STRATUS HAS DISSIPATED BUT WELL DEVELOPED CU
FIELD HAS BROKEN OUT OVER THE WEST AND SOUTH CENTRAL. THIS HAS
RESULTED IN TEMPERATURES PUSHING INTO THE LOW TO MID 70S WITH MID
50S DEW POINT TEMPERATURES FROM WESTERN NORTH DAKOTA INTO EASTERN
MONTANA AND NORTHWEST SOUTH DAKOTA. CURRENT SPC ANALYSIS IS
SHOWING CAPES OF 1000-1500 J/KG WITH DIMINISHING CIHN OVER THE
MONDAK REGION WITH INCREASING LAPSE RATES. CONVECTION HAS RECENTLY
INITIATED OVER THE BIGHORNS AND BLACK HILLS. GGW 18Z SOUNDING AND
CURRENT LAPS SOUNDING NEAR KOLF INDICATE A NEAR COMPLETE ERODED
CAP OVER EASTERN MONTANA. LATEST WATER VAPOR SATELLITE IMAGERY
SHOW AN APPROACHING SHORTWAVE TROUGH LIFTING NORTHEAST THROUGH
WYOMING WHICH SHOULD HELP TO INITIATE CONVECTION AWAY FROM THE
MOUNTAINS. WITH THIS SAID...MODELS ARE NOT POINTING TO STRONG
CONVECTION OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON
AND EARLY EVENING. GFS/ECMWF BRING BEST CHANCES INTO THE FAR WEST
LATE TONIGHT WITH CONVECTION CONTINUING EAST ACROSS THE AREA ON
MONDAY. 12 UTC NAM AND 17 UTC HRRR BRING CONVECTION FIRING OFF THE
BIGHORNS INTO SOUTHEAST MONTANA BUT THEN SUPPRESS REFLECTIVITIES
AS THEY MOVE INTO WESTERN NORTH DAKOTA. 12 UTC HIRES ARW/NMM EAST
BOTH POINT MORE TOWARD LATE NIGHT CONVECTION MOVING INTO THE WEST
AND LINGERING INTO MONDAY...WITH YET ANOTHER ROUND OF CONVECTION
ON MONDAY.
FOR NOW WILL LEAN TOWARD SLIGHT CHANCE POPS EAST TO CHANCE POPS
WEST THIS EVENING...THEN INCREASING AFTER MIDNIGHT WITH HIGHEST
POPS REMAINING IN THE WEST. THEN BASICALLY A BROAD BRUSH OF HIGH
CHANCE POPS ON MONDAY DUE TO SO MUCH UNCERTAINTY ON
TIMING/PLACEMENT. WITH AFOREMENTIONED SEVERE WEATHER INGREDIENTS
WILL KEEP A MENTION OF SEVERE LATE THIS AFTERNOON AND THIS
EVENING. IF CONVECTION WOULD DEVELOP AND MOVE INTO WESTERN NORTH
DAKOTA...THE GREATEST THREAT WOULD LIKELY BE LARGE HAIL AND VERY
HEAVY RAIN CAUSING LOCALIZED FLOODING PROBLEMS.
ALTHOUGH SPC SLIGHT RISK DOES INCLUDE A PORTION OF THE FAR
SOUTHWEST ON MONDAY...WILL HOLD OFF ON MENTIONING THIS IN THE
FORECAST FOR NOW. WILL LET LATER SHIFTS RE-EVALUATE.
MODELS DO INDICATE INCREASING 925MB MOISTURE TONIGHT. CONSIDERED
ADDING A MENTION OF FOG...BUT THINK THE BIGGEST ISSUE WILL BE LOW
STRATUS AND LIFR CEILINGS. COULD SEE SOME MVFR VISIBILITIES BUT
WILL HOLD OFF ON ADDING FOG FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 PM CDT SUN MAY 26 2013
A VERY ACTIVE WEATHER PATTERN WILL PERSIST ACROSS THE NORTHERN
PLAINS THROUGH MUCH IF NOT ALL OF THE EXTENDED PERIOD.
LONG WAVE TROUGH WEST AND RIDGING EAST WILL MAINTAIN SOUTHWESTERLY
FLOW ALOFT ACROSS THE DAKOTAS MONDAY NIGHT. SHOWERS AND POSSIBLY
SEVERE THUNDERSTORMS WILL BE ONGOING AT THE START OF THE PERIOD
MONDAY EVENING AS A STRONG S/WV LIFTS NORTHEAST THROUGH THE REGION.
SCALED BACK PRECIPITATION CHANCES TUESDAY/TUESDAY EVENING AS A S/WV
RIDGE ADVANCES NORTHEAST THROUGH THE STATE ALONG WITH DRIER AIR INTO
MY WEST. SHOWER/THUNDERSTORM CHANCES INCREASE TUESDAY NIGHT AS THE
RIDGE CONTINUES OFF TO OUR NORTH AND EAST RESULTING IN FLOW ALOFT
TRANSITIONING TO SOUTHWEST ONCE AGAIN...WITH A LEAD IMPULSE MOVING
NORTH THROUGH THE WESTERN DAKOTAS.
BY WEDNESDAY MORNING THE BASE OF THE WESTERN CONUS TROUGH WILL BE
OVER THE SOUTHERN ROCKIES...WHICH IS DEPICTED BY BOTH THE 12Z
GFS/ECMWF TO SWING NORTH THROUGH THE CENTRAL PLAINS INTO THE DAKOTAS
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. FOR THURSDAY...THE BASE OF
THE TROUGH MORPHS INTO A CUTOFF LOW WHICH MAY LINGER ACROSS THE
NORTHERN PLAINS INTO SATURDAY IF THE 12Z ECMWF VERIFIES. THE 12Z GFS
IS MORE PROGRESSIVE...WITH THE LOW BECOMING AN OPEN WAVE AND MOVING
OVER THE WESTERN GREAT LAKES REGION BY SATURDAY MORNING. BOTH MODEL
SOLUTIONS RESULT IN HIGH CHANCES FOR SHOWERS AND THUNDERSTORMS
WEDNESDAY-WEDNESDAY NIGHT-THURSDAY...WITH A CHANCE OF STRONG TO
SEVERE STORMS AS WELL. FORECAST UNCERTAINTY INCREASES AFTER WARDS FOR
FRIDAY THROUGH THE WEEKEND WITH THE ABOVE MENTIONED DIFFERENCES
BETWEEN THE GFS/ECMWF.
TEMPERATURES WILL AVERAGE NEAR TO SLIGHTLY ABOVE NORMAL EARLY NEXT
WEEK...THEN WILL AVERAGE NEAR TO SLIGHTLY BELOW NORMAL FOR THE END
OF THE WORK WEEK THROUGH NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1240 AM CDT MON MAY 27 2013
A LINE OF THUNDERSTORMS THROUGH EASTERN MONTANA WAS PUSHING EAST
WHILE INDIVIDUAL CELLS WERE PUSHING NORTHEAST. THIS LINE WILL BE
INTO NORTHWEST NORTH DAKOTA...KISN...AROUND 27/07Z. THE SOUTHERN
END OF THE LINE WAS WEAKENING AND MAY NOT MAKE IT TO KDIK IN TACT.
OTHERWISE...MOIST SOUTHEAST FLOW CONTINUES THROUGH THE FORECAST
PERIOD KEEPING MVFR / IFR CEILINGS IN THE FORECAST FOR THE TAF SITES.
PATCHY FOG WAS FOUND AROUND THE AREA AND THERE IS A REFLECTION OF
THAT IN THE 27/06Z TAF ISSUANCE.
BEHIND THE THUNDERSTORMS...LATER MONDAY...STEADIER LIGHT RAIN IS
FORECAST WEST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...TWH
LONG TERM...NH
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1141 PM CDT SUN MAY 26 2013
.DISCUSSION...
LOOK FOR STRATUS TO RETURN TO WEST CENTRAL TEXAS WITHIN THE NEXT
SEVERAL HOURS. SEE THE BELOW AVIATION.
&&
.AVIATION...
MODELS THIS CYCLE DELAY THE STRATUS ONSET ACROSS OUR SOUTHERN
COUNTIES FOR A FEW MORE HOURS. THE LATEST IR IMAGERY SUPPORTS
THIS PREDICTION...WITH ONLY A SMALL PATCH OF STRATUS CURRENTLY
DEVELOPING SOUTH OF OUR COUNTIES. THUS...I BELIEVE A TIMING OF
EITHER 07Z OR 08Z LOOKS BEST THIS CYCLE FOR MVFR CEILINGS FOR OUR
SOUTHERN THREE TERMINALS. THE RUC 925 MB RELATIVE HUMIDITY FIELD
STILL INCREASES TO SATURATION AS FAR NORTH AS SAN ANGELO BY 12Z.
HOWEVER...GIVEN WHAT I CURRENTLY OBSERVE ON IR IMAGERY...MY
CONFIDENCE IS LOW FOR MVFR CEILINGS AT SAN ANGELO. SO...I WILL
LIKELY MAINTAIN VFR FORECASTS FOR THE NEXT 24 HOURS FOR THE
ABILENE AND SAN ANGELO TERMINALS. AGAIN...SURFACE WINDS TOMORROW
WILL BE FROM THE SOUTH AND GUSTY.
HUBER
&&
.PREV DISCUSSION... /ISSUED 900 PM CDT SUN MAY 26 2013/
UPDATE...
FORECAST IS BEING UPDATED MAINLY FOR POPS AND SKY CONDITION...SEE
DISCUSSION.
DISCUSSION...
ISOLATED THUNDERSTORMS HAVE DEVELOPED THIS EVENING IN THE TEXAS
PANHANDLE SOUTHEAST OF AMARILLO...AND NEAR FORT STOCKTON. WITH
THE ABSENCE OF OTHER CONVECTIVE DEVELOPMENT TO OUR WEST...NOT
EXPECTING SHOWERS AND STORMS TO ENTER OUR AREA TONIGHT. HAVE
REMOVED THE POPS AND DECREASED THE CLOUD COVERAGE PER RECENT TRENDS
IN SATELLITE IMAGERY. WITH MOISTENING SOUTHEASTERLY BOUNDARY LAYER
FLOW OVERNIGHT...EXPECT LOW CLOUD DEVELOPMENT ACROSS OUR
SOUTHEASTERN COUNTIES TOWARD MORNING. THE LOW CLOUD FIELD SHOULD
ERODE MID TO LATE MORNING ON MONDAY...WITH A DIURNAL CUMULUS FIELD
IN THE AFTERNOON. MINOR ADJUSTMENTS WERE ALSO MADE TO TEMPERATURE
AND DEWPOINT GRIDS TO BRING IN LINE WITH SURFACE OBSERVATIONS THIS
EVENING. UPDATED FORECAST PRODUCTS WILL BE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 631 PM CDT SUN MAY 26 2013/
DISCUSSION...
LOOK FOR STRATUS TO BRING MVFR CEILINGS BACK TO MUCH OF WEST
CENTRAL TEXAS LATER TONIGHT. PLEASE SEE THE BELOW AVIATION
SECTION FOR MORE INFORMATION.
AVIATION...
THE LATEST RUC 925 MB RELATIVE HUMIDITY FIELD INDICATES STRATUS
WILL DOMINATE MUCH OF WEST CENTRAL TEXAS SOUTH OF INTERSTATE 20 BY
06Z TONIGHT. FOR NOW...I DECIDED TO CONTINUE WITH VFR CONDITIONS
AT SAN ANGELO...AS WELL AS ABILENE...FOR THE NEXT 24 HOURS. BY 18Z
TOMORROW...EXPECT VFR CONDITIONS TO AGAIN DOMINATE WEST CENTRAL TEXAS.
AS FOR SURFACE WINDS TOMORROW...MODELS INDICATE A SURFACE TROUGH
ACROSS WEST TEXAS WILL CREATE A MODERATE SURFACE PRESSURE GRADIENT
ACROSS WEST CENTRAL TEXAS. THUS...WATCH FOR GUSTY SOUTHERLY
SURFACE WINDS TO DOMINATE WEST CENTRAL TEXAS TOMORROW...ESPECIALLY
DURING THE AFTERNOON HOURS.
HUBER
PREV DISCUSSION... /ISSUED 327 PM CDT SUN MAY 26 2013/
SHORT TERM...
SIMILAR SCENARIO IN OUR WESTERN COUNTIES EXPECTED THIS EVENING AS
OCCURRED LAST EVENING WITH 0-6KM SHEAR OF 25-30KT AND MLCAPES OF
1500-2000 J/KG. DRYLINE WILL STRETCH FROM THE BIG BEND THROUGH THE
PERMIAN BASIN LATE THIS AFTERNOON WITH THUNDERSTORMS EXPECTED TO
DEVELOP ONCE AGAIN ALONG THE DRYLINE DURING TIME OF MAX HEATING.
ANY STORMS THAT DO DEVELOP MAY ONCE AGAIN IMPACT OUR WESTERN
COUNTIES BUT SHOULD BE IN A WEAKENING PHASE DUE TO THE LOSS OF
DIURNAL HEATING BY THE TIME THEY ENTER OUR COUNTIES. AT THIS TIME
DO NOT EXPECT ANY STORMS TO ENDURE PAST MIDNIGHT...SO SHOULD NOT
HAVE ANY STORMS PROPAGATING THROUGH THE CWA AS WE HAD LAST NIGHT.
LOOKING FOR CONTINUED WARMING WITH AFTERNOON HIGHS TOMORROW A FEW
DEGREES WARMER THAN TODAY...LOW TO MID 90S. MORNING LOWS SHOULD
ALSO BE A LITTLE WARMER...IN THE UPPER 60S TO AROUND 70.
15
LONG TERM...
THE WEST COAST TROUGH WILL DEEPEN EARLY NEXT WEEK AS A STRONG WAVE
MOVES INTO THE PACNW...AMPLIFYING THE SYNOPTIC PATTERN AS THE
MID LEVEL RIDGE BUILDS OVER THE EAST CONUS. PRONOUNCED SOUTHWEST
FLOW ALOFT WILL MAINTAIN/INTENSIFY THE MID LEVEL CAPPING INVERSION
THROUGH TUESDAY. THE MONDAY/TUESDAY DAYTIME PERIODS LOOK TO BE
BREEZY...WARM AND DRY /FOR THE MOST PART/ WITH TEMPERATURES
WARMING INTO THE LOWER 90S. A FEW DIURNAL THUNDERSTORMS ARE
EXPECTED TO FIRE EACH AFTERNOON IN THE VICINITY OF THE DRYLINE TO
THE WEST AND MAY MAKE A RUN FOR OUR WESTERN COUNTIES. THE CAP IS
STRONG BUT IF THE STRONG INSTABILITY IS TAPPED...SOME STORMS MAY
HAVE THE POTENTIAL TO BECOME SEVERE. HOWEVER...MOST AREAS WILL
REMAIN DRY.
ON WEDNESDAY...THE MODELS APPEAR TO BE CONVERGING ON A SOLUTION
THAT IS A COMPROMISE BETWEEN THE PREVIOUS RUNS OF THE GFS AND
ECMWF. THIS NEW SOLUTION DEPICTS A NEGATIVELY TILTED SHORTWAVE
TROUGH EJECTING INTO THE PLAINS BY PEAK HEATING ON WEDNESDAY.
SYNOPTIC SCALE ASCENT WILL WORK ON THE CAPPING INVERSION
THROUGHOUT THE DAY AND IS EXPECTED TO COOL MID LEVEL TEMPS
SUFFICIENTLY FOR THE CAP TO BREAK BY THURSDAY AFTERNOON. THERE IS
SOME HINT THAT WE COULD SEE ONGOING CONVECTION EARLY WEDNESDAY BUT
THIS SHOULD WEAKEN THROUGHOUT THE DAY AS MID LEVEL WARM ADVECTION
WANES. SLIGHTLY COOLER TEMPS ARE EXPECTED WITH HIGHS GENERALLY IN
THE MID/UPPER 80S. FORMIDABLE DEEP LAYER SHEAR /0-6KM BULK SHEAR
OF 35-40 KTS/ AND STRONG SURFACE BASED INSTABILITY WILL HEIGHTEN
THE POTENTIAL FOR SEVERE CONVECTION...WITH LARGE HAIL AND DAMAGING
WINDS BEING THE PRIMARY THREATS. ANY STORMS THAT DEVELOP WILL
PERSIST INTO THE EVENING HOURS.
BY THURSDAY...THIS WAVE WILL BE EAST OF THE AREA WITH A MORE
SUBSIDENT REGIME ANTICIPATED DURING THE DAY. IF ANY STORMS DO
DEVELOP...I THINK COVERAGE WILL BE VERY LIMITED. THUS...NO
MENTIONABLE POPS WERE CARRIED FOR THURSDAY AND THURSDAY NIGHT.
TEMPS WILL REBOUND TO NEAR NORMAL VALUES WITH HIGHS GENERALLY IN
THE UPPER 80S TO LOWER 90S. THIS TREND WILL CONTINUE ON FRIDAY
WITH TEMPS AT OR ABOVE 90 DEGREES IN MOST LOCATIONS WITH THE BEST
CHANCE FOR AFTERNOON AND EVENING STORMS FOUND TO THE NORTH AND
WEST OF THE CWA.
THE MODELS DISAGREE WITH THE PATTERN FOR THIS WEEKEND. THE GFS
CONTINUES TO SHOW A WEAK COLD FRONT MOVING SOUTH INTO WEST CENTRAL
TX WITH INCREASING RAIN CHANCES WHILE THE ECMWF KEEPS THIS FRONT
TO THE NORTH OF THE AREA. GIVEN THE LACK OF CONFIDENCE IN EITHER
SOLUTION...I USED A GFS/ECMWF BLEND FOR THE WEEKEND. I DID INCLUDE
A SLIGHT CHANCE FOR THUNDERSTORMS ACROSS THE BIG COUNTRY ON
SATURDAY AFTERNOON BUT THIS IS CONDITIONAL ON THE GFS SOLUTION OF
A COLD FRONT IN THE VICINITY COMING TO FRUITION.
JOHNSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 70 92 68 90 70 / 10 10 10 5 20
SAN ANGELO 70 92 71 92 71 / 10 5 10 5 20
JUNCTION 69 91 71 90 72 / 10 5 5 5 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HUBER
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1125 PM CDT SUN MAY 26 2013
.AVIATION...
THE COMBINATION OF A DRYLINE TO THE EAST OF THE THREE TAF SITES ALONG
WITH A SOUTHWESTERLY FLOW ALOFT WILL CAUSE CONVECTION TO ONCE AGAIN
DEVELOP MONDAY AFTERNOON AND EVENING. THIS CONVECTION WILL REMAIN
WELL EAST OF THE AMARILLO TAF SITE. VFR CONDITIONS WILL PREVAIL
THROUGH THE TAF FORECAST PERIOD. SOUTHERLY TO SOUTHWESTERLY WINDS 15
TO 25 KNOTS WITH HIGHER GUSTS WILL BE THE RULE...HOWEVER WINDS WILL
DIMINISH TO AROUND 10 TO 15 KNOTS TONIGHT UNTIL AROUND 15Z MONDAY AT
BOTH THE GUYMON AND DALHART TAF SITES...AND THEN DIMINISH AGAIN AFTER
01Z TUESDAY.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 1040 PM CDT SUN MAY 26 2013/
UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...NOW LIMITING SCATTERED EVENING
THUNDERSTORMS TO COLLINGSWORTH COUNTY IN SOUTHEAST CORNER OF TEXAS
PANHANDLE ONLY. UPDATED TEXT PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
PREV DISCUSSION... /ISSUED 856 PM CDT SUN MAY 26 2013/
UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...REDUCING COVERAGE/POPS FOR EVENING
THUNDERSTORMS. HAVE CONFINED SCATTERED THUNDERSTORMS TO SOUTHEAST
TEXAS PANHANDLE...AND HAVE TRIMMED ISOLATED TO A SMALLER PORTION OF
EASTERN PARTS OF FORECAST AREA.
WILL ALLOW RED FLAG WARNING TO EXPIRE AT 9 PM.
UPDATED TEXT PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
PREV DISCUSSION... /ISSUED 700 PM CDT SUN MAY 26 2013/
UPDATE...
HAVE UPDATED GRAPHICAL FORECASTS...CALLING FOR SCATTERED TO ISOLATED
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST TEXAS PANHANDLE THROUGH
THE EVENING. EXPECT CONVECTION TO BE MAINLY CONTAINED SOUTHEAST
TEXAS PANHANDLE...WHERE NEWLY DEVELOPED CELLS WILL BE
PROPAGATING...DUE TO SUPPORT OF WEAK SHORTWAVE TROF. UPDATED TEXT
PRODUCTS WILL BE ISSUED SHORTLY.
COCKRELL
PREV DISCUSSION... /ISSUED 626 PM CDT SUN MAY 26 2013/
AVIATION...
00Z TAF CYCLE
A DRYLINE JUST EAST OF THE GUYMON AND AMARILLO TAF SITES ALONG WITH
AN UPPER TROUGH MOVING ACROSS THE PANHANDLES EARLY TONIGHT WILL
PRODUCE ISOLATED TO SCATTERED CONVECTION. THIS CONVECTION IS EXPECTED
TO REMAIN EAST OF THE THREE TAF SITES. VFR CONDITIONS ALONG WITH
SOUTHWESTERLY WINDS 15 TO 25 KNOTS WITH HIGHER GUSTS AFTER 15Z
MONDAY...AND 10 TO 20 KNOTS BEFORE 15Z MONDAY WILL PREVAIL.
SCHNEIDER
PREV DISCUSSION... /ISSUED 405 PM CDT SUN MAY 26 2013/
DISCUSSION...
THERE REMAINS A LARGE AMOUNT OF POTENTIAL FOR WEATHER ACROSS THE
PANHANDLES FOR THE NEXT SEVERAL DAYS BUT THE QUESTION WILL BE CAN WE
TURN THAT POTENTIAL INTO REALITY.
ACROSS THE NORTHWEST TEXAS AND WESTERN OKLAHOMA PANHANDLE REMAIN A
PRIME AREA FOR CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP THIS
AFTERNOON AS THE DRYLINE SNEAKS INTO THE PANHANDLES. AS A RESULT
WILL LEAVE THE RED FLAG IN PLACE AND UNMODIFIED. FOR THE EASTERN
PANHANDLES THERE REMAINS A STRONG TO SEVERE STORM POTENTIAL THIS
AFTERNOON INTO THE OVERNIGHT HOURS. TTU WRF AND RUC HRRR SOLUTIONS
SHOW ISOLATED CONVECTION INITIATING ALONG AND EAST OF A VEGA TO
GUYMON LINE. RUC BUFR SOUNDINGS SHOW A WEAK CAP INHIBITING
INITIATION OF THESE STORMS UNTIL 6-7PM THIS EVENING. SHOULD THESE
STORMS FORM THEY WOULD BE ABLE TO TAP INTO ELEVATED INSTABILITY IN
THE RANGE OF 1000-1500 J/KG. DEEP LAYER SHEAR IN THE AREA OF LIKELY
INITIATION IS 25 TO 35 KT WITH A SLIGHT VEERING PATTERN. GIVEN
THE DEEP DRY LAYER BENEATH THE EXPECTED STORM BASES DAMAGING WINDS
OF 65 TO 70 MPH WOULD BE THE PRIMARY HAZARD BUT A HAIL THREAT CAN
NOT BE RULED OUT. ALL OF THIS IS ASSUMING THE WEAK CAP CAN BE
OVERCOME TO ALLOW STORMS TO DEVELOP. ANY STORMS THAT MAY DEVELOP
SHOULD DIMINISH BY 2 AM MONDAY MORNING.
DURING THE DAY MONDAY...THE DRYLINE WILL RACE ACROSS THE PANHANDLES
AND INTO WESTERN OKLAHOMA. THIS WILL PLACE THE VAST MAJORITY OF THE
PANHANDLES UNDER EXTREMELY DRY CONDITIONS WHICH COULD LEAD TO THE
RAPID SPREAD OF FIRE. WITH THAT BEING SAID RECENT RAINS PLUS ANY
ADDITIONAL RAIN WE GET TONIGHT WILL HELP TO MITIGATE SOME OF THIS
POTENTIAL. HAVE DECIDED TO NOT CARRY HEADLINES FOR MONDAY DUE TO THE
UNCERTAINTY OF PRECIP AMOUNTS AND COVERAGE FROM ANY STORMS
TONIGHT...BUT IF NO PRECIPITATION OCCURS A RED FLAG WARNING MAY BE
NEEDED FOR THE SIZABLE CHUNK OF THE AREA.
MODELS HAVE COME INTO A DECENT AGREEMENT FOR THE MID WEEK SYSTEM
WITH THE ECMWF LAGGING BEHIND THE OTHER MODELS SLIGHTLY. ALSO OF
NOTE HAS BEEN A SLIGHT INCREASE IN SPEED OF THE SYSTEM PLACING
BETTER PRECIP CHANCES ON TUESDAY AND CAUSING PRECIP CHANCES TO OCCUR
EARLIER IN THE DAY ON WEDNESDAY.
TUESDAY WILL BE A MIX OF FIRE WEATHER CONCERNS ACROSS THE WEST AND
ISOLATED SEVERE WEATHER CONCERNS ACROSS THE SOUTHEAST. THE POSITION
OF THE DRYLINE WILL BE THE MAJOR DETERMINING FACTOR AS TO WHO GETS
WHAT. FOR NOW HAVE GONE WITH A SPLIT OF THE GFS AND NAM ON DRYLINE
PLACEMENT WHICH ENDS UP BEING ROUGHLY ALONG A GUYMON TO CLAUDE LINE.
LOCATIONS WEST OF THIS LINE WILL HAVE A BETTER CHANCE FOR SEEING
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS...AND LOCATION
EAST OF THIS LINE WILL HAVE THE BETTER CHANCE OF SEEING
PRECIPITATION. LOOKING AT THE SYNOPTIC SCALE...A SHORTWAVE IS PROGGED TO
ROTATE AROUND THE BASE OF THE MAIN UPPER LEVEL TROUGH. THIS SYNOPTIC
LIFT COUPLED WITH CONVERGENCE ALONG THE DRYLINE COULD BE ENOUGH TO
INITIATE STORMS DURING THE AFTERNOON HOURS OF TUESDAY. DEEP LAYER
SHEAR FOR THIS TIME RANGES FROM 20 TO 35 KT AND INSTABILITY VALUES
RANGE FROM 1500 TO 2500 J/KG. STRONG TO SEVERE STORMS CAN NOT BE
RULED OUT AT THIS TIME WITH LARGE HAIL AND DAMAGING WINDS BEING THE
PRIMARY THREATS.
WEDNESDAY THE MAIN UPPER LEVEL TROUGH LOOKS TO TAKE A NEUTRAL TO
SLIGHTLY NEGATIVE TILT AS IT APPROACHES THE PANHANDLES. INSTABILITY
VALUES LOOK TO HAVE LOWERED SLIGHT WHICH COULD ALSO MEAN THAT THE
SEVERE THREAT MAY ALSO HAVE DIMINISHED SLIGHTLY. WITH THAT BEING
SAID CAPE VALUES OF 1000 TO 2000 J/KG AND DEEP LAYER SHEAR OF 35 TO
45 KT WILL KEEP AT LEAST THE CHANCE FOR STRONG STORMS AND A POSSIBLE
ISOLATED SEVERE STORM POSSIBLE. LARGE HAIL AND DAMAGING WINDS WILL
BE THE PRIMARY HAZARD.
THURSDAY THE UPPER FLOW BECOMES MORE ZONAL TO KEEP THAT AREA DRY AND
A WEAK COLD FRONT WILL DROP INTO THE PANHANDLES FRIDAY. CONDITIONS
LOOK TO REMAIN DRY GOING INTO THE WEEKEND.
FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS ARE STILL EXPECTED TO DEVELOP
ACROSS THE NORTHWESTERN TEXAS PANHANDLE AND WESTERN OKLAHOMA
PANHANDLE THIS AFTERNOON. OVERNIGHT THE DRYLINE WILL RETREAT AND
ALLOW RELATIVE HUMIDITIES TO RECOVER. HOWEVER...THE NORTHWESTERN
TEXAS AND WESTERN OKLAHOMA PANHANDLE MAY ONLY RECOVER SLIGHTLY WITH
MAXIMUM RELATIVE HUMIDITIES OF 30 TO 40 PERCENT.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE LIKELY ON
MONDAY FOR MUCH OF THE PANHANDLES AS RELATIVE HUMIDITIES DROP INTO
THE TEENS AND SINGLE DIGITS WITH SOUTHWEST 20 FOOT WINDS OF 20 TO 25
MPH WITH HIGHER GUSTS. THE RECENT RAINFALL ACROSS THE SOUTHERN TEXAS
PANHANDLE AND ANY ADDITIONAL RAINFALL TONIGHT WILL PROVIDE SOME
LIMITATIONS ON FIRE POTENTIAL...TO GO ALONG WITH LOW FUEL LOADING
DUE TO THE ONGOING DROUGHT. FOR NOW WILL KEEP HEADLINES SILENT FOR
THIS TIME PERIOD.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY DEVELOP ACROSS
THE WESTERN PANHANDLES TUESDAY AFTERNOON AS RELATIVE HUMIDITIES DROP
INTO THE SINGLE DIGITS ONCE AGAIN BEHIND THE DRYLINE AND 20 FOOT
SOUTHERLY WINDS OF 15 TO 25 MPH WINDS. HOWEVER PRECIP CHANCES WILL
BEGIN TO ENTER THE PANHANDLES DURING THE LATE AFTERNOON AND EVENING
HOURS WHICH COULD BRING AN EARLY END TO FIRE WEATHER CONDITIONS.
FIRE WEATHER CONDITIONS FROM WEDNESDAY THROUGH THE REST OF THE WORK
WEEK WILL BE HIGHLY DEPENDENT ON PRECIPITATION EXPECTED TUESDAY AND
WEDNESDAY. SHOULD THE WESTERN PANHANDLES GET LITTLE TO NO
PRECIPITATION TUESDAY AND WEDNESDAY...THEN ELEVATED TO NEAR CRITICAL
FIRE WEATHER CONDITIONS COULD BE POSSIBLE TUESDAY AFTERNOON...AND
ELEVATED FIRE WEATHER CONDITIONS THURSDAY AND FRIDAY.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/03
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1123 PM CDT SUN MAY 26 2013
.UPDATE...
ISSUED AT 913 PM CDT SUN MAY 26 2013
CURRENTLY MONITORING SOME CONVECTION THAT HAS DEVELOPED ALONG THE
WESTERN MINNESOTA/IOWA BORDER ALONG THE NORTHEASTERN SIDE OF THE
850MB MOISTURE TRANSPORT. THE RAP HAS BEEN THE MOST CONSISTENT
THIS AFTERNOON/EVENING WITH SHOWING THIS MOISTURE TRANSPORT AND
0-3KM MUCAPE LIFTING NORTH-NORTHEAST OVERNIGHT WITH THIS
CONVECTION LIKELY REACHING NORTHEAST IOWA AND SOUTHEAST MINNESOTA
AFTER 6Z TONIGHT.
WITH SOIL CONDITIONS FAIRLY SATURATED ACROSS NORTHEAST IOWA AND
SOUTHEAST MINNESOTA DUE TO AN EXCESS OF 3 TO 6 INCHES OF RAINFALL
OVER THE PAST FEW WEEKS...AM INCREASINGLY CONCERNED FOR THE
POTENTIAL OF FLASH FLOODING ACROSS THIS REGION. THE MOST LIKELY
PERIOD FOR FLOODING IS EXPECTED TO COME ON MONDAY NIGHT AS A
STRONGER MID LEVEL SHORTWAVE TROUGH PROPAGATES NORTHEAST THROUGH
THE SOUTHWESTERLY FLOW ALOFT. WITH DEEP FORCING COMBINING WITH
HIGH PRECIPITABLE WATER VALUES APPROACHING 200 PERCENT OF NORM AND
INCREASING INSTABILITY...THE THREAT FOR FLASH FLOODING IS THE
HIGHEST MONDAY NIGHT INTO TUESDAY MORNING. BECAUSE OF THIS...HAVE
ISSUED A FLASH FLOOD WATCH FOR ALL OF NORTH CENTRAL AND NORTHEAST
IOWA. CONSIDERED A FLASH FLOOD WATCH FOR ALL OF SOUTHEASTERN
MINNESOTA...BUT WITH COLLABORATION FROM MPX HAVE DECIDED TO HOLD
OFF ON THAT AREA FOR NOW DUE TO CONFIDENCE IN HEAVY RAINFALL NOT
BEING AS HIGH THERE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 310 PM CDT SUN MAY 26 2013
WARM FRONT THIS AFTERNOON IS SLOWLY MOVING NORTH ACROSS MISSOURI.
THE REMAINS OF THE CONVECTIVE COMPLEX FROM LAST NIGHT AND THIS
MORNING CONTINUES TO MOVE OFF TO THE EAST AND SHOULD NEARLY BE
OUT OF THE AREA BY 00Z. SECONDARY COMPLEX HAS DEVELOPED OVER
NORTHWEST IOWA AHEAD OF A SHORT WAVE TROUGH MOVING ACROSS SOUTH
DAKOTA. MESO MODELS ARE NOT HANDLING THIS FEATURE WELL AT ALL WITH
POSSIBLY THE EXCEPTION OF THE LOCAL ARXLAPS. THE 26.18Z RUN
CONTINUES TO MOVE THIS TO THE EAST/SOUTHEAST WITH ADDITIONAL
DEVELOPMENT FORMING SOUTH OF THE AREA ON A POSSIBLE BOUNDARY LEFT
BEHIND BY THIS MORNINGS COMPLEX. EITHER WAY...EXPECT MOST OF THE
ACTIVITY TO REMAIN SOUTH OF THE AREA EXCEPT FOR POSSIBLY SOME
SHOWERS COMING ACROSS THE SOUTHERN PARTS OF THE AREA THIS EVENING.
LOOKING TO THE OVERNIGHT HOURS...ANOTHER SHORT WAVE TROUGH IS
COMING ACROSS EASTERN WYOMING AND THE 26.12Z NAM AND GFS SHOW THE
MOISTURE TRANSPORT INCREASING AHEAD OF THIS WAVE WITH ANOTHER
COMPLEX OF STORMS EXPECTED TO DEVELOP OVER SOUTH DAKOTA. MODELS
THEN SHOW VARIED SOLUTIONS ON WHERE THIS COMPLEX GOES. THE NAM
BRINGS IT EAST ON THE NOSE OF THE MOISTURE TRANSPORT AND INTO THE
AREA AFTER MIDNIGHT. THE GFS AND 26.00Z ECMWF TAKE IT OFF TO THE
NORTHEAST IN THE SYNOPTIC FLOW WITH THE SHORT WAVE TROUGH. THE
26.12Z HI-RES ARW AND NMM BOTH START THE COMPLEX MOVING TO THE
EAST LIKE THE NAM BUT THEN RAPIDLY DIVE IT SOUTH TOWARD THE FRONT
AND BETTER CAPE AND NEVER GET IT HERE. GIVEN WHAT THE COMPLEXES
HAVE DONE THE PAST COUPLE OF NIGHTS WITH LITTLE OVERALL CHANGE IN
THE GENERAL PATTERN...PLAN TO SHOW THIS COMPLEX COMING INTO THE
AREA AFTER MIDNIGHT AND THEN MOVE EAST/SOUTHEAST ACROSS THE AREA
MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM CDT SUN MAY 26 2013
STARTING TO BECOME CONCERNED THAT THE AREA COULD REALLY GET
PLASTERED WITH RAINFALL MONDAY NIGHT. THE UPPER LEVEL FLOW SHOULD
START TO BECOME A LITTLE MORE SOUTHWEST. THE NEXT SHORT WAVE
TROUGH WILL BE COMING OUT OF THE CENTRAL ROCKIES MONDAY AND MOVING
TOWARD THE AREA FOR MONDAY NIGHT. AS THIS WAVE COMES TOWARD THE
AREA...BOTH THE NAM AND GFS REALLY CRANK UP THE MOISTURE TRANSPORT
AS THE WARM FRONT STARTS TO APPROACH THE FROM THE SOUTH. THE NOSE
OF THE MOISTURE TRANSPORT IS EXPECTED TO BECOME FOCUSED ON THE
FORECAST AREA. THE ISENTROPIC UP GLIDE ON THE 300K SURFACE BECOMES
STRONG WITH THE NAM SHOWING VALUES OF 4 TO 6 UBAR/S. THE
COMBINATION OF THE FORCING FROM THE SHORT WAVE TROUGH...ISENTROPIC
UP GLIDE AND MOISTURE TRANSPORT SHOULD PRODUCE SHOWERS AND STORMS
FOR MUCH OF THE AREA WITH THE AXIS OF HEAVIEST RAIN ALONG THE I90
CORRIDOR. THE GFS FOCUSES ON THE SAME AREA BUT IS QUICKER WITH THE
DEVELOPMENT THAN THE NAM. HOWEVER...THE ECMWF KEEPS THE COMPLEX
MUCH CLOSER TO THE FRONT ACROSS THE IOWA/MISSOURI BORDER WITH
ANOTHER ONE TIED TO THE SHORT WAVE TROUGH GOING BY TO THE NORTH.
AT THIS TIME...PREFER THE SOLUTIONS OF THE NAM AND GFS BUT DID NOT
GO TO CATEGORICAL RAIN CHANCES AT THIS TIME TO HONOR THE ECMWF
SOLUTION. THAT COMPLEX IS THEN EXPECTED TO MOVE OUT TUESDAY BEFORE
THE POSSIBILITY OF ANOTHER ONE FOR TUESDAY NIGHT. BY THIS
TIME...CONFIDENCE ON WHERE THE FRONT WILL BE REALLY STARTS TO GO
DOWN BUT MOST MODELS EITHER HAVE IT OVER THE FORECAST AREA OR
EVEN TO THE NORTH AS THE FLOW BECOMES PROGRESSIVELY MORE
SOUTHWEST. BY THE MIDDLE OF THE WEEK...AN UPPER LEVEL LOW WILL BE
SLIDING TOWARD THE UPPER MIDWEST FROM THE PACIFIC NORTHWEST. THIS
IS EXPECTED TO KEEP THE SHORT WAVES ROTATING ACROSS THE REGION FOR
CONTINUED CHANCES OF SHOWERS AND THUNDERSTORMS. AT THIS TIME...IT
DOES NOT LOOK LIKE THERE WILL BE A BREAK IN THIS PATTERN UNTIL
NEXT WEEKEND AS THE LONG WAVE TROUGH AND UPPER LEVEL LOW FINALLY
START TO MOVE PAST THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1123 PM CDT SUN MAY 26 2013
A FAIRLY SHARP TRANSITION ZONE FROM VFR CONDITIONS TO IFR
CONDITIONS FROM THE MISSISSIPPI RIVER TO THE SOUTHWEST. EXPECT
THAT CEILINGS WILL GRADUALLY DROP THROUGH THE OVERNIGHT HOURS WITH
IFR MORE LIKELY TO OCCUR AT RST THAN LSE. THE CURRENT CONVECTION
ALONG THE IOWA/MINNESOTA BORDER IS EXPECTED TO STAY SOUTH OF THE
TAF SITES WITH THE BETTER CHANCES FOR RAIN AND/OR THUNDERSTORMS
COMING LATER ON MONDAY. OVERALL...CONFIDENCE IS NOT HIGH IN THE
EXACT TIMING OF WHEN THE ROUNDS OF PRECIPITATION WILL COME
THROUGH...BUT CONDITIONS SHOULD REMAIN MVFR TO IFR THROUGHOUT
REGARDLESS.
&&
.HYDROLOGY...
ISSUED AT 310 PM CDT SUN MAY 26 2013
WITH SEVERAL CONVECTIVE COMPLEXES EXPECTED TO IMPACT THE AREA OVER
THE NEXT FEW DAYS...THE CONCERN FOR FLOODING IS RISING. LAST NIGHTS
RAINS WERE GENERALLY AROUND A HALF INCH OR LESS AND EXPECTING
ABOUT THE SAME AMOUNTS AGAIN TONIGHT. THIS WILL FURTHER SATURATE
THE SOILS AND POSSIBLY SET THE STAGE FOR FLOODING MONDAY NIGHT AND
TUESDAY IF THAT COMPLEX DOES INDEED MOVE ACROSS THE AREA WITH
HEAVY RAIN. RAINFALL AMOUNTS THROUGH TUESDAY NIGHT COULD APPROACH
TWO INCHES WITH LOCALLY HIGHER AMOUNTS EXPECTED WITH
THUNDERSTORMS. SOILS AND RIVERS OVER SOUTHEAST MINNESOTA AND
NORTHEAST IOWA CAN NOT TAKE A LOT OF WATER BEFORE FLOODING WILL
START. WILL ISSUE AN ESF TO ADDRESS THESE CONCERNS. WILL LIKELY
NEED TO ISSUE A FLASH FLOOD WATCH WITH LATER FORECASTS IF IT
CONTINUES TO LOOK LIKE THE AREA WILL GET HIT MONDAY NIGHT AND
TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR IAZ008>011-018-019-
029-030.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS MIAMI FL
1056 AM EDT MON MAY 27 2013
.UPDATE...
THE MORNING SURFACE ANALYSIS SHOWED THE RIDGE AXIS ORIENTED FROM
EAST TO WEST ACROSS NORTHERN FLORIDA AND THE NORTHERN GULF COAST
STATES WITH MODERATE EASTERLY FLOW STREAMING ACROSS OUR LOCAL
AREA. HIGHER MOISTURE HAS BEGUN TO LIFT NORTH ACROSS THE FLORIDA
STRAITS AND INTO THE SOUTHERN PORTIONS OF THE FLORIDA PENINSULA.
THE LATEST OBSERVATIONS AROUND THE LOCAL AREA SHOWED A DECENT
DEWPOINT GRADIENT ACROSS THE AREA WITH MID TO UPPER 60S AROUND THE
LAKE REGION AND LOWER 70S ACROSS THE SOUTHERN PORTION OF THE
PENINSULA. THE MODEL SOUNDING AT MIA REFLECTS THIS INCREASE WITH A
PRECIPITABLE WATER OF 1.42", WHICH WAS AROUND AN INCH YESTERDAY
EVENING. THE LATEST RADAR LOOP SHOWED THE BEST SHOWER COVERAGE
FARTHER SOUTH OVER THE FLORIDA STRAITS WITH MAINLY ISOLATED
COVERAGE OVER OUR SOUTHERN AREAS OR SOUTH OF A LINE FROM FORT
LAUDERDALE TO NAPLES. THE LATEST HRRR HAS INITIALIZED WELL WITH
THIS COVERAGE AND GENERALLY INDICATES THE BEST AFTERNOON COVERAGE
REMAINING OVER THE INTERIOR AND GULF COAST AREAS WITH THE MODERATE
DEEP EASTERLY FLOW IN PLACE. OUTSIDE OF A FEW MINOR TWEAKS TO THE
GRIDDED FORECAST DATABASE...THE PREVIOUS FORECAST REMAINS ON TRACK
WITH NO MAJOR UPDATES NECESSARY AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 648 AM EDT MON MAY 27 2013/
AVIATION...
A STRONG EASTERLY FLOW WILL CONTINUE THROUGH THE TAF PERIOD. THIS
WILL EQUATE TO STRONGER SUSTAINED WINDS DURING THE DAY WITH GUSTS
TO 20 TO 25 KTS IN SOME LOCATIONS. ALSO, THIS WILL BRING INCREASED
MOISTURE AND SCATTERED SHOWERS DEVELOPING MID DAY ACROSS SOUTH
FLORIDA. CURRENT MODELS RUNS SHOW THE MAIN AREA OF SHOWERS SHOULD
BE INLAND AND IN THE FAR SOUTHERN PORTION OF THE AREA. GIVEN THIS,
HAVE REMOVED MENTION OF PRECIPITATION FOR NOW, WITH THE EXCEPTION
OF KTMB WHICH HAS VCSH AFTER 17Z. HOWEVER, THERE DOES REMAIN A
CHANCE FOR SHOWERS ALONG THE ATLANTIC COAST AND THERE IS ALSO A
SLIGHT CHANCE FOR A THUNDERSTORM TO DEVELOP IN THE LATE MORNING
THROUGH THE OVERNIGHT HOURS. HOWEVER, CONFIDENCE IS TOO LOW FOR
EITHER TO MENTION IN TAFS AT THIS TIME.
PREV DISCUSSION... /ISSUED 231 AM EDT MON MAY 27 2013/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
WEAK SYNOPTIC FEATURES WILL AFFECT SOUTH FLORIDA EARLY THIS WEEK WITH
INCREASING MOISTURE AND INSTABILITY. A VERY STRONG SUBSIDENCE CAP
THAT HAS BEEN PERSISTENT THE PAST FEW DAYS WILL RAPIDLY ERODE THIS
MORNING ACCORDING TO FORECAST SOUNDINGS WITH PWAT INCREASING TO NEAR
NORMAL LEVELS FOR LATE MAY. CURRENTLY THIS IS AROUND ONE INCH BUT
WILL BE INCREASING TO AROUND 1.7-1.9 INCHES BY THIS AFTERNOON AND
CONTINUING THROUGH THE END OF THE WEEK. THIS ALREADY SOMEWHAT
EVIDENT FROM RADAR SIGNATURES WITH SCATTERED SHOWER ACTIVITY OVER
THE FLORIDA STRAITS. THERE HAS NOT BEEN ANY LIGHTNING AS YET BUT AS
THE ATMOSPHERE MOISTENS AND DESTABILIZES THERE COULD BE SOME ISOLATED
THUNDER BY THIS AFTERNOON ESPECIALLY OVER THE SOUTHERN PORTIONS. IN
ADDITION, BOTH THE GFS AND ECMWF ARE SHOWING A WEAK MID LEVEL LOW
DEVELOPING OFF THE SOUTHEAST COAST OF THE PENINSULA BY LATE TUESDAY
FURTHER DESTABILIZING CONDITIONS.
AT THE SURFACE, STRONG HIGH PRESSURE OVER THE SOUTHEAST STATES WILL
CONTINUE WHICH WILL RESULT IN A HIGH RISK OF RIP CURRENTS AT ALL OF
THE EAST COAST BEACHES. THIS WILL ALSO MAINTAIN AN INCREASING
SOUTHEAST FLOW WHILE AT THE SAME TIME DEEPENING SO THE STEERING FLOW
FOR CONVECTIVE ACTIVITY WILL BE FROM THE E-SE.
LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)...
THE WEAK MID LEVEL TROUGH WILL MOVE LITTLE THROUGH THE END OF THE
WEEK KEEPING THE CHANCES FOR SHOWERS AND THUNDERSTORMS ELEVATED.
SURFACE HIGH PRESSURE WILL ALSO CONTINUE TO STRETCH FROM THE
ATLANTIC TO THE SOUTHEAST STATES AND THIS WILL RETAIN HIGH CHANCES
FOR RIP CURRENTS AT THE ATLANTIC BEACHES THROUGHOUT THE EXTENDED
PERIOD.
MARINE...
PERSISTENT EASTERLY WIND OF 15 TO 20 KNOTS AND OCCASIONALLY HIGHER
WILL KEEP SEAS ELEVATED THROUGH THE WEEK.
FIRE WEATHER...
DEEP TROPICAL MOISTURE WILL RETURN TO SOUTH FLORIDA TODAY AND
CONTINUE THROUGH THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 75 83 74 / 20 10 30 20
FORT LAUDERDALE 82 76 84 77 / 20 20 40 30
MIAMI 85 75 85 76 / 20 30 50 40
NAPLES 88 71 89 72 / 20 20 60 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK THROUGH FRIDAY AFTERNOON FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS POCATELLO ID
905 AM MDT MON MAY 27 2013
.UPDATE...WV SAT IMAGERY SHOWS SHORTWAVE CIRCULATION EXITING
EASTERN IDAHO INTO SOUTHERN MONTANA THIS MORNING. RADAR SHOWS WEAK
CONVECTION ASSOCIATED WITH THIS FEATURE...BUT ALREADY PAST EASTERN
IDAHO. NEXT PACIFIC TROUGH ALREADY LINED UP ALONG COAST AND
PUSHING MOISTURE AND PRECIPITATION INTO THE PACNW STATES. GFS AND
NAM WITH SUPPORT FROM THE HRRR CONTINUE TO ADVERTISE WEAK
CONVECTION REMAINING ALONG THE NORTHEAST PORTIONS OF THE REGION
TODAY IN WAKE OF DEPARTING SHORTWAVE. NEGATIVE TILT TROUGH PUSHES
WELL INTO OREGON BY EARLY AFTERNOON...BEGINNING TO SPREAD LARGE
PRECIP SHIELD WITH EMBEDDED WEAK CONVECTION INTO WESTERN IDAHO.
TIMING WILL BE CLOSE BUT CANNOT RULE OUT WEAK PRECIPITATION MOVING
INTO WESTERN EDGES OF FORECAST AREA BY 00Z. BELIEVE BULK OF THE
PRECIPITATION WILL ARRIVE LATER TONIGHT. CURRENT FCST SHOWS TIMING
OF THESE FEATURES QUITE WELL AND THUS ANTICIPATE NO UPDATES TODAY. DMH
&&
.PREV DISCUSSION... /ISSUED 237 AM MDT MON MAY 27 2013/
DISCUSSION...UPPER TROUGH EVIDENT ON WV IMAGERY OVER THE ID/MT
BORDER AND EXITING THE AREA THIS MORNING. THIS SHOULD RESULT IN
FAIRLY DRY WEATHER OVER SOUTHEAST IDAHO TODAY. FURTHER UPSTREAM...A
SECOND SHORTWAVE IS POISED TO IMPACT THE PACIFIC NORTHWEST. THE
GREATEST FORCING OVER IDAHO WITH THIS NEXT SYSTEM WILL BE TUESDAY
MORNING AND AFTERNOON AS THE TROUGH MOVES EASTWARD AND DIPS
SOUTHWARD A BIT. PROJECTED PW VALUES ARE AROUND 0.5 TO 0.75
INCHES...WHICH IS ABOVE NORMAL FOR THIS TIME OF YEAR. HAVE NUDGED
UP POPS AND QPF FROM PREVIOUS FORECAST FOR TUESDAY AND TUESDAY
NIGHT. UPPER TROUGH THEN SHIFTS EASTWARD TUESDAY NIGHT ALLOWING
WEAK RIDGING TO MOVE ACROSS SOUTHERN IDAHO. THE UPPER JET STAYS
SOUTH OF OUR BORDER THROUGH MID-WEEK...KEEPING US IN THE
RELATIVELY COOLER AIR UNTIL THE WEEKEND. MODELS DEVELOP UPPER
RIDGE OVER THE AREA FOR NEXT WEEKEND AND SHOULD RESULT IN DRY
WEATHER AND WARMER TEMPERATURES. HINSBERGER &&
AVIATION...A LOW PRESSURE TROUGH WAS NOTED LIFTING NE THROUGH THE
AREA EARLY THIS MORNING WHILE A STRONGER PACIFIC WAVE WAS SHEARING
SE INTO THE OREGON/WASHINGTON COASTAL WATERS. MODELS SUGGEST THAT
THE INITIAL WAVE WILL CLEAR THE REGION THIS MORNING WITH FAIRLY DRY
CONDITIONS PREVAILING AT THE TERMINAL SITES THROUGHOUT THE DAY.
INCREASING MID AND UPPER LEVEL MOISTURE IS EXPECTED TO OVERSPREAD
THE REGION THIS EVENING AS THE NEXT UPSTREAM SYSTEM ADVANCES INTO
OREGON. LOWER CLOUDS AND SCATTERED SHOWERS WILL SPREAD ACROSS SE
IDAHO LATE TONIGHT/TUESDAY MORNING AS THE TROUGH SPREADS INTO SRN
IDAHO. MODEL CROSS SECTIONS SUGGEST AT LEAST MVFR CIGS AT KBYI AND
KSUN. HUSTON
FIRE WEATHER...AN UPPER LEVEL TROUGH WAS NOTED LIFTING NORTHEAST
INTO SOUTHWEST MONTANA EARLY THIS MORNING WHILE A DECENT PACIFIC
WAVE WAS OBSERVED SHEARING SOUTHEAST INTO THE OREGON/WASHINGTON
COASTAL WATERS. CONDITIONS ARE EXPECTED TO BE FAIRLY DRY TODAY
BEHIND THE EXITING WAVE WHILE INCREASING CLOUDS AND SHOWERS SPREAD
INTO THE AREA TONIGHT AS THE NEXT UPSTREAM WAVE MOVES INTO
SOUTHERN IDAHO. WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS ARE
EXPECTED TUESDAY AND TUESDAY NIGHT AS THE UPPER TROUGH SHIFTS SLOWLY
THROUGH THE REGION. A SECONDARY DISTURBANCE FOLLOWS
WEDNESDAY...WHICH SHOULD SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS
THROUGHOUT THE DAY...LINGERING INTO THURSDAY. IMPROVING CONDITIONS
ARE ANTICIPATED FRIDAY/SATURDAY AS A RIDGE OF HIGH PRESSURE MIGRATES
THROUGH THE REGION. HUSTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1101 AM CDT MON MAY 27 2013
.DISCUSSION...
1055 AM CDT
EARLY CHANGES MADE TO GOING FORECAST FOR THE REST OF TODAY INCLUDE
CUTTING DOWN POPS FOR MUCH OF THE NORTHERN FORECAST AREA THROUGH
AT LEAST EARLY AFTERNOON. ALSO ADJUSTED TEMPERATURES DOWN THE MOST
OVER THIS AREA AS THE COOL MEMORIAL DAY WEEKEND CONTINUES RIGHT
THROUGH THE HOLIDAY.
THE BROAD WARM AIR ADVECTION PATTERN CONTINUES OVER THE AREA
NORTH OF THE SURFACE STATIONARY BOUNDARY WHICH IS DRAPED ACROSS
FAR SOUTHERN IA INTO THE MID-SECTION OF IL. A REMNANT MCV AS SEEN
ON VISIBLE SATELLITE AND RADAR IMAGERY IS MOVING NORTHEAST INTO
NORTHWEST IN LATE THIS MORNING AND IS STARVED OF INSTABILITY...SO
JUST SOME SCATTERED ARCS OF SHOWERS HAVE BEEN SEEN WITH THIS.
SUPPRESSION WEST OF THIS HAS BEEN KEEPING MUCH OF THE NORTHERN HALF
OF THE CWA MAINLY DRY THIS MORNING AND LIMITING THE EASTWARD
PROGRESSION OF THE NEXT AREA OF SHOWERS AND CONVECTION FROM IA.
OBSERVATIONAL TRENDS SUPPORT HIGH RES GUIDANCE SOLUTIONS THAT TAKE
THE MCS IN NORTHEAST MO EASTWARD ACROSS CENTRAL/SOUTH CENTRAL IL
WHICH SHOULD KEEP THE SURFACE FRONT TO THE SOUTH. SO ALL IN ALL
THERE MAY BE LITTLE IN THE WAY OF PRECIP THROUGH MID-AFTERNOON
BESIDES SOME WIDELY SCATTERED SHOWERS OR SPRINKLES. BY LATE
AFTERNOON...THE INFLUENCE OF THE SHORT WAVE IN IA AND MORE FOCUSED
WARM AIR ADVECTION IS FORECAST TO MOVE OVER THE AREA. HOWEVER
LIMITED MOISTURE TRANSPORT RETURN PRIOR TO SUNSET MAY STILL KEEP
MUCH OF THE SHOWER COVERAGE SCATTERED AND MAINLY THUNDER-FREE.
THE EAST WIND NORTH OF THE BOUNDARY ALONG WITH LOW
CIGS...PRIMARILY ALONG AND NORTH OF THE I-88 CORRIDOR...WILL KEEP
TEMPERATURES FROM RECOVERING MUCH. HAVE LOWERED MAX TEMPS QUITE A
BIT TOWARD THE RAP SOLUTION. SOME LOCATIONS ARE LIKELY ONLY TO
CLIMB A COUPLE DEGREES MORE...ESPECIALLY IN LAKE COUNTY IL.
MTF
&&
.PREV DISCUSSION...
318 AM CDT
THE UNSETTLED WEATHER WILL CONTINUE FOR THE NEXT SEVERAL
DAYS...WHICH WILL BE MARKED BY PERIODS OF SHOWERS AND THUNDERSTORMS
AS WELL AS THE RETURN OF MORE SUMMER-LIKE TEMPERATURES.
FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY MORNING
HOURS...THE FOCUS WILL REMAIN ON THE ONGOING SHOWERS AND
THUNDERSTORMS OVER THE SOUTHERN PORTIONS OF THE CWA. AS OF 3AM
CDT...MUCH OF THE PCPN HAS MOVED OUT OF LIVINGSTON AND FORD COUNTIES
AND IS DIMINISHING OVER IROQUOIS COUNTY. BENTON/JASPER/NEWTON
COUNTIES SHOULD SEE MODERATE TO OCNLY HEAVY PCPN WITH EMBEDDED
THUNDER FOR A FEW MORE HOURS...BUT SHOULD BE WINDING DOWN BY
DAYBREAK. THIS LINE OF HEAVY RAIN IS ALONG THE ELEVATED WARM
FRONT...WITH THE SFC WARM FRONT STILL WELL TO THE SOUTH...FROM NRN
MO TO SRN IL/IN. LATEST RADAR ESTIMATES INDICATE THAT SWATH OF 2-4
INCHES HAS FALLEN GENERALLY ALONG A LINE FROM...PONTIAC TO WATSEKA.
THESE PCPN SHOULD EXTEND EAST TOWARD REMINGTON BEFORE ALL IS SAID
AND DONE. RADAR ESTIMATES AS HIGH AS 5 INCHES ARE INDICATED
IN NORTHWESTERN LIVINGSTON COUNTY...NEAR CORNELL AND LONG POINT.
UNFORTUNATELY...THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY IN THE
MEMORIAL DAY FORECAST AS THE AREA MAY YET BE IMPACTED BY BOUNDARIES
SET OUT BY THE STRONG CONVECTIVE CLUSTERS OVER THE MISSOURI VALLEY.
THE GENERAL TREND FOR THE DAY WILL START OUT WITH SOME SCT SHOWERS
OVER THE NORTHERN PORTIONS OF THE CWA...TOWARD THE WISCONSIN BORDER
AND SOME LINGERING RAIN TO THE SOUTH. THERE WILL LIKELY BE AT LEAST
SOME PERIODS OF DRY WEATHER OVER THE AREA...BUT WITH THE FREQUENTLY
DISCUSSED WARM FRONT SLOWLY MAKING ITS WAY NORTHWARD AND A SERIES OF
SHORT WAVES RIPPLING THROUGH THE DEAMPLIFYING MIDLEVEL FLOW OVER THE
AREA...PERIODS OF SHOWERS AND THUNDERSTORMS ARE LIKELY THROUGH THE
DAY AND INTO TONIGHT. WHILE THE CHANCES FOR SEVERE WEATHER ARE
LOW...ANY THUNDERSTORMS THAT DO FORM CAN MAKE OUTDOOR ACTIVITIES
HAZARDOUS. ALSO...THE ENVIRONMENT HAS BEEN PRIMED WITH INCREASING
AMOUNTS OF DEEP LAYER MOISTURE...SO LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE AS WELL. THE ONE POSITIVE NOTE THAT CAN BE MENTIONED FOR
TODAY IS THE TEMPERATURE TREND. WHILE SKIES WILL LIKELY BE CLOUDY
FOR MUCH OF THE DAY...GRADUALLY BUILDING HEIGHTS ALOFT WILL ALLOW
FOR TEMPERATURES A LITTLE HIGHER THAN RECENT DAYS...WITH HIGHS
RANGING FROM AROUND 60F ALONG THE NORTHERN ILLINOIS SHORE OF LAKE
MICHIGAN...TO THE MIDDLE 70S OVER THE SOUTHWESTERN PORTIONS OF THE
CWA...INCLUDING THE PONTIAC METRO AREA.
THE WARM FRONT IS EXPECTED TO LIFT NWD THROUGH NRN IL/IN OVERNIGHT
TONIGHT AND THEN CONTINUE NWD INTO WISCONSIN ON TUESDAY. THIS WILL
INITIATE THE EXPECTED WARMING TREND IN EARNEST...WITH SOUTHWESTERLY
FLOW SETTING UP IN THE LOWER LEVELS...DRAWING WARMER/MOISTER AIR
INTO THE REGION...AS UPPER RIDGING BEGINS TO BUILD FROM THE SERN
CONUS THROUGH THE UPPER MISSISSIPPI VALLEY. THIS COMBINATION WILL
BRING TEMPERATURES WELL INTO THE 80S...BUT WILL ALSO BRING DEWPOINTS
IN THE MIDDLE TO UPPER 60S. THE TEMPERATURE AND DEWPOINT TREND WILL
BE ON THE INCREASE THROUGH WEDNESDAY AND THURSDAY AS WELL...WITH
DEWPOINTS APPROACHING 70F OVER MUCH OF THE AREA AND TEMPERATURES
REACHING INTO THE MIDDLE 80S...WITH SOME AREAS POSSIBLY REACHING THE
UPPER 80S. THE STRONG SOUTHWESTERLY FLOW WILL OVERCOME ANY LAKE
INFLUENCE AND THE WARMER CONDITIONS WILL BE ABLE TO PENETRATE UP TO
THE LAKE FRONT. WITH UPPER TROUGHING DEVELOPING OVER THE WRN
CONUS...SWLY FLOW WILL SET UP ALOFT AS WELL...WITH THE MODELS
ADVERTISING A SERIES OF IMPULSES RIDING NEWD UP THE BACKSIDE OF THE
RIDGE. WHILE THE MODELS ARE...TYPICALLY...INDICATING TIMING AND
STRENGTH DIFFERENCES TO THE INDIVIDUAL IMPULSES...THE SIGNAL IS
CLEAR THAT THESE WILL BRING ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. WITH DEEP LAYER MOISTURE STILL ON THE
INCREASE...WITH PWATS EXPECTED TO BE 1.5-2.0 INCHES THROUGH THE
PERIOD...LOCALLY HEAVY RAINFALL WILL BE A POSSIBILITY.
THE WARM...HUMID...UNSETTLED WEATHER WILL CONTINUE THROUGH FRIDAY.
BY SATURDAY...THE DEEPENING UPPER TROUGH WILL CLOSE OFF INTO A
LARGE...SPRAWLING UPPER LOW AND EVENTUALLY PUSH A COLD FRONT THROUGH
THE REGION. THE LATEST RUNS OF THE GFS/ECMWF ARE INDICATING THAT
THIS NEXT COLD FRONT SHOULD PUSH THROUGH THE AREA ON SATURDAY.
SINCE THIS IS A MODIFIED PACIFIC SYSTEM RATHER THAN A POLAR SYSTEM
DROPPING OUT OF CANADA...TEMPERATURES ARE ONLY EXPECTED TO DROP BACK
INTO THE 70S FOR NEXT WEEKEND.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* IFR CIGS PERSIST...PSBLY SOME IMPROVEMENT LATER THIS MORNING
THRU EARLY THIS AFTN TO LOW END MVFR.
* EAST/SOUTHEAST WINDS 10-14KT WITH OCCASIONAL GUSTS IN THE
16-20KT RANGE.
* PATCHY DZ WILL END...BEST CHC FOR SHRA/TSRA ARND 00Z THRU
OVERNIGHT HOURS.
BEACHLER
//DISCUSSION...UPDATED 12Z...
TOUGH FORECAST CONTINUES WITH CIG TRENDS AND SHRA/TSRA
CHANCES/TIMING THE MAIN CHALLENGES. IFR CIGS DEVELOPED A FEW HOURS
AGO IN THE WAKE OF A BAND OF SHRA/TSRA THAT PASSED MAINLY TO THE
SOUTH OF THE TERMINALS. WEAK LOW PRESSURE IS JUST NORTH OF STL
WITH A WARM FRONTAL BOUNDARY STRETCHING TO ITS EAST. THIS FRONT
LOOKS TO REMAIN SOUTH OF THE AREA INTO THIS EVENING THANKS TO THE
PASSAGE OF SHRA/TSRA SOUTH OF THE TERMINALS OVERNIGHT. THIS
COMPLICATES THE FORECAST BECAUSE WITH THE FRONT TO THE SOUTH IFR
CIGS MAY BE HELD IN PLACE FOR AN EXTENDED PERIOD OF TIME. RIGHT
NOW EXPECT IFR THROUGH MID TO LATE MORNING BUT AM THINKING THERE
WILL BE SOME IMPROVEMENT THIS AFTERNOON AS WARMING OCCURS AND
CURRENT POCKETS OF LIGHT RAIN EXIT THE AREA. CONFIDENCE IN HOW
QUICKLY IMPROVEMENT OCCURS IS LOW BUT DO NOT SEE IMPROVEMENT ANY
EARLIER THAN IN THE TAF. PROVIDED IMPROVEMENT DOES OCCUR...IT
WOULD LIKELY ONLY BE TO LOW END MVFR WITH SLOW IMPROVEMENT FROM
THERE.
LIGHT RAIN WILL CONTINUE TO EXIT TO THE EAST OVER THE NEXT FEW
HOURS. BEYOND THAT...A BAND OF RAIN DOWN NEAR PIA WILL LIKELY PASS
SOUTH OF THE TERMINALS THIS MORNING. A LARGE COMPLEX OF WEAKENING
SHRA/TSRA IS MOVING EAST ACROSS CENTRAL IOWA WITH A WELL DEFINED
CIRCULATION BEYOND IT. THIS CIRCULATION WILL LIKELY CONTINUE EAST
AND REACH THE AREA EARLY THIS AFTERNOON. THIS COULD SERVE SEVERAL
FUNCTIONS...IT MAY MAINTAIN SOME PRECIP ACTIVITY AND BRING IT
ACROSS THE AREA OR IT COULD BE A FOCUS FOR NEW DEVELOPMENT. GIVEN
THAT THE WARM FRONT IS WELL SOUTH AND INSTABILITY IS ALSO A WAYS
AWAY...AND THERE IS ABUNDANT CLOUD COVER NEW DEVELOPMENT SEEMS
UNLIKELY. BASED ON RADAR TRENDS AND OTHER PARAMETERS THERE MAY BE
VERY LITTLE LEFT OF THE CURRENT PRECIP SHIELD. PERHAPS THE MOST
LIKELY EFFECT WILL BE TO DISTURB THE SURFACE WINDS AS IT COMES
ACROSS. THERE IS STILL SOME CHANCE THAT THERE COULD BE SHRA/TSRA
LATER THIS AFTERNOON AND THIS EVENING SO WILL MAINTAIN A PROB30
FOR NOW BUT THERE MAY BE LITTLE ACTIVITY IN THE TERMINAL AREA.
SOME NEW GUIDANCE DELAYS ANY ORGANIZED ACTIVITY UNTIL TUESDAY
MORNING WHICH GIVEN THE FRONTAL BOUNDARY LIKELY REMAINING SOUTH
TODAY MAKES REASONABLE SENSE...THOUGH GUIDANCE HAS BEEN HANDLING
PRECIP TRENDS RATHER POORLY IN THIS PATTERN.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN IFR CIGS PERSISTING...MEDIUM CONFIDENCE IN
TIMING OF LOW END MVFR CIGS DEVELOPING.
* HIGH CONFIDENCE IN WIND FORECAST.
* LOW CONFIDENCE IN OVERALL SHRA/TSRA TIMING...MEDIUM CONFIDENCE
THAT THE BETTER CHANCES WOULD NOT BE UNTIL LATER TODAY AND
BEYOND.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH SATURDAY...MAINLY VFR...PERIODIC SHRA/TSRA
ESPECIALLY TUESDAY NIGHT AND FRIDAY. BREEZY SOUTH WINDS WEDNESDAY
THROUGH SATURDAY.
MDB
&&
.MARINE...
314 AM CDT
HIGH PRESSURE IS MOVING OFF TO THE EAST AND IS NOW POSITIONED FROM
HUDSON BAY DOWN ACROSS LAKE ERIE AND TO THE MID ATLANTIC COAST. LOW
PRESSURE CONTINUES TO DEVELOP ACROSS THE HIGH PLAINS WITH ONE LOW
CENTER OVER SOUTHEAST COLORADO AND FAR WESTERN KANSAS. THE PRESSURE
GRADIENT WILL TIGHTEN TODAY WITH LAKE MICHIGAN BETWEEN THESE TWO
SYSTEMS. SOUTHEAST WINDS WILL INCREASE AS A RESULT THEN TURN SOUTH
AND SOUTHWEST TUESDAY. SOUTH TO SOUTHWEST WINDS WILL THEN CONTINUE
THROUGH THE REST OF THE WEEK AS THE HIGH REMAINS TO THE EAST AND
SEVERAL LOW PRESSURE SYSTEMS MOVE NORTHWEST OF THE LAKE. WIND SPEEDS
WILL GENERALLY BE IN THE 15 TO 25 KT RANGE WITH PERIODIC INCREASES
TO THE HIGHER END OF THAT RANGE...WITH 30 KT POSSIBLE AT TIMES...BUT
THERE WILL ALSO BE PERIODS IN THE 10 TO 20 OR 15-20 KT RANGE. WARMER
AIR MOVING IN WILL HELP LIMIT THE GUSTS...ESPECIALLY OVER THE OPEN
WATERS BUT SOME OF THE TALLER PILOT HOUSES AND SHORE BASED OB SITES
COULD SEE GUSTS JUST ABOVE 30 KT AT TIMES AS THEY WOULD BE ABOVE THE
STABLE MARINE LAYER. NEARSHORE AREAS WILL FLIRT WITH SMALL CRAFT
ADVISORY CRITERIA AT TIMES AS WELL BUT AT THIS POINT WILL KEEP WINDS
AT 15 TO 25 KT WITH PERIODS OF 20-25 KT LOOKING BRIEF AND DIFFICULT
TO PIN DOWN.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1032 AM CDT MON MAY 27 2013
.DISCUSSION...
ISSUED 1030 AM CDT MON MAY 27 2013
WELL DEFINED MCV ON RADAR CENTERED JUST EAST OF BLOOMINGTON...
WITH LINGERING SHOWERS DIMINISHING AHEAD OF IT. MCS TO OUR WEST
CONTINUES TO DROP SOUTHEAST...WITH A COUPLE OF WAKE LOWS NORTH OF
IT ACROSS IOWA. THE CORE OF THE LINE OF STORMS IS PROJECTED TO
REMAIN IN MISSOURI. HAVE SEEN AN OVERALL EASTWARD PUSH OF THE RAIN
WHICH WAS NEAR QUINCY AT 1030 AM...AND THE HRRR MODEL...WHICH HAS
HANDLED THIS MCS PRETTY WELL...BRINGS THE REMNANTS THROUGH THE
SOUTHWEST HALF OF THE CWA EARLY AFTERNOON AND REACHING THE EASTERN
CWA LATE. HAVE SEEN TEMPS ACROSS THE SOUTHEAST SURGING TOWARD 80
DEGREES WITH SOME SUNSHINE FILTERING THROUGH...AND WILL NEED TO
MONITOR THE INSTABILITY HERE AS THE STORMS ARRIVE FOR ANY
ENHANCEMENT.
GEELHART
&&
.AVIATION...
ISSUED 700 AM CDT MON MAY 27 2013
MULTIPLE CONVECTIVE COMPLEXES WITH HEAVY RAINFALL AFFECTED
CENTRAL IL LAST NIGHT. THE LAST ONE WAS JUST MOVING ACROSS PIA/BMI
AT 12Z. THAT SYSTEM MAY CLIP SPI/DEC/CMI WITH A FEW SHOWERS...BUT
THUNDER SHOULD REMAIN NORTH OF THE SOUTHERN TERMINALS EARLY THIS
MORNING. SATELLITE AND RADAR IMAGES CONFIRM THE NEXT COMPLEX WILL
ARRIVE IN OUR AREA FROM THE WEST TOWARD MID-DAY TODAY...WITH
ANOTHER ROUND OF SHOWERS AND STORMS. SOME OF THE STORMS MAY
CONTAIN STRONG WINDS AND HAIL...MAINLY FARTHER WEST FOR PIA AND
SPI.
SOME MVFR FOG HAS BEEN LINGERING BEHIND THE MOST RECENT LINE OF
SHOWERS AND STORMS...SO WE INDICATED AT LEAST A FEW HOURS OF MVFR
AT PIA AND BMI. IFR CONDITIONS ARE LIKELY DURING THE STRONGER
STORMS...DUE TO A COMBINATION OF LOW VIS AND CIGS.
A WARM FRONT LIFTING NORTH TODAY SHOULD MOVE NORTH OF ALL TAF
SITES BY AFTERNOON...HELPING TO SHIFT WINDS TO THE SOUTHEAST
ACROSS THE BOARD. PREVAILING WIND SPEEDS WILL CLIMB INTO THE
12-15KT RANGE WITH GUSTS AROUND 20 KT AT TIMES.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 340 AM CDT MON MAY 27 2013
SHORT TERM...TODAY THROUGH TUESDAY
WARM FRONT AT 08Z EXTENDED FROM THE IA/MO BORDER SOUTHEAST TO NEAR
MOUNT VERNON. FRONT HAS BECOME MORE DIFFICULT TO DEFINE DUE TO
SEVERAL RECENT CONVECTIVE COMPLEXES AND RESULTING OUTFLOW. THESE
COMPLEXES HAVE BEEN FED BY STRONG 850-700 MB WARM/MOIST
ADVECTION...AND LATEST VWP/S OVER MO INDICATE 30-40 KT FLOW AT
THESE LEVELS SUPPLYING INSTABILITY INTO THE LOW AND MID LEVEL
BOUNDARIES. THIS ACTIVITY SHOULD FESTER INTO THE MORNING BEFORE
THE LLJ VEERS AND WEAKENS BY 15Z. NEXT LARGER UPSTREAM MCS OVER
WESTERN IA IS FORECAST TO DIMINISH BY HI-RES MODELS BY TIME IT
REACHES THE MS RIVER LATER THIS MORNING...BUT THIS COULD SEND
ANOTHER OUTFLOW BOUNDARY INTO THE CWA THIS AFTERNOON. IF CLEARING
OCCURS AFTER THIS MORNINGS STORMS...STRONG TO SEVERE T-STORMS WILL
BE POSSIBLE THIS AFTERNOON DUE TO SHEAR NEARBY SYNOPTIC AND
MESOSCALE BOUNDARIES AND ENHANCED INSTABILITY. SPC HAS EXPANDED
DAY 1 SLIGHT RISK TO INCLUDE THE WESTERN CWA. PRECIPITABLE WATER
REMAINS HIGH AT 1.5-1.7 INCHES SO PERIODS OF HEAVY RAIN POSSIBLE
ONCE AGAIN...AND WITH SATURATED GROUND FROM RECENT RAINS 1-HR FFG
NUMBERS ARE UNDER 1.5 INCHES FOR MUCH OF THE WESTERN HALF OF THE
CWA. WILL EXTEND CURRENT FLASH FLOOD WATCH THROUGH 12Z TUE AND
EXPAND TO INCLUDE ALL COUNTIES ALONG AND WEST OF A MCLEAN TO
SHELBY LINE.
THE WARM FRONT WILL GRADUALLY LIFT NORTH OF THE CWA ON TUESDAY BUT
THIS PROCESS MAY BE IMPEDED BY CONVECTIVE OUTFLOW. RECENT MODEL
RUNS NOW SHOW MORE STORMS WILL BE POSSIBLE TUESDAY...AND HAVE
HIGHEST CHANCES IN THE NORTHERN CWA CLOSER TO THE BOUNDARY.
FORECAST SOUNDINGS LOOK MORE IMPRESSIVE FOR SEVERE STORMS AS THE
BOUNDARY LAYER WILL BE MORE UNSTABLE THAN TODAY AND DEEP LAYER
SHEAR INCREASES.
LONG TERM...WEDNESDAY THROUGH SUNDAY
BY WEDNESDAY WE WILL BE FIRMLY IN THE WARM SECTOR WITH THE FRONT
LIFTING WELL NORTH. BRISK SOUTHERLY WINDS WILL PRODUCE WIDESPREAD
MID 80S HIGHS.
AFTER A BRIEF BREAK FROM THE ACTIVE PATTERN...AN UPPER LOW MOVING
INTO THE PLAINS WILL BRING INCREASING STORM CHANCES FROM THE WEST
FOR THURSDAY AND FRIDAY. 00Z MODEL RUNS ARE MORE PROGRESSIVE WITH
THIS SYSTEM THAN 24 HOURS AGO...AND HIGHER CHANCE POPS FOR THE
WESTERN HALF OF THE CWA FROM THE MODEL CONSENSUS FOR THU/FRI LOOK
GOOD. THE FAR EAST AND SOUTHEAST CWA MAY STAY DRY UNTIL LATER
FRIDAY AND INTO SATURDAY WHEN THE COLD FRONT IS FORECAST TO SHIFT
INTO THE STATE. THE SYNOPTIC SETUP FAVORS MORE HEAVY RAIN AND
POSSIBLE SEVERE WEATHER WITH THIS SYSTEM. TEMPS SHOULD COOL BACK
TO NORMAL IN THE POST-FRONTAL AIRMASS ON SUNDAY.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ILZ027>031-036>038-
040>043-047>053-061.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
936 AM MDT MON MAY 27 2013
.UPDATE...
ISSUED AT 925 AM MDT MON MAY 27 2013
MAIN CHANGES TO THE CURRENT FORECAST FOR TODAY WERE TO INCREASE
THE WINDS TODAY AND TO ADD A MENTION OF FOG FOR RED WILLOW COUNTY
UNTIL EARLY AFTERNOON.
LATEST OBSERVATIONS PLACE A SURFACE LOW IN THE NESS CITY AREA.
NORTH OF THE SURFACE LOW AN AXIS OF HIGHER DEW POINTS AND MID
LEVEL LIFT HAVE CONTRIBUTED TO A BAND OF LOW STRATUS. FURTHER
NORTH OVER RED WILLOW COUNTY AND VICINITY A COLD FRONT IS
BEGINNING TO MOVE INTO THE TRI-STATE AREA. AS THE COOLER AIR MOVES
IN THE BOUNDARY LAYER HAS BECOME SATURATED CAUSING VISIBILITIES TO
DROP TO HALF A MILE AT TIMES. THE FOG SHOULD LIFT NOT LONG INTO
THE EARLY AFTERNOON AS TEMPERATURES WARM WITH THE AFTERNOON
HEATING. AM THINKING THE COOLER AIR SHOULD NOT MOVE ANY FURTHER
SOUTH THAN HIGHWAY 24 AND NO FURTHER WEST THAN THE CO/KS BORDER
TODAY.
WINDS HAVE BEEN SOMEWHAT TRICKY AS NO GUIDANCE IS REALLY CATCHING
WHAT IS GOING ON. IN GENERAL THE WINDS WILL REMAIN BREEZY DUE TO A
TIGHT PRESSURE GRADIENT OVER THE EASTERN 2/3S OF THE AREA. THE
WINDS MAY BACK OFF SOME DURING THE MID AFTERNOON BEFORE
STRENGTHENING AGAIN AS A SURFACE HIGH PRESSURE MOVES INTO THE AREA
FROM THE WEST CAUSING THE PRESSURE GRADIENT TO TIGHTEN.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 435 AM MDT MON MAY 27 2013
MAIN FORECAST PROBLEM WILL BE CONTINUED CHANCES FOR THUNDERSTORMS.
SATELLITE SHOWING THE FLOW HAS DEAMPLIFIED OVER THE PACIFIC AND THE
PACIFIC NORTHWEST. WHAT USED TO BE A COMPLEX UPPER LOW OVER THE
PACIFIC NORTHWEST HAS NOW BEEN SPLIT APART WITH THE SOUTHERN
PORTION COMING EAST NOW AS AN OPEN SHORTWAVE TROUGH. WITH WEAKENING
MID LEVEL RIDGE TO OUR EAST...THIS LEAVES OUR AREA IN A SOUTHWEST
FLOW ALOFT WITH NUMEROUS SMALL SCALE SHORTWAVE TROUGHS EMBEDDED
WITHIN IT. A COMPLEX SURFACE PATTERN IS OVER THE AREA WITH A
RETREATING WARM FRONT OVER THE NORTHWEST PORTION OF THE AREA WHICH
IS EXTENDING FROM THE SURFACE LOW OVER SOUTHEAST COLORADO. THE DRY
LINE IS JUST TO THE EAST OF THAT. A SHALLOWER/COOLER AIR MASS IS TO
THE NORTH OF THIS WARM FRONT.
MODELS INITIALIZED WELL AT JET LEVEL. MODELS DID FINE AT MID LEVELS
WITH THE GFS...CANADIAN AND UKMET DOING THE BEST ON THE HEIGHTS AND
FEATURES. THE MODELS WERE WARM AT 700 MB WITH THE CANADIAN DOING
THE BEST. MODELS HAVING HARD TIME WITH THE SURFACE PATTERN. MAJORITY
HAVE THE SURFACE LOW THAT STARTS OUT OVER SOUTHEAST COLORADO TOO
FAR EAST BY 06Z. THE ECMWF AND RUC DEFINITELY IS HEAD AND SHOULDERS
ABOVE THE REST. WOULD ALSO HAVE TO GIVE THE ECMWF A SLIGHT EDGE ON
THE THERMAL FIELD AS WELL.
BASED ON RECENT POOR MODEL PERFORMANCE...COMPLEX NATURE OF SURFACE
PATTERN...AND CONVECTIVE FEEDBACK ISSUES WITH THE MODELS...THIS IS
A LOW CONFIDENCE FORECAST. THIS COMPOUNDED BY THE FACT THAT CERTAIN
NEIGHBORING OFFICES ARE MAKING BIG CHANGES WITHOUT TALKING.
TODAY/TONIGHT...SOME CONVECTION HAS DEVELOPED NORTH OF THE
RETREATING WARM FRONT WITH OTHER CONVECTION ON THE WESTWARD
EXTENSION OF THIS WEAVING/COMPLEX FRONTAL POSITION. RECENT TRENDS
AND MESOSCALE MODEL OUTPUT INDICATE ALL THIS PRECIPITATION WILL STAY
TO THE NORTH OF THE AREA. BUT WILL CONTINUE TO MONITOR.
LEFT FRONT QUADRANT OF THE JET STARTS OVER THE SOUTHERN PORTION OF
THE AREA AT 12Z AND IS AFFECTING/OVER THE NORTHERN PORTION OF THE
AREA BY THE END OF THE DAY. THIS FEATURE THEN MOVES SOUTHEAST DURING
THE NIGHT. RIGHT NOW THE MODELS ARE HAVING EXTREME DIFFICULTIES IN
RESOLVING BOUNDARY POSITION AND TIMING. MODELS TAKE A COMPACT 700
MB LOW OVER COLORADO AND MOVE IN TO THE NORTH OF THE AREA BY EARLY
AFTERNOON. DEPENDING ON WHICH MODEL OUTPUT YOU USE...SOME
WRAPAROUND OCCURS WITH THIS. CONSIDERING THE TRAJECTORY...AM NOT
BUYING IT. WITH THE JET...SURFACE BOUNDARY POSITION AND THIS
SYSTEM...BEST CHANCES FOR PRECIPITATION SHOULD BE IN THE NORTH AND
END BY LATE IN THE AFTERNOON. ADDITIONAL SHORTWAVE ENERGY MOVES
THROUGH DURING THE NIGHT BUT MOISTURE HAS BEEN SCOURED OUT. ENDED
PRECIPITATION BY LATE IN THE NIGHT AND THAT MAY BE TOO LATE.
WILL GET SOME FOG AND STRATUS IN THE NORTHWEST PORTION OF THE AREA
AS THE FRONT MOVES THROUGH. WITH AN EARLIER FRONTAL ARRIVAL
EXPECTED...HIGH TEMPERATURES SHOULD BE COOLER BUT AM NOT CERTAIN
ABOUT THAT.
TUESDAY/TUESDAY NIGHT...LEE TROUGH REDEVELOPS/STRENGTHENS AS
STRONGER SHORTWAVE STARTS APPROACHING FROM THE WEST. MAIN SURFACE
CONVERGENCE REMAINS TO THE WEST OF THE AREA THROUGH THE DAY.
SURFACE BOUNDARY DOES NOT MOVE INTO THE AREA UNTIL LATER IN THE
NIGHT. PLUS MAIN LIFT DOES NOT ARRIVE UNTIL DURING THE NIGHT AS
WELL. SO HAVE SLIGHT CHANCE DURING THE AFTERNOON WITH THE MAIN
CHANCE OF PRECIPITATION DURING THE NIGHT. WITH STRENGTHENING
EASTERLY WINDS DURING THE DAY...AM THINKING THAT CURRENT MAX
TEMPERATURES WILL NEED TO BE COOLED SOME WAS NOT ABLE TO SPEND A LOT
OF TIME ON THAT.
WEDNESDAY/WEDNESDAY NIGHT...MODELS MOVE/DEVELOP A LEFT FRONT QUADRANT
OF THE JET OVER THE CENTRAL/EASTERN PORTION OF THE AREA DURING THE
AFTERNOON. THEN MODELS DIFFER ON HOW THEY MOVE IT. SOME MOVE IT EAST
OF THE AREA BY LATE AFTERNOON WITH OTHERS KEEPING IT THERE. THEN
THE SLOWER MODELS MOVE IT EAST OF THE AREA DURING THE EVENING.
MODELS DIFFER ON THE SPEED IN WHICH THEY TAKE THE NEXT BOUNDARY
THROUGH. IF THIS IS SLOWER THEN BETTER PRECIPITATION CHANCES WILL
NEED TO BE PULLED BACK SLOWER. DID SIDE WITH THE SLOWER ARRIVAL BUT
THIS WILL NEED TO BE LOOKED AT. MAIN MID LEVEL LIFT ARRIVES IN THE
AFTERNOON AND EVENING. ALL THIS POINTS TO GOOD CHANCES OF
PRECIPITATION LATER IN THE DAY INTO THE EVENING...ESPECIALLY FOR
THE EASTERN PORTION OF THE AREA. NOT SURE ABOUT WHAT THE
TEMPERATURES WILL DO WITH THE DIFFERENCE IN THE BOUNDARY POSITIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 435 AM MDT MON MAY 27 2013
MODELS ARE IN A LITTLE BETTER AGREEMENT WITH MOVEMENT OF UPPER
LOW/TROUGH...MINOR DIFFERENCES IN PLACEMENT OF UPPER LOW/TROUGH
EXIST. THE GFS HAS THE UPPER LOW OVER THE NORTHERN ROCKIES MOVING
EAST AND THE ADJACENT SURFACE LOW OVER THE DAKOTAS ON THURSDAY AND
FRIDAY. THE ECMWF PLACES THE UPPER LOW/TROUGH SLIGHTLY FURTHER NORTH
AND WEST...WHICH IS SLOWER MOVING EAST BUT SHOULD NOT AFFECT THE
TIMING OF THE MAIN FEATURES TOO MUCH. AS THE SURFACE LOW AND UPPER
LOW MOVE EAST...A COLD FRONT WILL SWING THROUGH THE CWA THURSDAY
MORNING. COLD AIR ALOFT WILL FILTER IN BEHIND THE FRONT...THIS
COMBINED WITH VORTICITY WRAPPING AROUND THE UPPER LOW AND SOME MINOR
INSTABILITY WILL BRING A CHANCE FOR SHOWERS AND TSTORMS ON THURSDAY
AFTERNOON. THE UPPER LOW STARTS TO PULL AWAY FROM THE CWA ON FRIDAY
LEAVING SOME LINGERING CLOUDS AND ON SATURDAY CONDITIONS WILL BECOME
CLEAR AS HIGH PRESSURE MOVES INTO THE CWA. MORE SEASONABLE
TEMPERATURES IN THE MID TO UPPER 70S WILL OCCUR ON FRIDAY AND
SATURDAY. SOUTHERLY RETURN FLOW SETS UP ON SUNDAY AFTERNOON OVER THE
CWA AND THE GFS HAS LOW AMPLITUDE RIDGING OVER THE CWA WITH EMBEDDED
SHORTWAVES MOVING THROUGH COLORADO WHILE THE ECMWF HAS ZONAL FLOW
OVER THE CENTRAL PLAINS. POPS WERE LEFT OUT OF SUNDAY FOR NOW...THIS
MAY CHANGE DEPENDING ON HOW MODELS RESOLVE THEIR DIFFERENCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 538 AM MDT MON MAY 27 2013
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE PERIOD. SHOWERS
AND THUNDERSTORMS ARE POSSIBLE ONCE AGAIN AT BOTH TAF SITES DUE
TO A SURFACE LOW OVER COLORADO MOVING EAST. MVF CONDITIONS COULD
BE POSSIBLE TUESDAY MORNING DUE TO LOW STRATUS...BUT GIVEN THE
TREND OVER THE PAST FEW DAYS...NOT SURE HOW THAT WILL PAN OUT.
&&
.FIRE WEATHER...
ISSUED AT 435 AM MDT MON MAY 27 2013
FOR TODAY...DUE TO THE FRONT MOVING IN FASTER...IT LOOKS LIKE THE
AREA WILL ESCAPE ANY FIRE WEATHER ISSUES. IF FRONT DOES SLOW UP...
GREELEY AND WICHITA COULD REACH CRITERIA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...BULLER/ALW
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
610 AM MDT MON MAY 27 2013
.UPDATE...
ISSUED AT 607 AM MDT MON MAY 27 2013
JUST COMPLETED AN UPDATE. EXTENT OF FOG AND STRATUS HAS NOT
DEVELOPED AS EXPECTED AND LIMITED THEM IN THE UPDATE TO EASTERN
COLORADO. ALSO NEW THUNDERSTORM DEVELOPMENT WEST OF AREA IS HOLD
TOGETHER AND SO STARTED THUNDERSTORMS A LITTLE EARLIER OUT THERE
THAN WHAT WAS IN THERE. MODELS STILL PLAYING CATCH UP ON THE WIND
FIELD. WIND SHIFT IS FURTHER SOUTH THAN ANY MODEL DATA AND WHAT
CURRENT GRIDS HAD. SO USING THE FASTEST MODEL AND REALITY ADJUSTED
THE WIND FIELD FOR THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 435 AM MDT MON MAY 27 2013
MAIN FORECAST PROBLEM WILL BE CONTINUED CHANCES FOR THUNDERSTORMS.
SATELLITE SHOWING THE FLOW HAS DEAMPLIFIED OVER THE PACIFIC AND THE
PACIFIC NORTHWEST. WHAT USED TO BE A COMPLEX UPPER LOW OVER THE
PACIFIC NORTHWEST HAS NOW BEEN SPLIT APART WITH THE SOUTHERN
PORTION COMING EAST NOW AS AN OPEN SHORTWAVE TROUGH. WITH WEAKENING
MID LEVEL RIDGE TO OUR EAST...THIS LEAVES OUR AREA IN A SOUTHWEST
FLOW ALOFT WITH NUMEROUS SMALL SCALE SHORTWAVE TROUGHS EMBEDDED
WITHIN IT. A COMPLEX SURFACE PATTERN IS OVER THE AREA WITH A
RETREATING WARM FRONT OVER THE NORTHWEST PORTION OF THE AREA WHICH
IS EXTENDING FROM THE SURFACE LOW OVER SOUTHEAST COLORADO. THE DRY
LINE IS JUST TO THE EAST OF THAT. A SHALLOWER/COOLER AIR MASS IS TO
THE NORTH OF THIS WARM FRONT.
MODELS INITIALIZED WELL AT JET LEVEL. MODELS DID FINE AT MID LEVELS
WITH THE GFS...CANADIAN AND UKMET DOING THE BEST ON THE HEIGHTS AND
FEATURES. THE MODELS WERE WARM AT 700 MB WITH THE CANADIAN DOING
THE BEST. MODELS HAVING HARD TIME WITH THE SURFACE PATTERN. MAJORITY
HAVE THE SURFACE LOW THAT STARTS OUT OVER SOUTHEAST COLORADO TOO
FAR EAST BY 06Z. THE ECMWF AND RUC DEFINITELY IS HEAD AND SHOULDERS
ABOVE THE REST. WOULD ALSO HAVE TO GIVE THE ECMWF A SLIGHT EDGE ON
THE THERMAL FIELD AS WELL.
BASED ON RECENT POOR MODEL PERFORMANCE...COMPLEX NATURE OF SURFACE
PATTERN...AND CONVECTIVE FEEDBACK ISSUES WITH THE MODELS...THIS IS
A LOW CONFIDENCE FORECAST. THIS COMPOUNDED BY THE FACT THAT CERTAIN
NEIGHBORING OFFICES ARE MAKING BIG CHANGES WITHOUT TALKING.
TODAY/TONIGHT...SOME CONVECTION HAS DEVELOPED NORTH OF THE
RETREATING WARM FRONT WITH OTHER CONVECTION ON THE WESTWARD
EXTENSION OF THIS WEAVING/COMPLEX FRONTAL POSITION. RECENT TRENDS
AND MESOSCALE MODEL OUTPUT INDICATE ALL THIS PRECIPITATION WILL STAY
TO THE NORTH OF THE AREA. BUT WILL CONTINUE TO MONITOR.
LEFT FRONT QUADRANT OF THE JET STARTS OVER THE SOUTHERN PORTION OF
THE AREA AT 12Z AND IS AFFECTING/OVER THE NORTHERN PORTION OF THE
AREA BY THE END OF THE DAY. THIS FEATURE THEN MOVES SOUTHEAST DURING
THE NIGHT. RIGHT NOW THE MODELS ARE HAVING EXTREME DIFFICULTIES IN
RESOLVING BOUNDARY POSITION AND TIMING. MODELS TAKE A COMPACT 700
MB LOW OVER COLORADO AND MOVE IN TO THE NORTH OF THE AREA BY EARLY
AFTERNOON. DEPENDING ON WHICH MODEL OUTPUT YOU USE...SOME
WRAPAROUND OCCURS WITH THIS. CONSIDERING THE TRAJECTORY...AM NOT
BUYING IT. WITH THE JET...SURFACE BOUNDARY POSITION AND THIS
SYSTEM...BEST CHANCES FOR PRECIPITATION SHOULD BE IN THE NORTH AND
END BY LATE IN THE AFTERNOON. ADDITIONAL SHORTWAVE ENERGY MOVES
THROUGH DURING THE NIGHT BUT MOISTURE HAS BEEN SCOURED OUT. ENDED
PRECIPITATION BY LATE IN THE NIGHT AND THAT MAY BE TOO LATE.
WILL GET SOME FOG AND STRATUS IN THE NORTHWEST PORTION OF THE AREA
AS THE FRONT MOVES THROUGH. WITH AN EARLIER FRONTAL ARRIVAL
EXPECTED...HIGH TEMPERATURES SHOULD BE COOLER BUT AM NOT CERTAIN
ABOUT THAT.
TUESDAY/TUESDAY NIGHT...LEE TROUGH REDEVELOPS/STRENGTHENS AS
STRONGER SHORTWAVE STARTS APPROACHING FROM THE WEST. MAIN SURFACE
CONVERGENCE REMAINS TO THE WEST OF THE AREA THROUGH THE DAY.
SURFACE BOUNDARY DOES NOT MOVE INTO THE AREA UNTIL LATER IN THE
NIGHT. PLUS MAIN LIFT DOES NOT ARRIVE UNTIL DURING THE NIGHT AS
WELL. SO HAVE SLIGHT CHANCE DURING THE AFTERNOON WITH THE MAIN
CHANCE OF PRECIPITATION DURING THE NIGHT. WITH STRENGTHENING
EASTERLY WINDS DURING THE DAY...AM THINKING THAT CURRENT MAX
TEMPERATURES WILL NEED TO BE COOLED SOME WAS NOT ABLE TO SPEND A LOT
OF TIME ON THAT.
WEDNESDAY/WEDNESDAY NIGHT...MODELS MOVE/DEVELOP A LEFT FRONT QUADRANT
OF THE JET OVER THE CENTRAL/EASTERN PORTION OF THE AREA DURING THE
AFTERNOON. THEN MODELS DIFFER ON HOW THEY MOVE IT. SOME MOVE IT EAST
OF THE AREA BY LATE AFTERNOON WITH OTHERS KEEPING IT THERE. THEN
THE SLOWER MODELS MOVE IT EAST OF THE AREA DURING THE EVENING.
MODELS DIFFER ON THE SPEED IN WHICH THEY TAKE THE NEXT BOUNDARY
THROUGH. IF THIS IS SLOWER THEN BETTER PRECIPITATION CHANCES WILL
NEED TO BE PULLED BACK SLOWER. DID SIDE WITH THE SLOWER ARRIVAL BUT
THIS WILL NEED TO BE LOOKED AT. MAIN MID LEVEL LIFT ARRIVES IN THE
AFTERNOON AND EVENING. ALL THIS POINTS TO GOOD CHANCES OF
PRECIPITATION LATER IN THE DAY INTO THE EVENING...ESPECIALLY FOR
THE EASTERN PORTION OF THE AREA. NOT SURE ABOUT WHAT THE
TEMPERATURES WILL DO WITH THE DIFFERENCE IN THE BOUNDARY POSITIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 435 AM MDT MON MAY 27 2013
MODELS ARE IN A LITTLE BETTER AGREEMENT WITH MOVEMENT OF UPPER
LOW/TROUGH...MINOR DIFFERENCES IN PLACEMENT OF UPPER LOW/TROUGH
EXIST. THE GFS HAS THE UPPER LOW OVER THE NORTHERN ROCKIES MOVING
EAST AND THE ADJACENT SURFACE LOW OVER THE DAKOTAS ON THURSDAY AND
FRIDAY. THE ECMWF PLACES THE UPPER LOW/TROUGH SLIGHTLY FURTHER NORTH
AND WEST...WHICH IS SLOWER MOVING EAST BUT SHOULD NOT AFFECT THE
TIMING OF THE MAIN FEATURES TOO MUCH. AS THE SURFACE LOW AND UPPER
LOW MOVE EAST...A COLD FRONT WILL SWING THROUGH THE CWA THURSDAY
MORNING. COLD AIR ALOFT WILL FILTER IN BEHIND THE FRONT...THIS
COMBINED WITH VORTICITY WRAPPING AROUND THE UPPER LOW AND SOME MINOR
INSTABILITY WILL BRING A CHANCE FOR SHOWERS AND TSTORMS ON THURSDAY
AFTERNOON. THE UPPER LOW STARTS TO PULL AWAY FROM THE CWA ON FRIDAY
LEAVING SOME LINGERING CLOUDS AND ON SATURDAY CONDITIONS WILL BECOME
CLEAR AS HIGH PRESSURE MOVES INTO THE CWA. MORE SEASONABLE
TEMPERATURES IN THE MID TO UPPER 70S WILL OCCUR ON FRIDAY AND
SATURDAY. SOUTHERLY RETURN FLOW SETS UP ON SUNDAY AFTERNOON OVER THE
CWA AND THE GFS HAS LOW AMPLITUDE RIDGING OVER THE CWA WITH EMBEDDED
SHORTWAVES MOVING THROUGH COLORADO WHILE THE ECMWF HAS ZONAL FLOW
OVER THE CENTRAL PLAINS. POPS WERE LEFT OUT OF SUNDAY FOR NOW...THIS
MAY CHANGE DEPENDING ON HOW MODELS RESOLVE THEIR DIFFERENCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 538 AM MDT MON MAY 27 2013
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE PERIOD. SHOWERS
AND THUNDERSTORMS ARE POSSIBLE ONCE AGAIN AT BOTH TAF SITES DUE
TO A SURFACE LOW OVER COLORADO MOVING EAST. MVF CONDITIONS COULD
BE POSSIBLE TUESDAY MORNING DUE TO LOW STRATUS...BUT GIVEN THE
TREND OVER THE PAST FEW DAYS...NOT SURE HOW THAT WILL PAN OUT.
&&
.FIRE WEATHER...
ISSUED AT 435 AM MDT MON MAY 27 2013
FOR TODAY...DUE TO THE FRONT MOVING IN FASTER...IT LOOKS LIKE THE
AREA WILL ESCAPE ANY FIRE WEATHER ISSUES. IF FRONT DOES SLOW UP...
GREELEY AND WICHITA COULD REACH CRITERIA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...BULLER/ALW
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
545 AM MDT MON MAY 27 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 435 AM MDT MON MAY 27 2013
MAIN FORECAST PROBLEM WILL BE CONTINUED CHANCES FOR THUNDERSTORMS.
SATELLITE SHOWING THE FLOW HAS DEAMPLIFIED OVER THE PACIFIC AND THE
PACIFIC NORTHWEST. WHAT USED TO BE A COMPLEX UPPER LOW OVER THE
PACIFIC NORTHWEST HAS NOW BEEN SPLIT APART WITH THE SOUTHERN
PORTION COMING EAST NOW AS AN OPEN SHORTWAVE TROUGH. WITH WEAKENING
MID LEVEL RIDGE TO OUR EAST...THIS LEAVES OUR AREA IN A SOUTHWEST
FLOW ALOFT WITH NUMEROUS SMALL SCALE SHORTWAVE TROUGHS EMBEDDED
WITHIN IT. A COMPLEX SURFACE PATTERN IS OVER THE AREA WITH A
RETREATING WARM FRONT OVER THE NORTHWEST PORTION OF THE AREA WHICH
IS EXTENDING FROM THE SURFACE LOW OVER SOUTHEAST COLORADO. THE DRY
LINE IS JUST TO THE EAST OF THAT. A SHALLOWER/COOLER AIR MASS IS TO
THE NORTH OF THIS WARM FRONT.
MODELS INITIALIZED WELL AT JET LEVEL. MODELS DID FINE AT MID LEVELS
WITH THE GFS...CANADIAN AND UKMET DOING THE BEST ON THE HEIGHTS AND
FEATURES. THE MODELS WERE WARM AT 700 MB WITH THE CANADIAN DOING
THE BEST. MODELS HAVING HARD TIME WITH THE SURFACE PATTERN. MAJORITY
HAVE THE SURFACE LOW THAT STARTS OUT OVER SOUTHEAST COLORADO TOO
FAR EAST BY 06Z. THE ECMWF AND RUC DEFINITELY IS HEAD AND SHOULDERS
ABOVE THE REST. WOULD ALSO HAVE TO GIVE THE ECMWF A SLIGHT EDGE ON
THE THERMAL FIELD AS WELL.
BASED ON RECENT POOR MODEL PERFORMANCE...COMPLEX NATURE OF SURFACE
PATTERN...AND CONVECTIVE FEEDBACK ISSUES WITH THE MODELS...THIS IS
A LOW CONFIDENCE FORECAST. THIS COMPOUNDED BY THE FACT THAT CERTAIN
NEIGHBORING OFFICES ARE MAKING BIG CHANGES WITHOUT TALKING.
TODAY/TONIGHT...SOME CONVECTION HAS DEVELOPED NORTH OF THE
RETREATING WARM FRONT WITH OTHER CONVECTION ON THE WESTWARD
EXTENSION OF THIS WEAVING/COMPLEX FRONTAL POSITION. RECENT TRENDS
AND MESOSCALE MODEL OUTPUT INDICATE ALL THIS PRECIPITATION WILL STAY
TO THE NORTH OF THE AREA. BUT WILL CONTINUE TO MONITOR.
LEFT FRONT QUADRANT OF THE JET STARTS OVER THE SOUTHERN PORTION OF
THE AREA AT 12Z AND IS AFFECTING/OVER THE NORTHERN PORTION OF THE
AREA BY THE END OF THE DAY. THIS FEATURE THEN MOVES SOUTHEAST DURING
THE NIGHT. RIGHT NOW THE MODELS ARE HAVING EXTREME DIFFICULTIES IN
RESOLVING BOUNDARY POSITION AND TIMING. MODELS TAKE A COMPACT 700
MB LOW OVER COLORADO AND MOVE IN TO THE NORTH OF THE AREA BY EARLY
AFTERNOON. DEPENDING ON WHICH MODEL OUTPUT YOU USE...SOME
WRAPAROUND OCCURS WITH THIS. CONSIDERING THE TRAJECTORY...AM NOT
BUYING IT. WITH THE JET...SURFACE BOUNDARY POSITION AND THIS
SYSTEM...BEST CHANCES FOR PRECIPITATION SHOULD BE IN THE NORTH AND
END BY LATE IN THE AFTERNOON. ADDITIONAL SHORTWAVE ENERGY MOVES
THROUGH DURING THE NIGHT BUT MOISTURE HAS BEEN SCOURED OUT. ENDED
PRECIPITATION BY LATE IN THE NIGHT AND THAT MAY BE TOO LATE.
WILL GET SOME FOG AND STRATUS IN THE NORTHWEST PORTION OF THE AREA
AS THE FRONT MOVES THROUGH. WITH AN EARLIER FRONTAL ARRIVAL
EXPECTED...HIGH TEMPERATURES SHOULD BE COOLER BUT AM NOT CERTAIN
ABOUT THAT.
TUESDAY/TUESDAY NIGHT...LEE TROUGH REDEVELOPS/STRENGTHENS AS
STRONGER SHORTWAVE STARTS APPROACHING FROM THE WEST. MAIN SURFACE
CONVERGENCE REMAINS TO THE WEST OF THE AREA THROUGH THE DAY.
SURFACE BOUNDARY DOES NOT MOVE INTO THE AREA UNTIL LATER IN THE
NIGHT. PLUS MAIN LIFT DOES NOT ARRIVE UNTIL DURING THE NIGHT AS
WELL. SO HAVE SLIGHT CHANCE DURING THE AFTERNOON WITH THE MAIN
CHANCE OF PRECIPITATION DURING THE NIGHT. WITH STRENGTHENING
EASTERLY WINDS DURING THE DAY...AM THINKING THAT CURRENT MAX
TEMPERATURES WILL NEED TO BE COOLED SOME WAS NOT ABLE TO SPEND A LOT
OF TIME ON THAT.
WEDNESDAY/WEDNESDAY NIGHT...MODELS MOVE/DEVELOP A LEFT FRONT QUADRANT
OF THE JET OVER THE CENTRAL/EASTERN PORTION OF THE AREA DURING THE
AFTERNOON. THEN MODELS DIFFER ON HOW THEY MOVE IT. SOME MOVE IT EAST
OF THE AREA BY LATE AFTERNOON WITH OTHERS KEEPING IT THERE. THEN
THE SLOWER MODELS MOVE IT EAST OF THE AREA DURING THE EVENING.
MODELS DIFFER ON THE SPEED IN WHICH THEY TAKE THE NEXT BOUNDARY
THROUGH. IF THIS IS SLOWER THEN BETTER PRECIPITATION CHANCES WILL
NEED TO BE PULLED BACK SLOWER. DID SIDE WITH THE SLOWER ARRIVAL BUT
THIS WILL NEED TO BE LOOKED AT. MAIN MID LEVEL LIFT ARRIVES IN THE
AFTERNOON AND EVENING. ALL THIS POINTS TO GOOD CHANCES OF
PRECIPITATION LATER IN THE DAY INTO THE EVENING...ESPECIALLY FOR
THE EASTERN PORTION OF THE AREA. NOT SURE ABOUT WHAT THE
TEMPERATURES WILL DO WITH THE DIFFERENCE IN THE BOUNDARY POSITIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 435 AM MDT MON MAY 27 2013
MODELS ARE IN A LITTLE BETTER AGREEMENT WITH MOVEMENT OF UPPER
LOW/TROUGH...MINOR DIFFERENCES IN PLACEMENT OF UPPER LOW/TROUGH
EXIST. THE GFS HAS THE UPPER LOW OVER THE NORTHERN ROCKIES MOVING
EAST AND THE ADJACENT SURFACE LOW OVER THE DAKOTAS ON THURSDAY AND
FRIDAY. THE ECMWF PLACES THE UPPER LOW/TROUGH SLIGHTLY FURTHER NORTH
AND WEST...WHICH IS SLOWER MOVING EAST BUT SHOULD NOT AFFECT THE
TIMING OF THE MAIN FEATURES TOO MUCH. AS THE SURFACE LOW AND UPPER
LOW MOVE EAST...A COLD FRONT WILL SWING THROUGH THE CWA THURSDAY
MORNING. COLD AIR ALOFT WILL FILTER IN BEHIND THE FRONT...THIS
COMBINED WITH VORTICITY WRAPPING AROUND THE UPPER LOW AND SOME MINOR
INSTABILITY WILL BRING A CHANCE FOR SHOWERS AND TSTORMS ON THURSDAY
AFTERNOON. THE UPPER LOW STARTS TO PULL AWAY FROM THE CWA ON FRIDAY
LEAVING SOME LINGERING CLOUDS AND ON SATURDAY CONDITIONS WILL BECOME
CLEAR AS HIGH PRESSURE MOVES INTO THE CWA. MORE SEASONABLE
TEMPERATURES IN THE MID TO UPPER 70S WILL OCCUR ON FRIDAY AND
SATURDAY. SOUTHERLY RETURN FLOW SETS UP ON SUNDAY AFTERNOON OVER THE
CWA AND THE GFS HAS LOW AMPLITUDE RIDGING OVER THE CWA WITH EMBEDDED
SHORTWAVES MOVING THROUGH COLORADO WHILE THE ECMWF HAS ZONAL FLOW
OVER THE CENTRAL PLAINS. POPS WERE LEFT OUT OF SUNDAY FOR NOW...THIS
MAY CHANGE DEPENDING ON HOW MODELS RESOLVE THEIR DIFFERENCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 538 AM MDT MON MAY 27 2013
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE PERIOD. SHOWERS
AND THUNDERSTORMS ARE POSSIBLE ONCE AGAIN AT BOTH TAF SITES DUE
TO A SURFACE LOW OVER COLORADO MOVING EAST. MVF CONDITIONS COULD
BE POSSIBLE TUESDAY MORNING DUE TO LOW STRATUS...BUT GIVEN THE
TREND OVER THE PAST FEW DAYS...NOT SURE HOW THAT WILL PAN OUT.
&&
.FIRE WEATHER...
ISSUED AT 435 AM MDT MON MAY 27 2013
FOR TODAY...DUE TO THE FRONT MOVING IN FASTER...IT LOOKS LIKE THE
AREA WILL ESCAPE ANY FIRE WEATHER ISSUES. IF FRONT DOES SLOW UP...
GREELEY AND WICHITA COULD REACH CRITERIA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...BULLER/ALW
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
435 AM MDT MON MAY 27 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 435 AM MDT MON MAY 27 2013
MAIN FORECAST PROBLEM WILL BE CONTINUED CHANCES FOR THUNDERSTORMS.
SATELLITE SHOWING THE FLOW HAS DEAMPLIFIED OVER THE PACIFIC AND THE
PACIFIC NORTHWEST. WHAT USED TO BE A COMPLEX UPPER LOW OVER THE
PACIFIC NORTHWEST HAS NOW BEEN SPLIT APART WITH THE SOUTHERN
PORTION COMING EAST NOW AS AN OPEN SHORTWAVE TROUGH. WITH WEAKENING
MID LEVEL RIDGE TO OUR EAST...THIS LEAVES OUR AREA IN A SOUTHWEST
FLOW ALOFT WITH NUMEROUS SMALL SCALE SHORTWAVE TROUGHS EMBEDDED
WITHIN IT. A COMPLEX SURFACE PATTERN IS OVER THE AREA WITH A
RETREATING WARM FRONT OVER THE NORTHWEST PORTION OF THE AREA WHICH
IS EXTENDING FROM THE SURFACE LOW OVER SOUTHEAST COLORADO. THE DRY
LINE IS JUST TO THE EAST OF THAT. A SHALLOWER/COOLER AIR MASS IS TO
THE NORTH OF THIS WARM FRONT.
MODELS INITIALIZED WELL AT JET LEVEL. MODELS DID FINE AT MID LEVELS
WITH THE GFS...CANADIAN AND UKMET DOING THE BEST ON THE HEIGHTS AND
FEATURES. THE MODELS WERE WARM AT 700 MB WITH THE CANADIAN DOING
THE BEST. MODELS HAVING HARD TIME WITH THE SURFACE PATTERN. MAJORITY
HAVE THE SURFACE LOW THAT STARTS OUT OVER SOUTHEAST COLORADO TOO
FAR EAST BY 06Z. THE ECMWF AND RUC DEFINITELY IS HEAD AND SHOULDERS
ABOVE THE REST. WOULD ALSO HAVE TO GIVE THE ECMWF A SLIGHT EDGE ON
THE THERMAL FIELD AS WELL.
BASED ON RECENT POOR MODEL PERFORMANCE...COMPLEX NATURE OF SURFACE
PATTERN...AND CONVECTIVE FEEDBACK ISSUES WITH THE MODELS...THIS IS
A LOW CONFIDENCE FORECAST. THIS COMPOUNDED BY THE FACT THAT CERTAIN
NEIGHBORING OFFICES ARE MAKING BIG CHANGES WITHOUT TALKING.
TODAY/TONIGHT...SOME CONVECTION HAS DEVELOPED NORTH OF THE
RETREATING WARM FRONT WITH OTHER CONVECTION ON THE WESTWARD
EXTENSION OF THIS WEAVING/COMPLEX FRONTAL POSITION. RECENT TRENDS
AND MESOSCALE MODEL OUTPUT INDICATE ALL THIS PRECIPITATION WILL STAY
TO THE NORTH OF THE AREA. BUT WILL CONTINUE TO MONITOR.
LEFT FRONT QUADRANT OF THE JET STARTS OVER THE SOUTHERN PORTION OF
THE AREA AT 12Z AND IS AFFECTING/OVER THE NORTHERN PORTION OF THE
AREA BY THE END OF THE DAY. THIS FEATURE THEN MOVES SOUTHEAST DURING
THE NIGHT. RIGHT NOW THE MODELS ARE HAVING EXTREME DIFFICULTIES IN
RESOLVING BOUNDARY POSITION AND TIMING. MODELS TAKE A COMPACT 700
MB LOW OVER COLORADO AND MOVE IN TO THE NORTH OF THE AREA BY EARLY
AFTERNOON. DEPENDING ON WHICH MODEL OUTPUT YOU USE...SOME
WRAPAROUND OCCURS WITH THIS. CONSIDERING THE TRAJECTORY...AM NOT
BUYING IT. WITH THE JET...SURFACE BOUNDARY POSITION AND THIS
SYSTEM...BEST CHANCES FOR PRECIPITATION SHOULD BE IN THE NORTH AND
END BY LATE IN THE AFTERNOON. ADDITIONAL SHORTWAVE ENERGY MOVES
THROUGH DURING THE NIGHT BUT MOISTURE HAS BEEN SCOURED OUT. ENDED
PRECIPITATION BY LATE IN THE NIGHT AND THAT MAY BE TOO LATE.
WILL GET SOME FOG AND STRATUS IN THE NORTHWEST PORTION OF THE AREA
AS THE FRONT MOVES THROUGH. WITH AN EARLIER FRONTAL ARRIVAL
EXPECTED...HIGH TEMPERATURES SHOULD BE COOLER BUT AM NOT CERTAIN
ABOUT THAT.
TUESDAY/TUESDAY NIGHT...LEE TROUGH REDEVELOPS/STRENGTHENS AS
STRONGER SHORTWAVE STARTS APPROACHING FROM THE WEST. MAIN SURFACE
CONVERGENCE REMAINS TO THE WEST OF THE AREA THROUGH THE DAY.
SURFACE BOUNDARY DOES NOT MOVE INTO THE AREA UNTIL LATER IN THE
NIGHT. PLUS MAIN LIFT DOES NOT ARRIVE UNTIL DURING THE NIGHT AS
WELL. SO HAVE SLIGHT CHANCE DURING THE AFTERNOON WITH THE MAIN
CHANCE OF PRECIPITATION DURING THE NIGHT. WITH STRENGTHENING
EASTERLY WINDS DURING THE DAY...AM THINKING THAT CURRENT MAX
TEMPERATURES WILL NEED TO BE COOLED SOME WAS NOT ABLE TO SPEND A LOT
OF TIME ON THAT.
WEDNESDAY/WEDNESDAY NIGHT...MODELS MOVE/DEVELOP A LEFT FRONT QUADRANT
OF THE JET OVER THE CENTRAL/EASTERN PORTION OF THE AREA DURING THE
AFTERNOON. THEN MODELS DIFFER ON HOW THEY MOVE IT. SOME MOVE IT EAST
OF THE AREA BY LATE AFTERNOON WITH OTHERS KEEPING IT THERE. THEN
THE SLOWER MODELS MOVE IT EAST OF THE AREA DURING THE EVENING.
MODELS DIFFER ON THE SPEED IN WHICH THEY TAKE THE NEXT BOUNDARY
THROUGH. IF THIS IS SLOWER THEN BETTER PRECIPITATION CHANCES WILL
NEED TO BE PULLED BACK SLOWER. DID SIDE WITH THE SLOWER ARRIVAL BUT
THIS WILL NEED TO BE LOOKED AT. MAIN MID LEVEL LIFT ARRIVES IN THE
AFTERNOON AND EVENING. ALL THIS POINTS TO GOOD CHANCES OF
PRECIPITATION LATER IN THE DAY INTO THE EVENING...ESPECIALLY FOR
THE EASTERN PORTION OF THE AREA. NOT SURE ABOUT WHAT THE
TEMPERATURES WILL DO WITH THE DIFFERENCE IN THE BOUNDARY POSITIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 435 AM MDT MON MAY 27 2013
MODELS ARE IN A LITTLE BETTER AGREEMENT WITH MOVEMENT OF UPPER
LOW/TROUGH...MINOR DIFFERENCES IN PLACEMENT OF UPPER LOW/TROUGH
EXIST. THE GFS HAS THE UPPER LOW OVER THE NORTHERN ROCKIES MOVING
EAST AND THE ADJACENT SURFACE LOW OVER THE DAKOTAS ON THURSDAY AND
FRIDAY. THE ECMWF PLACES THE UPPER LOW/TROUGH SLIGHTLY FURTHER NORTH
AND WEST...WHICH IS SLOWER MOVING EAST BUT SHOULD NOT AFFECT THE
TIMING OF THE MAIN FEATURES TOO MUCH. AS THE SURFACE LOW AND UPPER
LOW MOVE EAST...A COLD FRONT WILL SWING THROUGH THE CWA THURSDAY
MORNING. COLD AIR ALOFT WILL FILTER IN BEHIND THE FRONT...THIS
COMBINED WITH VORTICITY WRAPPING AROUND THE UPPER LOW AND SOME MINOR
INSTABILITY WILL BRING A CHANCE FOR SHOWERS AND TSTORMS ON THURSDAY
AFTERNOON. THE UPPER LOW STARTS TO PULL AWAY FROM THE CWA ON FRIDAY
LEAVING SOME LINGERING CLOUDS AND ON SATURDAY CONDITIONS WILL BECOME
CLEAR AS HIGH PRESSURE MOVES INTO THE CWA. MORE SEASONABLE
TEMPERATURES IN THE MID TO UPPER 70S WILL OCCUR ON FRIDAY AND
SATURDAY. SOUTHERLY RETURN FLOW SETS UP ON SUNDAY AFTERNOON OVER THE
CWA AND THE GFS HAS LOW AMPLITUDE RIDGING OVER THE CWA WITH EMBEDDED
SHORTWAVES MOVING THROUGH COLORADO WHILE THE ECMWF HAS ZONAL FLOW
OVER THE CENTRAL PLAINS. POPS WERE LEFT OUT OF SUNDAY FOR NOW...THIS
MAY CHANGE DEPENDING ON HOW MODELS RESOLVE THEIR DIFFERENCES.
&&
.AVIATION....(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1132 PM MDT SUN MAY 26 2013
SOME GUIDANCE CONTINUES TO SUPPORT FOG DEVELOPMENT ACROSS
SOUTHWEST NEBRASKA SPREADING SOUTH TOWARDS THE I-70 CORRIDOR AFTER
09Z WITH BEST CHANCE FOR FOG IN THE 11-15Z TIMEFRAME. CURRENT
SURFACE PATTERN COMPLICATED BY SEVERAL FRONTS AND SURFACE TROUGH
IN PROXIMITY TO BOTH TERMINALS...AND POSSIBLE OUTFLOW MOVING
SOUTH/SOUTHEAST FROM CENTRAL NEBRASKA. SHORT RANGE GUIDANCE IS
DOING A LITTLE BETTER WITH THIS AND IS MUCH LESS FAVORABLE FOR
FOG/STRATUS AT KGLD...THOUGH IT DOES STILL SUPPORT SOME
FOG/STRATUS NEAR KMCK. IN ADDITION SHOWERS/THUNDERSTORMS HAVE
DEVELOPED LATE THIS EVENING OVER SW NEBRASKA JUST NORTH OF WARM
FRONT.
I DECIDED TO ADD VCSH TO KMCK THROUGH THE EARLY TAF
PERIOD TO COVER CURRENT TRENDS AND BROUGHT TEMPO IFR CIG/VIS IN
THE 11-14Z TIMEFRAME FOR WHEN BEST CHANCE OF FOG IS (CONFIDENCE IN
PREVAILING IS STILL LOW). I AM MORE CONFIDENT IN PREVAILING VFR
FOR KGLD...THOUGH WILL HAVE TO MONITOR CURRENT TRENDS.
THUNDERSTORMS WILL BE POSSIBLE OVERNIGHT AND AGAIN MONDAY
AFTERNOON/EVENING...HOWEVER COVERAGE IS A BIG QUESTION AND I
DECIDED AGAINST KEEPING MENTION IN TAFS FOR NOW.
&&
.FIRE WEATHER...
ISSUED AT 435 AM MDT MON MAY 27 2013
FOR TODAY...DUE TO THE FRONT MOVING IN FASTER...IT LOOKS LIKE THE
AREA WILL ESCAPE ANY FIRE WEATHER ISSUES. IF FRONT DOES SLOW UP...
GREELEY AND WICHITA COULD REACH CRITERIA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...DR
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1004 AM EDT MON MAY 27 2013
.UPDATE...
ISSUED AT 1003 AM EDT MON MAY 27 2013
THE NEAR TERM TEMPS...DEWPOINTS AND SKY AS WELL AS POPS WERE ADJUSTED
BASED ON RECENT OBS AS WELL AS SATELLITE AND RADAR TRENDS. TEMPS ARE
WARMING UP RATHER QUICKLY IN THE SOUTHWEST WHERE THE FLOW IS MORE
SOUTHERLY AND THERE ARE FEW IN THE WAY OF CLOUDS BEHIND A NORTHWARD
LIFTING WARM FRONT. THE DIURNAL CLIMO CURVE IN GENERAL IS NOT
CAPTURING THE TEMPERATURE RISE AND OPTED TO GO WITH MORE A MOS
DERIVED TEMP CURVE FOR TODAY. MEANWHILE...A BAND OF CLOUDS IS WORKING
INTO THE SOUTHEASTERN PART OF THE CWA. BEHIND THIS BAND...SKIES
SHOULD BE MOSTLY SUNNY IN ALL AREAS INTO THE EARLY AFTERNOON WHEN CU
MAY BEGIN TO FORM. MODELS...ESPECIALLY THE 6Z NAM APPEARS TO BE TOO
AGGRESSIVE WITH THE INCREASE IN LOW LEVEL MOISTURE AND SFC AND
BOUNDARY LAYER DEWPOINTS WHEN COMPARED TO 12Z RAOB FROM NASHVILLE.
INSTABILITY IN THE 6Z NAM FORECAST SOUNDINGS IS LIKELY OVERDONE AS
DEWPOINTS WILL LIKELY MIX INTO THE LOW TO MID 50S RATHER THAN MID TO
UPPER 50S IN THE 6Z NAM...AND THIS MAY LEAD TO OBSERVED CAPE MUCH AS
1000 J/KG LESS THAN THE 6Z NAM FORECAST SOUNDINGS. THE 11Z HRRR SHOWS
VERY LITTLE CONVECTIVE DEVELOPMENT TODAY WITH CONVECTION GENERALLY
ALONG A CORRIDOR NEAR OR MAINLY NORTH OF THE OH RIVER THEN SOUTHEAST
TOWARD THE CENTRAL APPALACHIANS. THE 11Z HRRR HINTS AT SOME POSSIBLE
DEVELOPMENT NEAR THE WV BORDER AND ITS SCENARIO APPEARS REASONABLE.
FOR THIS UPDATE...CONFINED SLIGHT CHANCE POPS TO THE AFTERNOON INTO
EARLY EVENING AND OVER THE EASTERN THIRD TO HALF OF THE CWA. THE
BOTTOMLINE IS MOST LOCATIONS WILL LIKELY NOT EXPERIENCE ANY
CONVECTION TODAY.
THE 12Z NAM AND 9Z SREF HINT AT SOME CONVECTION THIS EVENING AND
BRING A WEAK SHORTWAVE ACROSS THE AREA. THE 11Z HRRR DOES NOT HAVE
THIS AND CONFIDENCE IN THIS IS NOT HIGH...BUT TRENDS WITH THIS WILL
BE MONITORED AS THE ENTIRE SUITE OF 12Z MODEL RUNS ARRIVE.
UPDATE ISSUED AT 651 AM EDT MON MAY 27 2013
NO MAJOR CHANGES WERE MADE TO THE FORECAST THIS MORNING. RAN THE ESTF
TOOL TO INGEST THE LATEST OBSERVATIONAL DATA AND INTEGRATE IT WITH
THE 4 AM FORECAST DATA. OVERALL THE FORECAST IS ON TRACK SO FAR
TODAY. SCATTERED SHOWERS AND STORMS CONTINUE TO MOVE ACROSS SOUTHERN
INDIANA AND OHIO...WITH A FEW OF THESE OCCASIONALLY STRAYING SOUTH
INTO THE NORTHERN FRINGES OF THE FORECAST AREA. THIS TREND IS
EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS. ACTIVITY IS EXPECTED
TO INCREASE A BIT DURING THE PEAK HEATING OF THE DAY...AS A ILL
DEFINED WARM FRONT MOVES IN FROM THE SOUTHWEST. NO UPDATE IS PLANNED
AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 301 AM EDT MON MAY 27 2013
MODELS WERE IN PRETTY GOOD AGREEMENT FOR THE SHORT TERM PORTION OF
THE FORECAST. THE CONSENSUS VIEW IS FOR ISOLATED SHOWERS AND STORMS
TO PUSH JUST TO THE SOUTH OF THE OHIO RIVER TODAY AND AGAIN LATE IN
THE DAY ON TUESDAY. THE LATEST RADAR IMAGERY SHOWED SCATTERED SHOWERS
AND STORMS MOVING ACROSS SOUTHERN INDIANA...NORTH CENTRAL
KENTUCKY...AND SOUTHWESTERN OHIO. A FEW OF THESE MIGHT MAKE INTO THE
NORTHERN MOST AREAS OF THE FORECAST BY EARLY THIS MORNING.
THEREFORE...SLIGHT CHANCE POPS WERE LEFT IN PLACE TO ACCOUNT FOR THIS
POTENTIAL. A WEAK WARM FRONT IS STILL PROGGED TO PUSH ACROSS THE AREA
THROUGHOUT THE DAY TODAY...WHICH WILL BRING THE POTENTIAL FOR FURTHER
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS...PARTICULARLY THIS
AFTERNOON DURING PEAK HEATING. AFTER A LULL IN THE ACTION MONDAY
NIGHT AND TUESDAY MORNING...THE WARM FRONT IS EXPECTED TO BECOME
ACTIVE ONCE AGAIN...WITH ISOLATED SHOWERS AND STORMS POSSIBLE ACROSS
THE NORTHERN AND NORTHEASTERN THIRD OF THE FORECAST AREA. RIGHT NOW
THE LIMITING FACTORS APPEAR TO BE THE AMOUNT LOW LEVEL MOISTURE
AVAILABLE AND THE DIFFUSE NATURE OF THE WARM FRONT. TEMPERATURES
TODAY AND TOMORROW WILL TOP OUT AT WELL ABOVE NORMAL VALUES...AS
SOUTHERLY FLOW BECOMES ESTABLISHED. TODAYS HIGHS ARE EXPECTED TO MAX
OUT IN THE LOW TO MID 80S...WITH MID 80S EXPECTED AREA WIDE ON
TUESDAY...AS CLOUD COVER THINS OUT QUITE A BIT.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 408 AM EDT MON MAY 27 2013
UPPER LEVEL RIDGING OVER THE SOUTHEAST CONUS AND LOW LEVEL SOUTHERLY
FLOW WILL BRING A PERIOD OF WARM SUMMER-LIKE WEATHER UNTIL THE
WEEKEND. WHILE THERE IS A REMOTE POSSIBILITY OF DIURNALLY DRIVEN
THUNDERSTORMS POPPING UP...THE POP IN ANY GIVEN 12 HOUR PERIOD IS
WELL BELOW 20 PERCENT UNTIL THE WEEKEND.
AN UPPER LEVEL TROUGH AND ITS ASSOCIATED SURFACE COLD FRONT ARE
EXPECTED TO APPROACH DURING THE WEEKEND. THIS WILL BRING A
POSSIBILITY OF SHOWERS AND THUNDERSTORMS SATURDAY NIGHT AND SUNDAY.
WITH THE INCREASE IN CLOUDS AND POSSIBLE PRECIP ON SUNDAY...TEMPS
WILL ALSO COOL OFF A BIT. THE MOST LIKELY TIME FOR COLD FRONTAL
PASSAGE IS SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 651 AM EDT MON MAY 27 2013
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD AT ALL THREE
AIRPORTS. ISOLATED SHOWERS AND STORMS ARE STILL ON TAP FROM LATE THIS
MORNING THROUGH LATE THIS AFTERNOON. MOST OF THE ACTIVITY WILL OCCUR
EAST OF THE I75 CORRIDOR AND NORTH THE HAL ROGERS PARKWAY AND HIGHWAY
80 CORRIDOR. SCATTERED MIDDLE AND BROKEN HIGH LEVEL CLOUD COVER WILL
STREAM ACROSS THE AREA THROUGHOUT THE DAY...AHEAD OF AN APPROACHING
WARM FRONT. WINDS WILL BE OUT OF THE SOUTH AND WILL INCREASE TO 5 TO
10 MPH FOR MOST LOCATIONS BY THIS AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...AR
LONG TERM...HAL
AVIATION...AR
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
952 AM EDT MON MAY 27 2013
.Forecast Update...
Issued at 950 AM EDT Mon May 27 2013
Still looking like isolated to scattered convection will develop
later this afternoon. GOES Sounder data indicates the airmass has
dried out some now, but more moisture will advect into the region
this afternoon. In addition we have a weak warm front in the
vicinity, which is difficult to pick up in the wind field but a
little more apparent in the temp/dewpoint fields, with 60/low 50s
over our northeast and 70/60 over the southwest. We also have
residual boundaries from activity to our north overnight, along with
an atmosphere that should become less capped over the north later
this afternoon, as per RAP and NAM soundings. Given the combination
of these factors, have shifted the isolated storm line a little
south, but kept south central Kentucky dry for today. Some of the
high-res models are bringing a more organized line of storms in from
the west, from the system now over northern Missouri, and will have
to watch trends upstream to see if an update is necessary later.
Most of these models have any line that does move east weakening
quickly with sunset, but still have kept in isolated storm into the
evening to account for this possibility.
Issued at 630 AM EDT Mon May 27 2013
Current forecast remains on track at this time. Did adjust PoPs
downward across the region for the next several hours as convection
to our north continues to pull away from our area with little in the
way of downstream development. We do anticipate isolated to
scattered development later this afternoon. Temperatures are
nearing their overnight minimums with readings in the mid to upper
50s and will start to recover in the next hour once the sun comes up.
&&
.Short Term (Now - Tuesday)...
Issued at 325 AM EDT Mon May 27 2013
IR satellite and surface observations reveal clear mostly clear to
partly cloudy skies across the region this morning. Main batch of
cloudiness is across southern Indiana associated with convective
debris. Temperatures ranged from the middle 50s in our eastern
counties with lower 60s across our western sections. Some isolated
convection continues to move across far northern KY this morning.
This activity should continue to head on off to the east and may
clip our northern Bluegrass counties. For this reason, will hold on
to isolated shower/storm chances for the remainder of the morning
hours. Temperatures should continue to cool over the next few hours
with most locations dropping into the mid-upper 50s with readings
around 60 in the urban areas.
For Today, we`re likely to see partly cloudy skies across the
region. Weak frontal boundary that has been across the northern
sections will slowly advance northward during the day. Latest model
data suggests a weak upper level wave will approach the region from
the west during the afternoon hours. Overall moisture profile is
not all that great across the region. However, with slightly more
insolation today, we should have a little more instability to work
with this afternoon. Current indications are that the best chances
of showers and storms would generally be across southern Indiana and
portions of north-central Kentucky this afternoon...generally north
of the Western Ky and Bluegrass Parkways with drier conditions in
southern Kentucky. We should see warmer temperatures today with
highs in the lower 80s in southern Indiana and northern Kentucky
with mainly lower-middle 80s across southern Kentucky.
Dry conditions look likely as we head into the evening hours tonight
as any convection will probably slacken off with the loss of heating
and increasing stability within the PBL. Lows will cool into the
lower to middle 60s. High pressure and associated upper level
ridging will build into the region for Tuesday resulting in sunny
and warmer conditions with highs in the 81 to 86 degree range.
.Long Term (Tuesday Night- Sunday)...
Issued at 300 AM EDT Mon May 27 2013
Ridging aloft and high pressure at the surface will remain in
control for the latter half of the work week. Winds will be out of
the south with partly cloudy skies. Dry weather is expected through
this time frame. Temperatures will be on the warm side with highs
each day in the mid to upper 80s. Lows will range from the mid to
upper 60s.
Going into the weekend a low pressure system will track across the
Great Lakes region. A cold front associated with this system will
slowly approach the area Saturday and looks to finally push
through Sunday afternoon/night. Showers and thunderstorms will
accompany this front. For Saturday the best chance for showers and
thunderstorms will be along and north of the Ohio River.
Precipitation will slowly spread southeast overnight Saturday with a
better chance for precip areawide on Sunday. Temps Saturday look to
still top out in the mid 80s with highs in the lower 80s on Sunday.
Lows will be in the 60s.
&&
.Aviation (12Z TAF Issuance)...
Issued at 630 AM EDT Mon May 27 2013
VFR conditions are expected to continue at the TAF sites through the
upcoming forecast period. Convective debris, in the form of
mid-high level cloud cover continues to overspread the northern
sections of the forecast area this morning. This will mainly affect
KSDF and KLEX but will have no impact on aviation. Surface winds
will start of light and variable and then pick up out of the south
by mid-morning and into the afternoon hours. Upper level
disturbance is still on track to pass through the region later this
afternoon which may spark an isolated shower or storm this
afternoon. Coverage is still sparse to include in the upcoming TAF
forecast at this time.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Updates..........MJ/RJS
Short Term.......MJ
Long Term........EER
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
723 AM EDT MON MAY 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 532 AM EDT MON MAY 27 2013
WATER VAROR IMAGERY AND RUC ANALYSIS SHOW THE BEGINNINGS OF AN
ACTIVE PATTERN SHAPING UP FOR THE UPPER GREAT LAKES THIS WEEK. MEAN
TROF SETTLING INTO THE WRN CONUS THRU MIDWEEK AND THEN SLOW SHIFTING
E WILL SEND NMRS SHORTWAVES THRU THE CNTRL CONUS AND INTO THE GREAT
LAKES. MODELS WILL NO DOUBT STRUGGLE WITH THE CONVECTION ASSOCIATED
WITH THE WAVES...AND THE FCST WILL HAVE MUCH MORE THAN NORMAL
UNCERTAINTY BEYOND THE SHORT TERM. SEVERAL CLUSTERS OF SHRA/TSRA
HAVE BEEN OCCURRING FROM THE DAKOTAS TO THE OHIO VALLEY DURING THE
NIGHT...A SIGN OF THE ACTIVE PATTERN EVOLVING THIS WEEK.
MEANWHILE...DRY AIR CONTINUES TO LINGER OVER THE UPPER LAKES (NOTE
THE DRY 00Z SOUNDINGS FROM KGRB/KAPX).
THERE ARE 3 SHORTWAVES OF INTEREST FOR THE SHORT TERM. THE FIRST OF
IS OVER ERN MT/WRN ND...THE SECOND IS OVER WRN IA AND THE THIRD IS
OVER THE SRN ROCKIES. THE FIRST WAVE IS PRODUCING CONVECTION OVER
THE WRN DAKOTAS. THIS WAVE IS ON A TRACK TO LIFT NE AROUND THE RIDGE
EXTENDING N THRU THE MISSISSIPPI VALLEY TOWARD HUDSON BAY...AND WILL
NOT BE A FACTOR HERE. THE SECOND WAVE SHOULD WEAKEN AS IT CUTS THRU
THE RIDGE...AND ITS ASSOCIATED CONVECTION SHOULD ALSO WEAKEN AS IT
OUTRUNS THE INSTABILITY POOL OVER THE PLAINS. THE THIRD WAVE WILL
HELP STRENGTHEN THE LOW LEVEL JET TONIGHT AS IT MOVES OUT ACROSS THE
PLAINS. WITH FRONTAL BOUNDARY CURRENTLY WELL TO THE SW AND S AND NOT
LIKELY TO MAKE MUCH PROGRESS TODAY...DRY WEATHER WILL BE THE RULE
TODAY AND PROBABLY RIGHT INTO THE EVENING HRS. ALL MODELS WITH THE
EXCEPTION OF THE GEM HAVE TRENDED NOTABLY SLOWER ADVANCING PCPN
TOWARD UPPER MI. WILL THUS RUN WITH A DRY FCST INTO THE EVENING.
TONIGHT...STRENGTHENING LOW-LEVEL JET IN RESPONSE TO AFOREMENTIONED
SHORTWAVE WILL HELP GENERATE MORE SHRA/TSRA ACROSS THE PLAINS TOWARD
THE UPPER MISSISSIPPI VALLEY/WRN LAKES. DIFFICULT TO SAY HOW FAR N
AND E PCPN WILL ADVANCE...BUT WITH ADVANCING WARM FRONT STILL A GOOD
DISTANCE TO THE SW...WOULD EXPECT BULK OF SHRA/TSRA ACTIVITY TO
REMAIN TO THE S AND SW. HOWEVER...NRN FRINGES OF PCPN MAY STILL
SPREAD FAR ENOUGH N TO AFFECT AT LEAST SRN UPPER MI...AND WILL
INCLUDE SCHC/CHC POPS OVERNIGHT.
ALTHOUGH CI BLOWOFF FROM CONVECTION OVER ERN NEBRASKA/WRN IA IS
CURRENTLY SPREADING INTO UPPER MI...EXPECT THESE HIGH CLOUDS TO THIN
OUT SOME DURING THE DAY AS CONVECTION WEAKENS. SO...THERE SHOULD
STILL BE FAIRLY STRONG HEATING TODAY AND THUS DEEP MIXING TO BRING
DRIER AIR DOWN TO THE SFC. DWPTS SHOULD FALL TO THE LOW/MID 30S THIS
AFTN...PERHAPS LOWER OVER THE CNTRL/E BASED ON POTENTIAL MIXING
HEIGHTS. WITH HIGH TEMPS UP AROUND 70F IN THE INTERIOR...RH SHOULD
BOTTOM OUT IN THE 25-30PCT RANGE W AND 20-25PCT RANGE E. WINDS WILL
BE A LITTLE STRONGER TODAY AS SFC HIGH PRES RIDGE DRIFTS FARTHER E
OF THE AREA. WILL PROBABLY SEE AFTN GUSTS AROUND 20MPH OVER THE W
AND CNTRL AND 15MPH OVER THE E. WITH THE RECENT DRY DAYS...FIRE WX
CONCERNS WILL BE HIGHER TODAY GIVEN THE LOW RH AND A LITTLE STRONGER
WIND.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 532 AM EDT MON MAY 27 2013
TRICKY FORECAST FOR TUESDAY INTO TUESDAY NIGHT CONCERNING
PRECIPITATION CHANCES. OVERALL...SHORT WAVE ENERGY CURRENTLY MOVING
INTO THE CENTRAL PLAINS WILL MOVE INTO THE WESTERN GREAT LAKES
REGION LATER TONIGHT INTO TUESDAY. MEANWHILE...A WARM FRONTAL
BOUNDARY WILL MOVE NORTH INTO THE UPPER GREAT LAKES ON TUESDAY. THIS
WARM FRONT WILL LIKELY SERVE AS THE FOCUS FOR SHOWERS AND
THUNDERSTORMS...SIMILAR TO WHAT IT IS DOING THIS MORNING. THE
PROBLEM IS THAT THE NWP ARE HANDLING THIS WARM FRONT RATHER
POORLY...ALONG WITH THE 850MB JET THAT INTERSECTS THE FRONT. THE 12Z
ECMWF IS BY FAR THE FARTHEST WEST WITH THE LLJ AND ASSOCIATED
PCPN...PLACING THE HEAVIER PCPN ACROSS THE WESTERN LAKE AND WESTERN
UPPER MICHIGAN LATE TONIGHT INTO TUESDAY (ALTHOUGH THE 00Z ECMWF HAS
TRENDED AWAY FROM THIS SOLN). NOT SURE IF THE 12Z RUN MAKES SENSE AS
THE PCPN SEEMS TO RACE OUT AHEAD OF THE PRIMARY WARM FRONT.
MEANWHILE...THE NAM AND GFS CONTINUE TO BE SLOWER WITH PCPN MOVING
INTO THE AREA (WITH THE GFS BEING EVEN SLOWER)...BUT THEY KEEP THE
PCPN TIED TO THE FRONT...WITH THE HEAVIEST PCPN FURTHER SOUTH INTO
WISCONSIN WHERE THE LLJ IS JUSXTAPOSITIONED WITH THE BETTER
INSTABILITY. FINALLY...THE REGIONAL GEM IS SIMILAR WITH THE HEAVIEST
PCPN WELL SOUTH OF THE AREA BUT IT SPREADS PCPN INTO UPPER MICHIGAN
TOO FAST AND WELL AHEAD OF THE WARM FRONT. HAVE OPTED TO TREND
TOWARD A SLOWER NAM/GFS COMPROMISE SOLN WITH LIKELY POPS INTO
SOUTHERN UPPER MICH TUE MORNING...THEN SPREADING NORTH/EAST DURING
THE DAY AS THE WARM FRONT LIFTS NORTH. THE WESTERN AREAS WILL ALSO
TEND TO DRY OUT LATER IN THE DAY BEHIND THE SHORT WAVE. NOT TERRIBLY
IMPRESSED WITH THUNDER CHANCES ON TUESDAY. WITH THE SLOWER MOVEMENT
OF THE WARM FRONT...THE BEST INSTABILITY WILL REMAIN IN WISCONSIN.
SIMPLY DUE TO THE FORCING ALONG THE FRONT...CANNOT COMPLETELY RULE
OUT THUNDER BUT THE EXPECTATION IS THAT THE BEST THUNDER CHANCES
WOULD STAY ACROSS THE FAR SOUTH CLOSER TO THE BETTER INSTABILITY.
SHOULD END UP BEING A GENERALLY QUIET TUESDAY NIGHT AND WEDNESDAY
MORNING ACROSS THE AREA WITH UPPER AND SFC RIDGING ACROSS THE AREA.
WILL LIKELY BE A LITTLE MUGGY WITH THE AREA BEING IN THE WARM SECTOR
AND DEWPOINTS IN THE UPPER 50S. BUT GIVEN LACK OF FORCING OVERNIGHT
WILL GO WITH A DRY FORECAST AFTER ANY REMAINING SHOWERS/STORMS EXIT
EAST. ON WEDNESDAY...POPS WERE LOWERED WITH LACK OF ANY SIGNIFICANT
FOCUS FOR THUNDERSTORMS DESPITE MLCAPE VALUES OF 1000-1500 J/KG.
BETTER FOCUS FOR STORMS WITH THE NOSE OF THE 50KT LOW LEVEL JET AND
DEEP MOISTURE TRANSPORT INTO THE AREA EXPECTED WEDNESDAY NIGHT. THIS
MAY BE THE MOST LIKELY PERIOD FOR STRONG/SEVERE STORMS WITH FORWARD
PROPOGATING STORMS LIKELY MOVING INTO THE AREA FROM WISCONSIN.
FOR THE THU-SUNDAY PERIOD...THE AREA WILL BE FIRMLY IN THE WARM
SECTOR ON THURSDAY...AS THE LOW LEVEL JET BACKS TO A MORE SOUTHERLY
DIRECTION AND THE NOSE FOCUSES OVER NW WISCONSIN. EXPECT MORE
CONVECTION TO DEVELOP IN THIS AREA THURSDAY AND MOVE INTO UPPER
MICHIGAN DURING THE AFTN AND EVENING HOURS AS THE GFS AND 00Z ECMWF
ARE IN GOOD AGREEMENT IN SHOWING ANOTHER SHORT WAVE MOVING ACROSS
THE AREA. THE UPPER TROUGH AND SURFACE LOW FINALLY MOVES EAST
STARTING FRIDAY WITH THE SYSTEM MOVING ACROSS THE AREA BY SATURDAY.
WILL CONTINUE WITH CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
SATURDAY. ANOTHER WARM AND MUGGY DAY ON FRIDAY...THEN TURNING COOLER
BY SUNDAY AS 850MB TEMPS DROP TO +6C BEHIND THE SYSTEM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 722 AM EDT MON MAY 27 2013
ALTHOUGH HIGH PRES OVER THE GREAT LAKES REGION WILL BE DRIFTING E...
ASSOCIATED DRY LOW LEVEL AIR MASS WILL LIKELY LINGER AND MAINTAIN
VFR CONDITIONS AT KIWD/KCMX/KSAW THROUGH THIS FCST PERIOD. A WARM
FRONT OVER THE PLAINS WILL BE MOVING N TONIGHT...BUT LATEST GUIDANCE
IS TRENDING TOWARD KEEPING SHRA ASSOCIATED WITH FRONTAL BOUNDARY TO
THE S OF THE AREA. SOUTHEASTERLY WINDS WILL INCREASE TODAY WITH
GUSTS APPROACHING 20 KT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 532 AM EDT MON MAY 27 2013
WITH GENERALLY WEAK PRES GRADIENT AND STABLE CONDITIONS OVER LAKE
SUPERIOR...EXPECT WINDS TO BE UNDER 25KT THRU THE WEEK. HOWEVER...
WITH THE POTENTIAL FOR CLUSTERS OF SHRA/TSRA TO PASS ACROSS/NEAR THE
UPPER GREAT LAKES...THERE COULD BE SHORT PERIODS OF ENHANCED WINDS
AT TIMES (STRONGER SE WINDS OVER ERN LAKE SUPERIOR AND STRONGER NE
WINDS OVER WRN LAKE SUPERIOR). ONCE SOME RAINFALL OCCURS OVER THE
LAKE...FOG WILL LIKELY DEVELOP...AND IT COULD BECOME DENSE MID TO
LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...MRD
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
650 AM CDT MON MAY 27 2013
.AVIATION...12Z TAF ISSUANCE...
VFR CONDITIONS THIS MORNING...WITH MVFR CIGS ACROSS THE FAR SRN
AREAS OF THE FORECAST...POSSIBLY IMPACTING BRD AND HYR BEFORE 18Z.
COULD ALSO SEE A FEW SHOWERS AROUND BRD THIS AFTERNOON.
OTHERWISE...CONDITIONS SHOULD REMAIN VFR AND DRY UNTIL THIS
EVENING WHERE LIGHT RAIN SHOWERS COULD DEVELOP ACROSS SRN/CENTRAL
MN AND MOVE NORTHWARD WITH MVFR CIGS AND GUSTY SE WINDS.
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT MON MAY 27 2013/
SHORT TERM...TODAY THROUGH TUESDAY...
STRENGTH AND PERSISTENCE OF LOW LEVEL RIDGING OVER THE CENTRAL AND
EASTERN GREAT LAKES REGION CONTINUES TO BE GREATER THAN PREVIOUS
MODEL FORECASTS THIS MORNING..WITH DRY/COOL EASTERLY FLOW
PERSISTING. THE OVERALL REASONING WITH THIS FORECAST PACKAGE HAS
NOT CHANGED A LOT FROM YESTERDAY AT THIS TIME..WITH THE ONE MAJOR
EXCEPTION THAT THE NORTHWARD THRUST OF MOISTURE AND INSTABILITY
SEEMS TO BE DELAYED 12-24 HOURS FROM PREVIOUS THINKING.
THUS..CHANCES FOR PRECIP TODAY/TONIGHT ARE SMALLER ACROSS THE
DULUTH CWA AS THE ENTIRE PATTERN SUGGESTS A SOUTHWARD SUPPRESSION
OF CONVECTIVE ACTIVITY THROUGH TONIGHT AS OUTFLOW FROM LARGE MCS
IN IOWA ACTS TO REINFORCE WARM FRONTAL BOUNDARY. AS A RESULT..WE
HAVE REDUCED POPS FOR TODAY AND TONIGHT IN MOST AREAS..ALTHOUGH
THERE WILL STILL BE SMALL CHANCES FOR SHOWERS/TSTORMS ACROSS THE
SOUTH THIS AFTERNOON AND TONIGHT.
S/W TROF IN BROAD WSW FLOW ALOFT WILL APPROACH THE AREA FROM THE
WEST LATE TONIGHT..AND SHOULD FINALLY ALLOW THE 925-850
THERMAL/MOISTURE GRADIENT TO MOVE NORTHWARD TO NEAR THE SW PART OF
THE DULUTH CWA. THIS SHOULD BRING VERY GOOD CHANCES FOR SHOWERS
AND THUNDERSTORMS TO THE SOUTHEAST HALF TO TWO THIRDS OF THE CWA
ON TUESDAY. HOWEVER..IT NOW APPEARS THAT THE BEST SEVERE THREAT
WILL REMAIN FARTHER SOUTH.
LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
AN UPPER S/W AND ASSOCIATED SFC WARM FRONT WILL LIFT TO THE NE TUE
NIGHT/WED MORNING AS HIGH PRESSURE BUILDS IN FROM THE SW. THERE WILL
BE RAIN SHOWERS AND A FEW WEAK THUNDERSTORMS WITH THIS WAVE...AND
QUICKLY TAPER OFF FROM WEST TO EAST THROUGH THE NIGHT. ANOTHER
PERIOD OF SHOWERS AND STORMS IS EXPECTED TO DEVELOP WED AFTERNOON AS
A POTENT UPPER LOW TRACKS EWD THROUGH THE NRN ROCKIES INTO THE UPPER
MIDWEST...AND A SFC WARM FRONT LIFTS SLOWLY NWD THROUGH THE REGION.
A STRONGER SURGE OF WARM/MOIST/UNSTABLE AIR WILL ADVECT IN FROM THE
SOUTH ON THE LEADING EDGE OF A 40-50KT LLJ. THE INTERACTION OF THIS
UPPER WAVE AND UNSTABLE AIR MASS WILL ALLOW FOR THUNDERSTORMS TO
DEVELOP WED NIGHT. A FEW OF THESE STORMS COULD BECOME STRONG TO
SEVERE...AND PRODUCE LOCALLY HEAVY RAINFALL AS WELL. COULD SEE A
BRIEF BREAK IN THE SHOWERS THUR MORNING BEFORE ANOTHER ROUND OF
SHOWERS AND STORMS DEVELOP THUR AFTERNOON AND LAST THROUGH FRI
MORNING. THE ACTIVE WEATHER WILL LIKELY CONTINUE INTO THE WEEKEND.
HOWEVER...THE INSTABILITY WILL DECREASE...AND KEEP THUNDER CHANCES
AT A MINIMUM. CONDITIONS GRADUALLY DRY OUT ON SUNDAY AS HIGH
PRESSURE OVER ALBERTA/MANITOBA MOVES IN FROM THE NW.
TEMPERATURES WILL START OUT RATHER WARM...WITH RELATIVELY HIGH
HUMIDITIES...TUESDAY/WEDNESDAY. HIGHS WILL RANGE FROM THE UPPER 60S
TO MID/UPPER 70S ACROSS THE REGION. A SLIGHT COOLING TREND WILL
START UP FRIDAY AND CONTINUE THROUGH THE WEEKEND. HIGH TEMPS WILL
DROP FROM THE 70S...INTO THE 60S. OVERNIGHT LOWS THROUGH THE
EXTENDED PERIOD WILL RANGE FROM THE 50S AND 60S EARLY...TO THE 40S
AND 50S LATE.
AVIATION...06Z TAF ISSUANCE...
VFR CONDITIONS WERE OCCURRING ACROSS THE NORTHLAND AS OF LATE
EVENING...WITH MVFR CEILINGS INCHING CLOSER TO KBRD. THESE LOWER
CEILINGS WILL AFFECT KBRD FIRST...THEN SLOWLY MOVE NORTH AND WEST.
THE LATEST RAP DELAYS THESE CEILINGS OVER THE REST OF THE TAF
SITES...AND SUGGEST THEY WILL NOT AFFECT KDLH/KINL/KHIB/KHYR UNTIL
LATE MONDAY AFTERNOON OR EVENING. WE ARE GOING TO FOLLOW THIS
TREND.
A FEW LIGHT SHOWERS/SPRINKLES CONTINUED OVER PORTIONS OF THE SOUTH
AND WEST...BUT RADAR SHOWED COVERAGE AND INTENSITY DECREASING. WE
PULLED SHOWERS OUT OF MOST TAFS THROUGH THE PERIOD...AS THE MODELS
TREND OF SLOWING THINGS DOWN CONTINUES.
&&
.POINT TEMPS/POPS...
DLH 60 51 66 52 / 30 50 50 20
INL 72 52 70 53 / 10 30 20 40
BRD 65 55 71 54 / 30 60 40 10
HYR 67 56 71 56 / 40 60 60 20
ASX 67 53 64 51 / 30 50 60 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1057 AM CDT MON MAY 27 2013
.MESOSCALE DISCUSSION...
ISSUED AT 1034 AM CDT MON MAY 27 2013
THE SETUP FOR THE REMAINDER OF TODAY REMAINS RATHER COMPLEX. FIRST
OFF...WE CONTINUE TO MONITOR AN MCS ALONG AND IMMEDIATELY SOUTH OF
THE INTERSTATE 70 CORRIDOR. WHILE THE LOW LEVEL JET HAS STARTED TO
WEAKEN...THE KSGF VAD WIND PROFILE CONTINUES TO INDICATE AROUND 40
KNOTS OF MAGNITUDE. THE LATEST RAP RUN HAS FINALLY CAUGHT ONTO
THIS SLOWER DEMISE TO THE LOW LEVEL JET. WE ARE THEREFORE
EXPECTING THE MCS TO CONTINUE ITS SOUTHEASTWARD DRIFT INTO
CENTRAL MISSOURI FOR THE NEXT FEW HOURS UNTIL THE JET FINALLY
WEAKENS.
ONCE WE GET INTO EARLY THIS AFTERNOON...WE WILL THEN BE LOOKING AT
MORE IN THE WAY OF SURFACE BASED CONVECTION POTENTIAL.
MODIFICATION OF THE 12 UTC KSGF RAOB ALONG WITH SHORT RANGE
FORECAST SOUNDINGS INDICATES THERE WILL BE LITTLE IN THE WAY OF A
CAPPING INVERSION THIS AFTERNOON. MLCAPE VALUES WILL BE IN THE
2000 TO 3000 J/KG RANGE. THUS...OUTFLOW FROM THE MCS MAY CONTINUE
TO KICK UP ADDITIONAL UPDRAFTS. ADDITIONALLY...SATELLITE IMAGERY
INDICATES SOME SORT OF MID LEVEL WEAKNESS DRIFTING EAST ALONG THE
KANSAS/OKLAHOMA STATE LINE. THIS FEATURE MAY ALSO SERVE AS A FOCUS
FOR CONVECTION THIS AFTERNOON.
WITH ALL OF THAT SAID...WE HAVE RAISED POPS OVER MOST AREAS FROM
17 UTC THROUGH SUNSET. THE HIGHEST POPS WERE PLACED ACROSS THE
TRUMAN AND LAKE OF THE OZARKS REGION TO COVER THE MCS. THE MAIN
THREATS FROM ANY STORMS WILL BE FREQUENT LIGHTNING AND LOCALLY
TORRENTIAL RAINFALL. ONCE STORMS BECOME SURFACE BASED...WE WILL
HAVE TO WATCH FOR ANY EASTWARD MOVING LINE SEGMENTS FOR GUSTY WIND
POTENTIAL GIVEN THE ORIENTATION OF LOW LEVEL SHEAR VECTORS.
&&
.UPDATE...
ISSUED AT 539 AM CDT MON MAY 27 2013
QUICK UPDATE TO MORNING FORECAST JUST SENT TO UPDATE POPS OVER
CENTRAL MISSOURI BASED ON LATEST RADAR TRENDS. MCS CONTINUES TO
DIVE SOUTH TOWARD KANSAS CITY EARLY THIS MORNING...AND SEEMS TO BE
HOLDING TOGETHER WELL FOR NOW. THE ENVIRONMENT BECOMES SOMEWHAT
MORE HOSTILE FURTHER SOUTH...AND SO CONTINUED SOUTHWARD MOVEMENT
ALONG WITH A DECREASE IN LLJ STRENGTH SHOULD RESULT IN A WEAKENING
TREND WITH TIME. NONETHELESS...AT LEAST SCATTERED THUNDERSTORMS
SEEM POSSIBLE OVER CENTRAL MISSOURI BY 9 AM OR SO...AND CHANCES
MAY PUSH A LITTLE FURTHER SOUTH TOWARD I-44 CLOSER TO MID DAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CDT MON MAY 27 2013
THE REMAINS OF A MCS HAVE DROPPED SOUTH INTO CENTRAL MISSOURI AS
OF 2 AM...ALBEIT IN A RAPIDLY DECAYING FASHION. THUNDERSTORMS
ASSOCIATED WITH THIS ACTIVITY CONTINUE TO PERCOLATE NORTH OF THE
U.S. 54 CORRIDOR...AND THIS TREND SHOULD CONTINUE THROUGH EARLY TO
MID MORNING. A WELL-DEFINED OUTFLOW BOUNDARY ASSOCIATED WITH THIS
ACTIVITY STRETCHES ACROSS MOST OF CENTRAL AND WEST-CENTRAL
MISSOURI...AND SOME ADDITIONAL ELEVATED ACTIVITY MAY BE POSSIBLE
BEFORE SUNRISE ALONG THE WESTERN FLANK OF THIS OUTFLOW...WHERE
THERE WILL BE AT LEAST SOME INTERSECTION WITH THE LLJ AXIS.
ANOTHER MCS IS CURRENTLY DROPPING SOUTHEAST THROUGH THE MISSOURI
RIVER VALLEY (APPROACHING OMAHA AREA AS OF 2 AM)...AND WILL CONTINUE
SOUTHEAST INTO NORTHERN MISSOURI BEFORE SUNRISE. AS WAS THE CASE
WITH THE FIRST MCS...A DIMINISHING TREND IS EXPECTED ONCE IT OUTRUNS
A MORE FAVORABLE SHEAR ENVIRONMENT AND BECOMES VERY OUTFLOW
DOMINATE. SOME OUTFLOW FROM THIS COMPLEX MAY MAKE IT INTO THE
NORTHERN SECTIONS OF THE CWA THIS MORNING AS WELL.
ADDITIONAL CONVECTION APPEARS POSSIBLE LATER TODAY OVER THE NORTHERN
CWA...TIED TO THE REMNANT OUTFLOW BOUNDARIES ACROSS CENTRAL MISSOURI.
ANYTHING THAT DEVELOPS DURING THE DAYTIME HOURS TODAY SHOULD BE
FAIRLY ISOLATED IN NATURE...AND SHOULD DISSIPATE FAIRLY QUICKLY
WITH SUNSET.
OTHERWISE...BREEZY CONDITIONS WILL CONTINUE TODAY...WITH HIGHS AGAIN
WARMING INTO THE LOW TO MID 80S. READINGS MAY BE JUST A FEW DEGREES
COOLER OVER THE NORTHEASTERN CWA WHERE CLOUD COVER AND ISOLATED
THUNDERSTORMS WILL LIMIT HEATING TO SOME DEGREE.
LATER THIS EVENING INTO TONIGHT...WIDESPREAD CONVECTION IS EXPECTED
TO DEVELOP ACROSS NORTHERN KANSAS AND SOUTHERN NEBRASKA...WITH SOME
INDICATIONS THAT ACTIVITY WILL ORGANIZE INTO A FORWARD PROPAGATING
MCS. THIS MCS SHOULD MAINLY AFFECT AREAS NORTH OF I-70 LATER
TONIGHT...THOUGH WE WILL NEED TO WATCH FOR THE POTENTIAL FOR OUTFLOW
SETTLING SOUTH WITH TIME...PERHAPS AFFECTING SOME OF OUR
SOUTHEASTERN KANSAS COUNTIES AND AREAS NORTH OF U.S. 54.
FOR NOW...DON`T THINK THE POTENTIAL IS TERRIBLY HIGH...AND WILL
JUST CARRY SLIGHTS ACROSS THIS AREA AFTER 06Z.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM CDT MON MAY 27 2013
A GRADUAL AMPLIFICATION OF THE OVERALL CONUS PATTERN WILL COMMENCE
LATER TONIGHT INTO THE DAY TUESDAY. AS THE WESTERN TROUGH
DEEPENS...SOUTHWEST FLOW ALOFT SHOULD ADVECT IN RATHER WARM MID
LEVEL TEMPS FOR TUESDAY...LITERALLY KEEPING A LID ON CONVECTION
OVER THE CWA.
BY WEDNESDAY...HEIGHT FALLS WILL COMMENCE OVER THE AREA...SUGGESTING
A GRADUAL WEAKENING IN INHIBITION WITH TIME. THUNDERSTORM POTENTIAL
WILL INCREASE WEDNESDAY EVENING AND ESPECIALLY WEDNESDAY NIGHT...AS
WIDESPREAD CONVECTION DEVELOPS ACROSS THE PLAINS AND MOVES
EAST/NORTHEAST. WE`LL NEED TO WATCH FOR A FEW STRONGER STORMS
WEDNESDAY NIGHT AS OVERALL BULK SHEAR INCREASES WITH TIME...BUT THE
PRIMARY SURFACE BOUNDARIES REMAINING WELL TO OUR WEST...THINK THAT
SEVERE WX WILL BE THE EXCEPTION.
ON THURSDAY...SEVERAL ADDITIONAL ROUNDS OF CONVECTION SHOULD FIRE TO
OUR WEST...AGAIN MOVING WITH TIME INTO THE CWA. WITH STORM
MOTION VECTORS TO THE NORTHEAST...AREAS WEST OF U.S. 65 SHOULD SEE
THE GREATEST STORM COVERAGE.
BY FRIDAY INTO SATURDAY...A COLD FRONT WILL FINALLY BEGIN TO SWEEP
SOUTHEAST ACROSS THE CENTRAL PLAINS. A LINE OF CONVECTION SHOULD
FIRE ALONG THE COLD FRONT FRIDAY...AND MOVE SLOWLY ACROSS THE CWA
WITH THE FRONT THROUGH SATURDAY. WITH SHEAR VECTORS PARALLEL TO THE
FRONTAL BOUNDARY...WIDESPREAD SEVERE WEATHER MAY BE HARD TO COME
BY. THAT SAID...1500 J/KG OF MLCAPE AHEAD OF THE FRONT WILL BE MORE
THE SUFFICIENT FOR A FEW STRONGER STORMS. PERHAPS OF GREATER CONCERN
IS A HEAVY RAIN THREAT...AS STORMS TRAIN ALONG THE SURFACE BOUNDARY
FROM SOUTHWEST TO NORTHEAST. WITH DEWPOINTS IN THE UPPER 60S TO LOW 70S
AND PWAT VALUES APPROACHING 1.75 INCHES (NEARLY 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR)...RAINFALL RATES WILL
BE HEALTHY. CONSIDERING THE INITIAL ROUNDS OF CONVECTION WEDNESDAY NIGHT
AND THURSDAY...STORM TOTAL RAINFALL LOOKS TO BE SOMEWHAT HIGHER
ALONG AND NORTH OF I-44.
THE COLD FRONT SHOULD CLEAR THE AREA BY LATE SATURDAY AND SATURDAY
NIGHT...WITH HIGH PRESSURE BUILDING IN BY SUNDAY. THIS LOOKS TO
RESULT IN A PLEASANT END TO THE WEEKEND...WITH TEMPERATURES LIKELY
RIGHT AROUND OR JUST BELOW NORMAL FOR THE FIRST OF JUNE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 638 AM CDT MON MAY 27 2013
RATHER COMPLEX FORECAST OVER THE NEXT 24 HOURS. ALTOCUMULUS DECK
AROUND 5000 FT IS PRODUCING A FEW SHOWERS ACROSS CENTRAL MISSOURI
AND THE EASTERN OZARKS...AND SHOULD NOT AFFECT THE JLN/SGF/BBG
AERODROMES. A LINE OF THUNDERSTORMS MOVING SOUTHWARD ACROSS
NORTHEAST KANSAS AND NORTHWEST MISSOURI WILL LIKELY FALL APART AS
THE MORNING PROGRESSES...THOUGH LEAVE A BOUNDARY NEARBY ACROSS THE
AREA. A FEW OTHER BOUNDARIES ARE PRESENT WHICH COULD RESULT IN THE
POTENTIAL FOR WIDELY SCATTERED SHRA/TSRA THIS AFTERNOON...
ESPECIALLY ACROSS CENTRAL MISSOURI. CONFIDENCE IS JUST TOO LOW AT
THIS TIME TO INCLUDE ANY RISK FOR JLN/SGF/BBG. THIS CHANGES
TONIGHT AS A MORE ROBUST CLUSTER OF THUNDERSTORM DEVELOPS OVER
SOUTHERN NEBRASKA AND NORTHERN KANSAS AND MOVES TO THE EAST
SOUTHEAST. THIS WILL HAVE THE POTENTIAL TO CLIP THE JLN/SGF
AERODROMES. LOW LEVEL WIND SHEAR WILL ONCE AGAIN BE AN ISSUE
TONIGHT AS A SOUTHWESTERLY LOW LEVEL JET SPREADS OVER THE REGION.
OVERALL EXPECT VFR CONDITIONS WITH BRIEF BOUTS OF IFR POSSIBLE
WITH ANY THUNDERSTORM ACTIVITY.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...SCHAUMANN
UPDATE...BOXELL
SHORT TERM...BOXELL
LONG TERM...BOXELL
AVIATION...GAGAN
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
748 AM CDT MON MAY 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT MON MAY 27 2013
ONCE AGAIN DEALING WITH A COMPLEX FORECAST WITH THE SENSIBLE WEATHER
STRONGLY CONTROLLED BY MESOSCALE FACTORS...SOMETHING THE MODELS
TYPICALLY HAVE DIFFICULTY IN RESOLVING. THE CONVECTIVE SYSTEM
CURRENTLY EXTENDING THROUGH EASTERN MO HAS BEEN WEAKENING AND
SHRINKING OVER THE LAST FEW HOURS AS IT MOVES ESEWD TOWARDS THE MS
RIVER. I SEE NO REASON FOR THIS TREND NOT TO CONTINUE...WITH A
CONTINUED DECREASE IN INTENSITY AND COVERAGE AS IT OUTRUNS THE
INSTABILITY AND BETTER LOW LEVEL FORCING. ATTENTION THEN TURNS TO
THE MATURE BOW ECHO SYSTEM/MCS ACROSS WESTERN IOWA/SERN NEBRASKA.
THIS WELL-DEFINED SYSTEM IS BEING FEED BY A 40+KT SWLY LLJ WITH
MUCAPES OF 1500-2000 J/KG. VIRTUALLY ALL THE EXPLICIT CONVECTION
ALLOWING MODELS INCLUDING THE HRRR BRING THIS SYSTEM SEWD THIS
MORNING AND HAVE IT IMPACTING THE AREA ALONG AND NORTH OF
I-70...PRIMARILY THIS AFTERNOON. I`M NOT SURE ABOUT THE TIMING OR
THE EXACT STRUCTURE OF THE FINAL PRODUCT BUT THIS SCENARIO LOOKS
QUITE REASONABLE AND I HAVE LIKELY POPS OVER A MOST OF THE NRN
2/3RDS OF THE CWA. THE SYSTEM IS MOVING AT A PRETTY GOOD CLIP
RIGHT NOW AND PURE EXTRAPOLATION WOULD HAVE IT ENTERING THE NW
PORTION OF THE CWA 14Z OR SO...HOWEVER IT MAY BECOME MORE ELONGATED
WITH TIME. THE LONGER IT TAKES TO ENTER THE CWA...THE GREATER THE
OPPORTUNITY FOR THE AIR MASS AHEAD OF IT TO DESTABILIZE AND THEN FOR
THE SYSTEM AND ITS MESOSCALE BOUNDARY TO INTERACT WITH. IT COULD
POSE A LOCALLY HEAVY RAIN AND WIND THREAT DEPENDING ON ITS FINAL
INTENSITY.
NORTHERN PORTIONS OF MO INTO WEST CENTRAL IL LOOK ACTIVE AGAIN
TONIGHT. A SHORTWAVE WILL BE MOVING ENEWD FROM THE PLAINS INTO THE
MID/UPPER MS VALLEY PROVIDING LARGE SCALE ASCENT ALONG WITH
FORCING VIA A STOUT 50+ KT VEERING SWLY LLJ. THIS WILL PROVIDE
STRONG SUPPORT FOR AT LEAST ONE AND POSSIBLY SEVERAL MCSS WHICH
TRACK EASTWARD FROM THE CENTRAL PLAINS AND EFFECT PORTIONS OF NRN
MO. AGAIN THERE COULD BE A WIND AND HEAVY RAIN THREAT WITH ANY
SYSTEM.
GLASS
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 400 AM CDT MON MAY 27 2013
THE CHANCE OF SHOWERS AND THUNDERSTORMS LINGERS A BIT LONGER THAN
PREVIOUSLY FORECAST INTO TUESDAY AND TUESDAY NIGHT ACCOUNTING FOR
RESIDUAL BOUNDARIES FROM TONIGHTS ACTIVITY...HOWEVER OVERALL THE
AREA IMPACTED SHOULD BE SHRINKING AND TEMPERATURES WILL BE WARMING
TUESDAY AND WEDNESDAY AS A RIDGE BUILDS THRU THE ERN U.S. BY THE
LATER PART OF THE WEEK AND INTO THE WEEKEND WE GET BACK INTO AN
ACTIVE PATTERN AS A DEEP UPPER TROF SLOWLY PROGRESSES EASTWARD
INTO THE NATIONS MIDSECTION.
GLASS
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 742 AM CDT MON MAY 27 2013
DEALING WITH NEXT MCS THAT IS DROPPING SOUTH AND SOUTHEAST INTO MO
AS OF 1230Z. IN THE MEANTIME...KUIN HAS SOME LINGERING MVFR
CIGS...WHICH SHOULD LIFT TO VFR BY 16Z AS NEXT ROUND OF STORMS
MOVES IN. OTHERWISE...STORMS TO MOVE INTO KCOU BY 16Z AND METRO
AREA BY 19Z. STILL HARD TO PIN DOWN EXACT TIMING OF PCPN...SO JUST
HAVE VCTS MENTION AT THIS TIME. STORMS TO WEAKEN AND EXIT BETWEEN
21Z AND 00Z. ANOTHER ROUND OF STORMS POSSIBLE LATE TONIGHT...BUT
ONCE AGAIN TIMING AND COVERAGE HARD TO PIN DOWN...SO JUST HAVE
VCTS MENTION AFTER 07Z-10Z TUESDAY TIMEFRAME.
SPECIFICS FOR KSTL...DEALING WITH NEXT MCS THAT IS DROPPING SOUTH
AND SOUTHEAST INTO MO AS OF 1230Z. STORMS TO MOVE INTO METRO AREA
BY 19Z. STILL HARD TO PIN DOWN EXACT TIMING OF PCPN...SO JUST HAVE
VCTS MENTION AT THIS TIME. STORMS TO WEAKEN AND EXIT BY 00Z TUESDAY.
ANOTHER ROUND OF STORMS POSSIBLE LATE TONIGHT...BUT ONCE AGAIN
TIMING AND COVERAGE HARD TO PIN DOWN...SO JUST HAVE VCTS MENTION
AFTER 10Z TUESDAY.
BYRD
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
638 AM CDT MON MAY 27 2013
.AVIATION...12Z TAFS FOR KOFK...KLNK AND KOMA.
SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT KLNK AND KOMA
THROUGH ABOUT 17Z THIS MORNING WITH ATTENDANT MVFR CIGS/VSBYS.
SOME AREAS OF IFR CIGS NEAR KOFK SHOULD LIFT TO VFR BY 18Z. THEN
MORE THUNDERSTORMS ARE LIKELY DURING THE LATE AFTERNOON AND
EVENING...MOSTLY LIKELY DEVELOPING IN SOUTH CENTRAL NEBRASKA AND
EXPANDING EAST WITH TIME. SOME STRONG THUNDERSTORMS ARE POSSIBLE
BETWEEN 00Z AND 06Z AT ALL TAF SITES. STORMS SHOULD PERSIST PAST
06Z...WITH A GRADUAL DECREASE IN INTENSITY AND COVERAGE LATE IN
THE TAF PERIOD. THERE IS SOME INDICATION IFR CIGS WILL DEVELOP
AFTER STORMS END BETWEEN 06Z AND 12Z...BUT WILL ADDRESS THIS
SCENARIO WITH LATER TAF ISSUANCES.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 425 AM CDT MON MAY 27 2013/
DISCUSSION...
VERY SHORT TERM CONCERNS WILL BE SEVERE THUNDERSTORM WATCH THAT
CONTINUES UNTIL 5AM FOR PARTS OF SOUTHERN NEBRASKA AND SOUTHWEST
IOWA. THEN...FORECAST CONCERNS CONTINUE TO BE THUNDERSTORMS AND
SEVERE WEATHER POTENTIONAL/HEAVY RAIN IN ACTIVE WEATHER PATTERN
THIS WEEK.
THE 00Z OAX SOUNDING HAD CAPE OF NEARLY 4000J/KG...STEEP MID LEVEL
SHEAR...PRECIPITABLE WATER OF 1.52 INCHES (185%)...FREEZING LEVEL OF
13,500...AND SFC-2KM SRH OF 258M2/S2. THE SURFACE WARM FRONT WAS
SOUTH OF COLUMBUS TO PLATTSMOUTH INTO SOUTHWEST IOWA. AT
00Z...THUNDERSTORMS FORMED IN SOUTHWEST IOWA ALONG THE WARM
FRONT/OUTFLOW BOUNDARY AND BY 02Z...THUNDERSTORMS HAD DEVELOPED OVER
NORTH CENTRAL NEBRASKA AND WERE SPREADING SOUTHEAST ACROSS THE
FORECAST AREA AT 06Z. THE STRONGER WINDS ALOFT WERE HAVING A TOUGH
TIME MAKING IT DOWN TO THE SURFACE...HOWEVER THE STRONGER WINDS DID
START TO REACH THE GROUND AS THE STORMS APPROACHED THE FREMONT AREA
AND AS THEY MOVED THROUGH PARTS OF DOUGLAS CO. FREMONT HAD A WIND
REPORT OF 77 MPH AND WEST OF EPPLEY 67 MPH...WITH SOME WINDS 50 TO
55 MPH.
THE 00Z H5 PATTERN HAD A TROF OVER THE WESTERN U.S. +10C AIR AT
H7 HAD SPREAD INTO SOUTH CNTRL NEB AND +9 AT OAX. THE H85 DEWPOINT
WAS 17DEG C AT KOAX.
THROUGH 06Z MONDAY NIGHT...PRECIPITABLE WATER REMAINS HIGHS...FROM
AROUND 1.5 TO 1.6 INCHES...THEN RETURNS NORTHWARD BY 00Z TUESDAY
EVENING AND REMAINS HIGH THROUGH WEDNESDAY NIGHT. THE UPPER LEVEL
JET AND H5 PATTERN WILL REMAIN FAVORABLE FOR THUNDERSTORMS TO
DEVELOP OVER THE FORECAST AREA.
TODAY...THE SURFACE BOUNDARY WILL BE AFFECTED BY THE CONVECTION
THIS MORNING AND WILL MAINTAIN SOME THUNDERSTORMS OVER PARTS OF
THE AREA UNTIL THE LOW LEVEL JET WEAKENS. THE OVERALL TREND IS A
DIURNAL WEAKENING THIS MORNING...HOWEVER LOW LEVEL FLOW RETURN
THIS AFTERNOON AND EVEN MORESO OVERNIGHT AS A 50KT LOW LEVEL JET
DEVELOPS ACROSS KANSAS AND SHORTWAVE TROF ENERGY ONCE AGAIN MOVES
ACROSS THE REGION. WITH THE FRONTAL LOCATION UNCERTAIN...TRENDED
COOLER WITH THE TEMPERATURES IN THE NORTH AND LEFT HIGHS IN THE
80S SOUTH. THIS PATTERN CONTINUES THROUGH THE WEEK AND THE UPPER
LEVEL TROF SHIFTS EASTWARD INTO THE PLAINS WEDNESDAY. WE ARE STILL
IN THE SEVERE WEATHER OUTLOOK FOR DAYS 1 THRU 3 AND HEAVY RAIN
WILL BE POSSIBLE WITH THE STORMS THAT DEVELOP. ALTHOUGH WE ARE NOT
IN THE EXCESSIVE OUTLOOK. WILL NEED TO ASSESS HEAVY RAIN POTENTIAL
AND FLASH FLOOD WATCH EACH SHIFT DUE TO THE REPEATED RAINS
EXPECTED.
AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
TSRA SHOULD CONTINUE IN THE KOFK AREA THE NEXT SEVERAL HOURS...
WITH THE STRONGEST ACTIVITY LIKELY BEFORE 07Z. THERE IS STILL
SOME UNCERTAINTY HOW FAR SOUTHEAST STORMS WILL REACH OVERNIGHT...
BUT HRRR MODEL DEVELOPS ACTIVITY TOWARD NORTHEAST KANSAS AND
NORTHWEST MISSOURI BY A LITTLE AFTER SUNRISE.
EXPECT A GRADUAL DECREASE IN CEILINGS THROUGH 14Z...THEN A GRADUAL
UPWARD TREND TOWARD VFR CONDITIONS AT ALL THREE SITES BY EARLY
AFTERNOON MONDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
933 AM CDT MON MAY 27 2013
.UPDATE...
ISSUED AT 930 AM CDT MON MAY 27 2013
MINIMAL CHANGES FOR THIS UPDATE. LIGHT SHOWERS ACROSS N CENTRAL ND
CONTINUE TO WEAKEN AND NOT LIKELY TO REACH FAR NW FA. OTHER
SHOWERS CONTINUE ACROSS NW-N CENTRAL SD HOWEVER NOT CONFIDENT
ENOUGH THAT THEY WILL HOLD TOGETHER SO WILL MAINTAIN DRY FORECAST
FOR NOW. CLOUDS COVER ALL BUT FAR NE FA AND WITH LOW CONVECTIVE
TEMPERATURES AND MOIST LAYER AOB 3-4K FT FEEL ANY SOLAR WILL BE
VERY LIMITED. THIS WILL RESULT IN TEMPERATURES SIMILAR TO YSTDY SO
CURRENT MAX VALUES SEEM GOOD.
UPDATE ISSUED AT 650 AM CDT MON MAY 27 2013
WATCHING A BAND OF SHOWERS/THUNDER ACROSS WESTERN NORTH DAKOTA
SLOWLY PROPAGATE TO THE EAST. THIS ACTIVITY WOULD MOVE INTO THE
WESTERN FA AROUND 15Z-16Z AT ITS CURRENT PACE. THE RESPONSIBLE
UPPER WAVE IS PROPAGATING TO THE NORTHEAST...AND STILL EXPECT THIS
ACTIVITY TO WEAKEN. IF THEY HOLD TOGETHER...THE NEXT UPDATE CAN
TAKE CARE OF THIS. THE LAST FEW HRRR RUNS ARE INITIATING SHOWERS
WITHIN THE FA AROUND 15Z-17Z...POSSIBLY ASSOCIATED WITH AN UPPER
WAVE CURRENTLY PRODUCING SHOWERS ACROSS NORTHWEST SOUTH DAKOTA.
WILL STICK WITH THE DRY FORECAST AND MONITOR...IT SEEMS UNLIKELY
THAT ANY MEASURABLE PRECIP WILL OCCUR GIVEN THE STABLE AIRMASS
(ALTHOUGH WOULD NOT DOUBT SOME SPRINKLES). NOT MUCH HAS CHANGED
WITH THE THINKING REGARDING CLOUDS AND MAX TEMPS FOR TODAY...THE
NEXT UPDATE SHOULD HAVE A MUCH BETTER IDEA WITH HOW THE LOW CLOUDS
WILL BEHAVE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT MON MAY 27 2013
THE CHALLENGE WILL BE SHOWER/THUNDER CHANCES AND TIMING/PLACEMENT
OF SHORTWAVES IN SOUTHWEST FLOW ALOFT. THE MODELS ALL INDICATE THE
SAME GENERAL SOLUTION...BUT DIFFER GREATLY WITH WHERE THEY
INITIATE AND PROPAGATE CONVECTIVE COMPLEXES. THE ECMWF...AND
ESPECIALLY THE GEM...HAVE VERIFIED THE BEST OVER THE PAST COUPLE
DAYS...AND WILL FOLLOW FOR DETAILS.
FOR TODAY...THERE ARE TWO SHORTWAVES AND ASSOCIATED CONVECTIVE
COMPLEXES THAT COULD AFFECT THE FA. ONE IS ENTERING IOWA...AND
PROPAGATING SOUTHEAST...AND WILL REMAIN WELL TO THE SOUTH. THE
SECOND IS ACROSS WESTERN NORTH DAKOTA. THE STRONGEST FORCING FROM
THIS SHORTWAVE WILL CONTINUE PROPAGATING TO THE NORTHEAST...AND
SHOULD MISS THE FA. THE AIRMASS REMAINS STABLE AS LOW LEVEL
SOUTHEAST FLOW CONTINUES...AND EXPECT ANYTHING THAT APPROACHES THE
FA TO FALL APART (MUCH LIKE YESTERDAY). SO...WENT WITH A DRY
FORECAST FOR TODAY (THERE COULD BE SPRINKLES OR AN ISOLATED
SHOWER...BUT NOT MUCH MORE THAN THAT).
CLOUDS HAVE DEVELOPED ACROSS THE ENTIRE FA AS 925MB WINDS ARE NOW
SOUTHERLY...AS OPPOSED TO SOUTHEAST. MODELS INDICATE 925MB WINDS
BECOMING MORE SOUTHEAST BY THE AFTERNOON...AND ADVECTING A DRIER
LOW LEVEL AIRMASS INTO PARTS OF THE EASTERN FA. MAX TEMPS WILL BE
SIMILAR TO YESTERDAY...LOW TO MID 60S UNDER LOW CLOUDS...AND LOW
TO MID 70S WHERE PARTLY CLOUDY. FOLLOWED THE RAP FOR PLACEMENT OF
CLOUDS AND ASSOCIATED TEMPERATURES...WHICH WILL LIKELY NEED TO BE
ADJUSTED A BIT (VERY SIMILAR TO YESTERDAY).
TONIGHT-TUESDAY...A SIMILAR SITUATION SHOULD PLAY OUT FOR THIS
PERIOD AS TO WHAT IS OCCURRING TONIGHT. ANTICIPATE TWO CONVECTIVE
COMPLEXES TO INITIATE THIS EVENING...WITH ONE ACROSS THE WESTERN
DAKOTAS AND THE OTHER ACROSS CENTRAL/EASTERN SOUTH DAKOTA (THE
ASSOCIATED SHORTWAVES CAN EASILY BEEN SEEN UPSTREAM ON WATER VAPOR
IMAGERY). THESE COMPLEXES COULD BRUSH THE NW AND SE FA...ALTHOUGH
INSTABILITY REMAINS WEAK WITHIN THIS FA. THE ECMWF IS MUCH
FURTHER NORTH AND BULLISH WITH THE SOUTHERN COMPLEX...BUT WILL
DISCOUNT AS IT HAD A SIMILAR BIAS WITH THE CURRENT ACTIVITY. KEPT
THE CHANCE POPS ACROSS THE FAR WESTERN AND SOUTHERN FA...AND
REMOVED THE THUNDER CHANCES FOR THE REMAINDER OF THE FA (THE
AMERICAN MODELS HAVE HAD A WET BIAS AND ANY DISSIPATING SHOWERS
WILL NOT HAVE AN IMPACT). WEAK RIDING EXPECTED BY TUESDAY
AFTERNOON AND EXPECT SUNSHINE AND WARMER TEMPERATURES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON MAY 27 2013
TUESDAY NIGHT-WEDNESDAY NIGHT...
WEAK RIDING TO START THIS PERIOD WITH UPPER FLOW BECOMING MORE
SOUTHERLY BY WEDNESDAY AFTERNOON/EVENING. THIS SHOULD LEAD TO DRY
WEATHER INTO MUCH OF WEDNESDAY AFTERNOON...WITH THUNDER CHANCES
INCREASING LATER WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. SEVERE
POTENTIAL WILL DEPEND ON HOW QUICKLY THE HIGHER LOW LEVEL MOISTURE
AND THE WARM FRONT CAN ADVECT NORTHWARD. THE GEM/NAM ARE FURTHER
NORTH WITH THIS FEATURE THAN THE GFS/ECMWF BY LATE WEDNESDAY
AFTERNOON. SPC KEEPS THE HIGHER SEVERE PROBABILITIES SOUTH OF THE
FA (LINING UP WITH THE GFS/ECMWF). USUALLY...THE WARM FRONT DOES
STAY SOUTH...WE SHALL SEE. AS FORCING INCREASES WEDNESDAY
NIGHT...INSTABILITY SHOULD BE WEAKER AND THE SEVERE THREAT
DEPENDENT OF THE STRENGTH OF THE LOW LEVEL JET (ANTICIPATE A FEW
STRONGER STORMS).
THURSDAY-SUNDAY...
MODELS REMAIN FAIRLY CONSISTENT WITH CLOSING OFF AN UPPER LOW
OVER MONTANA BY THURSDAY FROM THE 500MB SOUTHWEST FLOW. AS A
RESULT STRONG WAA ON THURSDAY ACROSS THE CWFA MAY BRING A SOUTH TO
NORTH CONVECTIVE COMPLEX THROUGH THE AREA. KEPT THE LIKELY POPS
INTO THE AFTERNOON THURSDAY. BY 00Z FRI THE ECMWF AND GEM BOTH
CENTER THE UPPER LOW IN E MT OR W ND WHEREAS THE GFS BRINGS IT
FARTHER TO THE SE OVER NC SD WITH THE SFC LOW NEAR BIS. THE ECMWF
AND GEM SOLN WOULD BRING THE DRY SLOT ACROSS THE AREA FRI AND SAT
COMPARED TO THE MORE CONVECTIVE AND WETTER GFS WHICH KEEPS WARM
FRONTAL BOUNDARY DRAPED ACROSS THE CWFA. BY SUNDAY THE WAVE IS
PUSHED EAST WITH SHOWERS ENDING. HI TEMPS TO BE HIGHLY DEPENDENT
ON CLOUD COVER FRI AND SAT...WARMER IN THE DRY SLOT AND COOLER IF
GFS VERIFIES...70S VS 60S. SEASONABLY COOL ON SUNDAY IN THE WAKE
OF THE SYSTEM WITH HIGHS IN 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 650 AM CDT MON MAY 27 2013
IFR/MVFR CIGS ACROSS CENTRAL NORTH DAKOTA GRADUALLY BECOME MVFR
ACROSS EASTERN NORTH DAKOTA...AND THEN VFR EAST OF THE RED RIVER
VALLEY. LOW LEVEL FLOW CHANGES VERY LITTLE THROUGH THE DAY...AND
EXPECT LITTLE CHANGE TO CIGS AS A RESULT (ALTHOUGH THEY MAY LIFT
FOR A FEW HOURS THIS AFTERNOON).
&&
.HYDROLOGY...
ISSUED AT 118 PM CDT SUN MAY 26 2013
ALL TRIBUTARIES TO THE RED RIVER ARE FALLING ACROSS THE FORECAST
AREA. THE BUFFALO RIVER AT DILWORTH HAS APPARENTLY CRESTED AND WILL
FALL SLOWLY DURING THIS WEEK. ON THE MAIN STEM OF THE RED RIVER...
THE RIVER IS STEADY OR FALLING IN THE SOUTHERN PART OF THE VALLEY.
IT IS STILL SLOWLY RISING OVER THE NORTHERN VALLEY AT PEMBINA...AND
NEAR CREST AT DRAYTON. OSLO CRESTED EARLIER TODAY AT AROUND MINOR
FLOOD STAGE OF 26 FEET.
RIVER FLOOD WARNINGS REMAIN IN EFFECT AT JUST THREE LOCATIONS...
PEMBINA AND DRAYTON ON THE RED AND DILWORTH ON THE BUFFALO.
AREAL FLOOD WARNINGS REMAIN IN EFFECT FOR PEMBINA...WALSH...AND
EASTERN CAVALIER COUNTIES THROUGH TUESDAY. WATER LEVELS ACROSS THIS
AREA SHOULD GRADUALLY DECREASE OVER THE NEXT FEW DAYS WITH MODEST
ADDITIONAL RAINFALL ANTICIPATED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...TG
HYDROLOGY...WJB
AREA FORECAST DISCUSSION
NWS RENO NV
930 AM PDT MON MAY 27 2013
.SYNOPSIS...
LOW PRESSURE OVER THE WESTERN U.S. WILL SPREAD RAIN ACROSS NORTHEAST
CALIFORNIA AND NORTHWEST NEVADA TODAY AND TONIGHT, WITH SCATTERED
SHOWERS DEVELOPING LATER TODAY ACROSS THE REMAINDER OF THE REGION
MAINLY NORTH OF HIGHWAY 50. ANOTHER ROUND OF LIGHTER RAIN SHOWERS
IS POSSIBLE BY LATE TUESDAY NIGHT NORTH OF INTERSTATE 80. BREEZY
CONDITIONS ARE EXPECTED THROUGH MIDWEEK, FOLLOWED BY DRY WEATHER
WITH A WARMING TREND LATER IN THE WEEK.
&&
.MORNING UPDATE...
BASED ON RADAR TRENDS AND LATEST HRRR HIGH RESOLUTION GUIDANCE WILL
INCREASE POPS IN THE SIERRA ZONES FROM TAHOE NORTH. DECENT BAND OF
SHOWERS SPILLING OVER INTO AREAS EAST OF SUSANVILLE TOO. NO OTHER
CHANGES TO THE DAY 1 FORECAST. LOOKING AT NEW 12Z GUIDANCE, MODELS
ARE SHOWING BROAD AREA OF PRECIP DEVELOPING OVERNIGHT IN RESPONSE TO
JET STREAK AND INSTABILITY. WILL LIKELY BE INCREASING POPS FOR NV
ZONES TONIGHT WITH THE AFTERNOON PACKAGE.
CS
&&
.SHORT TERM...
RAIN IS CURRENTLY SPREADING EAST ACROSS NORTHWEST CALIFORNIA AND
SOUTHERN OREGON AS UPPER LEVEL TROUGH AND PLUME OF DEEPER MOISTURE
REACHES THESE AREAS. THIS RAIN WILL CONTINUE ADVANCING EAST THIS
MORNING AND MAINLY OCCUR IN AREAS FROM SUSANVILLE-GERLACH
NORTHWARD FOR MUCH OF THE DAY AND INTO TONIGHT, WITH RAINFALL
TOTALS OF 0.25 TO 0.50 INCH LIKELY. FARTHER SOUTH THE
PRECIPITATION AMOUNTS WILL DROP OFF IN MOST AREAS AS THE LATEST
GUIDANCE HAS GENERALLY SHIFTED THE STORM TRACK FARTHER NORTH
COMPARED TO PREVIOUS MODEL RUNS.
UPPER LEVEL FORCING AND INCREASING INSTABILITY IS PROJECTED TO
ARRIVE BY LATE AFTERNOON, WITH THUNDERSTORMS POSSIBLE ACROSS THE
WEST CENTRAL NV BASIN AND PARTS OF NORTHWEST NV AFTER 5 PM AND
CONTINUING THROUGH THE EVENING. THE LATEST GUIDANCE KEEPS SOME
UPPER LEVEL DYNAMICS OVER EASTERN PERSHING/CHURCHILL COUNTIES
OVERNIGHT, SO SHOWERS COULD CONTINUE REDEVELOPING IN THESE AREAS
INTO EARLY TUESDAY MORNING.
FOR THE RENO-TAHOE AREA SOUTH INTO MONO-MINERAL COUNTIES, THE
PRECIPITATION IS LOOKING LESS IMPRESSIVE AS THE DEEP MOISTURE
PLUME BECOMES THINNER AND MORE FRAGMENTED AS IT MOVES SOUTH ALONG
THE CA COAST. EXCEPT FOR AREAS NEAR THE SIERRA CREST, SHADOWING
LOOKS MORE LIKELY TO LIMIT RAINFALL AMOUNTS TO LESS THAN 0.10 INCH
ACROSS THE MAJORITY OF WESTERN NV INCLUDING THE RENO-CARSON
VICINITY. THE HIGH ELEVATION SNOW POTENTIAL IS ALSO REDUCED
ESPECIALLY SOUTH OF TAHOE, WITH MAYBE AN INCH OR SO ABOVE 8500
FEET NEAR THE SIERRA CREST, PRODUCING ONLY MINIMAL IMPACTS ON
TRAVEL OVER THE HIGHER MOUNTAIN PASSES TONIGHT. ON THE MORE
HEAVILY TRAVELED ROUTES ACROSS THE SIERRA SUCH AS I-80 AND HIGHWAY
50, ROADS SHOULD JUST BE WET TONIGHT.
ANOTHER DAY OF BREEZY WEST WINDS IS EXPECTED, WITH WINDS
INCREASING BY LATE MORNING IN THE TAHOE BASIN AND BY EARLY
AFTERNOON FOR WESTERN NV SOUTHWARD TO MONO COUNTY. HOWEVER, THE
PRESENCE OF WIDESPREAD CLOUD COVER WILL RESULT IN STRONGER RIDGE
WINDS DEVELOPING LATER TODAY HAVING MORE DIFFICULTY MIXING DOWN TO
LOWER ELEVATIONS. OCCASIONAL GUSTS NEAR OR SLIGHTLY ABOVE 30 MPH
WILL STILL BE POSSIBLE AROUND RENO-CARSON AND IN AREAS SOUTH OF
HIGHWAY 50, BUT THESE GUSTS ARE LIKELY TO COVER A SHORTER DURATION
AND BE MORE LOCALIZED COMPARED TO THE PAST FEW DAYS. LOCALLY CHOPPY
CONDITIONS CAN BE EXPECTED ON SOME LAKES TODAY, BUT WIND SPEEDS
AND WAVE HEIGHTS ARE LESS LIKELY TO REACH CRITERIA FOR LAKE WIND
ADVISORIES DUE TO THE EXPECTED CLOUD COVER AND LESS EFFICIENT
MIXING.
PRECIP SHOULD TAPER OFF ON TUESDAY WITH A DRIER NORTHWEST FLOW
PREVAILING. WINDS AGAIN WILL NEED TO BE WATCHED WITH POTENTIAL
GUSTS NEAR 30 MPH. ANOTHER WEAKER SHORTWAVE MOVING INTO THE
NORTHWEST U.S. COULD BRING SOME LIGHT RAIN SHOWERS MAINLY IN
NORTHEAST CA-NORTHWEST NV LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING. THE NAM BRINGS SOME LIGHT RAIN AS FAR SOUTH AS THE
SIERRA WEST OF TAHOE AND INTO MUCH OF PERSHING COUNTY, WHILE THE
ECMWF/GFS CONFINE MOST OF THE RAIN TO AREAS NORTH OF SUSANVILLE-
GERLACH WITH THIS SYSTEM, WHILE WINDS INCREASE YET AGAIN FROM I-80
SOUTHWARD. MJD
.LONG TERM...THURSDAY THROUGH SUNDAY...
UNLIKE PREVIOUS DAYS THE MEDIUM RANGE MODELS ARE NOW ALL IN GENERAL
AGREEMENT WITH MAJOR FEATURES THROUGH THE BULK OF THE EXTENDED
FORECAST. THE OPERATIONAL MODELS START TO BUILD A MID/UPPER LVL
RIDGE WEST OF THE FORECAST AREA THURSDAY WHILE A WEAK SFC BOUNDARY
DROPS SOUTH ACROSS THE REGION LATE THURSDAY INTO FRIDAY MORNING.
THIS COULD RESULT IN INCREASED WINDS OVER THE SIERRA THURSDAY NIGHT
AS THE THERMAL/PRESSURE GRADIENT STRENGTHENS AND PRODUCE CHOPPY
CONDITIONS THURSDAY NIGHT/FRIDAY MORNING ON LAKE TAHOE.
A FEW GEFS ENSEMBLE MEMBERS DO NOT BUILD THE RIDGE QUITE AS
MUCH...BUT THE OVERALL CONSENSUS IS RIDGING THROUGH AT LEAST EARLY
SATURDAY. THIS WILL MEAN INCREASING TEMPS FRIDAY INTO THE WEEKEND
WITH LOWER HUMIDITY FOR THE MID SLOPES AND RIDGES BY LATE FRIDAY.
MODELS ARE ALSO IN GOOD AGREEMENT THAT THE RIDGE WILL BEGIN TO
FLATTEN BY LATE SATURDAY INTO SUNDAY..BUT THERE ARE DIFFERENCES IN
THE DETAILS BY SUNDAY REGARDING HOW MUCH THE RIDGE WILL FLATTEN. THE
GFS IS A LITTLE MORE AGGRESSIVE THAN THE ECMWF...BUT THE GEFS
ENSEMBLE MEMBERS SHOW ENOUGH SPREAD TO PRECLUDE GOING WITH THE
STRAIGHT GFS SOLUTION. HIGH TEMPERATURE GUIDANCE FROM THE OPERATIONAL
GFS IS NEAR THE HIGH END OF THE ENSEMBLE GUIDANCE...SO KEPT TEMPS A
LITTLE UNDER THIS GUIDANCE. THE ECMWF GUIDANCE IS A LITTLE
HIGHER...HINTING AT 90S FOR THE WESTERN NV BASINS BY SUNDAY.
A WEAK TROUGH BEGINS TO DROP INTO THE WEST COAST LATE SUNDAY...BUT
SHOULD NOT PRODUCE ENOUGH INSTABILITY FOR THUNDER OVER OUR AREA.
MODELS ARE SHOWING ENOUGH LOW LVL THERMAL GRADIENT TO BEGIN
INCREASING THE WINDS FOR SUNDAY. THEN BEYOND THE EXTENDED PERIOD
MONDAY LOOKS LIKE IT COULD BE A BREEZY DAY AS WELL AS THE PRESSURE
GRADIENT BEGINS TO INCREASE. 20
&&
.AVIATION...
AS LOW PRESSURE PUSHES ACROSS NRN CA THIS MORNING/AFTERNOON...PCPN
WILL BEGIN TO SPREAD INTO THE NRN PORTIONS OF THE FORECAST AREA. THE
BEST CHANCES FOR PCPN WILL REMAIN NORTH OF I-80 THIS AFTERNOON THEN
SPREAD INTO THE BASIN OVERNIGHT. WITH INCREASING MSTR AND BETTER
CHANCES FOR PCPN LATE THIS AFTERNOON AND THIS EVENING THINK CIGS
WILL BEGIN TO LOWER FOR ALL AREAS EXCEPT AREAS SOUTH OF MONO LAKE TO
HAWTHORNE. MVFR CONDITIONS ARE LIKELY IN THE NRN SIERRA...NORTHEAST
CA AND FAR NW NV THIS AFTERNOON AND EVENING DUE TO LOWERED CIGS.
WHILE WINDS WILL INCREASE ALOFT TODAY...MUCH OF THIS WIND WILL NOT
MIX TO THE SFC DUE TO INCREASED MSTR. MOST SFC WINDS GUSTS WILL BE
25 KTS OR LESS...BUT THERE COULD BE A FEW GUSTS CLOSER TO 30 KTS
NEAR KMMH AND KHTH LATER THIS AFTERNOON.
PCPN DECREASES IN AREAL COVERAGE BY MIDDAY TUESDAY WITH A RETURN TO
VFR CONDITIONS ALL AREAS AND LIGHTER WINDS. 20
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
326 PM EDT MON MAY 27 2013
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
LATEST RUC 50H FIELD OVERLAID ON SATELLITE WATER VAPOR IMAGERY
SHOWS SUBTLE DISTURBANCES EMBEDDED WITHIN THE NEARLY ZONAL FLOW
ALOFT. SURFACE ANALYSIS SHOWS THE SURFACE RIDGE SETTLING ALONG THE
MID ATLANTIC COAST AND ESTABLISHING A MOIST SOUTHERLY WIND FLOW THIS
AFTERNOON. A MODIFIED 12Z FFC SOUNDING AND SUPPORTED BY LATEST SPC
MESO ANALYSIS INDICATE AFTERNOON CAPES WILL TOP OUT AROUND 500-600
J/KG WITH A MODERATE MID LEVEL CAP. WEAK INSTABILITY... LACK OF DEEP
LAYER SHEAR AND FORCING SUGGEST THE GREATER CHANCE FOR ISOLATED
AFTERNOON EVENING SHOWERS AND THUNDERSTORMS WOULD BE NORTH GA WHERE
OROGRAPHIC LIFT AND SUBTLE UPPER DISTURBANCES MAY PROVIDE SUFFICIENT
FORCING FOR DEVELOPMENT. WILL CONTINUE TO SHOW ISOLATED THUNDER FOR
NORTH GA THIS AFTERNOON AND EVENING... AND ONCE AGAIN ON TUESDAY.
OTHERWISE... MODELS ARE IN GOOD AGREEMENT WITH SURFACE AND UPPER
LEVEL RIDGE BUILDING OVER THE STATE TUE-WED IN RESPONSE TO DEEPENING
LOW PRESSURE OVER THE PLAINS THROUGH MID WEEK. AS A RESULT... EXPECT
SLIGHTLY LESS OF A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS NORTH
GA TUE AFTERNOON/EVENING... AND NIL CHANCE ON WEDNESDAY.
AS FOR TEMPS... LEANED SLIGHTLY COOLER THAN GUIDANCE FOR LOWS
TONIGHT WITH LIGHT WINDS UNDER MOSTLY CLEAR SKIES INITIALLY... ALTHO
EXPECT THE SSE FLOW TO ADVECT SOME LOW LEVEL STRATUS NORTHWARD FROM
ATLANTIC AND GULF TOWARD MORNING. THEN WENT WITH A MAV AND MET BLEND
FOR THE REMAINING PERIODS AS A WARMING TREND CONTINUES IN RESPONSE
BUILDING HIGH PRESSURE AND CONTINUED DRY CONDITIONS.
39
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. THINGS CONTINUE TO
LOOK LIKE A MORE SUMMER- LIKE PATTERN DEVELOPING THIS WEEK. MODELS
IN GOOD AGREEMENT IN BUILDING THE H5 RIDGE OVER THE CWA THROUGH
THE UPCOMING WEEKEND. HIGH PRESSURE AT THE SURFACE WILL BE BECOME
CENTERED OFF THE EAST COAST. THIS WILL BRING AN EAST TO SOUTHEAST
SURFACE FLOW TO THE CWA THEREBY INCREASING HUMIDITIES THROUGH THE
WEEK. THERE COULD BE A FEW ISOLATED AFTERNOON/EVENING
THUNDERSTORMS DEVELOPING EACH AFTERNOON...BUT WITH THE H5 RIDGE
HOLDING FIRM OVER THE CWA...THIS RISK SHOULD BE LESS THAN 20
PERCENT. A COLD FRONT WILL MOVE INTO THE TENNESSEE VALLEY BY NEXT
WEEKEND AS THE UPPER RIDGE WEAKENS. AT THE SAME TIME A SHORT WAVE
MOVES INTO THE OHIO AND TENNESSEE VALLEYS. THIS WILL BRING A
SLIGHT CHANCE OF THUNDERSTORMS MAINLY TO NORTH GA SUNDAY AND
MONDAY.
01/17
&&
.AVIATION...
18Z UPDATE...
VFR CONDITIONS CONTINUE THRU THE PERIOD...ALTHO DEVELOPING CU
FIELD THIS AFTERNOON WILL LIKELY BECOME BKN BY 20-21Z. THIS BKN060
WILL LIKELY OCCUR AGAIN TUE AFTERNOON AS A MOIST SE WIND FLOW
PREVAILS. THESE SE WINDS WILL SPREAD LOW STRATUS (SCT010-020) INTO
ATLANTA TAF SITES BY 10-12Z TUE...BUT GUIDANCE HOLDS ANY BKN CIGS
SOUTH OF ATL AT THIS TIME. CURRENTLY...ALTHO AREA OBS SHOW A SSW
WIND... EXPECT WINDS TO BACK SSE BY 18-19Z... THEN REMAIN SE THRU
THE TAF PERIOD. WIND SPEEDS WILL BE 6-8KTS EACH AFTN...3-5KTS
OVERNIGHT. CHANCE OF TSRA TOO LOW TO MENTION IN TAFS AT THIS TIME.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON POTENTIAL FOR LOW STRATUS 10-12Z TUE.
HIGH ON ALL OTHER ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 59 87 60 87 / 10 10 10 5
ATLANTA 63 86 65 86 / 10 5 5 5
BLAIRSVILLE 58 83 57 82 / 20 20 20 5
CARTERSVILLE 59 87 62 88 / 10 10 10 5
COLUMBUS 63 88 64 89 / 5 5 5 5
GAINESVILLE 61 87 61 85 / 20 20 10 5
MACON 60 88 62 89 / 5 5 5 5
ROME 58 88 62 90 / 20 20 10 5
PEACHTREE CITY 57 86 59 86 / 10 5 5 5
VIDALIA 63 89 64 88 / 5 5 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...39
LONG TERM....01
AVIATION...39
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
322 PM CDT MON MAY 27 2013
.DISCUSSION...
1055 AM CDT
EARLY CHANGES MADE TO GOING FORECAST FOR THE REST OF TODAY INCLUDE
CUTTING DOWN POPS FOR MUCH OF THE NORTHERN FORECAST AREA THROUGH
AT LEAST EARLY AFTERNOON. ALSO ADJUSTED TEMPERATURES DOWN THE MOST
OVER THIS AREA AS THE COOL MEMORIAL DAY WEEKEND CONTINUES RIGHT
THROUGH THE HOLIDAY.
THE BROAD WARM AIR ADVECTION PATTERN CONTINUES OVER THE AREA
NORTH OF THE SURFACE STATIONARY BOUNDARY WHICH IS DRAPED ACROSS
FAR SOUTHERN IA INTO THE MID-SECTION OF IL. A REMNANT MCV AS SEEN
ON VISIBLE SATELLITE AND RADAR IMAGERY IS MOVING NORTHEAST INTO
NORTHWEST IN LATE THIS MORNING AND IS STARVED OF INSTABILITY...SO
JUST SOME SCATTERED ARCS OF SHOWERS HAVE BEEN SEEN WITH THIS.
SUPPRESSION WEST OF THIS HAS BEEN KEEPING MUCH OF THE NORTHERN HALF
OF THE CWA MAINLY DRY THIS MORNING AND LIMITING THE EASTWARD
PROGRESSION OF THE NEXT AREA OF SHOWERS AND CONVECTION FROM IA.
OBSERVATIONAL TRENDS SUPPORT HIGH RES GUIDANCE SOLUTIONS THAT TAKE
THE MCS IN NORTHEAST MO EASTWARD ACROSS CENTRAL/SOUTH CENTRAL IL
WHICH SHOULD KEEP THE SURFACE FRONT TO THE SOUTH. SO ALL IN ALL
THERE MAY BE LITTLE IN THE WAY OF PRECIP THROUGH MID-AFTERNOON
BESIDES SOME WIDELY SCATTERED SHOWERS OR SPRINKLES. BY LATE
AFTERNOON...THE INFLUENCE OF THE SHORT WAVE IN IA AND MORE FOCUSED
WARM AIR ADVECTION IS FORECAST TO MOVE OVER THE AREA. HOWEVER
LIMITED MOISTURE TRANSPORT RETURN PRIOR TO SUNSET MAY STILL KEEP
MUCH OF THE SHOWER COVERAGE SCATTERED AND MAINLY THUNDER-FREE.
THE EAST WIND NORTH OF THE BOUNDARY ALONG WITH LOW
CIGS...PRIMARILY ALONG AND NORTH OF THE I-88 CORRIDOR...WILL KEEP
TEMPERATURES FROM RECOVERING MUCH. HAVE LOWERED MAX TEMPS QUITE A
BIT TOWARD THE RAP SOLUTION. SOME LOCATIONS ARE LIKELY ONLY TO
CLIMB A COUPLE DEGREES MORE...ESPECIALLY IN LAKE COUNTY IL.
MTF
//PREV DISCUSSION...
318 AM CDT
THE UNSETTLED WEATHER WILL CONTINUE FOR THE NEXT SEVERAL
DAYS...WHICH WILL BE MARKED BY PERIODS OF SHOWERS AND THUNDERSTORMS
AS WELL AS THE RETURN OF MORE SUMMER-LIKE TEMPERATURES.
FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY MORNING
HOURS...THE FOCUS WILL REMAIN ON THE ONGOING SHOWERS AND
THUNDERSTORMS OVER THE SOUTHERN PORTIONS OF THE CWA. AS OF 3AM
CDT...MUCH OF THE PCPN HAS MOVED OUT OF LIVINGSTON AND FORD COUNTIES
AND IS DIMINISHING OVER IROQUOIS COUNTY. BENTON/JASPER/NEWTON
COUNTIES SHOULD SEE MODERATE TO OCNLY HEAVY PCPN WITH EMBEDDED
THUNDER FOR A FEW MORE HOURS...BUT SHOULD BE WINDING DOWN BY
DAYBREAK. THIS LINE OF HEAVY RAIN IS ALONG THE ELEVATED WARM
FRONT...WITH THE SFC WARM FRONT STILL WELL TO THE SOUTH...FROM NRN
MO TO SRN IL/IN. LATEST RADAR ESTIMATES INDICATE THAT SWATH OF 2-4
INCHES HAS FALLEN GENERALLY ALONG A LINE FROM...PONTIAC TO WATSEKA.
THESE PCPN SHOULD EXTEND EAST TOWARD REMINGTON BEFORE ALL IS SAID
AND DONE. RADAR ESTIMATES AS HIGH AS 5 INCHES ARE INDICATED
IN NORTHWESTERN LIVINGSTON COUNTY...NEAR CORNELL AND LONG POINT.
UNFORTUNATELY...THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY IN THE
MEMORIAL DAY FORECAST AS THE AREA MAY YET BE IMPACTED BY BOUNDARIES
SET OUT BY THE STRONG CONVECTIVE CLUSTERS OVER THE MISSOURI VALLEY.
THE GENERAL TREND FOR THE DAY WILL START OUT WITH SOME SCT SHOWERS
OVER THE NORTHERN PORTIONS OF THE CWA...TOWARD THE WISCONSIN BORDER
AND SOME LINGERING RAIN TO THE SOUTH. THERE WILL LIKELY BE AT LEAST
SOME PERIODS OF DRY WEATHER OVER THE AREA...BUT WITH THE FREQUENTLY
DISCUSSED WARM FRONT SLOWLY MAKING ITS WAY NORTHWARD AND A SERIES OF
SHORT WAVES RIPPLING THROUGH THE DEAMPLIFYING MID LEVEL FLOW OVER THE
AREA...PERIODS OF SHOWERS AND THUNDERSTORMS ARE LIKELY THROUGH THE
DAY AND INTO TONIGHT. WHILE THE CHANCES FOR SEVERE WEATHER ARE
LOW...ANY THUNDERSTORMS THAT DO FORM CAN MAKE OUTDOOR ACTIVITIES
HAZARDOUS. ALSO...THE ENVIRONMENT HAS BEEN PRIMED WITH INCREASING
AMOUNTS OF DEEP LAYER MOISTURE...SO LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE AS WELL. THE ONE POSITIVE NOTE THAT CAN BE MENTIONED FOR
TODAY IS THE TEMPERATURE TREND. WHILE SKIES WILL LIKELY BE CLOUDY
FOR MUCH OF THE DAY...GRADUALLY BUILDING HEIGHTS ALOFT WILL ALLOW
FOR TEMPERATURES A LITTLE HIGHER THAN RECENT DAYS...WITH HIGHS
RANGING FROM AROUND 60F ALONG THE NORTHERN ILLINOIS SHORE OF LAKE
MICHIGAN...TO THE MIDDLE 70S OVER THE SOUTHWESTERN PORTIONS OF THE
CWA...INCLUDING THE PONTIAC METRO AREA.
THE WARM FRONT IS EXPECTED TO LIFT NWD THROUGH NRN IL/IN OVERNIGHT
TONIGHT AND THEN CONTINUE NWD INTO WISCONSIN ON TUESDAY. THIS WILL
INITIATE THE EXPECTED WARMING TREND IN EARNEST...WITH SOUTHWESTERLY
FLOW SETTING UP IN THE LOWER LEVELS...DRAWING WARMER/MOISTER AIR
INTO THE REGION...AS UPPER RIDGING BEGINS TO BUILD FROM THE SERN
CONUS THROUGH THE UPPER MISSISSIPPI VALLEY. THIS COMBINATION WILL
BRING TEMPERATURES WELL INTO THE 80S...BUT WILL ALSO BRING DEW POINTS
IN THE MIDDLE TO UPPER 60S. THE TEMPERATURE AND DEW POINT TREND WILL
BE ON THE INCREASE THROUGH WEDNESDAY AND THURSDAY AS WELL...WITH
DEW POINTS APPROACHING 70F OVER MUCH OF THE AREA AND TEMPERATURES
REACHING INTO THE MIDDLE 80S...WITH SOME AREAS POSSIBLY REACHING THE
UPPER 80S. THE STRONG SOUTHWESTERLY FLOW WILL OVERCOME ANY LAKE
INFLUENCE AND THE WARMER CONDITIONS WILL BE ABLE TO PENETRATE UP TO
THE LAKE FRONT. WITH UPPER TROUGHING DEVELOPING OVER THE WRN
CONUS...SWLY FLOW WILL SET UP ALOFT AS WELL...WITH THE MODELS
ADVERTISING A SERIES OF IMPULSES RIDING NEWD UP THE BACKSIDE OF THE
RIDGE. WHILE THE MODELS ARE...TYPICALLY...INDICATING TIMING AND
STRENGTH DIFFERENCES TO THE INDIVIDUAL IMPULSES...THE SIGNAL IS
CLEAR THAT THESE WILL BRING ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. WITH DEEP LAYER MOISTURE STILL ON THE
INCREASE...WITH PWATS EXPECTED TO BE 1.5-2.0 INCHES THROUGH THE
PERIOD...LOCALLY HEAVY RAINFALL WILL BE A POSSIBILITY.
THE WARM...HUMID...UNSETTLED WEATHER WILL CONTINUE THROUGH FRIDAY.
BY SATURDAY...THE DEEPENING UPPER TROUGH WILL CLOSE OFF INTO A
LARGE...SPRAWLING UPPER LOW AND EVENTUALLY PUSH A COLD FRONT THROUGH
THE REGION. THE LATEST RUNS OF THE GFS/ECMWF ARE INDICATING THAT
THIS NEXT COLD FRONT SHOULD PUSH THROUGH THE AREA ON SATURDAY.
SINCE THIS IS A MODIFIED PACIFIC SYSTEM RATHER THAN A POLAR SYSTEM
DROPPING OUT OF CANADA...TEMPERATURES ARE ONLY EXPECTED TO DROP BACK
INTO THE 70S FOR NEXT WEEKEND.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CIGS WILL HOVER IN THE LOW END MVFR...POSSIBLY SLIGHT
IMPROVEMENT LATER.
* EAST WINDS WILL PERSIST...WITH SOME TURNING TO THE SOUTHEAST
LATE THIS EVE. SPEEDS GENERALLY ARND 10-12KT...OCCASIONAL GUSTS
IN THE MID/UPR TEENS.
* SHRA/TSRA MAY BEGIN TO DEVELOP AFT 00Z THRU OVERNIGHT.
BEACHLER
//DISCUSSION...UPDATED 20Z...
CIGS HAVE BEGUN TO IMPROVE TO LOW END MVFR CONDITIONS ACROSS
NORTHEAST IL/NORTHWEST IN AIRFIELDS. SCT SHRA/TSRA HAVE ALSO
DEVELOPED THIS AFTERNOON ACROSS CENTRAL/SOUTHERN IL. THE WARM
FRONTAL BOUNDARY CONTINUES TO RESIDE ACROSS CENTRAL IL...AND IS
EXPECTED TO SLOWLY LIFT BACK TO THE NORTH THIS EVENING.
PREVIOUS DISCUSSION UPDATED 18Z...
SIGNIFICANT CHALLENGES CONTINUE WITH THIS AFTN FORECAST PACKAGE.
MAIN CONCERN IS ON TIMING OF IMPROVING CIGS FROM IFR CONDITIONS TO
LOW END MVFR. LATEST OBS HAVE SHOWN A MINOR BUMP TO BORDERLINE
IFR/MVFR CIGS...AND WITH HEATING FROM ALOFT SHUD SEE CIGS STAY AT
CURRENT LEVELS OF ARND 1000FT AGL...THEN SLOW IMPROVEMENT TO ARND
1500FT AGL BY LATE THIS AFTN. WITH THE CONVECTION WELL SOUTHWEST
OF THE NORTHERN IL/NORTHWEST IN AIRFIELDS...THE BOUNDARY HAS
PUSHED FURTHER SOUTH. THIS AS A RESULT WILL KEEP EASTERLY WINDS
THRU EARLY THIS EVE...THEN THE BOUNDARY WILL BEGIN TO LIFT BACK TO
THE NORTH. AS THIS OCCURS...THE WIND DIRECTIONS WILL BEGIN TO TURN
SOUTHEASTERLY ALTHOUGH VERY SLOWLY WITH THE LACK OF A PUSH TO
BRING WINDS MORE SOUTHERLY UNTIL TUE LATE MORNING. CIGS WILL
CONTINUE TO HOVER ARND MVFR CONDS...POSSIBLY BRIEFLY GOING TO VFR
LATE THIS EVENING...HOWEVER THIS ALL HINGES UPON THE
COVERAGE/INTENSITY/TIMING OF CONVECTION.
THE OTHER CHALLENGE FOR THIS AFTN/EVE IS ON THE TIMING/COVERAGE OF
SHRA/TSRA. GUIDANCE HAS BACKED OFF ON THE ARRIVAL OF ANY
CONVECTION UNTIL CLOSER TO 00Z...POSSIBLY EVEN LATER. AS A RESULT
HAVE PUSHED BACK THE ARRIVAL OF CONVECTION. ALSO IT APPEARS THAT A
COMPLEX OF THUNDERSTORMS WILL DEVELOP TO THE WEST IN IOWA
OVERNIGHT...THEN SLIDE EAST. THEN IT APPEARS A LULL IN THE
SHRA/TSRA WILL OCCUR SOMETIME ARND DAYBREAK TUE THRU MID-
MORNING...BEFORE THE SECOND CONVECTIVE WAVE DEVELOPS AND ARRIVES.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN LOW END MVFR CIGS. LOW CONFIDENCE IN
TIMING OF CIGS PUSHING HIGHER INTO HIGHER END MVFR.
* MEDIUM CONFIDENCE IN WIND FORECAST.
* LOW CONFIDENCE IN OVERALL SHRA/TSRA TIMING...MEDIUM CONFIDENCE
THAT THE BETTER CHANCES WOULD NOT BE UNTIL LATER THIS EVENING AND
BEYOND.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH SATURDAY...MAINLY VFR...PERIODIC SHRA/TSRA
ESPECIALLY TUESDAY NIGHT AND FRIDAY. BREEZY SOUTH WINDS WEDNESDAY
THROUGH SATURDAY.
MDB
&&
.MARINE...
320 PM CDT
AS HIGH PRESSURE MOVES EAST OVER QUEBEC AND NEW ENGLAND AND OFF THE
ATLANTIC COAST TONIGHT A BROAD AREA OF LOW PRESSURE CENTERED IN THE
CENTRAL HIGH PLAINS WILL MOVE NORTHEAST TO NEAR THE EASTERN DAKOTAS
BY MORNING. THIS LOW CONTINUES NORTHEASTWARD ACROSS THE UPPER
MIDWEST TO WESTERN ONTARIO DURING TUESDAY...LIFTING A WARM FRONT
NORTHWARD DURING THE DAY WHICH WILL PASS NORTH OF THE LAKE BY EARLY
TUESDAY EVENING.
NORTH OF THE WARM FRONT TUESDAY THERE WILL BE A MODERATE TO FRESH
BREEZE OUT OF THE EAST TO SOUTHEAST WHILE SOUTH OF THE WARM FRONT
THERE WILL FRESH TO STRONG SOUTH AND SOUTHWEST BREEZES.
WHILE THERE WILL BE A PROLONGED PERIOD OF SOUTH TO SOUTHWEST WINDS
FOLLOWING THE WARM FRONT BUT DUE TO THE STABLE SETUP OF WARM AIR
OVER COOL WATER WIND SPEEDS NEAR AND AT THE LAKE SURFACE WILL BE
MUCH REDUCED SO WAVE GROWTH WILL BE LIMITED.
THE SOUTH AND SOUTHWEST WINDS WILL PERSIST UNTIL LATE
SATURDAY/SATURDAY NIGHT WHEN A COLD FRONT MOVES EAST ACROSS THE
LAKE SHIFTING WINDS TO OUT OF THE WEST AND NORTHWEST. THIS COLD
FRONT WILL TRAIL FROM LOW PRESSURE THAT MOVES EAST-NORTHEAST
THROUGH THE NORTHERN GREAT LAKES TO SOUTHERN QUEBEC.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ010-ILZ019-ILZ021-ILZ023-ILZ032-ILZ033-
ILZ039...7 PM MONDAY TO NOON TUESDAY.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
302 PM CDT MON MAY 27 2013
.DISCUSSION...
1055 AM CDT
EARLY CHANGES MADE TO GOING FORECAST FOR THE REST OF TODAY INCLUDE
CUTTING DOWN POPS FOR MUCH OF THE NORTHERN FORECAST AREA THROUGH
AT LEAST EARLY AFTERNOON. ALSO ADJUSTED TEMPERATURES DOWN THE MOST
OVER THIS AREA AS THE COOL MEMORIAL DAY WEEKEND CONTINUES RIGHT
THROUGH THE HOLIDAY.
THE BROAD WARM AIR ADVECTION PATTERN CONTINUES OVER THE AREA
NORTH OF THE SURFACE STATIONARY BOUNDARY WHICH IS DRAPED ACROSS
FAR SOUTHERN IA INTO THE MID-SECTION OF IL. A REMNANT MCV AS SEEN
ON VISIBLE SATELLITE AND RADAR IMAGERY IS MOVING NORTHEAST INTO
NORTHWEST IN LATE THIS MORNING AND IS STARVED OF INSTABILITY...SO
JUST SOME SCATTERED ARCS OF SHOWERS HAVE BEEN SEEN WITH THIS.
SUPPRESSION WEST OF THIS HAS BEEN KEEPING MUCH OF THE NORTHERN HALF
OF THE CWA MAINLY DRY THIS MORNING AND LIMITING THE EASTWARD
PROGRESSION OF THE NEXT AREA OF SHOWERS AND CONVECTION FROM IA.
OBSERVATIONAL TRENDS SUPPORT HIGH RES GUIDANCE SOLUTIONS THAT TAKE
THE MCS IN NORTHEAST MO EASTWARD ACROSS CENTRAL/SOUTH CENTRAL IL
WHICH SHOULD KEEP THE SURFACE FRONT TO THE SOUTH. SO ALL IN ALL
THERE MAY BE LITTLE IN THE WAY OF PRECIP THROUGH MID-AFTERNOON
BESIDES SOME WIDELY SCATTERED SHOWERS OR SPRINKLES. BY LATE
AFTERNOON...THE INFLUENCE OF THE SHORT WAVE IN IA AND MORE FOCUSED
WARM AIR ADVECTION IS FORECAST TO MOVE OVER THE AREA. HOWEVER
LIMITED MOISTURE TRANSPORT RETURN PRIOR TO SUNSET MAY STILL KEEP
MUCH OF THE SHOWER COVERAGE SCATTERED AND MAINLY THUNDER-FREE.
THE EAST WIND NORTH OF THE BOUNDARY ALONG WITH LOW
CIGS...PRIMARILY ALONG AND NORTH OF THE I-88 CORRIDOR...WILL KEEP
TEMPERATURES FROM RECOVERING MUCH. HAVE LOWERED MAX TEMPS QUITE A
BIT TOWARD THE RAP SOLUTION. SOME LOCATIONS ARE LIKELY ONLY TO
CLIMB A COUPLE DEGREES MORE...ESPECIALLY IN LAKE COUNTY IL.
MTF
//PREV DISCUSSION...
318 AM CDT
THE UNSETTLED WEATHER WILL CONTINUE FOR THE NEXT SEVERAL
DAYS...WHICH WILL BE MARKED BY PERIODS OF SHOWERS AND THUNDERSTORMS
AS WELL AS THE RETURN OF MORE SUMMER-LIKE TEMPERATURES.
FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY MORNING
HOURS...THE FOCUS WILL REMAIN ON THE ONGOING SHOWERS AND
THUNDERSTORMS OVER THE SOUTHERN PORTIONS OF THE CWA. AS OF 3AM
CDT...MUCH OF THE PCPN HAS MOVED OUT OF LIVINGSTON AND FORD COUNTIES
AND IS DIMINISHING OVER IROQUOIS COUNTY. BENTON/JASPER/NEWTON
COUNTIES SHOULD SEE MODERATE TO OCNLY HEAVY PCPN WITH EMBEDDED
THUNDER FOR A FEW MORE HOURS...BUT SHOULD BE WINDING DOWN BY
DAYBREAK. THIS LINE OF HEAVY RAIN IS ALONG THE ELEVATED WARM
FRONT...WITH THE SFC WARM FRONT STILL WELL TO THE SOUTH...FROM NRN
MO TO SRN IL/IN. LATEST RADAR ESTIMATES INDICATE THAT SWATH OF 2-4
INCHES HAS FALLEN GENERALLY ALONG A LINE FROM...PONTIAC TO WATSEKA.
THESE PCPN SHOULD EXTEND EAST TOWARD REMINGTON BEFORE ALL IS SAID
AND DONE. RADAR ESTIMATES AS HIGH AS 5 INCHES ARE INDICATED
IN NORTHWESTERN LIVINGSTON COUNTY...NEAR CORNELL AND LONG POINT.
UNFORTUNATELY...THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY IN THE
MEMORIAL DAY FORECAST AS THE AREA MAY YET BE IMPACTED BY BOUNDARIES
SET OUT BY THE STRONG CONVECTIVE CLUSTERS OVER THE MISSOURI VALLEY.
THE GENERAL TREND FOR THE DAY WILL START OUT WITH SOME SCT SHOWERS
OVER THE NORTHERN PORTIONS OF THE CWA...TOWARD THE WISCONSIN BORDER
AND SOME LINGERING RAIN TO THE SOUTH. THERE WILL LIKELY BE AT LEAST
SOME PERIODS OF DRY WEATHER OVER THE AREA...BUT WITH THE FREQUENTLY
DISCUSSED WARM FRONT SLOWLY MAKING ITS WAY NORTHWARD AND A SERIES OF
SHORT WAVES RIPPLING THROUGH THE DEAMPLIFYING MIDLEVEL FLOW OVER THE
AREA...PERIODS OF SHOWERS AND THUNDERSTORMS ARE LIKELY THROUGH THE
DAY AND INTO TONIGHT. WHILE THE CHANCES FOR SEVERE WEATHER ARE
LOW...ANY THUNDERSTORMS THAT DO FORM CAN MAKE OUTDOOR ACTIVITIES
HAZARDOUS. ALSO...THE ENVIRONMENT HAS BEEN PRIMED WITH INCREASING
AMOUNTS OF DEEP LAYER MOISTURE...SO LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE AS WELL. THE ONE POSITIVE NOTE THAT CAN BE MENTIONED FOR
TODAY IS THE TEMPERATURE TREND. WHILE SKIES WILL LIKELY BE CLOUDY
FOR MUCH OF THE DAY...GRADUALLY BUILDING HEIGHTS ALOFT WILL ALLOW
FOR TEMPERATURES A LITTLE HIGHER THAN RECENT DAYS...WITH HIGHS
RANGING FROM AROUND 60F ALONG THE NORTHERN ILLINOIS SHORE OF LAKE
MICHIGAN...TO THE MIDDLE 70S OVER THE SOUTHWESTERN PORTIONS OF THE
CWA...INCLUDING THE PONTIAC METRO AREA.
THE WARM FRONT IS EXPECTED TO LIFT NWD THROUGH NRN IL/IN OVERNIGHT
TONIGHT AND THEN CONTINUE NWD INTO WISCONSIN ON TUESDAY. THIS WILL
INITIATE THE EXPECTED WARMING TREND IN EARNEST...WITH SOUTHWESTERLY
FLOW SETTING UP IN THE LOWER LEVELS...DRAWING WARMER/MOISTER AIR
INTO THE REGION...AS UPPER RIDGING BEGINS TO BUILD FROM THE SERN
CONUS THROUGH THE UPPER MISSISSIPPI VALLEY. THIS COMBINATION WILL
BRING TEMPERATURES WELL INTO THE 80S...BUT WILL ALSO BRING DEWPOINTS
IN THE MIDDLE TO UPPER 60S. THE TEMPERATURE AND DEWPOINT TREND WILL
BE ON THE INCREASE THROUGH WEDNESDAY AND THURSDAY AS WELL...WITH
DEWPOINTS APPROACHING 70F OVER MUCH OF THE AREA AND TEMPERATURES
REACHING INTO THE MIDDLE 80S...WITH SOME AREAS POSSIBLY REACHING THE
UPPER 80S. THE STRONG SOUTHWESTERLY FLOW WILL OVERCOME ANY LAKE
INFLUENCE AND THE WARMER CONDITIONS WILL BE ABLE TO PENETRATE UP TO
THE LAKE FRONT. WITH UPPER TROUGHING DEVELOPING OVER THE WRN
CONUS...SWLY FLOW WILL SET UP ALOFT AS WELL...WITH THE MODELS
ADVERTISING A SERIES OF IMPULSES RIDING NEWD UP THE BACKSIDE OF THE
RIDGE. WHILE THE MODELS ARE...TYPICALLY...INDICATING TIMING AND
STRENGTH DIFFERENCES TO THE INDIVIDUAL IMPULSES...THE SIGNAL IS
CLEAR THAT THESE WILL BRING ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. WITH DEEP LAYER MOISTURE STILL ON THE
INCREASE...WITH PWATS EXPECTED TO BE 1.5-2.0 INCHES THROUGH THE
PERIOD...LOCALLY HEAVY RAINFALL WILL BE A POSSIBILITY.
THE WARM...HUMID...UNSETTLED WEATHER WILL CONTINUE THROUGH FRIDAY.
BY SATURDAY...THE DEEPENING UPPER TROUGH WILL CLOSE OFF INTO A
LARGE...SPRAWLING UPPER LOW AND EVENTUALLY PUSH A COLD FRONT THROUGH
THE REGION. THE LATEST RUNS OF THE GFS/ECMWF ARE INDICATING THAT
THIS NEXT COLD FRONT SHOULD PUSH THROUGH THE AREA ON SATURDAY.
SINCE THIS IS A MODIFIED PACIFIC SYSTEM RATHER THAN A POLAR SYSTEM
DROPPING OUT OF CANADA...TEMPERATURES ARE ONLY EXPECTED TO DROP BACK
INTO THE 70S FOR NEXT WEEKEND.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CIGS WILL HOVER IN THE LOW END MVFR...POSSIBLY SLIGHT
IMPROVEMENT LATER.
* EAST WINDS WILL PERSIST...WITH SOME TURNING TO THE SOUTHEAST
LATE THIS EVE. SPEEDS GENERALLY ARND 10-12KT...OCCASIONAL GUSTS
IN THE MID/UPR TEENS.
* SHRA/TSRA MAY BEGIN TO DEVELOP AFT 00Z THRU OVERNIGHT.
BEACHLER
//DISCUSSION...UPDATED 20Z...
CIGS HAVE BEGUN TO IMPROVE TO LOW END MVFR CONDITIONS ACROSS
NORTHEAST IL/NORTHWEST IN AIRFIELDS. SCT SHRA/TSRA HAVE ALSO
DEVELOPED THIS AFTERNOON ACROSS CENTRAL/SOUTHERN IL. THE WARM
FRONTAL BOUNDARY CONTINUES TO RESIDE ACROSS CENTRAL IL...AND IS
EXPECTED TO SLOWLY LIFT BACK TO THE NORTH THIS EVENING.
PREVIOUS DISCUSSION UPDATED 18Z...
SIGNIFICANT CHALLENGES CONTINUE WITH THIS AFTN FORECAST PAKCAGE.
MAIN CONCERN IS ON TIMING OF IMPROVING CIGS FROM IFR CONDITIONS TO
LOW END MVFR. LATEST OBS HAVE SHOWN A MINOR BUMP TO BORDERLINE
IFR/MVFR CIGS...AND WITH HEATING FROM ALOFT SHUD SEE CIGS STAY AT
CURRENT LEVELS OF ARND 1000FT AGL...THEN SLOW IMPROVEMENT TO ARND
1500FT AGL BY LATE THIS AFTN. WITH THE CONVECTION WELL SOUTHWEST
OF THE NORTHERN IL/NORTHWEST IN AIRFIELDS...THE BOUNDARY HAS
PUSHED FURTHER SOUTH. THIS AS A RESULT WILL KEEP EASTERLY WINDS
THRU EARLY THIS EVE...THEN THE BOUNDARY WILL BEGIN TO LIFT BACK TO
THE NORTH. AS THIS OCCURS...THE WIND DIRECTIONS WILL BEGIN TO TURN
SOUTHEASTERLY ALTHOUGH VERY SLOWLY WITH THE LACK OF A PUSH TO
BRING WINDS MORE SOUTHERLY UNTIL TUE LATE MORNING. CIGS WILL
CONTINUE TO HOVER ARND MVFR CONDS...POSSIBLY BRIEFLY GOING TO VFR
LATE THIS EVENING...HOWEVER THIS ALL HINGES UPON THE
COVERAGE/INTENSITY/TIMING OF CONVECTION.
THE OTHER CHALLENGE FOR THIS AFTN/EVE IS ON THE TIMING/COVERAGE OF
SHRA/TSRA. GUIDANCE HAS BACKED OFF ON THE ARRIVAL OF ANY
CONVECTION UNTIL CLOSER TO 00Z...POSSIBLY EVEN LATER. AS A RESULT
HAVE PUSHED BACK THE ARRIVAL OF CONVECTION. ALSO IT APPEARS THAT A
COMPLEX OF THUNDERSTORMS WILL DEVELOP TO THE WEST IN IOWA
OVERNIGHT...THEN SLIDE EAST. THEN IT APPEARS A LULL IN THE
SHRA/TSRA WILL OCCUR SOMETIME ARND DAYBREAK TUE THRU MID-
MORNING...BEFORE THE SECOND CONVECTIVE WAVE DEVELOPS AND ARRIVES.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN LOW END MVFR CIGS. LOW CONFIDENCE IN
TIMING OF CIGS PUSHING HIGHER INTO HIGHER END MVFR.
* MEDIUM CONFIDENCE IN WIND FORECAST.
* LOW CONFIDENCE IN OVERALL SHRA/TSRA TIMING...MEDIUM CONFIDENCE
THAT THE BETTER CHANCES WOULD NOT BE UNTIL LATER THIS EVENING AND
BEYOND.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH SATURDAY...MAINLY VFR...PERIODIC SHRA/TSRA
ESPECIALLY TUESDAY NIGHT AND FRIDAY. BREEZY SOUTH WINDS WEDNESDAY
THROUGH SATURDAY.
MDB
&&
.MARINE...
314 AM CDT
HIGH PRESSURE IS MOVING OFF TO THE EAST AND IS NOW POSITIONED FROM
HUDSON BAY DOWN ACROSS LAKE ERIE AND TO THE MID ATLANTIC COAST. LOW
PRESSURE CONTINUES TO DEVELOP ACROSS THE HIGH PLAINS WITH ONE LOW
CENTER OVER SOUTHEAST COLORADO AND FAR WESTERN KANSAS. THE PRESSURE
GRADIENT WILL TIGHTEN TODAY WITH LAKE MICHIGAN BETWEEN THESE TWO
SYSTEMS. SOUTHEAST WINDS WILL INCREASE AS A RESULT THEN TURN SOUTH
AND SOUTHWEST TUESDAY. SOUTH TO SOUTHWEST WINDS WILL THEN CONTINUE
THROUGH THE REST OF THE WEEK AS THE HIGH REMAINS TO THE EAST AND
SEVERAL LOW PRESSURE SYSTEMS MOVE NORTHWEST OF THE LAKE. WIND SPEEDS
WILL GENERALLY BE IN THE 15 TO 25 KT RANGE WITH PERIODIC INCREASES
TO THE HIGHER END OF THAT RANGE...WITH 30 KT POSSIBLE AT TIMES...BUT
THERE WILL ALSO BE PERIODS IN THE 10 TO 20 OR 15-20 KT RANGE. WARMER
AIR MOVING IN WILL HELP LIMIT THE GUSTS...ESPECIALLY OVER THE OPEN
WATERS BUT SOME OF THE TALLER PILOT HOUSES AND SHORE BASED OB SITES
COULD SEE GUSTS JUST ABOVE 30 KT AT TIMES AS THEY WOULD BE ABOVE THE
STABLE MARINE LAYER. NEARSHORE AREAS WILL FLIRT WITH SMALL CRAFT
ADVISORY CRITERIA AT TIMES AS WELL BUT AT THIS POINT WILL KEEP WINDS
AT 15 TO 25 KT WITH PERIODS OF 20-25 KT LOOKING BRIEF AND DIFFICULT
TO PIN DOWN.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
106 PM CDT MON MAY 27 2013
.DISCUSSION...
1055 AM CDT
EARLY CHANGES MADE TO GOING FORECAST FOR THE REST OF TODAY INCLUDE
CUTTING DOWN POPS FOR MUCH OF THE NORTHERN FORECAST AREA THROUGH
AT LEAST EARLY AFTERNOON. ALSO ADJUSTED TEMPERATURES DOWN THE MOST
OVER THIS AREA AS THE COOL MEMORIAL DAY WEEKEND CONTINUES RIGHT
THROUGH THE HOLIDAY.
THE BROAD WARM AIR ADVECTION PATTERN CONTINUES OVER THE AREA
NORTH OF THE SURFACE STATIONARY BOUNDARY WHICH IS DRAPED ACROSS
FAR SOUTHERN IA INTO THE MID-SECTION OF IL. A REMNANT MCV AS SEEN
ON VISIBLE SATELLITE AND RADAR IMAGERY IS MOVING NORTHEAST INTO
NORTHWEST IN LATE THIS MORNING AND IS STARVED OF INSTABILITY...SO
JUST SOME SCATTERED ARCS OF SHOWERS HAVE BEEN SEEN WITH THIS.
SUPPRESSION WEST OF THIS HAS BEEN KEEPING MUCH OF THE NORTHERN HALF
OF THE CWA MAINLY DRY THIS MORNING AND LIMITING THE EASTWARD
PROGRESSION OF THE NEXT AREA OF SHOWERS AND CONVECTION FROM IA.
OBSERVATIONAL TRENDS SUPPORT HIGH RES GUIDANCE SOLUTIONS THAT TAKE
THE MCS IN NORTHEAST MO EASTWARD ACROSS CENTRAL/SOUTH CENTRAL IL
WHICH SHOULD KEEP THE SURFACE FRONT TO THE SOUTH. SO ALL IN ALL
THERE MAY BE LITTLE IN THE WAY OF PRECIP THROUGH MID-AFTERNOON
BESIDES SOME WIDELY SCATTERED SHOWERS OR SPRINKLES. BY LATE
AFTERNOON...THE INFLUENCE OF THE SHORT WAVE IN IA AND MORE FOCUSED
WARM AIR ADVECTION IS FORECAST TO MOVE OVER THE AREA. HOWEVER
LIMITED MOISTURE TRANSPORT RETURN PRIOR TO SUNSET MAY STILL KEEP
MUCH OF THE SHOWER COVERAGE SCATTERED AND MAINLY THUNDER-FREE.
THE EAST WIND NORTH OF THE BOUNDARY ALONG WITH LOW
CIGS...PRIMARILY ALONG AND NORTH OF THE I-88 CORRIDOR...WILL KEEP
TEMPERATURES FROM RECOVERING MUCH. HAVE LOWERED MAX TEMPS QUITE A
BIT TOWARD THE RAP SOLUTION. SOME LOCATIONS ARE LIKELY ONLY TO
CLIMB A COUPLE DEGREES MORE...ESPECIALLY IN LAKE COUNTY IL.
MTF
//PREV DISCUSSION...
318 AM CDT
THE UNSETTLED WEATHER WILL CONTINUE FOR THE NEXT SEVERAL
DAYS...WHICH WILL BE MARKED BY PERIODS OF SHOWERS AND THUNDERSTORMS
AS WELL AS THE RETURN OF MORE SUMMER-LIKE TEMPERATURES.
FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY MORNING
HOURS...THE FOCUS WILL REMAIN ON THE ONGOING SHOWERS AND
THUNDERSTORMS OVER THE SOUTHERN PORTIONS OF THE CWA. AS OF 3AM
CDT...MUCH OF THE PCPN HAS MOVED OUT OF LIVINGSTON AND FORD COUNTIES
AND IS DIMINISHING OVER IROQUOIS COUNTY. BENTON/JASPER/NEWTON
COUNTIES SHOULD SEE MODERATE TO OCNLY HEAVY PCPN WITH EMBEDDED
THUNDER FOR A FEW MORE HOURS...BUT SHOULD BE WINDING DOWN BY
DAYBREAK. THIS LINE OF HEAVY RAIN IS ALONG THE ELEVATED WARM
FRONT...WITH THE SFC WARM FRONT STILL WELL TO THE SOUTH...FROM NRN
MO TO SRN IL/IN. LATEST RADAR ESTIMATES INDICATE THAT SWATH OF 2-4
INCHES HAS FALLEN GENERALLY ALONG A LINE FROM...PONTIAC TO WATSEKA.
THESE PCPN SHOULD EXTEND EAST TOWARD REMINGTON BEFORE ALL IS SAID
AND DONE. RADAR ESTIMATES AS HIGH AS 5 INCHES ARE INDICATED
IN NORTHWESTERN LIVINGSTON COUNTY...NEAR CORNELL AND LONG POINT.
UNFORTUNATELY...THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY IN THE
MEMORIAL DAY FORECAST AS THE AREA MAY YET BE IMPACTED BY BOUNDARIES
SET OUT BY THE STRONG CONVECTIVE CLUSTERS OVER THE MISSOURI VALLEY.
THE GENERAL TREND FOR THE DAY WILL START OUT WITH SOME SCT SHOWERS
OVER THE NORTHERN PORTIONS OF THE CWA...TOWARD THE WISCONSIN BORDER
AND SOME LINGERING RAIN TO THE SOUTH. THERE WILL LIKELY BE AT LEAST
SOME PERIODS OF DRY WEATHER OVER THE AREA...BUT WITH THE FREQUENTLY
DISCUSSED WARM FRONT SLOWLY MAKING ITS WAY NORTHWARD AND A SERIES OF
SHORT WAVES RIPPLING THROUGH THE DEAMPLIFYING MIDLEVEL FLOW OVER THE
AREA...PERIODS OF SHOWERS AND THUNDERSTORMS ARE LIKELY THROUGH THE
DAY AND INTO TONIGHT. WHILE THE CHANCES FOR SEVERE WEATHER ARE
LOW...ANY THUNDERSTORMS THAT DO FORM CAN MAKE OUTDOOR ACTIVITIES
HAZARDOUS. ALSO...THE ENVIRONMENT HAS BEEN PRIMED WITH INCREASING
AMOUNTS OF DEEP LAYER MOISTURE...SO LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE AS WELL. THE ONE POSITIVE NOTE THAT CAN BE MENTIONED FOR
TODAY IS THE TEMPERATURE TREND. WHILE SKIES WILL LIKELY BE CLOUDY
FOR MUCH OF THE DAY...GRADUALLY BUILDING HEIGHTS ALOFT WILL ALLOW
FOR TEMPERATURES A LITTLE HIGHER THAN RECENT DAYS...WITH HIGHS
RANGING FROM AROUND 60F ALONG THE NORTHERN ILLINOIS SHORE OF LAKE
MICHIGAN...TO THE MIDDLE 70S OVER THE SOUTHWESTERN PORTIONS OF THE
CWA...INCLUDING THE PONTIAC METRO AREA.
THE WARM FRONT IS EXPECTED TO LIFT NWD THROUGH NRN IL/IN OVERNIGHT
TONIGHT AND THEN CONTINUE NWD INTO WISCONSIN ON TUESDAY. THIS WILL
INITIATE THE EXPECTED WARMING TREND IN EARNEST...WITH SOUTHWESTERLY
FLOW SETTING UP IN THE LOWER LEVELS...DRAWING WARMER/MOISTER AIR
INTO THE REGION...AS UPPER RIDGING BEGINS TO BUILD FROM THE SERN
CONUS THROUGH THE UPPER MISSISSIPPI VALLEY. THIS COMBINATION WILL
BRING TEMPERATURES WELL INTO THE 80S...BUT WILL ALSO BRING DEWPOINTS
IN THE MIDDLE TO UPPER 60S. THE TEMPERATURE AND DEWPOINT TREND WILL
BE ON THE INCREASE THROUGH WEDNESDAY AND THURSDAY AS WELL...WITH
DEWPOINTS APPROACHING 70F OVER MUCH OF THE AREA AND TEMPERATURES
REACHING INTO THE MIDDLE 80S...WITH SOME AREAS POSSIBLY REACHING THE
UPPER 80S. THE STRONG SOUTHWESTERLY FLOW WILL OVERCOME ANY LAKE
INFLUENCE AND THE WARMER CONDITIONS WILL BE ABLE TO PENETRATE UP TO
THE LAKE FRONT. WITH UPPER TROUGHING DEVELOPING OVER THE WRN
CONUS...SWLY FLOW WILL SET UP ALOFT AS WELL...WITH THE MODELS
ADVERTISING A SERIES OF IMPULSES RIDING NEWD UP THE BACKSIDE OF THE
RIDGE. WHILE THE MODELS ARE...TYPICALLY...INDICATING TIMING AND
STRENGTH DIFFERENCES TO THE INDIVIDUAL IMPULSES...THE SIGNAL IS
CLEAR THAT THESE WILL BRING ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. WITH DEEP LAYER MOISTURE STILL ON THE
INCREASE...WITH PWATS EXPECTED TO BE 1.5-2.0 INCHES THROUGH THE
PERIOD...LOCALLY HEAVY RAINFALL WILL BE A POSSIBILITY.
THE WARM...HUMID...UNSETTLED WEATHER WILL CONTINUE THROUGH FRIDAY.
BY SATURDAY...THE DEEPENING UPPER TROUGH WILL CLOSE OFF INTO A
LARGE...SPRAWLING UPPER LOW AND EVENTUALLY PUSH A COLD FRONT THROUGH
THE REGION. THE LATEST RUNS OF THE GFS/ECMWF ARE INDICATING THAT
THIS NEXT COLD FRONT SHOULD PUSH THROUGH THE AREA ON SATURDAY.
SINCE THIS IS A MODIFIED PACIFIC SYSTEM RATHER THAN A POLAR SYSTEM
DROPPING OUT OF CANADA...TEMPERATURES ARE ONLY EXPECTED TO DROP BACK
INTO THE 70S FOR NEXT WEEKEND.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* BORDERLINE IFR/MVFR CIGS...WILL IMPROVE TO MVFR LATE THIS AFTN.
* EAST WINDS WILL PERSIST...WITH SOME TURNING TO THE SOUTHEAST
LATE THIS EVE. SPEEDS GENERALLY ARND 10-12KT...OCCASIONAL GUSTS
IN THE MID/UPR TEENS.
* PATCHY DZ ENDING...SHRA/TSRA MAY BEGIN TO DEVELOP AFT 00Z THRU
OVERNIGHT.
BEACHLER
//DISCUSSION...UPDATED 18Z...
SIGNIFICANT CHALLENGES CONTINUE WITH THIS AFTN FORECAST PAKCAGE.
MAIN CONCERN IS ON TIMING OF IMPROVING CIGS FROM IFR CONDITIONS TO
LOW END MVFR. LATEST OBS HAVE SHOWN A MINOR BUMP TO BORDERLINE
IFR/MVFR CIGS...AND WITH HEATING FROM ALOFT SHUD SEE CIGS STAY AT
CURRENT LEVELS OF ARND 1000FT AGL...THEN SLOW IMPROVEMENT TO ARND
1500FT AGL BY LATE THIS AFTN. WITH THE CONVECTION WELL SOUTHWEST
OF THE NORTHERN IL/NORTHWEST IN AIRFIELDS...THE BOUNDARY HAS
PUSHED FURTHER SOUTH. THIS AS A RESULT WILL KEEP EASTERLY WINDS
THRU EARLY THIS EVE...THEN THE BOUNDARY WILL BEGIN TO LIFT BACK TO
THE NORTH. AS THIS OCCURS...THE WIND DIRECTIONS WILL BEGIN TO TURN
SOUTHEASTERLY ALTHOUGH VERY SLOWLY WITH THE LACK OF A PUSH TO
BRING WINDS MORE SOUTHERLY UNTIL TUE LATE MORNING. CIGS WILL
CONTINUE TO HOVER ARND MVFR CONDS...POSSIBLY BRIEFLY GOING TO VFR
LATE THIS EVENING...HOWEVER THIS ALL HINGES UPON THE
COVERAGE/INTENSITY/TIMING OF CONVECTION.
THE OTHER CHALLENGE FOR THIS AFTN/EVE IS ON THE TIMING/COVERAGE OF
SHRA/TSRA. GUIDANCE HAS BACKED OFF ON THE ARRIVAL OF ANY
CONVECTION UNTIL CLOSER TO 00Z...POSSIBLY EVEN LATER. AS A RESULT
HAVE PUSHED BACK THE ARRIVAL OF CONVECTION. ALSO IT APPEARS THAT A
COMPLEX OF THUNDERSTORMS WILL DEVELOP TO THE WEST IN IOWA
OVERNIGHT...THEN SLIDE EAST. THEN IT APPEARS A LULL IN THE
SHRA/TSRA WILL OCCUR SOMETIME ARND DAYBREAK TUE THRU MID-
MORNING...BEFORE THE SECOND CONVECTIVE WAVE DEVELOPS AND ARRIVES.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIGS PERSISTING AT BORDERLINE IFR/MVFR...LOW
CONFIDENCE IN TIMING OF PUSHING SOLIDLY INTO LOW END MVFR CIGS.
* HIGH CONFIDENCE IN WIND FORECAST.
* LOW CONFIDENCE IN OVERALL SHRA/TSRA TIMING...MEDIUM CONFIDENCE
THAT THE BETTER CHANCES WOULD NOT BE UNTIL LATER THIS EVENING AND
BEYOND.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH SATURDAY...MAINLY VFR...PERIODIC SHRA/TSRA
ESPECIALLY TUESDAY NIGHT AND FRIDAY. BREEZY SOUTH WINDS WEDNESDAY
THROUGH SATURDAY.
MDB
&&
.MARINE...
314 AM CDT
HIGH PRESSURE IS MOVING OFF TO THE EAST AND IS NOW POSITIONED FROM
HUDSON BAY DOWN ACROSS LAKE ERIE AND TO THE MID ATLANTIC COAST. LOW
PRESSURE CONTINUES TO DEVELOP ACROSS THE HIGH PLAINS WITH ONE LOW
CENTER OVER SOUTHEAST COLORADO AND FAR WESTERN KANSAS. THE PRESSURE
GRADIENT WILL TIGHTEN TODAY WITH LAKE MICHIGAN BETWEEN THESE TWO
SYSTEMS. SOUTHEAST WINDS WILL INCREASE AS A RESULT THEN TURN SOUTH
AND SOUTHWEST TUESDAY. SOUTH TO SOUTHWEST WINDS WILL THEN CONTINUE
THROUGH THE REST OF THE WEEK AS THE HIGH REMAINS TO THE EAST AND
SEVERAL LOW PRESSURE SYSTEMS MOVE NORTHWEST OF THE LAKE. WIND SPEEDS
WILL GENERALLY BE IN THE 15 TO 25 KT RANGE WITH PERIODIC INCREASES
TO THE HIGHER END OF THAT RANGE...WITH 30 KT POSSIBLE AT TIMES...BUT
THERE WILL ALSO BE PERIODS IN THE 10 TO 20 OR 15-20 KT RANGE. WARMER
AIR MOVING IN WILL HELP LIMIT THE GUSTS...ESPECIALLY OVER THE OPEN
WATERS BUT SOME OF THE TALLER PILOT HOUSES AND SHORE BASED OB SITES
COULD SEE GUSTS JUST ABOVE 30 KT AT TIMES AS THEY WOULD BE ABOVE THE
STABLE MARINE LAYER. NEARSHORE AREAS WILL FLIRT WITH SMALL CRAFT
ADVISORY CRITERIA AT TIMES AS WELL BUT AT THIS POINT WILL KEEP WINDS
AT 15 TO 25 KT WITH PERIODS OF 20-25 KT LOOKING BRIEF AND DIFFICULT
TO PIN DOWN.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1233 PM CDT MON MAY 27 2013
.DISCUSSION...
ISSUED 1030 AM CDT MON MAY 27 2013
WELL DEFINED MCV ON RADAR CENTERED JUST EAST OF BLOOMINGTON...
WITH LINGERING SHOWERS DIMINISHING AHEAD OF IT. MCS TO OUR WEST
CONTINUES TO DROP SOUTHEAST...WITH A COUPLE OF WAKE LOWS NORTH OF
IT ACROSS IOWA. THE CORE OF THE LINE OF STORMS IS PROJECTED TO
REMAIN IN MISSOURI. HAVE SEEN AN OVERALL EASTWARD PUSH OF THE RAIN
WHICH WAS NEAR QUINCY AT 1030 AM...AND THE HRRR MODEL...WHICH HAS
HANDLED THIS MCS PRETTY WELL...BRINGS THE REMNANTS THROUGH THE
SOUTHWEST HALF OF THE CWA EARLY AFTERNOON AND REACHING THE EASTERN
CWA LATE. HAVE SEEN TEMPS ACROSS THE SOUTHEAST SURGING TOWARD 80
DEGREES WITH SOME SUNSHINE FILTERING THROUGH...AND WILL NEED TO
MONITOR THE INSTABILITY HERE AS THE STORMS ARRIVE FOR ANY
ENHANCEMENT.
GEELHART
&&
.AVIATION...
ISSUED 1233 PM CDT MON MAY 27 2013
LINE OF THUNDERSTORMS PUSHING EAST FROM THE MISSISSIPPI RIVER AT
MIDDAY...SHOULD REACH KSPI TOWARD 1930Z AND KCMI TOWARD 22Z. HAVE
MENTIONED SOME TEMPO IFR CONDITIONS AS THE WORST OF THE LINE
PASSES. MORE GENERAL IFR CONDITIONS LIKELY FURTHER NORTH TOWARD
KPIA/KBMI ON THE NORTH SIDE OF THE CONVECTIVE CLUSTER. AS HAS BEEN
THE CASE THE LAST COUPLE DAYS...EVENING CONVECTIVE REDEVELOPMENT
IS A SIGNIFICANT CONCERN...AND FAVORED MORE ALONG/NORTH OF
KPIA/KBMI WHERE THE WARM FRONT BECOMES BETTER ESTABLISHED. HAVE
MENTIONED PREVAILING MVFR CONDITIONS WITH -TSRA IN THOSE AREAS AND
ONLY VCTS FURTHER SOUTH WHERE IT IS MORE QUESTIONABLE. TUESDAY
MORNING...SHOULD SEE GUSTY WINDS DEVELOP AS HIGHER WINDS ALOFT MIX
TOWARD THE SURFACE...WITH SOME POTENTIAL FOR THUNDER AGAIN BY LATE
MORNING.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 340 AM CDT MON MAY 27 2013
SHORT TERM...TODAY THROUGH TUESDAY
WARM FRONT AT 08Z EXTENDED FROM THE IA/MO BORDER SOUTHEAST TO NEAR
MOUNT VERNON. FRONT HAS BECOME MORE DIFFICULT TO DEFINE DUE TO
SEVERAL RECENT CONVECTIVE COMPLEXES AND RESULTING OUTFLOW. THESE
COMPLEXES HAVE BEEN FED BY STRONG 850-700 MB WARM/MOIST
ADVECTION...AND LATEST VWP/S OVER MO INDICATE 30-40 KT FLOW AT
THESE LEVELS SUPPLYING INSTABILITY INTO THE LOW AND MID LEVEL
BOUNDARIES. THIS ACTIVITY SHOULD FESTER INTO THE MORNING BEFORE
THE LLJ VEERS AND WEAKENS BY 15Z. NEXT LARGER UPSTREAM MCS OVER
WESTERN IA IS FORECAST TO DIMINISH BY HI-RES MODELS BY TIME IT
REACHES THE MS RIVER LATER THIS MORNING...BUT THIS COULD SEND
ANOTHER OUTFLOW BOUNDARY INTO THE CWA THIS AFTERNOON. IF CLEARING
OCCURS AFTER THIS MORNINGS STORMS...STRONG TO SEVERE T-STORMS WILL
BE POSSIBLE THIS AFTERNOON DUE TO SHEAR NEARBY SYNOPTIC AND
MESOSCALE BOUNDARIES AND ENHANCED INSTABILITY. SPC HAS EXPANDED
DAY 1 SLIGHT RISK TO INCLUDE THE WESTERN CWA. PRECIPITABLE WATER
REMAINS HIGH AT 1.5-1.7 INCHES SO PERIODS OF HEAVY RAIN POSSIBLE
ONCE AGAIN...AND WITH SATURATED GROUND FROM RECENT RAINS 1-HR FFG
NUMBERS ARE UNDER 1.5 INCHES FOR MUCH OF THE WESTERN HALF OF THE
CWA. WILL EXTEND CURRENT FLASH FLOOD WATCH THROUGH 12Z TUE AND
EXPAND TO INCLUDE ALL COUNTIES ALONG AND WEST OF A MCLEAN TO
SHELBY LINE.
THE WARM FRONT WILL GRADUALLY LIFT NORTH OF THE CWA ON TUESDAY BUT
THIS PROCESS MAY BE IMPEDED BY CONVECTIVE OUTFLOW. RECENT MODEL
RUNS NOW SHOW MORE STORMS WILL BE POSSIBLE TUESDAY...AND HAVE
HIGHEST CHANCES IN THE NORTHERN CWA CLOSER TO THE BOUNDARY.
FORECAST SOUNDINGS LOOK MORE IMPRESSIVE FOR SEVERE STORMS AS THE
BOUNDARY LAYER WILL BE MORE UNSTABLE THAN TODAY AND DEEP LAYER
SHEAR INCREASES.
LONG TERM...WEDNESDAY THROUGH SUNDAY
BY WEDNESDAY WE WILL BE FIRMLY IN THE WARM SECTOR WITH THE FRONT
LIFTING WELL NORTH. BRISK SOUTHERLY WINDS WILL PRODUCE WIDESPREAD
MID 80S HIGHS.
AFTER A BRIEF BREAK FROM THE ACTIVE PATTERN...AN UPPER LOW MOVING
INTO THE PLAINS WILL BRING INCREASING STORM CHANCES FROM THE WEST
FOR THURSDAY AND FRIDAY. 00Z MODEL RUNS ARE MORE PROGRESSIVE WITH
THIS SYSTEM THAN 24 HOURS AGO...AND HIGHER CHANCE POPS FOR THE
WESTERN HALF OF THE CWA FROM THE MODEL CONSENSUS FOR THU/FRI LOOK
GOOD. THE FAR EAST AND SOUTHEAST CWA MAY STAY DRY UNTIL LATER
FRIDAY AND INTO SATURDAY WHEN THE COLD FRONT IS FORECAST TO SHIFT
INTO THE STATE. THE SYNOPTIC SETUP FAVORS MORE HEAVY RAIN AND
POSSIBLE SEVERE WEATHER WITH THIS SYSTEM. TEMPS SHOULD COOL BACK
TO NORMAL IN THE POST-FRONTAL AIRMASS ON SUNDAY.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ILZ027>031-036>038-
040>043-047>053-061.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1131 AM CDT MON MAY 27 2013
.DISCUSSION...
1055 AM CDT
EARLY CHANGES MADE TO GOING FORECAST FOR THE REST OF TODAY INCLUDE
CUTTING DOWN POPS FOR MUCH OF THE NORTHERN FORECAST AREA THROUGH
AT LEAST EARLY AFTERNOON. ALSO ADJUSTED TEMPERATURES DOWN THE MOST
OVER THIS AREA AS THE COOL MEMORIAL DAY WEEKEND CONTINUES RIGHT
THROUGH THE HOLIDAY.
THE BROAD WARM AIR ADVECTION PATTERN CONTINUES OVER THE AREA
NORTH OF THE SURFACE STATIONARY BOUNDARY WHICH IS DRAPED ACROSS
FAR SOUTHERN IA INTO THE MID-SECTION OF IL. A REMNANT MCV AS SEEN
ON VISIBLE SATELLITE AND RADAR IMAGERY IS MOVING NORTHEAST INTO
NORTHWEST IN LATE THIS MORNING AND IS STARVED OF INSTABILITY...SO
JUST SOME SCATTERED ARCS OF SHOWERS HAVE BEEN SEEN WITH THIS.
SUPPRESSION WEST OF THIS HAS BEEN KEEPING MUCH OF THE NORTHERN HALF
OF THE CWA MAINLY DRY THIS MORNING AND LIMITING THE EASTWARD
PROGRESSION OF THE NEXT AREA OF SHOWERS AND CONVECTION FROM IA.
OBSERVATIONAL TRENDS SUPPORT HIGH RES GUIDANCE SOLUTIONS THAT TAKE
THE MCS IN NORTHEAST MO EASTWARD ACROSS CENTRAL/SOUTH CENTRAL IL
WHICH SHOULD KEEP THE SURFACE FRONT TO THE SOUTH. SO ALL IN ALL
THERE MAY BE LITTLE IN THE WAY OF PRECIP THROUGH MID-AFTERNOON
BESIDES SOME WIDELY SCATTERED SHOWERS OR SPRINKLES. BY LATE
AFTERNOON...THE INFLUENCE OF THE SHORT WAVE IN IA AND MORE FOCUSED
WARM AIR ADVECTION IS FORECAST TO MOVE OVER THE AREA. HOWEVER
LIMITED MOISTURE TRANSPORT RETURN PRIOR TO SUNSET MAY STILL KEEP
MUCH OF THE SHOWER COVERAGE SCATTERED AND MAINLY THUNDER-FREE.
THE EAST WIND NORTH OF THE BOUNDARY ALONG WITH LOW
CIGS...PRIMARILY ALONG AND NORTH OF THE I-88 CORRIDOR...WILL KEEP
TEMPERATURES FROM RECOVERING MUCH. HAVE LOWERED MAX TEMPS QUITE A
BIT TOWARD THE RAP SOLUTION. SOME LOCATIONS ARE LIKELY ONLY TO
CLIMB A COUPLE DEGREES MORE...ESPECIALLY IN LAKE COUNTY IL.
MTF
//PREV DISCUSSION...
318 AM CDT
THE UNSETTLED WEATHER WILL CONTINUE FOR THE NEXT SEVERAL
DAYS...WHICH WILL BE MARKED BY PERIODS OF SHOWERS AND THUNDERSTORMS
AS WELL AS THE RETURN OF MORE SUMMER-LIKE TEMPERATURES.
FOR THE REMAINDER OF THE NIGHT AND INTO THE EARLY MORNING
HOURS...THE FOCUS WILL REMAIN ON THE ONGOING SHOWERS AND
THUNDERSTORMS OVER THE SOUTHERN PORTIONS OF THE CWA. AS OF 3AM
CDT...MUCH OF THE PCPN HAS MOVED OUT OF LIVINGSTON AND FORD COUNTIES
AND IS DIMINISHING OVER IROQUOIS COUNTY. BENTON/JASPER/NEWTON
COUNTIES SHOULD SEE MODERATE TO OCNLY HEAVY PCPN WITH EMBEDDED
THUNDER FOR A FEW MORE HOURS...BUT SHOULD BE WINDING DOWN BY
DAYBREAK. THIS LINE OF HEAVY RAIN IS ALONG THE ELEVATED WARM
FRONT...WITH THE SFC WARM FRONT STILL WELL TO THE SOUTH...FROM NRN
MO TO SRN IL/IN. LATEST RADAR ESTIMATES INDICATE THAT SWATH OF 2-4
INCHES HAS FALLEN GENERALLY ALONG A LINE FROM...PONTIAC TO WATSEKA.
THESE PCPN SHOULD EXTEND EAST TOWARD REMINGTON BEFORE ALL IS SAID
AND DONE. RADAR ESTIMATES AS HIGH AS 5 INCHES ARE INDICATED
IN NORTHWESTERN LIVINGSTON COUNTY...NEAR CORNELL AND LONG POINT.
UNFORTUNATELY...THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY IN THE
MEMORIAL DAY FORECAST AS THE AREA MAY YET BE IMPACTED BY BOUNDARIES
SET OUT BY THE STRONG CONVECTIVE CLUSTERS OVER THE MISSOURI VALLEY.
THE GENERAL TREND FOR THE DAY WILL START OUT WITH SOME SCT SHOWERS
OVER THE NORTHERN PORTIONS OF THE CWA...TOWARD THE WISCONSIN BORDER
AND SOME LINGERING RAIN TO THE SOUTH. THERE WILL LIKELY BE AT LEAST
SOME PERIODS OF DRY WEATHER OVER THE AREA...BUT WITH THE FREQUENTLY
DISCUSSED WARM FRONT SLOWLY MAKING ITS WAY NORTHWARD AND A SERIES OF
SHORT WAVES RIPPLING THROUGH THE DEAMPLIFYING MIDLEVEL FLOW OVER THE
AREA...PERIODS OF SHOWERS AND THUNDERSTORMS ARE LIKELY THROUGH THE
DAY AND INTO TONIGHT. WHILE THE CHANCES FOR SEVERE WEATHER ARE
LOW...ANY THUNDERSTORMS THAT DO FORM CAN MAKE OUTDOOR ACTIVITIES
HAZARDOUS. ALSO...THE ENVIRONMENT HAS BEEN PRIMED WITH INCREASING
AMOUNTS OF DEEP LAYER MOISTURE...SO LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE AS WELL. THE ONE POSITIVE NOTE THAT CAN BE MENTIONED FOR
TODAY IS THE TEMPERATURE TREND. WHILE SKIES WILL LIKELY BE CLOUDY
FOR MUCH OF THE DAY...GRADUALLY BUILDING HEIGHTS ALOFT WILL ALLOW
FOR TEMPERATURES A LITTLE HIGHER THAN RECENT DAYS...WITH HIGHS
RANGING FROM AROUND 60F ALONG THE NORTHERN ILLINOIS SHORE OF LAKE
MICHIGAN...TO THE MIDDLE 70S OVER THE SOUTHWESTERN PORTIONS OF THE
CWA...INCLUDING THE PONTIAC METRO AREA.
THE WARM FRONT IS EXPECTED TO LIFT NWD THROUGH NRN IL/IN OVERNIGHT
TONIGHT AND THEN CONTINUE NWD INTO WISCONSIN ON TUESDAY. THIS WILL
INITIATE THE EXPECTED WARMING TREND IN EARNEST...WITH SOUTHWESTERLY
FLOW SETTING UP IN THE LOWER LEVELS...DRAWING WARMER/MOISTER AIR
INTO THE REGION...AS UPPER RIDGING BEGINS TO BUILD FROM THE SERN
CONUS THROUGH THE UPPER MISSISSIPPI VALLEY. THIS COMBINATION WILL
BRING TEMPERATURES WELL INTO THE 80S...BUT WILL ALSO BRING DEWPOINTS
IN THE MIDDLE TO UPPER 60S. THE TEMPERATURE AND DEWPOINT TREND WILL
BE ON THE INCREASE THROUGH WEDNESDAY AND THURSDAY AS WELL...WITH
DEWPOINTS APPROACHING 70F OVER MUCH OF THE AREA AND TEMPERATURES
REACHING INTO THE MIDDLE 80S...WITH SOME AREAS POSSIBLY REACHING THE
UPPER 80S. THE STRONG SOUTHWESTERLY FLOW WILL OVERCOME ANY LAKE
INFLUENCE AND THE WARMER CONDITIONS WILL BE ABLE TO PENETRATE UP TO
THE LAKE FRONT. WITH UPPER TROUGHING DEVELOPING OVER THE WRN
CONUS...SWLY FLOW WILL SET UP ALOFT AS WELL...WITH THE MODELS
ADVERTISING A SERIES OF IMPULSES RIDING NEWD UP THE BACKSIDE OF THE
RIDGE. WHILE THE MODELS ARE...TYPICALLY...INDICATING TIMING AND
STRENGTH DIFFERENCES TO THE INDIVIDUAL IMPULSES...THE SIGNAL IS
CLEAR THAT THESE WILL BRING ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. WITH DEEP LAYER MOISTURE STILL ON THE
INCREASE...WITH PWATS EXPECTED TO BE 1.5-2.0 INCHES THROUGH THE
PERIOD...LOCALLY HEAVY RAINFALL WILL BE A POSSIBILITY.
THE WARM...HUMID...UNSETTLED WEATHER WILL CONTINUE THROUGH FRIDAY.
BY SATURDAY...THE DEEPENING UPPER TROUGH WILL CLOSE OFF INTO A
LARGE...SPRAWLING UPPER LOW AND EVENTUALLY PUSH A COLD FRONT THROUGH
THE REGION. THE LATEST RUNS OF THE GFS/ECMWF ARE INDICATING THAT
THIS NEXT COLD FRONT SHOULD PUSH THROUGH THE AREA ON SATURDAY.
SINCE THIS IS A MODIFIED PACIFIC SYSTEM RATHER THAN A POLAR SYSTEM
DROPPING OUT OF CANADA...TEMPERATURES ARE ONLY EXPECTED TO DROP BACK
INTO THE 70S FOR NEXT WEEKEND.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* IFR CIGS PERSIST...PSBLY SOME IMPROVEMENT EARLY THIS AFTN TO
LOW END MVFR.
* EAST/SOUTHEAST WINDS 10-14KT WITH OCCASIONAL GUSTS IN THE
16-20KT RANGE.
* PATCHY DZ WILL END...BEST CHC FOR SHRA/TSRA AFD 00Z THRU OVERNIGHT
HOURS.
BEACHLER
//DISCUSSION...UPDATED 12Z...
TOUGH FORECAST CONTINUES WITH CIG TRENDS AND SHRA/TSRA
CHANCES/TIMING THE MAIN CHALLENGES. IFR CIGS DEVELOPED A FEW HOURS
AGO IN THE WAKE OF A BAND OF SHRA/TSRA THAT PASSED MAINLY TO THE
SOUTH OF THE TERMINALS. WEAK LOW PRESSURE IS JUST NORTH OF STL
WITH A WARM FRONTAL BOUNDARY STRETCHING TO ITS EAST. THIS FRONT
LOOKS TO REMAIN SOUTH OF THE AREA INTO THIS EVENING THANKS TO THE
PASSAGE OF SHRA/TSRA SOUTH OF THE TERMINALS OVERNIGHT. THIS
COMPLICATES THE FORECAST BECAUSE WITH THE FRONT TO THE SOUTH IFR
CIGS MAY BE HELD IN PLACE FOR AN EXTENDED PERIOD OF TIME. RIGHT
NOW EXPECT IFR THROUGH MID TO LATE MORNING BUT AM THINKING THERE
WILL BE SOME IMPROVEMENT THIS AFTERNOON AS WARMING OCCURS AND
CURRENT POCKETS OF LIGHT RAIN EXIT THE AREA. CONFIDENCE IN HOW
QUICKLY IMPROVEMENT OCCURS IS LOW BUT DO NOT SEE IMPROVEMENT ANY
EARLIER THAN IN THE TAF. PROVIDED IMPROVEMENT DOES OCCUR...IT
WOULD LIKELY ONLY BE TO LOW END MVFR WITH SLOW IMPROVEMENT FROM
THERE.
LIGHT RAIN WILL CONTINUE TO EXIT TO THE EAST OVER THE NEXT FEW
HOURS. BEYOND THAT...A BAND OF RAIN DOWN NEAR PIA WILL LIKELY PASS
SOUTH OF THE TERMINALS THIS MORNING. A LARGE COMPLEX OF WEAKENING
SHRA/TSRA IS MOVING EAST ACROSS CENTRAL IOWA WITH A WELL DEFINED
CIRCULATION BEYOND IT. THIS CIRCULATION WILL LIKELY CONTINUE EAST
AND REACH THE AREA EARLY THIS AFTERNOON. THIS COULD SERVE SEVERAL
FUNCTIONS...IT MAY MAINTAIN SOME PRECIP ACTIVITY AND BRING IT
ACROSS THE AREA OR IT COULD BE A FOCUS FOR NEW DEVELOPMENT. GIVEN
THAT THE WARM FRONT IS WELL SOUTH AND INSTABILITY IS ALSO A WAYS
AWAY...AND THERE IS ABUNDANT CLOUD COVER NEW DEVELOPMENT SEEMS
UNLIKELY. BASED ON RADAR TRENDS AND OTHER PARAMETERS THERE MAY BE
VERY LITTLE LEFT OF THE CURRENT PRECIP SHIELD. PERHAPS THE MOST
LIKELY EFFECT WILL BE TO DISTURB THE SURFACE WINDS AS IT COMES
ACROSS. THERE IS STILL SOME CHANCE THAT THERE COULD BE SHRA/TSRA
LATER THIS AFTERNOON AND THIS EVENING SO WILL MAINTAIN A PROB30
FOR NOW BUT THERE MAY BE LITTLE ACTIVITY IN THE TERMINAL AREA.
SOME NEW GUIDANCE DELAYS ANY ORGANIZED ACTIVITY UNTIL TUESDAY
MORNING WHICH GIVEN THE FRONTAL BOUNDARY LIKELY REMAINING SOUTH
TODAY MAKES REASONABLE SENSE...THOUGH GUIDANCE HAS BEEN HANDLING
PRECIP TRENDS RATHER POORLY IN THIS PATTERN.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN IFR CIGS PERSISTING...LOW CONFIDENCE IN
TIMING OF LOW END MVFR CIGS DEVELOPING.
* HIGH CONFIDENCE IN WIND FORECAST.
* LOW CONFIDENCE IN OVERALL SHRA/TSRA TIMING...MEDIUM CONFIDENCE
THAT THE BETTER CHANCES WOULD NOT BE UNTIL LATER TODAY AND
BEYOND.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH SATURDAY...MAINLY VFR...PERIODIC SHRA/TSRA
ESPECIALLY TUESDAY NIGHT AND FRIDAY. BREEZY SOUTH WINDS WEDNESDAY
THROUGH SATURDAY.
MDB
&&
.MARINE...
314 AM CDT
HIGH PRESSURE IS MOVING OFF TO THE EAST AND IS NOW POSITIONED FROM
HUDSON BAY DOWN ACROSS LAKE ERIE AND TO THE MID ATLANTIC COAST. LOW
PRESSURE CONTINUES TO DEVELOP ACROSS THE HIGH PLAINS WITH ONE LOW
CENTER OVER SOUTHEAST COLORADO AND FAR WESTERN KANSAS. THE PRESSURE
GRADIENT WILL TIGHTEN TODAY WITH LAKE MICHIGAN BETWEEN THESE TWO
SYSTEMS. SOUTHEAST WINDS WILL INCREASE AS A RESULT THEN TURN SOUTH
AND SOUTHWEST TUESDAY. SOUTH TO SOUTHWEST WINDS WILL THEN CONTINUE
THROUGH THE REST OF THE WEEK AS THE HIGH REMAINS TO THE EAST AND
SEVERAL LOW PRESSURE SYSTEMS MOVE NORTHWEST OF THE LAKE. WIND SPEEDS
WILL GENERALLY BE IN THE 15 TO 25 KT RANGE WITH PERIODIC INCREASES
TO THE HIGHER END OF THAT RANGE...WITH 30 KT POSSIBLE AT TIMES...BUT
THERE WILL ALSO BE PERIODS IN THE 10 TO 20 OR 15-20 KT RANGE. WARMER
AIR MOVING IN WILL HELP LIMIT THE GUSTS...ESPECIALLY OVER THE OPEN
WATERS BUT SOME OF THE TALLER PILOT HOUSES AND SHORE BASED OB SITES
COULD SEE GUSTS JUST ABOVE 30 KT AT TIMES AS THEY WOULD BE ABOVE THE
STABLE MARINE LAYER. NEARSHORE AREAS WILL FLIRT WITH SMALL CRAFT
ADVISORY CRITERIA AT TIMES AS WELL BUT AT THIS POINT WILL KEEP WINDS
AT 15 TO 25 KT WITH PERIODS OF 20-25 KT LOOKING BRIEF AND DIFFICULT
TO PIN DOWN.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
356 PM CDT MON MAY 27 2013
.MESOSCALE DISCUSSION...
ISSUED AT 353 PM CDT MON MAY 27 2013
LATEST THOUGHTS WITH RESPECT TO CONVECTIVE DEVELOPMENT FOR THE REST
OF THE DAY. SHORT RANGE MODELS SUCH AS HRRR SHOW SUPERCELLULAR
DEVELOPMENT SPREADING OVER NC KANSAS OVER THE NEXT COUPLE HOURS.
THAT SCENARIO SEEMS UNLIKELY AT THIS POINT...AS THE MOISTURE
GRADIENT ALONG THE DRYLINE HAS BEEN ANALYZED IN THE KHYS TO KGBD
AREA. ALSO CURRENT VIS IMAGERY STILL SHOWS LITTLE IN THE WAY OF
CONVECTIVE TOWERS NEAR THE LOW LEVEL CONVERGENCE ZONE...LIKELY DUE
TO THE STRONG CAP IN PLACE. IT IS STARTING TO LOOK AS IF THE ONLY
WAY THE CAP WILL BREAK IS BY THE MID LEVEL WAVE CURRENTLY OVER THE
CO/KS BORDER (CURRENTLY KICKING OFF SOME CONVECTION IN THE HIGH
PLAINS). STILL NOT RULING OUT SUPERCELLULAR DEVELOPMENT WITH ALL OF
THE ADVERTISED HAZARDS...BUT IT COULD POSSIBLY START A LITTLE
FURTHER WEST AND A LITTLE LATER THAN ANTICIPATED...WHICH WOULD DELAY
ANY STORMS FROM REACHING REPUBLIC...CLOUD...AND OTTAWA COUNTIES
UNTIL A LITTLE LATER...PERHAPS 00Z TO 02Z. WILL CONTINUE TO MONITOR
THE TRENDS AND UPDATE ACCORDINGLY.
JL
&&
.SHORT TERM...
ISSUED AT 243 PM CDT MON MAY 27 2013
REST OF MONDAY THROUGH TONIGHT...
SURFACE ANALYSIS AT 18Z SHOWS A STRONG SURFACE CYCLONE AROUND 998 TO
1000 MB LOCATED JUST WEST OF KHYS. THE SURFACE TROUGH IS GETTING A
BIT DEEPER AS THE DAY PROGRESSES AS EARLIER IT WAS ANALYZED BETWEEN
1000 TO 1002 MB. THE TIGHT SURFACE PRESSURE GRADIENT HAS ALLOWED FOR
SOUTHERLY WINDS TO PUSH NORTHWARD USHERING IN GOOD RICH GULF
MOISTURE INTO EASTERN KANSAS. VISIBLE IMAGERY SHOWS A VERY WELL
DEFINED OUTFLOW BOUNDARY FROM THIS MORNING`S MCS LIES ON A LINE FROM
KIMP ARCING SOUTHEASTWARD TOWARD KPPF. SKIES HAVE BEEN CLEAR ACROSS
THE AREA LEADING TO SIGNIFICANT DESTABILIZATION...CHARACTERIZED BY
ML CAPE VALUES OF AROUND 3000 TO 4000 J/KG. AS MORE MOISTURE STREAMS
INTO THE AREA AND HEATING CONTINUES WE COULD SEE BOUNDARY LAYER
CONDITIONS IN THE LOWER 80S WITH DEWPOINTS IN THE UPPER 60S TO LOWER
70S. THIS WOULD LIKELY LEAD TO ML CAPE VALUES HIGHER THAN THE
CURRENT 3000 J/KG. ALSO AT THE SURFACE A VERY PRONOUNCED DRY LINE IS
CURRENTLY ANALYZED NOSING INTO THE KGBD AREA. HOT/DRY SOUTHWEST
WINDS ARE CURRENTLY ENCOUNTERING THE MOIST E/SE WINDS IN THAT KGBD
AREA. THIS AREA WILL PROVIDE THE BEST LOW LEVEL CONVERGENCE FOR
ASCENT...ONCE WE CAN ERODE THE CAP AND GET SOME MID LEVEL ASCENT.
CURRENTLY THE VISIBLE SATELLITE NEAR THE DRYLINE/OUTFLOW
BOUNDARY/WARM FRONT TRIPLE POINT AREA SHOWS LITTLE IN THE WAY OF
CUMULUS FIELD DEVELOPMENT AS THE CAP HOLDS STRONG. FURTHER WEST ON
SATELLITE IT LOOKS AS THOUGH HIGH BASED DEEP CONVECTION IS
OCCURRING...PROBABLY IN RESPONSE TO AN APPROACHING SHORTWAVE TROUGH
COMING OFF THE HIGH PLAINS. ONCE THAT MID LEVEL ASCENT REACHES
CENTRAL KANSAS EXPECT RAPID DEVELOPMENT OF STRONG THUNDERSTORMS
CAPABLE OF PRODUCING LARGE HAIL...STRONG WINDS...AND POSSIBLY SOME
TORNADOES.
EXPECT CONVECTIVE INITIATION TO OCCUR BETWEEN 21 AND 22Z WITH
INITIAL DEVELOPMENT TAKING PLACE BETWEEN KGBD AND K9K7 (ELLSWORTH).
DEEP LAYER SHEAR VECTORS COME OUT OF THE WEST AT 40 TO 50 KTS
INDICATING THAT STORMS WILL BE ABLE TO GROW UPSCALE TO SUPERCELLS
VERY QUICKLY WHILE MOVING EASTWARD. GIVEN THE STRONG SHEAR/CAPE
RELATIONSHIP IT APPEARS LIKELY THAT LARGE HAIL UP TO THE SIZE OF
BASEBALLS WILL OCCUR WITH ANY STORM THAT CAN REMAIN DISCRETE. SINCE
STORMS WILL BE SURFACE BASED IT IS ALSO LIKELY THAT THE STRONGEST
STORMS WILL BE ABLE TO PRODUCE STRONG WINDS POTENTIALLY REACHING 70
TO 80 MPH.
THE TORNADO THREAT FOR PORTIONS OF CENTRAL AND NORTH CENTRAL KANSAS
REMAIN RATHER ELEVATED FOR TONIGHT. THE MOST STRIKING PART OF THIS
PARTICULAR EVENT...OTHER THAN THE EXTREME CAPE/AND DEEP LAYER SHEAR
IS THE STRONGLY CLOCKWISE CURVED HODOGRAPHS. THE OUTFLOW
BOUNDARY...IN COMBO WITH THE SURFACE SYNOPTIC WINDS HAVE CAUSED A
STRONG SOUTHEASTERLY COMPONENT TO THE SURFACE WINDS. IN THE 21Z TO
03Z TIME FRAME MODELS INDICATED A BACKING AND STRENGTHENING OF THE
LOW LEVEL JET TO AROUND 25 KTS BY 00Z AND UP TO 40-50 KTS BY 03Z.
THIS WILL CAUSE A LENGTHENING OF THE LOW LEVEL HODOGRAPH...YIELDING
0-1 SRH VALUES APPROACHING 150 J/KG BY 00Z AND OVER 300 J/KG BY 03Z.
SHOULD A SUPERCELL OR TWO BE ABLE TO STAY DISCREET IN GOOD MOISTURE
WITH LOW LCL`S THE EXTREME LOW LEVEL SHEAR WILL MAKE TORNADIC
ACTIVITY A STRONG POSSIBILITY...ESPECIALLY ACROSS C/NC KANSAS...WEST
OF MANHATTAN.
IT IS TOUGH TO SAY EXACTLY HOW LONG THE STORMS WILL BE ABLE TO
REMAIN DISCREET...AS SOME SHORT RANGE MODELS INDICATE A QUICK
TRANSITION INTO LINEAR MODE...PERHAPS AS EARLY AS 01Z. SHOULD STORMS
REMAIN DISCREET THE TORNADO THREAT WILL CONTINUE THROUGH THE
NIGHT...HOWEVER AS STORMS BECOME MORE CONGEALED AND LINEAR IN NATURE
THE TORNADO THREAT WILL DIMINISH SOMEWHAT...BUT AS THE LOW LEVEL
SHEAR INCREASES OVERNIGHT EVEN LINEAR CONVECTION WILL BE ABLE TO
PRODUCE TORNADIC SPIN UPS...ESPECIALLY IF IT ENCOUNTERS ANY
LINGERING BOUNDARIES FROM PREVIOUS CONVECTION...ESPECIALLY THE PRE
EXISTING OUT FLOW BOUNDARY. THE LINEAR MCS WILL ALSO HAVE A STRONG
WIND THREAT AS IT MOVES EASTWARD THROUGH THE EASTERN HALF OF THE
FORECAST AREA LATER TONIGHT. SOME MODEL GUIDANCE INDICATES THAT THE
LINEAR CONVECTION MAY EXIT THE AREA BY MIDNIGHT...OR PERHAPS A
COUPLE HOURS THEREAFTER. EXPECT MOSTLY LIGHT LINGERING RAIN THROUGH
TUESDAY MORNING AFTER THE HEAVIEST RAIN FROM THE MCS MOVES EAST OF
THE AREA.
JL
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 243 PM CDT MON MAY 27 2013
SEVERE THUNDERSTORMS MAY RETURN TO THE AREA ON TUESDAY AFTERNOON BUT
MUCH REMAINS TO BE RESOLVED IN TERMS OF SMALL SCALE FEATURES AND
OUTFLOW FROM TONIGHTS CONVECTION. IT SEEMS AS THOUGH THE MORNING WILL
PROBABLY BE DRY WITH ANY MCS ACTIVITY HAVING PUSHED OUT OF THE AREA.
BY AFTERNOON MOST MODEL GUIDANCE SUGGESTS A SOUTHWEST TO NORTHEAST
ORIENTED CONVERGENCE ZONE NEARLY BISECTING THE FORECAST AREA. THIS
SHOULD BECOME A FOCUS FOR AFTERNOON CAP WEAKENING...LIKELY TO THE
POINT OF CONVECTIVE INITIATION WITHIN THE FORECAST AREA BY MID TO
LATE AFTERNOON. THIS WILL ONCE AGAIN BE A STRONGLY UNSTABLE AIRMASS
WITH AROUND 40 KTS OF DEEP LAYER SHEAR. IT MAY BE MORE DIFFICULT TO
MAINTAIN DISCRETE CONVECTION GIVEN THE ORIENTATION OF THE BOUNDARY
BUT WITH SUPERCELL ACTIVITY POSSIBLE AT LEAST INITIALLY...ALL MODES
OF SEVERE WEATHER WOULD SEEM PLAUSIBLE...WITH A FOCUS ACROSS NORTH
CENTRAL KANSAS...AND PERHAPS INTO NORTHEAST KANSAS. MAY SEE ANOTHER
ROUND OF OVERNIGHT MCS ACTIVITY DEPENDING UPON THE EVOLUTION OF THE
EVENING THUNDERSTORMS.
WEDNESDAY MORNING MAY SEE REMNANT MCS ACTIVITY HANGING AROUND THE
FORECAST AREA BEFORE CLEARING FROM WEST TO EAST DURING THE
AFTERNOON. THE PRIMARY TROUGH AXIS WILL BE APPROACHING FROM THE WEST
BY WEDNESDAY AFTERNOON WITH STRONG ASCENT OVERSPREADING WESTERN
KANSAS. WIDESPREAD THUNDERSTORMS WILL DEVELOP AMIDST THE ASCENT TO
THE WEST...AND WHILE THE STORM MOTION WILL HAVE QUITE A BIT OF A
NORTHERLY COMPONENT TO IT...THIS ACTIVITY WILL SPREAD EAST INTO
NORTH CENTRAL KANSAS BY EVENING...AND LIKELY GROW UPSCALE INTO AN
MCS WITH SEVERE POTENTIAL ON WEDNESDAY NIGHT.
THE THURSDAY FORECAST WILL BE GREATLY INFLUENCED BY CONVECTION LEFT
OVER FROM WEDNESDAY NIGHT. THERE ALSO SEEMS TO BE A CHANCE FOR
WIDESPREAD THUNDERSTORMS THROUGH THE MORNING AND PERHAPS EARLY
AFTERNOON AS THE STRONG SHORT WAVE TROUGH AXIS PASSES OVERHEAD.
SHOULD SEE SUBSIDENCE IMMEDIATELY BEHIND THIS WAVE THOUGH WHICH
COULD ALLOW SOME ATMOSPHERIC RECOVERY BY LATE AFTERNOON/EVENING.
CONVECTIVE MODE AND EVOLUTION ARE THE GREATEST QUESTION MARK ON
THURSDAY AS THERE IS SUFFICIENT INSTABILITY AND MORE THAN ENOUGH
WIND SHEAR TO SUPPORT POTENTIAL FOR AT LEAST ONE...IF NOT MULTIPLE
ROUNDS OF STRONG TO SEVERE THUNDERSTORMS. SHEAR PROFILES EXHIBIT
MUCH TURNING WITH HEIGHT...SUGGESTIVE OF ENHANCED LOW LEVEL
MESOCYCLONE POTENTIAL.
THURSDAY NIGHT THE MAIN UPPER LEVEL LOW CONTINUES TO ADVANCE
EASTWARD INTO THE NORTHERN PLAINS WHILE SHORTWAVES ROTATE FURTHER
SOUTH ACROSS OUR AREA. IT SEEMS THAT EACH SHORTWAVE WILL BRING THE
CHANCE OF SEVERE STORMS WITH INSTABILITY AND SHEAR IN
PLACE...ESPECIALLY THURSDAY NIGHT AS THE ECMWF WANTS TO INCREASE
THE INSTABILITY ACROSS KANSAS AND DEVELOP THUNDERSTORMS WHICH WILL
MOVE THROUGH NORTHEAST KANSAS. ON FRIDAY IT APPEARS THE MAIN
ENERGY WILL DRAG A FRONT ACROSS THE AREA BRINGING MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS WHICH MAY BE SEVERE. PRECIP LOOKS TO
CONTINUE INTO SATURDAY AS THE FRONT SLIDES SOUTHEAST. THE SEVERE
THREAT LOOKS TO REMAIN SOUTH OF THE AREA AT THIS POINT WITH BETTER
INSTABILITY ACROSS OKLAHOMA. THE MODELS BEGIN TO DISAGREE ON HOW
THE UPPER LEVEL ENERGY LIFTS NORTHEAST WITH THE GFS KEEPING MORE
ENERGY ACROSS THE SOUTHWEST AND IS SLOWER MOVING THE FRONT AND
PRECIP OUT OF THE AREA. THEREFORE HAVE KEPT THE POPS THROUGH
SUNDAY MORNING FOR OUR SOUTHEAST AREAS. SUNDAY AND BEYOND LOOK TO
BE DRY AS THE MAIN ENERGY WORKS INTO THE GREAT LAKES REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 107 PM CDT MON MAY 27 2013
LOW LEVEL STRATUS SHOULD GRADUALLY DISSIPATE OVER THE NEXT COUPLE
HOURS...AS VISIBLE IMAGERY SHOWS THAT THE CLOUDS ARE VERY THIN IN
NATURE. THIS IS EVIDENT ALSO BY THE SUNLIGHT PRESENT
OUTSIDE...GIVEN THE IFR STRATUS. LATER TONIGHT THERE WILL BE
STRONG THUNDERSTORMS IN C/NC KANSAS THAT WILL MOVE EASTWARD AND
AFFECT THE AVIATION SITES AROUND MIDNIGHT...WITH KMHK BEING
AFFECTED 1-2 HOURS PRIOR TO KTOP/KFOE. EXPECT THE HEAVIEST RAIN TO
EXIT THE AREA BY 8Z WITH A FEW LINGERING SHOWERS THROUGH 8-10Z.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE...LEIGHTON
SHORT TERM...LEIGHTON
LONG TERM...BARJENBRUCH/SANDERS
AVIATION...LEIGHTON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1153 AM MDT MON MAY 27 2013
.UPDATE...
ISSUED AT 925 AM MDT MON MAY 27 2013
MAIN CHANGES TO THE CURRENT FORECAST FOR TODAY WERE TO INCREASE
THE WINDS TODAY AND TO ADD A MENTION OF FOG FOR RED WILLOW COUNTY
UNTIL EARLY AFTERNOON.
LATEST OBSERVATIONS PLACE A SURFACE LOW IN THE NESS CITY AREA.
NORTH OF THE SURFACE LOW AN AXIS OF HIGHER DEW POINTS AND MID
LEVEL LIFT HAVE CONTRIBUTED TO A BAND OF LOW STRATUS. FURTHER
NORTH OVER RED WILLOW COUNTY AND VICINITY A COLD FRONT IS
BEGINNING TO MOVE INTO THE TRI-STATE AREA. AS THE COOLER AIR MOVES
IN THE BOUNDARY LAYER HAS BECOME SATURATED CAUSING VISIBILITIES TO
DROP TO HALF A MILE AT TIMES. THE FOG SHOULD LIFT NOT LONG INTO
THE EARLY AFTERNOON AS TEMPERATURES WARM WITH THE AFTERNOON
HEATING. AM THINKING THE COOLER AIR SHOULD NOT MOVE ANY FURTHER
SOUTH THAN HIGHWAY 24 AND NO FURTHER WEST THAN THE CO/KS BORDER
TODAY.
WINDS HAVE BEEN SOMEWHAT TRICKY AS NO GUIDANCE IS REALLY CATCHING
WHAT IS GOING ON. IN GENERAL THE WINDS WILL REMAIN BREEZY DUE TO A
TIGHT PRESSURE GRADIENT OVER THE EASTERN 2/3S OF THE AREA. THE
WINDS MAY BACK OFF SOME DURING THE MID AFTERNOON BEFORE
STRENGTHENING AGAIN AS A SURFACE HIGH PRESSURE MOVES INTO THE AREA
FROM THE WEST CAUSING THE PRESSURE GRADIENT TO TIGHTEN.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 435 AM MDT MON MAY 27 2013
MAIN FORECAST PROBLEM WILL BE CONTINUED CHANCES FOR THUNDERSTORMS.
SATELLITE SHOWING THE FLOW HAS DEAMPLIFIED OVER THE PACIFIC AND THE
PACIFIC NORTHWEST. WHAT USED TO BE A COMPLEX UPPER LOW OVER THE
PACIFIC NORTHWEST HAS NOW BEEN SPLIT APART WITH THE SOUTHERN
PORTION COMING EAST NOW AS AN OPEN SHORTWAVE TROUGH. WITH WEAKENING
MID LEVEL RIDGE TO OUR EAST...THIS LEAVES OUR AREA IN A SOUTHWEST
FLOW ALOFT WITH NUMEROUS SMALL SCALE SHORTWAVE TROUGHS EMBEDDED
WITHIN IT. A COMPLEX SURFACE PATTERN IS OVER THE AREA WITH A
RETREATING WARM FRONT OVER THE NORTHWEST PORTION OF THE AREA WHICH
IS EXTENDING FROM THE SURFACE LOW OVER SOUTHEAST COLORADO. THE DRY
LINE IS JUST TO THE EAST OF THAT. A SHALLOWER/COOLER AIR MASS IS TO
THE NORTH OF THIS WARM FRONT.
MODELS INITIALIZED WELL AT JET LEVEL. MODELS DID FINE AT MID LEVELS
WITH THE GFS...CANADIAN AND UKMET DOING THE BEST ON THE HEIGHTS AND
FEATURES. THE MODELS WERE WARM AT 700 MB WITH THE CANADIAN DOING
THE BEST. MODELS HAVING HARD TIME WITH THE SURFACE PATTERN. MAJORITY
HAVE THE SURFACE LOW THAT STARTS OUT OVER SOUTHEAST COLORADO TOO
FAR EAST BY 06Z. THE ECMWF AND RUC DEFINITELY IS HEAD AND SHOULDERS
ABOVE THE REST. WOULD ALSO HAVE TO GIVE THE ECMWF A SLIGHT EDGE ON
THE THERMAL FIELD AS WELL.
BASED ON RECENT POOR MODEL PERFORMANCE...COMPLEX NATURE OF SURFACE
PATTERN...AND CONVECTIVE FEEDBACK ISSUES WITH THE MODELS...THIS IS
A LOW CONFIDENCE FORECAST. THIS COMPOUNDED BY THE FACT THAT CERTAIN
NEIGHBORING OFFICES ARE MAKING BIG CHANGES WITHOUT TALKING.
TODAY/TONIGHT...SOME CONVECTION HAS DEVELOPED NORTH OF THE
RETREATING WARM FRONT WITH OTHER CONVECTION ON THE WESTWARD
EXTENSION OF THIS WEAVING/COMPLEX FRONTAL POSITION. RECENT TRENDS
AND MESOSCALE MODEL OUTPUT INDICATE ALL THIS PRECIPITATION WILL STAY
TO THE NORTH OF THE AREA. BUT WILL CONTINUE TO MONITOR.
LEFT FRONT QUADRANT OF THE JET STARTS OVER THE SOUTHERN PORTION OF
THE AREA AT 12Z AND IS AFFECTING/OVER THE NORTHERN PORTION OF THE
AREA BY THE END OF THE DAY. THIS FEATURE THEN MOVES SOUTHEAST DURING
THE NIGHT. RIGHT NOW THE MODELS ARE HAVING EXTREME DIFFICULTIES IN
RESOLVING BOUNDARY POSITION AND TIMING. MODELS TAKE A COMPACT 700
MB LOW OVER COLORADO AND MOVE IN TO THE NORTH OF THE AREA BY EARLY
AFTERNOON. DEPENDING ON WHICH MODEL OUTPUT YOU USE...SOME
WRAPAROUND OCCURS WITH THIS. CONSIDERING THE TRAJECTORY...AM NOT
BUYING IT. WITH THE JET...SURFACE BOUNDARY POSITION AND THIS
SYSTEM...BEST CHANCES FOR PRECIPITATION SHOULD BE IN THE NORTH AND
END BY LATE IN THE AFTERNOON. ADDITIONAL SHORTWAVE ENERGY MOVES
THROUGH DURING THE NIGHT BUT MOISTURE HAS BEEN SCOURED OUT. ENDED
PRECIPITATION BY LATE IN THE NIGHT AND THAT MAY BE TOO LATE.
WILL GET SOME FOG AND STRATUS IN THE NORTHWEST PORTION OF THE AREA
AS THE FRONT MOVES THROUGH. WITH AN EARLIER FRONTAL ARRIVAL
EXPECTED...HIGH TEMPERATURES SHOULD BE COOLER BUT AM NOT CERTAIN
ABOUT THAT.
TUESDAY/TUESDAY NIGHT...LEE TROUGH REDEVELOPS/STRENGTHENS AS
STRONGER SHORTWAVE STARTS APPROACHING FROM THE WEST. MAIN SURFACE
CONVERGENCE REMAINS TO THE WEST OF THE AREA THROUGH THE DAY.
SURFACE BOUNDARY DOES NOT MOVE INTO THE AREA UNTIL LATER IN THE
NIGHT. PLUS MAIN LIFT DOES NOT ARRIVE UNTIL DURING THE NIGHT AS
WELL. SO HAVE SLIGHT CHANCE DURING THE AFTERNOON WITH THE MAIN
CHANCE OF PRECIPITATION DURING THE NIGHT. WITH STRENGTHENING
EASTERLY WINDS DURING THE DAY...AM THINKING THAT CURRENT MAX
TEMPERATURES WILL NEED TO BE COOLED SOME WAS NOT ABLE TO SPEND A LOT
OF TIME ON THAT.
WEDNESDAY/WEDNESDAY NIGHT...MODELS MOVE/DEVELOP A LEFT FRONT QUADRANT
OF THE JET OVER THE CENTRAL/EASTERN PORTION OF THE AREA DURING THE
AFTERNOON. THEN MODELS DIFFER ON HOW THEY MOVE IT. SOME MOVE IT EAST
OF THE AREA BY LATE AFTERNOON WITH OTHERS KEEPING IT THERE. THEN
THE SLOWER MODELS MOVE IT EAST OF THE AREA DURING THE EVENING.
MODELS DIFFER ON THE SPEED IN WHICH THEY TAKE THE NEXT BOUNDARY
THROUGH. IF THIS IS SLOWER THEN BETTER PRECIPITATION CHANCES WILL
NEED TO BE PULLED BACK SLOWER. DID SIDE WITH THE SLOWER ARRIVAL BUT
THIS WILL NEED TO BE LOOKED AT. MAIN MID LEVEL LIFT ARRIVES IN THE
AFTERNOON AND EVENING. ALL THIS POINTS TO GOOD CHANCES OF
PRECIPITATION LATER IN THE DAY INTO THE EVENING...ESPECIALLY FOR
THE EASTERN PORTION OF THE AREA. NOT SURE ABOUT WHAT THE
TEMPERATURES WILL DO WITH THE DIFFERENCE IN THE BOUNDARY POSITIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 435 AM MDT MON MAY 27 2013
MODELS ARE IN A LITTLE BETTER AGREEMENT WITH MOVEMENT OF UPPER
LOW/TROUGH...MINOR DIFFERENCES IN PLACEMENT OF UPPER LOW/TROUGH
EXIST. THE GFS HAS THE UPPER LOW OVER THE NORTHERN ROCKIES MOVING
EAST AND THE ADJACENT SURFACE LOW OVER THE DAKOTAS ON THURSDAY AND
FRIDAY. THE ECMWF PLACES THE UPPER LOW/TROUGH SLIGHTLY FURTHER NORTH
AND WEST...WHICH IS SLOWER MOVING EAST BUT SHOULD NOT AFFECT THE
TIMING OF THE MAIN FEATURES TOO MUCH. AS THE SURFACE LOW AND UPPER
LOW MOVE EAST...A COLD FRONT WILL SWING THROUGH THE CWA THURSDAY
MORNING. COLD AIR ALOFT WILL FILTER IN BEHIND THE FRONT...THIS
COMBINED WITH VORTICITY WRAPPING AROUND THE UPPER LOW AND SOME MINOR
INSTABILITY WILL BRING A CHANCE FOR SHOWERS AND TSTORMS ON THURSDAY
AFTERNOON. THE UPPER LOW STARTS TO PULL AWAY FROM THE CWA ON FRIDAY
LEAVING SOME LINGERING CLOUDS AND ON SATURDAY CONDITIONS WILL BECOME
CLEAR AS HIGH PRESSURE MOVES INTO THE CWA. MORE SEASONABLE
TEMPERATURES IN THE MID TO UPPER 70S WILL OCCUR ON FRIDAY AND
SATURDAY. SOUTHERLY RETURN FLOW SETS UP ON SUNDAY AFTERNOON OVER THE
CWA AND THE GFS HAS LOW AMPLITUDE RIDGING OVER THE CWA WITH EMBEDDED
SHORTWAVES MOVING THROUGH COLORADO WHILE THE ECMWF HAS ZONAL FLOW
OVER THE CENTRAL PLAINS. POPS WERE LEFT OUT OF SUNDAY FOR NOW...THIS
MAY CHANGE DEPENDING ON HOW MODELS RESOLVE THEIR DIFFERENCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1143 AM MDT MON MAY 27 2013
VFR TO IFR CONDITIONS ARE FORECAST FOR THE 18Z TAFS. LATEST
VISIBLE SATELLITE IMAGERY INDICATES AN AREA OF IFR TO MVFR
CEILINGS BEHIND THE ADVANCING COLD FRONT...WITH
SHOWERS/THUNDERSTORMS DEVELOPING AHEAD OF THE FRONT. AS
TEMPERATURES WARM WITH AFTERNOON HEATING THE CEILINGS AT KMCK
SHOULD SLOWLY INCREASE...BECOMING SCATTERED BY LATE AFTERNOON.
OVERNIGHT CEILINGS/VIS WILL DROP AS HIGHER DEW POINTS ARE BROUGHT
INTO THE SITE. CONDITIONS WILL IMPROVE BY MID MORNING TUESDAY.
THERE IS A SMALL CHANCE FOR THUNDERSTORMS FOR THE KMCK SITE
THROUGH THE EVENING...HOWEVER THEY WILL BE ISOLATED SO DO NOT HAVE
ENOUGH CONFIDENCE AT THIS TIME TO PLACE A MENTION IN THE TAF.
FOR KGLD CLOUD DECK SHOULD REMAIN SCATTERED AHEAD OF THE COLD
FRONT. AM ANTICIPATING THUNDERSTORMS TO DEVELOP NEAR THE SITE
DURING THE LATE AFTERNOON/EARLY EVENING WHEN INSTABILITY AND LIFT
ARE BEST. DURING THE REST OF THE EVENING THERE MAY BE ISOLATED
STORMS LINGERING...BUT AM NOT VERY CONFIDENT THEY WILL BE NEAR THE
SITE. OVERNIGHT LOW CLOUDS RETURN AS HIGHER DEW POINTS ARE
ADVECTED OVER THE SITE. THE CEILINGS IMPROVE BY MID MORNING
TUESDAY.
&&
.FIRE WEATHER...
ISSUED AT 435 AM MDT MON MAY 27 2013
FOR TODAY...DUE TO THE FRONT MOVING IN FASTER...IT LOOKS LIKE THE
AREA WILL ESCAPE ANY FIRE WEATHER ISSUES. IF FRONT DOES SLOW UP...
GREELEY AND WICHITA COULD REACH CRITERIA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...JTL
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
625 PM EDT MON MAY 27 2013
.UPDATE...
ISSUED AT 625 PM EDT MON MAY 27 2013
NO PCPN WITHIN THE STATE AND THE STORMS IN ILL ARE EITHER MOVING
NORTH OR THE SOUTH END IS DISSIPATING. NEW MODELS INDICATE THE PCPN
WILL MOVE ACROSS IND/OH TO OUR NORTH BUT NOT INTO ERN KY DUE TO A
SIGNIFICANT LOW LEVEL RIDGE EXTENDING INTO THE COMMONWEALTH FROM THE
SOUTHERN ATLANTIC COAST. SWRN WINDS ARE STILL BREEZY BUT SHOULD
DIMINISH WITH THE SETTING SUN. WILL FURTHER UPDATE WHEN WINDS
DECREASE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 310 PM EDT MON MAY 27 2013
A WARM FRONT CONTINUES TO LIFT TO THE NORTH AND EAST OUT OF THE CWA
AND AS OF 3 PM WAS LOCATED FROM SOUTHEASTERN INDIANA EAST INTO
SOUTHERN OH AND THEN SOUTHEAST INTO THE WV COALFIELDS. AS OF MID
AFTERNOON...A RATHER ZONAL PATTERN WAS IN PLACE ACROSS MUCH OF THE
CONUS WITH A TROUGH WORKING INTO THE WEST COAST OF THE CONUS...AND A
SHORTWAVE TROUGH MOVING ACROSS THE UPPER MS VALLEY WHILE A DEEP
TROUGH CONTINUES TO WORK THROUGH THE CANADIAN MARITIMES.
THE SHORTWAVE TROUGH OVER THE UPPER MS VALLEY WILL MOVE INTO THE
NORTHERN GREAT LAKES TONIGHT AND INTO THE DAY ON TUE WITH RIDING
GRADUALLY BUILDING ACROSS THE SOUTHEASTERN STATES AND SOUTHERN
APPALACHIANS THROUGH THE END OF THE PERIOD.
GENERALLY FLAT CU HAS DEVELOPED SO FAR OVER THE JKL CWA BUT WITH
DEWPOINTS IN THE UPPER 50S NEAR THE VICINITY AND JUST BEHIND THE WARM
FRONT SOME ISOLATED SHRA AND OR TSRA CANNOT BE RULED OUT THROUGH THIS
EVENING. CU SHOULD DISSIPATE AS WE MOVE TOWARD SUNSET...BUT AT LEAST
SOME DEBRIS CLOUDS FROM CONVECTION NOW OVER THE MS VALLEY SHOULD
EVENTUALLY WORK ACROSS THE REGION TONIGHT. IT WOULD SEEM THAT DRIER
AIR OVER MUCH OF KY DOWN IN THE TN VALLEY SHOULD LEAD TO THE SOUTHERN
END OF THIS COMPLEX WEAKENING AS IT WORKS EAST THIS EVENING AND INTO
THE OVERNIGHT. THE LATEST HRRR HANDLING OF IT SEEMS MOST REASONABLE
AND THE 12Z NAM SEEMS TO BE OVERDOING CONVECTION ATTM IN THE LOWER OH
VALLEY EAST OF THE COMPLEX OVER MO AND IL. THE GFS ALSO HAS SOME LATE
NIGHT CONVECTION OVER THE CWA AS WELL. THE 12Z ECMWF KEEPS ALL THE
ACTION CLOSER TO THE WARM FRONT. OPTED TO GO WITH SOME SLIGHT CHANCES
MAINLY THIS EVENING ACROSS THE NORTH...NORTH OF THE MTN PARKWAY..BUT
CONFIDENCE IN THIS IS NOT HIGH.
MOISTURE SHOULD REMAIN LIMITED AND AT THIS POINT ANY TRIGGERS HARD TO
DISCERN FOR CONVECTION ON TUE. THERE MAY BE A WEAK SHORTWAVE OR TO
WORKING AROUND THE RIDGE...BUT WITH HEIGHTS PROGGED TO RISE ON TUE
INTO TUE NIGHT...WE HAVE OPTED TO GO WITH A DRY FORECAST FOR TUE.
TEMPERATURES SHOULD MODERATE FURTHER ON TUE...INTO THE MID TO UPPER
80S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 300 PM EDT MON MAY 27 2013
RIDGING WILL HOLD OVER THE EASTERN US THROUGH THE END OF THE WEEK.
THIS WILL KEEP OUR AREA WEST OF THE HIGH PRESSURE AREA IN AN AREA OF
RETURN FLOW. THIS WILL LEAD TO AN EXTENDED PERIOD OF MILD NIGHTS AND
WARM DAYS. INSTABILITY WILL GREATLY INCREASE FROM WEDNESDAY ONWARD
DURING THE DAYLIGHT HOURS...BUT WE WILL BE LACKING ANY TRIGGERS.
MODELS ARE STILL LIKELY OVER AGGRESSIVE WITH THE AMOUNT OF SURFACE
MOISTURE EACH DAY...SO LIKELY OVERDOING THE CAPE. HOWEVER...SOME
GOOD CU FIELDS SHOULD DEVELOP EACH AFTERNOON...AND IT MAY BE
POSSIBLE TO POP A VERY ISOLATED SHOWER OR STORM ALONG THE HIGHER
RIDES IN THE SOUTHEAST EACH AFTERNOON FROM WEDNESDAY THROUGH FRIDAY.
EACH DAY SHOULD FEATURE A SLIGHT BETTER CHANCE OF THIS HAPPENING AS
DEWPOINTS SHOULD CONTINUE TO INCH UP THROUGH THE REMAINDER OF THE
WEEK.
BY THIS WEEKEND...HIGH PRESSURE WILL RELINQUISH ITS HOLD ON THE AREA
AS A MID LEVEL SHORTWAVE APPROACHES FROM THE WEST. INCREASING FLOW
AHEAD OF THIS FEATURE ON SATURDAY...COULD YIELD A BETTER SHOT OF AN
ISOLATED SHOWER OR STORM BY SATURDAY AFTERNOON. THE CHANCES FOR
SHOWERS AND STORMS WILL INCREASE HEADING INTO SUNDAY AS THIS TROUGH
PUSHES EAST ACROSS THE AREA. PRESENTLY...MODELS IN FAIRLY GOOD
AGREEMENT ON TIMING...SO CONFIDENCE REMAINS HIGHER THAN NORMAL FOR
DAY 7. WITH THE FRONTAL PASSAGE...SLIGHTLY COOLER WEATHER SHOULD
RETURN TO THE AREA BY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 230 PM EDT MON MAY 27 2013
VFR CONDITIONS SHOULD PREVAIL THROUGHOUT THE TAF PERIOD AT ALL THREE
AIRPORTS. ISOLATED SHOWERS AND STORMS COULD AFFECT JKL THROUGH AROUND
0Z. OTHERWISE...CU NEAR 5 TO 6KFT SHOULD CONTINUE TO DEVELOP OVER THE
NEXT TWO TO THREE HOURS...BEFORE DIMINISHING. WITH THE WARM FRONT NOW
MOVING INTO WV...WINDS WILL AVERAGE OUT OF THE SOUTH SOUTHWEST TO
SOUTHWEST. WINDS WILL SLACKEN OVERNIGHT...BEFORE PICKING UP AT NEAR
10KT...ESPECIALLY LOZ AND SME AFTER 15Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DUSTY
SHORT TERM...JP
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
320 PM EDT MON MAY 27 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 310 PM EDT MON MAY 27 2013
A WARM FRONT CONTINUES TO LIFT TO THE NORTH AND EAST OUT OF THE CWA
AND AS OF 3 PM WAS LOCATED FROM SOUTHEASTERN INDIANA EAST INTO
SOUTHERN OH AND THEN SOUTHEAST INTO THE WV COALFIELDS. AS OF MID
AFTERNOON...A RATHER ZONAL PATTERN WAS IN PLACE ACROSS MUCH OF THE
CONUS WITH A TROUGH WORKING INTO THE WEST COAST OF THE CONUS...AND A
SHORTWAVE TROUGH MOVING ACROSS THE UPPER MS VALLEY WHILE A DEEP
TROUGH CONTINUES TO WORK THROUGH THE CANADIAN MARITIMES.
THE SHORTWAVE TROUGH OVER THE UPPER MS VALLEY WILL MOVE INTO THE
NORTHERN GREAT LAKES TONIGHT AND INTO THE DAY ON TUE WITH RIDING
GRADUALLY BUILDING ACROSS THE SOUTHEASTERN STATES AND SOUTHERN
APPALACHIANS THROUGH THE END OF THE PERIOD.
GENERALLY FLAT CU HAS DEVELOPED SO FAR OVER THE JKL CWA BUT WITH
DEWPOINTS IN THE UPPER 50S NEAR THE VICINITY AND JUST BEHIND THE WARM
FRONT SOME ISOLATED SHRA AND OR TSRA CANNOT BE RULED OUT THROUGH THIS
EVENING. CU SHOULD DISSIPATE AS WE MOVE TOWARD SUNSET...BUT AT LEAST
SOME DEBRIS CLOUDS FROM CONVECTION NOW OVER THE MS VALLEY SHOULD
EVENTUALLY WORK ACROSS THE REGION TONIGHT. IT WOULD SEEM THAT DRIER
AIR OVER MUCH OF KY DOWN IN THE TN VALLEY SHOULD LEAD TO THE SOUTHERN
END OF THIS COMPLEX WEAKENING AS IT WORKS EAST THIS EVENING AND INTO
THE OVERNIGHT. THE LATEST HRRR HANDLING OF IT SEEMS MOST REASONABLE
AND THE 12Z NAM SEEMS TO BE OVERDOING CONVECTION ATTM IN THE LOWER OH
VALLEY EAST OF THE COMPLEX OVER MO AND IL. THE GFS ALSO HAS SOME LATE
NIGHT CONVECTION OVER THE CWA AS WELL. THE 12Z ECMWF KEEPS ALL THE
ACTION CLOSER TO THE WARM FRONT. OPTED TO GO WITH SOME SLIGHT CHANCES
MAINLY THIS EVENING ACROSS THE NORTH...NORTH OF THE MTN PARKWAY..BUT
CONFIDENCE IN THIS IS NOT HIGH.
MOISTURE SHOULD REMAIN LIMITED AND AT THIS POINT ANY TRIGGERS HARD TO
DISCERN FOR CONVECTION ON TUE. THERE MAY BE A WEAK SHORTWAVE OR TO
WORKING AROUND THE RIDGE...BUT WITH HEIGHTS PROGGED TO RISE ON TUE
INTO TUE NIGHT...WE HAVE OPTED TO GO WITH A DRY FORECAST FOR TUE.
TEMPERATURES SHOULD MODERATE FURTHER ON TUE...INTO THE MID TO UPPER
80S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 300 PM EDT MON MAY 27 2013
RIDGING WILL HOLD OVER THE EASTERN US THROUGH THE END OF THE WEEK.
THIS WILL KEEP OUR AREA WEST OF THE HIGH PRESSURE AREA IN AN AREA OF
RETURN FLOW. THIS WILL LEAD TO AN EXTENDED PERIOD OF MILD NIGHTS AND
WARM DAYS. INSTABILITY WILL GREATLY INCREASE FROM WEDNESDAY ONWARD
DURING THE DAYLIGHT HOURS...BUT WE WILL BE LACKING ANY TRIGGERS.
MODELS ARE STILL LIKELY OVER AGGRESSIVE WITH THE AMOUNT OF SURFACE
MOISTURE EACH DAY...SO LIKELY OVERDOING THE CAPE. HOWEVER...SOME
GOOD CU FIELDS SHOULD DEVELOP EACH AFTERNOON...AND IT MAY BE
POSSIBLE TO POP A VERY ISOLATED SHOWER OR STORM ALONG THE HIGHER
RIDES IN THE SOUTHEAST EACH AFTERNOON FROM WEDNESDAY THROUGH FRIDAY.
EACH DAY SHOULD FEATURE A SLIGHT BETTER CHANCE OF THIS HAPPENING AS
DEWPOINTS SHOULD CONTINUE TO INCH UP THROUGH THE REMAINDER OF THE
WEEK.
BY THIS WEEKEND...HIGH PRESSURE WILL RELINQUISH ITS HOLD ON THE AREA
AS A MID LEVEL SHORTWAVE APPROACHES FROM THE WEST. INCREASING FLOW
AHEAD OF THIS FEATURE ON SATURDAY...COULD YIELD A BETTER SHOT OF AN
ISOLATED SHOWER OR STORM BY SATURDAY AFTERNOON. THE CHANCES FOR
SHOWERS AND STORMS WILL INCREASE HEADING INTO SUNDAY AS THIS TROUGH
PUSHES EAST ACROSS THE AREA. PRESENTLY...MODELS IN FAIRLY GOOD
AGREEMENT ON TIMING...SO CONFIDENCE REMAINS HIGHER THAN NORMAL FOR
DAY 7. WITH THE FRONTAL PASSAGE...SLIGHTLY COOLER WEATHER SHOULD
RETURN TO THE AREA BY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 230 PM EDT MON MAY 27 2013
VFR CONDITIONS SHOULD PREVAIL THROUGHOUT THE TAF PERIOD AT ALL THREE
AIRPORTS. ISOLATED SHOWERS AND STORMS COULD AFFECT JKL THROUGH AROUND
0Z. OTHERWISE...CU NEAR 5 TO 6KFT SHOULD CONTINUE TO DEVELOP OVER THE
NEXT TWO TO THREE HOURS...BEFORE DIMINISHING. WITH THE WARM FRONT NOW
MOVING INTO WV...WINDS WILL AVERAGE OUT OF THE SOUTH SOUTHWEST TO
SOUTHWEST. WINDS WILL SLACKEN OVERNIGHT...BEFORE PICKING UP AT NEAR
10KT...ESPECIALLY LOZ AND SME AFTER 15Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
236 PM EDT MON MAY 27 2013
.UPDATE...
ISSUED AT 230 PM EDT MON MAY 27 2013
THE WARM FRONT CONTINUES TO LIFT NORTH TO THE OH RIVER AND EAST
FURTHER INTO THE WV COALFIELDS. GRIDS WERE FRESHENED UP BASED ON
RECENT OBS AND SAT AND RADAR TRENDS. THE MOST RECENT HRRR GUIDANCE
DOES NOT DEVELOP ANY CONVECTION UNTIL EARLY EVENING WHILE THE NEW GFS
DEVELOPS A BIT OVER THE HIGHER TERRAIN OF THE APPALACHIANS ALSO
THROUGH EARLY EVENING. THE 12Z NAM DEVELOPED SOME CONVECTION IN THE
LOWER OH VALLEY PRIOR TO 18Z AND THIS IS NOT OCCURRING AS ACTIVITY
IS WELL TO THE WEST OVER THE MID MS VALLEY AREA. CONFIDENCE IN MODEL
HANDLING AND EVOLUTION OF ANY CONVECTION THROUGH THIS EVENING IS LOW...
BUT MOST...IF NOT ALL LOCATIONS SHOULD REMAIN DRY THROUGH EVENING.
UPDATE ISSUED AT 1003 AM EDT MON MAY 27 2013
THE NEAR TERM TEMPS...DEWPOINTS AND SKY AS WELL AS POPS WERE ADJUSTED
BASED ON RECENT OBS AS WELL AS SATELLITE AND RADAR TRENDS. TEMPS ARE
WARMING UP RATHER QUICKLY IN THE SOUTHWEST WHERE THE FLOW IS MORE
SOUTHERLY AND THERE ARE FEW IN THE WAY OF CLOUDS BEHIND A NORTHWARD
LIFTING WARM FRONT. THE DIURNAL CLIMO CURVE IN GENERAL IS NOT
CAPTURING THE TEMPERATURE RISE AND OPTED TO GO WITH MORE A MOS
DERIVED TEMP CURVE FOR TODAY. MEANWHILE...A BAND OF CLOUDS IS WORKING
INTO THE SOUTHEASTERN PART OF THE CWA. BEHIND THIS BAND...SKIES
SHOULD BE MOSTLY SUNNY IN ALL AREAS INTO THE EARLY AFTERNOON WHEN CU
MAY BEGIN TO FORM. MODELS...ESPECIALLY THE 6Z NAM APPEARS TO BE TOO
AGGRESSIVE WITH THE INCREASE IN LOW LEVEL MOISTURE AND SFC AND
BOUNDARY LAYER DEWPOINTS WHEN COMPARED TO 12Z RAOB FROM NASHVILLE.
INSTABILITY IN THE 6Z NAM FORECAST SOUNDINGS IS LIKELY OVERDONE AS
DEWPOINTS WILL LIKELY MIX INTO THE LOW TO MID 50S RATHER THAN MID TO
UPPER 50S IN THE 6Z NAM...AND THIS MAY LEAD TO OBSERVED CAPE MUCH AS
1000 J/KG LESS THAN THE 6Z NAM FORECAST SOUNDINGS. THE 11Z HRRR SHOWS
VERY LITTLE CONVECTIVE DEVELOPMENT TODAY WITH CONVECTION GENERALLY
ALONG A CORRIDOR NEAR OR MAINLY NORTH OF THE OH RIVER THEN SOUTHEAST
TOWARD THE CENTRAL APPALACHIANS. THE 11Z HRRR HINTS AT SOME POSSIBLE
DEVELOPMENT NEAR THE WV BORDER AND ITS SCENARIO APPEARS REASONABLE.
FOR THIS UPDATE...CONFINED SLIGHT CHANCE POPS TO THE AFTERNOON INTO
EARLY EVENING AND OVER THE EASTERN THIRD TO HALF OF THE CWA. THE
BOTTOMLINE IS MOST LOCATIONS WILL LIKELY NOT EXPERIENCE ANY
CONVECTION TODAY.
THE 12Z NAM AND 9Z SREF HINT AT SOME CONVECTION THIS EVENING AND
BRING A WEAK SHORTWAVE ACROSS THE AREA. THE 11Z HRRR DOES NOT HAVE
THIS AND CONFIDENCE IN THIS IS NOT HIGH...BUT TRENDS WITH THIS WILL
BE MONITORED AS THE ENTIRE SUITE OF 12Z MODEL RUNS ARRIVE.
UPDATE ISSUED AT 651 AM EDT MON MAY 27 2013
NO MAJOR CHANGES WERE MADE TO THE FORECAST THIS MORNING. RAN THE ESTF
TOOL TO INGEST THE LATEST OBSERVATIONAL DATA AND INTEGRATE IT WITH
THE 4 AM FORECAST DATA. OVERALL THE FORECAST IS ON TRACK SO FAR
TODAY. SCATTERED SHOWERS AND STORMS CONTINUE TO MOVE ACROSS SOUTHERN
INDIANA AND OHIO...WITH A FEW OF THESE OCCASIONALLY STRAYING SOUTH
INTO THE NORTHERN FRINGES OF THE FORECAST AREA. THIS TREND IS
EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS. ACTIVITY IS EXPECTED
TO INCREASE A BIT DURING THE PEAK HEATING OF THE DAY...AS A ILL
DEFINED WARM FRONT MOVES IN FROM THE SOUTHWEST. NO UPDATE IS PLANNED
AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 301 AM EDT MON MAY 27 2013
MODELS WERE IN PRETTY GOOD AGREEMENT FOR THE SHORT TERM PORTION OF
THE FORECAST. THE CONSENSUS VIEW IS FOR ISOLATED SHOWERS AND STORMS
TO PUSH JUST TO THE SOUTH OF THE OHIO RIVER TODAY AND AGAIN LATE IN
THE DAY ON TUESDAY. THE LATEST RADAR IMAGERY SHOWED SCATTERED SHOWERS
AND STORMS MOVING ACROSS SOUTHERN INDIANA...NORTH CENTRAL
KENTUCKY...AND SOUTHWESTERN OHIO. A FEW OF THESE MIGHT MAKE INTO THE
NORTHERN MOST AREAS OF THE FORECAST BY EARLY THIS MORNING.
THEREFORE...SLIGHT CHANCE POPS WERE LEFT IN PLACE TO ACCOUNT FOR THIS
POTENTIAL. A WEAK WARM FRONT IS STILL PROGGED TO PUSH ACROSS THE AREA
THROUGHOUT THE DAY TODAY...WHICH WILL BRING THE POTENTIAL FOR FURTHER
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS...PARTICULARLY THIS
AFTERNOON DURING PEAK HEATING. AFTER A LULL IN THE ACTION MONDAY
NIGHT AND TUESDAY MORNING...THE WARM FRONT IS EXPECTED TO BECOME
ACTIVE ONCE AGAIN...WITH ISOLATED SHOWERS AND STORMS POSSIBLE ACROSS
THE NORTHERN AND NORTHEASTERN THIRD OF THE FORECAST AREA. RIGHT NOW
THE LIMITING FACTORS APPEAR TO BE THE AMOUNT LOW LEVEL MOISTURE
AVAILABLE AND THE DIFFUSE NATURE OF THE WARM FRONT. TEMPERATURES
TODAY AND TOMORROW WILL TOP OUT AT WELL ABOVE NORMAL VALUES...AS
SOUTHERLY FLOW BECOMES ESTABLISHED. TODAYS HIGHS ARE EXPECTED TO MAX
OUT IN THE LOW TO MID 80S...WITH MID 80S EXPECTED AREA WIDE ON
TUESDAY...AS CLOUD COVER THINS OUT QUITE A BIT.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 408 AM EDT MON MAY 27 2013
UPPER LEVEL RIDGING OVER THE SOUTHEAST CONUS AND LOW LEVEL SOUTHERLY
FLOW WILL BRING A PERIOD OF WARM SUMMER-LIKE WEATHER UNTIL THE
WEEKEND. WHILE THERE IS A REMOTE POSSIBILITY OF DIURNALLY DRIVEN
THUNDERSTORMS POPPING UP...THE POP IN ANY GIVEN 12 HOUR PERIOD IS
WELL BELOW 20 PERCENT UNTIL THE WEEKEND.
AN UPPER LEVEL TROUGH AND ITS ASSOCIATED SURFACE COLD FRONT ARE
EXPECTED TO APPROACH DURING THE WEEKEND. THIS WILL BRING A
POSSIBILITY OF SHOWERS AND THUNDERSTORMS SATURDAY NIGHT AND SUNDAY.
WITH THE INCREASE IN CLOUDS AND POSSIBLE PRECIP ON SUNDAY...TEMPS
WILL ALSO COOL OFF A BIT. THE MOST LIKELY TIME FOR COLD FRONTAL
PASSAGE IS SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 230 PM EDT MON MAY 27 2013
VFR CONDITIONS SHOULD PREVAIL THROUGHOUT THE TAF PERIOD AT ALL THREE
AIRPORTS. ISOLATED SHOWERS AND STORMS COULD AFFECT JKL THROUGH AROUND
0Z. OTHERWISE...CU NEAR 5 TO 6KFT SHOULD CONTINUE TO DEVELOP OVER THE
NEXT TWO TO THREE HOURS...BEFORE DIMINISHING. WITH THE WARM FRONT NOW
MOVING INTO WV...WINDS WILL AVERAGE OUT OF THE SOUTH SOUTHWEST TO
SOUTHWEST. WINDS WILL SLACKEN OVERNIGHT...BEFORE PICKING UP AT NEAR
10KT...ESPECIALLY LOZ AND SME AFTER 15Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...AR
LONG TERM...HAL
AVIATION...JP
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1255 PM EDT MON MAY 27 2013
...Updated Aviation Discussion...
.Forecast Update...
Issued at 1220 PM EDT Mon May 27 2013
Quick update for temperatures today. The consensus of the short-term
models indicates we should get up closer to the mid 80s today for
most of the region, and almost full sunshine this morning is helping
temperatures to run up. KSDF now is in the low 80s. We should see
some cumulus pop up under these warm conditions to help slow down
the increase. As for afternoon storm chances, we have a band of
convergence tailing from the MCV over northeast IL now, and this
band has some enhanced cu over southwest IN. Timing this band has it
over the I-65 corridor by 18Z, and our northeast forecast area by
20Z. Think the best focus for storms will be in this band, with
subsidence behind it. Will keep isolated-widely scattered coverage
in grids for now. Upstream band over northern Missouri is behaving
close to HRRR and RAP forecasts as well as 4 km NAM. All of those
models show it dissipating towards sunset, before getting into our
region. Will keep watch in case it starts accelerating toward our
northwest area.
Issued at 950 AM EDT Mon May 27 2013
Still looking like isolated to scattered convection will develop
later this afternoon. GOES Sounder data indicates the airmass has
dried out some now, but more moisture will advect into the region
this afternoon. In addition we have a weak warm front in the
vicinity, which is difficult to pick up in the wind field but a
little more apparent in the temp/dewpoint fields, with 60/low 50s
over our northeast and 70/60 over the southwest. We also have
residual boundaries from activity to our north overnight, along with
an atmosphere that should become less capped over the north later
this afternoon, as per RAP and NAM soundings. Given the combination
of these factors, have shifted the isolated storm line a little
south, but kept south central Kentucky dry for today. Some of the
high-res models are bringing a more organized line of storms in from
the west, from the system now over northern Missouri, and will have
to watch trends upstream to see if an update is necessary later.
Most of these models have any line that does move east weakening
quickly with sunset, but still have kept in isolated storm into the
evening to account for this possibility.
Issued at 630 AM EDT Mon May 27 2013
Current forecast remains on track at this time. Did adjust PoPs
downward across the region for the next several hours as convection
to our north continues to pull away from our area with little in the
way of downstream development. We do anticipate isolated to
scattered development later this afternoon. Temperatures are
nearing their overnight minimums with readings in the mid to upper
50s and will start to recover in the next hour once the sun comes up.
&&
.Short Term (Now - Tuesday)...
Issued at 325 AM EDT Mon May 27 2013
IR satellite and surface observations reveal clear mostly clear to
partly cloudy skies across the region this morning. Main batch of
cloudiness is across southern Indiana associated with convective
debris. Temperatures ranged from the middle 50s in our eastern
counties with lower 60s across our western sections. Some isolated
convection continues to move across far northern KY this morning.
This activity should continue to head on off to the east and may
clip our northern Bluegrass counties. For this reason, will hold on
to isolated shower/storm chances for the remainder of the morning
hours. Temperatures should continue to cool over the next few hours
with most locations dropping into the mid-upper 50s with readings
around 60 in the urban areas.
For Today, we`re likely to see partly cloudy skies across the
region. Weak frontal boundary that has been across the northern
sections will slowly advance northward during the day. Latest model
data suggests a weak upper level wave will approach the region from
the west during the afternoon hours. Overall moisture profile is
not all that great across the region. However, with slightly more
insolation today, we should have a little more instability to work
with this afternoon. Current indications are that the best chances
of showers and storms would generally be across southern Indiana and
portions of north-central Kentucky this afternoon...generally north
of the Western Ky and Bluegrass Parkways with drier conditions in
southern Kentucky. We should see warmer temperatures today with
highs in the lower 80s in southern Indiana and northern Kentucky
with mainly lower-middle 80s across southern Kentucky.
Dry conditions look likely as we head into the evening hours tonight
as any convection will probably slacken off with the loss of heating
and increasing stability within the PBL. Lows will cool into the
lower to middle 60s. High pressure and associated upper level
ridging will build into the region for Tuesday resulting in sunny
and warmer conditions with highs in the 81 to 86 degree range.
.Long Term (Tuesday Night- Sunday)...
Issued at 300 AM EDT Mon May 27 2013
Ridging aloft and high pressure at the surface will remain in
control for the latter half of the work week. Winds will be out of
the south with partly cloudy skies. Dry weather is expected through
this time frame. Temperatures will be on the warm side with highs
each day in the mid to upper 80s. Lows will range from the mid to
upper 60s.
Going into the weekend a low pressure system will track across the
Great Lakes region. A cold front associated with this system will
slowly approach the area Saturday and looks to finally push
through Sunday afternoon/night. Showers and thunderstorms will
accompany this front. For Saturday the best chance for showers and
thunderstorms will be along and north of the Ohio River.
Precipitation will slowly spread southeast overnight Saturday with a
better chance for precip areawide on Sunday. Temps Saturday look to
still top out in the mid 80s with highs in the lower 80s on Sunday.
Lows will be in the 60s.
&&
.Aviation (18Z TAF Issuance)...
Issued at 1255 PM EDT Mon May 27 2013
Have a band of increasing cloud cover moving towards KSDF this hour,
but should pass through before being enough to support storms. Bases
are well into the VFR range, so no concerns here. Upstream storm
system still behaving well with high-res models, and they insist it
will weaken with loss of heating, so will keep storm chances out of
the TAFs late this aftn/evening. Winds should gust from the
southwest the rest of the aftn with a tightening pressure gradient
over us. Gusts of 15-20 knots are likely this afternoon, and again
starting late morning Tuesday.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Updates..........MJ/RJS
Short Term.......MJ
Long Term........EER
Aviation.........RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1224 PM EDT MON MAY 27 2013
.Forecast Update...
Issued at 1220 PM EDT Mon May 27 2013
Quick update for temperatures today. The consensus of the short-term
models indicates we should get up closer to the mid 80s today for
most of the region, and almost full sunshine this morning is helping
temperatures to run up. KSDF now is in the low 80s. We should see
some cumulus pop up under these warm conditions to help slow down
the increase. As for afternoon storm chances, we have a band of
convergence tailing from the MCV over northeast IL now, and this
band has some enhanced cu over southwest IN. Timing this band has it
over the I-65 corridor by 18Z, and our northeast forecast area by
20Z. Think the best focus for storms will be in this band, with
subsidence behind it. Will keep isolated-widely scattered coverage
in grids for now. Upstream band over northern Missouri is behaving
close to HRRR and RAP forecasts as well as 4 km NAM. All of those
models show it dissipating towards sunset, before getting into our
region. Will keep watch in case it starts accelerating toward our
northwest area.
Issued at 950 AM EDT Mon May 27 2013
Still looking like isolated to scattered convection will develop
later this afternoon. GOES Sounder data indicates the airmass has
dried out some now, but more moisture will advect into the region
this afternoon. In addition we have a weak warm front in the
vicinity, which is difficult to pick up in the wind field but a
little more apparent in the temp/dewpoint fields, with 60/low 50s
over our northeast and 70/60 over the southwest. We also have
residual boundaries from activity to our north overnight, along with
an atmosphere that should become less capped over the north later
this afternoon, as per RAP and NAM soundings. Given the combination
of these factors, have shifted the isolated storm line a little
south, but kept south central Kentucky dry for today. Some of the
high-res models are bringing a more organized line of storms in from
the west, from the system now over northern Missouri, and will have
to watch trends upstream to see if an update is necessary later.
Most of these models have any line that does move east weakening
quickly with sunset, but still have kept in isolated storm into the
evening to account for this possibility.
Issued at 630 AM EDT Mon May 27 2013
Current forecast remains on track at this time. Did adjust PoPs
downward across the region for the next several hours as convection
to our north continues to pull away from our area with little in the
way of downstream development. We do anticipate isolated to
scattered development later this afternoon. Temperatures are
nearing their overnight minimums with readings in the mid to upper
50s and will start to recover in the next hour once the sun comes up.
&&
.Short Term (Now - Tuesday)...
Issued at 325 AM EDT Mon May 27 2013
IR satellite and surface observations reveal clear mostly clear to
partly cloudy skies across the region this morning. Main batch of
cloudiness is across southern Indiana associated with convective
debris. Temperatures ranged from the middle 50s in our eastern
counties with lower 60s across our western sections. Some isolated
convection continues to move across far northern KY this morning.
This activity should continue to head on off to the east and may
clip our northern Bluegrass counties. For this reason, will hold on
to isolated shower/storm chances for the remainder of the morning
hours. Temperatures should continue to cool over the next few hours
with most locations dropping into the mid-upper 50s with readings
around 60 in the urban areas.
For Today, we`re likely to see partly cloudy skies across the
region. Weak frontal boundary that has been across the northern
sections will slowly advance northward during the day. Latest model
data suggests a weak upper level wave will approach the region from
the west during the afternoon hours. Overall moisture profile is
not all that great across the region. However, with slightly more
insolation today, we should have a little more instability to work
with this afternoon. Current indications are that the best chances
of showers and storms would generally be across southern Indiana and
portions of north-central Kentucky this afternoon...generally north
of the Western Ky and Bluegrass Parkways with drier conditions in
southern Kentucky. We should see warmer temperatures today with
highs in the lower 80s in southern Indiana and northern Kentucky
with mainly lower-middle 80s across southern Kentucky.
Dry conditions look likely as we head into the evening hours tonight
as any convection will probably slacken off with the loss of heating
and increasing stability within the PBL. Lows will cool into the
lower to middle 60s. High pressure and associated upper level
ridging will build into the region for Tuesday resulting in sunny
and warmer conditions with highs in the 81 to 86 degree range.
.Long Term (Tuesday Night- Sunday)...
Issued at 300 AM EDT Mon May 27 2013
Ridging aloft and high pressure at the surface will remain in
control for the latter half of the work week. Winds will be out of
the south with partly cloudy skies. Dry weather is expected through
this time frame. Temperatures will be on the warm side with highs
each day in the mid to upper 80s. Lows will range from the mid to
upper 60s.
Going into the weekend a low pressure system will track across the
Great Lakes region. A cold front associated with this system will
slowly approach the area Saturday and looks to finally push
through Sunday afternoon/night. Showers and thunderstorms will
accompany this front. For Saturday the best chance for showers and
thunderstorms will be along and north of the Ohio River.
Precipitation will slowly spread southeast overnight Saturday with a
better chance for precip areawide on Sunday. Temps Saturday look to
still top out in the mid 80s with highs in the lower 80s on Sunday.
Lows will be in the 60s.
&&
.Aviation (12Z TAF Issuance)...
Issued at 630 AM EDT Mon May 27 2013
VFR conditions are expected to continue at the TAF sites through the
upcoming forecast period. Convective debris, in the form of
mid-high level cloud cover continues to overspread the northern
sections of the forecast area this morning. This will mainly affect
KSDF and KLEX but will have no impact on aviation. Surface winds
will start of light and variable and then pick up out of the south
by mid-morning and into the afternoon hours. Upper level
disturbance is still on track to pass through the region later this
afternoon which may spark an isolated shower or storm this
afternoon. Coverage is still sparse to include in the upcoming TAF
forecast at this time.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Updates..........MJ/RJS
Short Term.......MJ
Long Term........EER
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
116 PM EDT MON MAY 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 532 AM EDT MON MAY 27 2013
WATER VAROR IMAGERY AND RUC ANALYSIS SHOW THE BEGINNINGS OF AN
ACTIVE PATTERN SHAPING UP FOR THE UPPER GREAT LAKES THIS WEEK. MEAN
TROF SETTLING INTO THE WRN CONUS THRU MIDWEEK AND THEN SLOW SHIFTING
E WILL SEND NMRS SHORTWAVES THRU THE CNTRL CONUS AND INTO THE GREAT
LAKES. MODELS WILL NO DOUBT STRUGGLE WITH THE CONVECTION ASSOCIATED
WITH THE WAVES...AND THE FCST WILL HAVE MUCH MORE THAN NORMAL
UNCERTAINTY BEYOND THE SHORT TERM. SEVERAL CLUSTERS OF SHRA/TSRA
HAVE BEEN OCCURRING FROM THE DAKOTAS TO THE OHIO VALLEY DURING THE
NIGHT...A SIGN OF THE ACTIVE PATTERN EVOLVING THIS WEEK.
MEANWHILE...DRY AIR CONTINUES TO LINGER OVER THE UPPER LAKES (NOTE
THE DRY 00Z SOUNDINGS FROM KGRB/KAPX).
THERE ARE 3 SHORTWAVES OF INTEREST FOR THE SHORT TERM. THE FIRST OF
IS OVER ERN MT/WRN ND...THE SECOND IS OVER WRN IA AND THE THIRD IS
OVER THE SRN ROCKIES. THE FIRST WAVE IS PRODUCING CONVECTION OVER
THE WRN DAKOTAS. THIS WAVE IS ON A TRACK TO LIFT NE AROUND THE RIDGE
EXTENDING N THRU THE MISSISSIPPI VALLEY TOWARD HUDSON BAY...AND WILL
NOT BE A FACTOR HERE. THE SECOND WAVE SHOULD WEAKEN AS IT CUTS THRU
THE RIDGE...AND ITS ASSOCIATED CONVECTION SHOULD ALSO WEAKEN AS IT
OUTRUNS THE INSTABILITY POOL OVER THE PLAINS. THE THIRD WAVE WILL
HELP STRENGTHEN THE LOW LEVEL JET TONIGHT AS IT MOVES OUT ACROSS THE
PLAINS. WITH FRONTAL BOUNDARY CURRENTLY WELL TO THE SW AND S AND NOT
LIKELY TO MAKE MUCH PROGRESS TODAY...DRY WEATHER WILL BE THE RULE
TODAY AND PROBABLY RIGHT INTO THE EVENING HRS. ALL MODELS WITH THE
EXCEPTION OF THE GEM HAVE TRENDED NOTABLY SLOWER ADVANCING PCPN
TOWARD UPPER MI. WILL THUS RUN WITH A DRY FCST INTO THE EVENING.
TONIGHT...STRENGTHENING LOW-LEVEL JET IN RESPONSE TO AFOREMENTIONED
SHORTWAVE WILL HELP GENERATE MORE SHRA/TSRA ACROSS THE PLAINS TOWARD
THE UPPER MISSISSIPPI VALLEY/WRN LAKES. DIFFICULT TO SAY HOW FAR N
AND E PCPN WILL ADVANCE...BUT WITH ADVANCING WARM FRONT STILL A GOOD
DISTANCE TO THE SW...WOULD EXPECT BULK OF SHRA/TSRA ACTIVITY TO
REMAIN TO THE S AND SW. HOWEVER...NRN FRINGES OF PCPN MAY STILL
SPREAD FAR ENOUGH N TO AFFECT AT LEAST SRN UPPER MI...AND WILL
INCLUDE SCHC/CHC POPS OVERNIGHT.
ALTHOUGH CI BLOWOFF FROM CONVECTION OVER ERN NEBRASKA/WRN IA IS
CURRENTLY SPREADING INTO UPPER MI...EXPECT THESE HIGH CLOUDS TO THIN
OUT SOME DURING THE DAY AS CONVECTION WEAKENS. SO...THERE SHOULD
STILL BE FAIRLY STRONG HEATING TODAY AND THUS DEEP MIXING TO BRING
DRIER AIR DOWN TO THE SFC. DWPTS SHOULD FALL TO THE LOW/MID 30S THIS
AFTN...PERHAPS LOWER OVER THE CNTRL/E BASED ON POTENTIAL MIXING
HEIGHTS. WITH HIGH TEMPS UP AROUND 70F IN THE INTERIOR...RH SHOULD
BOTTOM OUT IN THE 25-30PCT RANGE W AND 20-25PCT RANGE E. WINDS WILL
BE A LITTLE STRONGER TODAY AS SFC HIGH PRES RIDGE DRIFTS FARTHER E
OF THE AREA. WILL PROBABLY SEE AFTN GUSTS AROUND 20MPH OVER THE W
AND CNTRL AND 15MPH OVER THE E. WITH THE RECENT DRY DAYS...FIRE WX
CONCERNS WILL BE HIGHER TODAY GIVEN THE LOW RH AND A LITTLE STRONGER
WIND.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 532 AM EDT MON MAY 27 2013
TRICKY FORECAST FOR TUESDAY INTO TUESDAY NIGHT CONCERNING
PRECIPITATION CHANCES. OVERALL...SHORT WAVE ENERGY CURRENTLY MOVING
INTO THE CENTRAL PLAINS WILL MOVE INTO THE WESTERN GREAT LAKES
REGION LATER TONIGHT INTO TUESDAY. MEANWHILE...A WARM FRONTAL
BOUNDARY WILL MOVE NORTH INTO THE UPPER GREAT LAKES ON TUESDAY. THIS
WARM FRONT WILL LIKELY SERVE AS THE FOCUS FOR SHOWERS AND
THUNDERSTORMS...SIMILAR TO WHAT IT IS DOING THIS MORNING. THE
PROBLEM IS THAT THE NWP ARE HANDLING THIS WARM FRONT RATHER
POORLY...ALONG WITH THE 850MB JET THAT INTERSECTS THE FRONT. THE 12Z
ECMWF IS BY FAR THE FARTHEST WEST WITH THE LLJ AND ASSOCIATED
PCPN...PLACING THE HEAVIER PCPN ACROSS THE WESTERN LAKE AND WESTERN
UPPER MICHIGAN LATE TONIGHT INTO TUESDAY (ALTHOUGH THE 00Z ECMWF HAS
TRENDED AWAY FROM THIS SOLN). NOT SURE IF THE 12Z RUN MAKES SENSE AS
THE PCPN SEEMS TO RACE OUT AHEAD OF THE PRIMARY WARM FRONT.
MEANWHILE...THE NAM AND GFS CONTINUE TO BE SLOWER WITH PCPN MOVING
INTO THE AREA (WITH THE GFS BEING EVEN SLOWER)...BUT THEY KEEP THE
PCPN TIED TO THE FRONT...WITH THE HEAVIEST PCPN FURTHER SOUTH INTO
WISCONSIN WHERE THE LLJ IS JUSXTAPOSITIONED WITH THE BETTER
INSTABILITY. FINALLY...THE REGIONAL GEM IS SIMILAR WITH THE HEAVIEST
PCPN WELL SOUTH OF THE AREA BUT IT SPREADS PCPN INTO UPPER MICHIGAN
TOO FAST AND WELL AHEAD OF THE WARM FRONT. HAVE OPTED TO TREND
TOWARD A SLOWER NAM/GFS COMPROMISE SOLN WITH LIKELY POPS INTO
SOUTHERN UPPER MICH TUE MORNING...THEN SPREADING NORTH/EAST DURING
THE DAY AS THE WARM FRONT LIFTS NORTH. THE WESTERN AREAS WILL ALSO
TEND TO DRY OUT LATER IN THE DAY BEHIND THE SHORT WAVE. NOT TERRIBLY
IMPRESSED WITH THUNDER CHANCES ON TUESDAY. WITH THE SLOWER MOVEMENT
OF THE WARM FRONT...THE BEST INSTABILITY WILL REMAIN IN WISCONSIN.
SIMPLY DUE TO THE FORCING ALONG THE FRONT...CANNOT COMPLETELY RULE
OUT THUNDER BUT THE EXPECTATION IS THAT THE BEST THUNDER CHANCES
WOULD STAY ACROSS THE FAR SOUTH CLOSER TO THE BETTER INSTABILITY.
SHOULD END UP BEING A GENERALLY QUIET TUESDAY NIGHT AND WEDNESDAY
MORNING ACROSS THE AREA WITH UPPER AND SFC RIDGING ACROSS THE AREA.
WILL LIKELY BE A LITTLE MUGGY WITH THE AREA BEING IN THE WARM SECTOR
AND DEWPOINTS IN THE UPPER 50S. BUT GIVEN LACK OF FORCING OVERNIGHT
WILL GO WITH A DRY FORECAST AFTER ANY REMAINING SHOWERS/STORMS EXIT
EAST. ON WEDNESDAY...POPS WERE LOWERED WITH LACK OF ANY SIGNIFICANT
FOCUS FOR THUNDERSTORMS DESPITE MLCAPE VALUES OF 1000-1500 J/KG.
BETTER FOCUS FOR STORMS WITH THE NOSE OF THE 50KT LOW LEVEL JET AND
DEEP MOISTURE TRANSPORT INTO THE AREA EXPECTED WEDNESDAY NIGHT. THIS
MAY BE THE MOST LIKELY PERIOD FOR STRONG/SEVERE STORMS WITH FORWARD
PROPOGATING STORMS LIKELY MOVING INTO THE AREA FROM WISCONSIN.
FOR THE THU-SUNDAY PERIOD...THE AREA WILL BE FIRMLY IN THE WARM
SECTOR ON THURSDAY...AS THE LOW LEVEL JET BACKS TO A MORE SOUTHERLY
DIRECTION AND THE NOSE FOCUSES OVER NW WISCONSIN. EXPECT MORE
CONVECTION TO DEVELOP IN THIS AREA THURSDAY AND MOVE INTO UPPER
MICHIGAN DURING THE AFTN AND EVENING HOURS AS THE GFS AND 00Z ECMWF
ARE IN GOOD AGREEMENT IN SHOWING ANOTHER SHORT WAVE MOVING ACROSS
THE AREA. THE UPPER TROUGH AND SURFACE LOW FINALLY MOVES EAST
STARTING FRIDAY WITH THE SYSTEM MOVING ACROSS THE AREA BY SATURDAY.
WILL CONTINUE WITH CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
SATURDAY. ANOTHER WARM AND MUGGY DAY ON FRIDAY...THEN TURNING COOLER
BY SUNDAY AS 850MB TEMPS DROP TO +6C BEHIND THE SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1253 PM EDT MON MAY 27 2013
A HIGH PRES RIDGE WILL PERSIST OVER THE UPPER GREAT LAKES GENERALLY
MAINTAINING THE LOW-LVL DRY AIRMASS AND VFR CONDITIONS FOR KIWD/KCMX/KSAW
THROUGH THIS FCST PERIOD. A WARM FRONT OVER THE PLAINS WILL BE MOVING
N TONIGHT AND EARLY TUE...BUT GUIDANCE CONTINUES TO TREND TOWARD
KEEPING SHRA ASSOCIATED WITH FRONTAL BOUNDARY GENERALLY S OF THE
AREA. A FEW SHRA SKIRTING NORTH OF THE FRONTAL BOUNDARY COULD BRUSH
KSAW WITH SOME LIGHT -SHRA BY LATE TUE MORNING. SOUTHEASTERLY WINDS
WILL INCREASE THIS AFTERNOON WITH GUSTS APPROACHING 20 KT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 532 AM EDT MON MAY 27 2013
WITH GENERALLY WEAK PRES GRADIENT AND STABLE CONDITIONS OVER LAKE
SUPERIOR...EXPECT WINDS TO BE UNDER 25KT THRU THE WEEK. HOWEVER...
WITH THE POTENTIAL FOR CLUSTERS OF SHRA/TSRA TO PASS ACROSS/NEAR THE
UPPER GREAT LAKES...THERE COULD BE SHORT PERIODS OF ENHANCED WINDS
AT TIMES (STRONGER SE WINDS OVER ERN LAKE SUPERIOR AND STRONGER NE
WINDS OVER WRN LAKE SUPERIOR). ONCE SOME RAINFALL OCCURS OVER THE
LAKE...FOG WILL LIKELY DEVELOP...AND IT COULD BECOME DENSE MID TO
LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...MRD
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
359 PM CDT MON MAY 27 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 400 PM CDT MON MAY 27 2013
PERSISTENT AREA OF LIGHT SHOWERS AND DRIZZLE NOTED SOUTH OF A LINE
FROM KMSP TO KEAU AND EAST OF LINE FROM SHAKOPEE TO TRUMAN. THIS
REGION IS REMNANTS OF MCS WHICH FORMED OVER NORTHERN IOWA DURING
THE OVERNIGHT. AREA CORRELATES WELL WITH GFS40 THETA E ADVECTION.
CURRENT HRRR ALSO SEEMS TO HAVE A GOOD HANDLE OF AREAL COVERAGE
AND INTENSITY. REGION WAS STRUGGLING EARLIER THIS AFTERNOON AS IT
MARCHED NORTH INTO DRIER AIR COLUMN AND CONVERGENCE DEPICTED AT
250MB. EXPECT CONTINUED SLOW MIGRATION OF PRECIPITATION SHIELD
NORTH AS LATE DAY SURFACE HEATING CONTINUES TO MAINTAIN OR SLOWLY
ENHANCE CURRENT INTENSITY. LOOK FOR CESSATION OF MOST PRECIP. FROM
THIS FEATURE BY AROUND 28/06Z. FOR THE REMAINDER OF THE OVERNIGHT
EXPECT ANOTHER LATE NIGHT MCS TO FOLLOW THE PLACEMENT OF A WARM
FRONTAL BOUNDARY ABOVE CENTRAL TO NORTHERN IOWA. MCS WILL AGAIN
FORM OVER EASTERN SODAK AND FOLLOW 1000-500MB THICKNESS LINE
DROPPING ANOTHER THREE QUARTERS TO ONE INCH OF RAINFALL OVER PORTIONS
OF CENTRAL TO NORTHERN IOWA. SHOULD BE ANOTHER RATHER GLANCING
BLOW FOR THE FAR SW AND SOUTH CENTRAL PORTION OF THE MN CWA...SIMILAR
TO THE PREVIOUS THREE NIGHTS...WITH A FEW TENTHS TO POSSIBLY FOUR
TENTHS OF AN INCH EXPECTED OVER THIS REGION...WITH HEAVIEST AMOUNTS
OVER FAR SOUTH CENTRAL MINNESOTA.
MCS OVER NORTHERN IOWA SHOULD FOLLOW SAME TRAJECTORY AS TODAY`S
PCPN SHIELD...WITH POSSIBLY A FEW MORE EMBEDDED THUNDERSTORMS
AS LI`S GRADUALLY RECEDE INTO NEGATIVE TERRITORY. MOISTURE FROM
THIS SYSTEM WILL AGAIN BE ON THE WEAK SIDE...WITH MAINLY AROUND
ONE TENTH OF AN INCH ON AVERAGE ANTICIPATED PRIOR TO PASSAGE.
USED A BLEND BETWEEN NAM AND GFS40 FOR TUESDAY`S HIGH TEMPERATURES
...AND THEN THROTTLED BACK ONE CATEGORY. OF COURSE INTENSITY AND
FORWARD SPEED OF RAINFALL SHIELD MENTIONED ABOVE WILL DETERMINE
WHETHER TEMPERATURES NEED TO BE CUT EVEN FURTHER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 PM CDT MON MAY 27 2013
TUESDAY EVENING INTO WEDNESDAY MORNING IS EXPECTED TO BE A DRY TIME
FRAME...AS THE SURFACE WARM FRONT REMAINS TO THE SOUTH OVER SOUTHERN
IOWA AND THE LOW LEVEL MOISTURE/WARM AIR ADVECTION IS FOCUSED THERE
AS WELL. HOWEVER...SHOWERS AND THUNDERSTORMS SHOULD OVERSPREAD THE
AREA DURING THE DAY ON WEDNESDAY...AS THE WESTERN TROUGH SURGES
EASTWARD...AND THE FRONT AND ADVECTION PROCESSES SHIFT NORTHWARD IN
CONJUNCTION WITH A SHORTWAVE IMPULSE. STRONGLY DIFFLUENT FLOW ALOFT
COMBINES WITH THE LOW LEVEL JET INFLUENCES...AND COULD SET THE STAGE
FOR A FEW SEVERE STORMS ON WEDNESDAY AFTERNOON/EVE.
ON THURSDAY...THE UPPER TROUGH TAKES ON A NEGATIVE TILT...AS THE
WARM FRONT LIFTS ACROSS THE AREA. THIS WILL CONTINUE THE SEVERE
WEATHER THREAT AND ENHANCE THE FLOODING POTENTIAL AS WELL. PWATS
WILL REMAIN NEAR CLIMATOLOGICAL RECORD VALUES /1.5 TO 2.0
INCHES/...WHILE THE TROUGH STRUCTURE PROVIDES THE SHEAR SUFFICIENT
FOR STRONG POSSIBLY SEVERE STORMS. ON FRIDAY...THE COLD FRONTAL
BOUNDARY ASSOCIATED WITH THE SURFACE LOW PASSES ACROSS THE
AREA...AND CONTINUES THE THREAT FOR WIDESPREAD SHOWERS AND
THUNDERSTORMS.
ALTHOUGH THE THREAT FOR SEVERE STORMS WILL DIMINISH ON SATURDAY IN
THE WAKE OF THE SURFACE LOW...RAIN SHOWERS WILL CONTINUE TO BE
POSSIBLE OVER THE WEEKEND AS THE MID/UPPER TROUGH ROTATES OVER THE
UPPER MIDWEST.
HIGH TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL FOR THE
END OF MAY...RANGING THROUGH THE MID TO UPPER 70S...AND THEN DECLINE
TO AROUND 5 TO 10 DEGREES BELOW NORMAL FOR THE FIRST FEW DAYS IN
JUNE /65 TO 70 DEGREES/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 118 PM CDT MON MAY 27 2013
A LITTLE COMPLEX THIS AFTERNOON WITH REMNANTS OF SHOWER AND ISOLATED
THUNDERSTORM COMPLEX NOTED ON 0.5 DEGREE REFLECTIVIT OVER SE CWA.
AREA HAS SLOWLY BEEN ERODING IN BOTH AREA AND INTENSITY AS IT HAS
PROGRESSED NORTH FROM SOUTH CENTRAL MN. HRRR HAS PEGGED DEPRECIATION
IN REFLECTIVITY TRENDS QUITE WELL. IF THIS PANS OUT SYSTEM WILL
AFFECT PORTIONS OF EAST CENTRAL MN AND FAR SOUTHERN WEST CENTRAL
WISCONSIN THROUGH 00Z TIME FRAME...THEN DISSIPATE OR TREK NE OUT
OF AIRPORT REGION. MVFR CIGS CURRENTLY IN PLACE OVER ALL TAF
SITES...WITH AREA OF LOW MVFR TO POCKETS OF IFR CIGS NOTED OVER
SW MN. LOOK FOR SLOW LOWERING OF CLOUD DECK AFT 00Z MOST SITES
...WITH EASTERLY FLOW CONTINUINING INTO END OF PERIOD. LOOK FOR
IFR CIGS BY 09Z MOST LOCALES...WITH LIFR CIGS ALSO A POSSIBILITY.
FORCING AS DEPICTED ON EUROPEAN MODEL WILL PORTEND ANOTHER ROUND
OF SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING OVER SW MN AND
WEST CENTRAL WI BY 12Z...AND REMAINDER OF REGION BETWEEN 14 AND
18Z TIME FRAME. CIGS WILL RISE BACK TO MVFR CONDITIONS MOST LOCALES
ASSOCIATED WITH SAME.
KMSP...
IR SATELLITE INDICATED SMALL AREA OF VFR CIGS JUST TO SW OF
AIRPORT AT 18Z. EXPECT THIS TO FILL IN LATER THIS AFTN BACK TO
MVFR CONDITIONS. ALTHOUGH NORTHERN TREKKING MCS REMNANTS
CONTINUE TO SLOWLY DEGRADE OVER THE WESTERN PORTION...STILL
EXPECT SHORT PERIOD OF LIGHT DRIZZLE/-RW EARLY PORTION OF PERIOD.
ONCE COMPLEX MARCHES THROUGH REMAINDER OF LATE AFTN/EVEN HOURS
WILL BY DRY...WITH CIGS LOWERING BEHIND COMPLEX. SE FLOW THROUGH
PERIOD...WITH GOOD FORCING PROGNOSTICATING ANOTHER ROUND OF LIGHT
SHOWERS FROM 14Z THROUGH AT LEAST 18Z. THIS SECOND ROUND MAY LAST
INTO 20Z ON TUESDAY. TOMORROW EVEN WILL REMAIN DRY...WITH MVFR
CONTINUIING.
/OUTLOOK FOR KMSP/
TUE...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS S 5-10 KTS.
WED...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS S 10-15 KTS.
THU...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS S 15-20 KTS.
FRI...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SW-W 15-20KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...AJZ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
150 PM CDT MON MAY 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT MON MAY 27 2013...UPDATED FOR 18Z TAF.
THUNDERSTORMS WITH EXCESSIVE RAINFALL ARE ONCE AGAIN JUST SOUTH OF
OUR MN CWA EARLY THIS MORNING. THE ACTIVITY IS FOCUSED JUST NORTH OF
A STATIONARY FRONT THAT MEANDERS ACROSS NE/IA AND AT THE NOSE OF THE
LOW LEVEL MOISTURE TRANSPORT. CONVERSATION WITH THE SATELLITE
PRECIPITATION ESTIMATE GROUP INDICATED THAT AROUND A FOOT OF RAIN
HAS LIKELY FALLEN IN THE LAST 24 HOURS OVER PARTS OF NW IA. AS I
MENTIONED YESTERDAY...THE 850MB DEW POINT ON THE KOMA RAOB SATURDAY
EVENING WAS 15 DEG C. THEIR 850MB DEW POINT SUNDAY EVENING HAD RISEN
TO 17 DEG C.
THE COMPLEX OF STORMS OVER NW IA HAS TAKEN ON A CIRCULATION THIS
MORNING WITH A BOW RACING SOUTHEAST ACROSS WESTERN IA. SHORT TERM
WRF SOLUTIONS SHOW AN AREA OF SHOWERS AND PERHAPS AN ISOLATED
THUNDERSTORM PASSING SLOWLY EASTWARD ACROSS SOUTHERN MN THIS MORNING
WITH SOME SHOWERS REACHING INTO WEST CENTRAL WI THIS AFTERNOON. WE
HAVE BEEN OVER FORECASTING PRECIP THE PAST FEW DAYS AS A DRY
EASTERLY FLOW HAS PREVAILED...SIMILAR TO WHAT THE ECMWF INDICATED
FOR MUCH OF THE WEEKEND A FEW DAYS BACK. HENCE...WILL KEEP POPS
HIGHEST IN THE FAR SOUTH WITH DRY WEATHER IN THE NORTHERN CWA. RAIN
AMOUNTS THIS MORNING MAY REACH A HALF TO ONE INCH ALONG THE I-90
CORRIDOR WITH A SIGNIFICANT DROP TO THE NORTH.
TONIGHT IS A FORECAST PROBLEM ON RAINFALL ACROSS THE SOUTHERN AND
EASTERN CWA. THERE ARE TWO CAMPS. THE DETERMINISTIC RUNS WOULD DRIVE
SHOWERS AND THUNDERSTORMS NORTHEAST ACROSS OUR AREA AS A STRONG
SHORT WAVE LIFTS NORTHEAST FROM THE CENTRAL PLAINS. ON THE
OTHER HAND... THE VARIOUS WRF SOLUTIONS HAVE HARDLY ANYTHING AT ALL
FOR US WITH ANOTHER LONG NIGHT OF STORMINESS ACROSS NE...IA AND
NORTHERN IL. WHAT WE CAN SEE IS THAT THE STATIONARY FRONT ON THE
NAM/GFS AND THE VARIOUS WRF/S IS ACTUALLY PROGGED TO DROP A LITTLE
SOUTH TODAY BEFORE RETURNING BACK TO ITS POSITION BY TUESDAY
MORNING. IN ADDITION...THE LOW LEVEL MOISTURE TRANSPORT WHICH HAS
BEEN ORIENTATED SOUTH TO NORTH INTO EASTERN NE/WESTERN IA IS PROGGED
TO VEER DURING THE NIGHT WITH THE NOSE OF THE TRANSPORT INTO
SOUTHERN IA AND NORTHERN IL LATE IN THE NIGHT. THE POOL OF 15-17 DEG
850 MB DEW POINTS OVER NE IS ALSO FORECAST TO BREAK DOWN TONIGHT
WITH 12 DEG C DEW POINT FLOWING OUR WAY. THE ONE SOLUTION THAT DOES
NOT GO ALONG WITH THIS IS THE ECMWF. IT WOULD NOT ONLY BRING A SHORT
WAVE THROUGH... BUT ALSO THE LOW LEVEL MOISTURE TRANSPORT PUSHES
ACROSS SOUTHERN MN ALONG WITH 850 MB DEW POINTS OF 14 DEG C.
THEREFORE...THE DAY SHIFT MAY NEED TO ISSUE A FLASH FLOOD WATCH FOR
TONIGHT AND TUESDAY MORNING IF THE NAM/GFS AND THE WRF/S START
TRENDING TOWARDS THE ECMWF. OUR 3 HOURLY FFG VALUES ACROSS SOUTHERN
MN ARE IN THE 1.5 TO 2 INCH RANGE. SO...RAIN AMOUNTS ALONG THE I-90
CORRIDOR WILL NEED TO BE WATCHED THIS MORNING WITH MORE RAIN
INCOMING TONIGHT. WE HAVE SEEN OVER THE PAST FEW NIGHTS THE RAIN
AMOUNTS JUST TO OUR SOUTH AND WEST REACHING NEARLY 2 INCHES IN AN
HOUR... AND THIS WENT ON FOR SEVERAL HOURS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM CDT MON MAY 27 2013
FOR THE LONG TERM...WEDNESDAY THROUGH FRIDAY STILL LOOK WET...WITH
CHANCES FOR SEVERE WEATHER IN THERE AS WELL. THE 27.00 MEDIUM RANGE
MODEL RUNS HAVE CONTINUED THE TREND OF THEIR 26.12 RUNS OF THE
FRONT FOR MID-LATE WEEK MOVING THROUGH A BIT FASTER. AS A
RESULT...THE POTENTIAL FOR SEVERE WEATHER THAT WAS LOOKING GOOD
FOR THURSDAY AND FRIDAY LAST NIGHT IS NOW LOOKING MORE LIKE
WEDNESDAY AND THURSDAY.
THIS PERIOD LOOKS TO HAVE THE POTENTIAL TO START OFF WET TUESDAY
MORNING AS THE WARM FRONT IS FINALLY LIFTING NORTH THROUGH THE
AREA. MOST AGGRESSIVE MODEL WITH PRECIP GOING INTO TUESDAY MORNING
IS THE ECMWF. REST OF THE DETERMINISTIC MODELS...ALONG WITH HI-RES
CAMS SHOW MAIN H85 MOISTURE TRANSPORT FROM TONIGHT INTO TUESDAY
MORNING LAYING ACROSS IA INTO SRN WI. THE ECMWF HAS A MUCH
STRONGER H85 AND SFC WAVE LIFTING NORTH ACROSS MN DURING THIS
PERIOD...WHICH HELPS DIRECT A GOOD CHUNK OF THE MOISTURE TRANSPORT
UP ACROSS MN INTO WRN WI. HAVE LIKELY POPS GOING ACROSS ERN MN/WRN
WI TUESDAY MORNING...THOUGH GIVEN HOW MODELS HAVE PERFORMED THE
PAST COUPLE OF NIGHTS WITH BEING A LITTLE EAGER IN BRINGING PRECIP
NORTH...CONFIDENCE STILL A BIT SHAKY AS TO HOW THE MORNING WILL
PLAY OUT. GOOD NEWS ABOUT TUESDAY THOUGH...ALL MODELS SHOW A
DRYING TREND FOR THE AFTERNOON INTO TUESDAY NIGHT...WITH A DRY
PERIOD LOOKING POSSIBLE FOR MUCH OF THE AREA THEN. THERE IS EVEN
THE POTENTIAL TO SEE SOME HIGHS IN THE 80S OUT WEST IF THE NAM/GFS
CLEARING WERE TO MATERIALIZE OUT THERE.
TUESDAY NIGHT...A NEGATIVELY TILTED H5 WAVE WILL START WORKING OUT
ACROSS THE SRN PLAINS...WITH H85 WINDS BACKING CONSIDERABLY
THROUGH THE NIGHT...WITH ALL GUIDANCE SHOWING ANOTHER 40-50 KT LLJ
COMING OUT OF THE PLAINS AND COMING UP INTO ERN NEB/CENTRAL IOWA
BY WEDNESDAY MORNING. AS RESULT...STARTED TO INCREASE POPS AFTER
6Z WED MORNING TO ACCOUNT FOR THE INCREASED WAA/MOISTURE TRANSPORT
STARTING TO TAKE AIM AT SRN MN...THOUGH THAT MAY BE TOO AGGRESSIVE
WITH BRINGING PRECIP BACK.
FOR WEDNESDAY...THE NAM/GFS/ECMWF ALL SHOW A 40+ KT LLJ WORKING UP
INTO MN...WHICH WILL HELP SET THE STAGE FOR MORE WIDESPREAD
THUNDERSTORM ACTIVITY...ALONG WITH THE THREAT FOR SEVERE
WEATHER...AS INDICATED BY THE SLIGHT RISK ACROSS MOST OF THE MPX
CWA IN THE DAY 3 SPC OUTLOOK. IN ADDITION...DRYING TREND NOTED ON
TUESDAY IS ACTUALLY A WEAK COLD FRONT THAT WILL DROP INTO IOWA
TUESDAY NIGHT...BUT SURGE NORTH ACROSS MN/WI ON WEDNESDAY. SHEAR
PROFILES SHOW MOST OF THE SHEAR BEING OF THE SPEED
VARIETY...THOUGH NAM PROFILES...ESPECIALLY IN WRN MN DO SHOW SOME
LOW LEVEL TURNING OF THE WINDS. IN ADDITION TO THE MAINLY SPEED
SHEAR...SHEAR VECTORS ARE MAINLY LINED UP PARALLEL TO THE LOW
LEVEL FORCING FEATURES...WHICH STILL POINTS TO MAINLY LINEAR
CONVECTIVE MODES FOR WEDNESDAY INTO WEDNESDAY NIGHT.
FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MODELS SHOW SFC
FEATURES AND STRONG LLJ JUST GRADUALLY SHIFTING EAST...WITH THE
MPX CWA SITTING SQUARE UNDERNEATH THE LLJ DURING THIS PERIOD. THIS
SHOULD RESULT IN AT LEAST A COUPLE ROUNDS OF THUNDERSTORMS MOVING
ACROSS THE AREA. IN ADDITION...SEVERE WEATHER STILL LOOKS LIKE A
GOOD POSSIBILITY FOR THURSDAY AS WELL...WITH SIMILAR LARGE SCALE
FEATURES FORECAST FOR THURSDAY AS IS CURRENTLY BEING INDICATED FOR
WEDNESDAY. SEVERE THREAT THOUGH FOR THURSDAY WILL BE TIED CLOSELY
TO HOW POTENTIALLY WIDESPREAD CONVECTION WEDNESDAY INTO WEDNESDAY
NIGHT MODIFIES INSTABILITY PROFILES FOR THURSDAY. AT ANY
RATE...THE LARGE SCALE FORCING THURSDAY STILL POINTS TO THE
POTENTIAL FOR ANOTHER DAY OF SEVERE WEATHER. IN ADDITION...PWATS
WILL BE INCREASING TO BETWEEN 160 AND 200 PERCENT OF NORMAL /NOT
TOO FAR FROM THE MAY PWAT RECORD FOR MPX OF 1.68 INCHES/ AHEAD OF
THE COLD FRONT WEDNESDAY AND THURSDAY...WHICH MEANS A CLOSE EYE
WILL NEED TO BE KEPT ON THE HYDRO ASPECT OF THINGS AS WELL.
FOR FRIDAY...MEDIUM RANGE MODELS SHOW FRONT WORKING THROUGH
MN...WITH MAIN H85 MOISTURE TRANSPORT SITUATED EAST OF THE MPX
CWA. THIS WILL PUSH THE HEAVY RAIN THREAT EAST OF THE AREA ON
FRIDAY. HOWEVER...UPPER LOW ON FRIDAY WILL ALSO BE WORKING ACROSS
THE DAKOTAS INTO MN...WHICH WILL LEAD STEEPENING LAPSE RATES.
THIS SHOULD LEAD TO ONE MORE ROUND OF THUNDERSTORMS ALONG THE COLD
FRONT ON FRIDAY...WITH A THREAT FOR SEVERE WEATHER
CONTINUING...THOUGH SHEAR DOES NOT LOOK AS GOOD ON FRIDAY AS THE
LOW LEVEL AND MID LEVEL JETS SHIFT EAST OF THE MPX AREA.
FRIDAY NIGHT INTO SATURDAY...THE COLD FRONT LOOKS TO FINALLY PULL
CLEAR OF THE MPX AREA. HOWEVER...THE COLD TROUGH ALOFT WILL BE
OVERHEAD...WHICH WILL LEAD TO THE THREAT FOR DIURNALLY DRIVEN
INSTABILITY SHOWERS SATURDAY BENEATH THE COLD AIR ALOFT. SATURDAY
NIGHT...COOL/DRY CANADIAN HIGH PRESSURE LOOKS TO FINALLY START
MOVING INTO THE AREA...WHICH WILL FINALLY START TO DRY THINGS
OUT...THOUGH WILL RESULT IN A COOL START TO THE MONTH OF JUNE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 118 PM CDT MON MAY 27 2013
A LITTLE COMPLEX THIS AFTERNOON WITH REMNANTS OF SHOWER AND ISOLATED
THUNDERSTORM COMPLEX NOTED ON 0.5 DEGREE REFLECTIVIT OVER SE CWA.
AREA HAS SLOWLY BEEN ERODING IN BOTH AREA AND INTENSITY AS IT HAS
PROGRESSED NORTH FROM SOUTH CENTRAL MN. HRRR HAS PEGGED DEPRECIATION
IN REFLECTIVITY TRENDS QUITE WELL. IF THIS PANS OUT SYSTEM WILL
AFFECT PORTIONS OF EAST CENTRAL MN AND FAR SOUTHERN WEST CENTRAL
WISCONSIN THROUGH 00Z TIME FRAME...THEN DISSIPATE OR TREK NE OUT
OF AIRPORT REGION. MVFR CIGS CURRENTLY IN PLACE OVER ALL TAF
SITES...WITH AREA OF LOW MVFR TO POCKETS OF IFR CIGS NOTED OVER
SW MN. LOOK FOR SLOW LOWERING OF CLOUD DECK AFT 00Z MOST SITES
...WITH EASTERLY FLOW CONTINUINING INTO END OF PERIOD. LOOK FOR
IFR CIGS BY 09Z MOST LOCALES...WITH LIFR CIGS ALSO A POSSIBILITY.
FORCING AS DEPICTED ON EUROPEAN MODEL WILL PORTEND ANOTHER ROUND
OF SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING OVER SW MN AND
WEST CENTRAL WI BY 12Z...AND REMAINDER OF REGION BETWEEN 14 AND
18Z TIME FRAME. CIGS WILL RISE BACK TO MVFR CONDITIONS MOST LOCALES
ASSOCIATED WITH SAME.
KMSP...
IR SATELLITE INDICATED SMALL AREA OF VFR CIGS JUST TO SW OF
AIRPORT AT 18Z. EXPECT THIS TO FILL IN LATER THIS AFTN BACK TO
MVFR CONDITIONS. ALTHOUGH NORTHERN TREKKING MCS REMNANTS
CONTINUE TO SLOWLY DEGRADE OVER THE WESTERN PORTION...STILL
EXPECT SHORT PERIOD OF LIGHT DRIZZLE/-RW EARLY PORTION OF PERIOD.
ONCE COMPLEX MARCHES THROUGH REMAINDER OF LATE AFTN/EVEN HOURS
WILL BY DRY...WITH CIGS LOWERING BEHIND COMPLEX. SE FLOW THROUGH
PERIOD...WITH GOOD FORCING PROGNOSTICATING ANOTHER ROUND OF LIGHT
SHOWERS FROM 14Z THROUGH AT LEAST 18Z. THIS SECOND ROUND MAY LAST
INTO 20Z ON TUESDAY. TOMORROW EVEN WILL REMAIN DRY...WITH MVFR
CONTINUIING.
/OUTLOOK FOR KMSP/
TUE...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS S 5-10 KTS.
WED...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS S 10-15 KTS.
THU...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS S 15-20 KTS.
FRI...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SW-W 15-20KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...MPG
AVIATION...AJZ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1226 PM CDT MON MAY 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT MON MAY 27 2013
ONCE AGAIN DEALING WITH A COMPLEX FORECAST WITH THE SENSIBLE WEATHER
STRONGLY CONTROLLED BY MESOSCALE FACTORS...SOMETHING THE MODELS
TYPICALLY HAVE DIFFICULTY IN RESOLVING. THE CONVECTIVE SYSTEM
CURRENTLY EXTENDING THROUGH EASTERN MO HAS BEEN WEAKENING AND
SHRINKING OVER THE LAST FEW HOURS AS IT MOVES ESEWD TOWARDS THE MS
RIVER. I SEE NO REASON FOR THIS TREND NOT TO CONTINUE...WITH A
CONTINUED DECREASE IN INTENSITY AND COVERAGE AS IT OUTRUNS THE
INSTABILITY AND BETTER LOW LEVEL FORCING. ATTENTION THEN TURNS TO
THE MATURE BOW ECHO SYSTEM/MCS ACROSS WESTERN IOWA/SERN NEBRASKA.
THIS WELL-DEFINED SYSTEM IS BEING FEED BY A 40+KT SWLY LLJ WITH
MUCAPES OF 1500-2000 J/KG. VIRTUALLY ALL THE EXPLICIT CONVECTION
ALLOWING MODELS INCLUDING THE HRRR BRING THIS SYSTEM SEWD THIS
MORNING AND HAVE IT IMPACTING THE AREA ALONG AND NORTH OF
I-70...PRIMARILY THIS AFTERNOON. I`M NOT SURE ABOUT THE TIMING OR
THE EXACT STRUCTURE OF THE FINAL PRODUCT BUT THIS SCENARIO LOOKS
QUITE REASONABLE AND I HAVE LIKELY POPS OVER A MOST OF THE NRN
2/3RDS OF THE CWA. THE SYSTEM IS MOVING AT A PRETTY GOOD CLIP
RIGHT NOW AND PURE EXTRAPOLATION WOULD HAVE IT ENTERING THE NW
PORTION OF THE CWA 14Z OR SO...HOWEVER IT MAY BECOME MORE ELONGATED
WITH TIME. THE LONGER IT TAKES TO ENTER THE CWA...THE GREATER THE
OPPORTUNITY FOR THE AIR MASS AHEAD OF IT TO DESTABILIZE AND THEN FOR
THE SYSTEM AND ITS MESOSCALE BOUNDARY TO INTERACT WITH. IT COULD
POSE A LOCALLY HEAVY RAIN AND WIND THREAT DEPENDING ON ITS FINAL
INTENSITY.
NORTHERN PORTIONS OF MO INTO WEST CENTRAL IL LOOK ACTIVE AGAIN
TONIGHT. A SHORTWAVE WILL BE MOVING ENEWD FROM THE PLAINS INTO THE
MID/UPPER MS VALLEY PROVIDING LARGE SCALE ASCENT ALONG WITH
FORCING VIA A STOUT 50+ KT VEERING SWLY LLJ. THIS WILL PROVIDE
STRONG SUPPORT FOR AT LEAST ONE AND POSSIBLY SEVERAL MCSS WHICH
TRACK EASTWARD FROM THE CENTRAL PLAINS AND EFFECT PORTIONS OF NRN
MO. AGAIN THERE COULD BE A WIND AND HEAVY RAIN THREAT WITH ANY
SYSTEM.
GLASS
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 400 AM CDT MON MAY 27 2013
THE CHANCE OF SHOWERS AND THUNDERSTORMS LINGERS A BIT LONGER THAN
PREVIOUSLY FORECAST INTO TUESDAY AND TUESDAY NIGHT ACCOUNTING FOR
RESIDUAL BOUNDARIES FROM TONIGHTS ACTIVITY...HOWEVER OVERALL THE
AREA IMPACTED SHOULD BE SHRINKING AND TEMPERATURES WILL BE WARMING
TUESDAY AND WEDNESDAY AS A RIDGE BUILDS THRU THE ERN U.S. BY THE
LATER PART OF THE WEEK AND INTO THE WEEKEND WE GET BACK INTO AN
ACTIVE PATTERN AS A DEEP UPPER TROF SLOWLY PROGRESSES EASTWARD
INTO THE NATIONS MIDSECTION.
GLASS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1213 PM CDT MON MAY 27 2013
A LINE OF THUNDERSTORMS WILL MOVE ACROSS THE REGION THIS AFTN.
BRIEF PDS OF IFR VSBYS ARE EXPECTED DUE TO HEAVY RAINFALL. WINDS
WILL TURN NWLY FOR A FEW HOURS AFTER THE STORMS MOVE THROUGH
FOLLOWED BY A RETURN TO PREVAILING SLY FLOW. THERE IS A GREAT
DEAL OF UNCERTAINTY REGARDING CONVECTIVE TRENDS FOR LATE TONIGHT
BUT PCPN CHCS APPEAR TO BE HIGHEST AT KUIN. STRONGER WINDS SHOULD
MIX DOWN TO THE SFC TOMORROW AND PRODUCE WIND GUSTS OF 20-25 KTS.
SPECIFICS FOR KSTL...TWO AREAS OF THUNDERSTORMS ARE EXPECTED TO
AFFECT KSTL OVER THE NEXT 6 HOURS. THE FIRST AREA WILL BE WITHIN
THE 10 MILE VICINITY OF THE AIRPORT OVER THE NEXT HOUR OR SO. THE
SECOND AREA OF THUNDERSTORMS EXTENDED BETWEEN KCOU AND KUIN AT TAF
ISSUANCE AND THIS LINE IS EXPECTED TO REACH KSTL AROUND 20Z. THERE
IS A GREAT DEAL OF UNCERTAINTY REGARDING CONVECTIVE TRENDS FOR
LATE TONIGHT AND TOMORROW AFTN BECAUSE WHAT HAPPENS LATER WILL
DEPEND ON WHAT HAPPENS ACROSS THE REGION THIS AFTN. SWLY WINDS
WILL BECOME NWLY AFTER THE LINE OF THUNDERSTORMS MOVES THROUGH
THEN BECOME SLY AGAIN TONIGHT. STRONGER WINDS SHOULD MIX DOWN TO
THE SURFACE TOMORROW AND PRODUCE WIND GUSTS OF 20-25 KTS.
KANOFSKY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
510 PM CDT MON MAY 27 2013
.UPDATE...
ISSUED AT 508 PM CDT MON MAY 27 2013
A CLUSTER OF SHOWERS HAVE DEVELOPED IN THE PAST 30 MINUTES BETWEEN
GRAND FORKS AND DEVILS LAKE WITH OTHER CELLS INCLUDING THUNDER
AROUND JAMESTOWN. SO UPDATED TO ADD POPS THRU 03Z ACROSS ALL OF NE
ND AND THE NRN VALLEY FOR THIS ACTIVITY. 21Z RAP INDICATES THIS IS
MOSTLY HEAT DRIVEN AND WILL DISSIPATE BY 03Z AS MAIN RAIN AREA
REMAINS IN CNTRL ND. WILL NEED TO WATCH THAT PROGRESSION FOR
FUTURE UPDATES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM CDT MON MAY 27 2013
SHORTWAVE LIFTING NE INTO SE MT PROVIDING UPPER SUPPORT FOR STRONG
CONVECTION ACROSS MT/SD/ND BORDER AREA VCNTY SURFACE LOW. MODELS
IN GOOD AGREEMENT IN LIFTING THIS COMPLEX NNE OVERNIGHT. EASTERN
EDGE COULD CLIP WESTERN FA LATER TONIGHT SO WILL MAINTAIN HIGHER
POPS THERE. ANOTHER AREA OF DEVELOPMENT WILL BE ALONG BOUNDARY
FROM S CENTRAL SD INTO IOWA. THIS COMPLEX SHOULD REMAIN SOUTH OF
THE FA SO HAVE TRIMMED BACK ON POPS ACROSS THE SOUTH. FEEL GFS HAS
BEST HANDLE ON CURRENT AND EXPECTED DEWPOINTS SO WILL FOLLOW ITS
GUIDANCE FOR MIN TEMPERATURES.
COULD SEE SOME LINGERING SHRA MAINLY ACROSS THE NORTH TUESDAY AS
WAVE LIFTS INTO CANADA. CLOUDS AGAIN WILL IMPACT TEMPERATURES BUT
COLUMN SLIGHTLY WARMER AND COULD SEE SOME BREAKS IN THE CLOUDS IN
SUBSIDENCE ZONE BEHIND WAVE SO WILL STICK WITH WARMER MAXIMUM
TEMPERATURES.
LOOKS TO BE ANOTHER CONVECTIVE COMPLEX DEVELOPING TUESDAY NIGHT
ACROSS CENTRAL/NORTHERN HIGH PLAINS BUT AT THIS POINT SHOULD
REMAIN SW OF FA. WITH SURFACE DEWPOINTS ON THE INCREASE WILL SEE
WARMER MINIMUM TEMPERATURES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 325 PM CDT MON MAY 27 2013
WEDNESDAY SHOULD START OUT DRY HOWEVER AS MAIN WAVE BEGINS TO LIFT
NE CENTRAL PLAINS BOUNDARY WILL ALSO LIFT NE AND COULD SEE SOME
CONVECTION WORKING INTO SOUTHERN ZONES BY EVENING. BEST POTENTIAL
FOR SIGNIFICANT RAINFALL WILL BE WEDNESDAY NIGHT AS BOUNDARY LIFTS
THROUGH FA AND UPPER LOW CLOSES OFF. MODELS CONTINUE TO DIFFER ON
FAR NORTH BOUNDARY LIFTS AND WHERE HEAVIEST RAIN WILL FALL.
THURSDAY NIGHT THROUGH MONDAY...PRIMARY CONCERN WILL BE THE
EVOLUTION OF AN ELONGATED TROUGH ALOFT FROM THE PACIFIC NORTHWEST
INTO THE NORTHERN PLAINS. BY 00 UTC SATURDAY...THE VORTICITY MAXIMUM
IS NEAR PIERRE SD WITH THE GEM...THE ND/SD/MN TRI-STATE BORDER
REGION WITH THE GFS AND ALONG THE CANADIAN BORDER NORTH OF MINOT
WITH THE ECMWF. THE DGEX IS MOST SIMILAR TO THE GEM. AT THIS TIME...
THE ECMWF IS AN OUTLIER WHERE AFTER A QUICK SHOT OF PRECIPITATION
THURSDAY NIGHT INTO FRIDAY...IT LIFTS THE RESPONSIBLE WARM FRONT
NORTH OF THE BORDER AND KEEPS THE FORECAST AREA DRY. THE GFS/GEM/
DGEX...HOWEVER...PLACE THE NEARLY STATIONARY WARM FRONT ACROSS THE
FORECAST AREA...RESULTING IN RAINFALL ACCUMULATIONS GREATER THAN ONE
INCH. WILL LEAN TOWARD SIMILAR WETTER SOLUTIONS AT THIS TIME...WHICH
MATCHES WELL WITH ALL BLEND 40 TO 60 POPS THURSDAY NIGHT THROUGH
FRIDAY. THE ECMWF WRAP-AROUND PRECIPITATION IS ALSO FARTHER SOUTH
AND SLOWER THAN THE OTHER MODELS...BUT IT LOOKS LIKE A RETURN TO
DRIER CONDITIONS SATURDAY AND ESPECIALLY SATURDAY NIGHT INTO SUNDAY.
ANOTHER PACIFIC WAVE WILL RESULT IN ADDITIONAL RAIN CHANCES EARLY
NEXT WEEK. THE SYSTEM/S COLD FRONT WILL SWEEP ACROSS THE FORECAST
AREA ON FRIDAY...RESULTING IN COOLER TEMPERATURES FOR THE WEEKEND
WITH HIGHS IN THE 60S AND LOWS IN THE 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1220 PM CDT MON MAY 27 2013
MVFR/LOW VFR CEILINGS WILL PERSIST AT ALL TAF SITES THROUGH 18 UTC
TUESDAY. OVERNIGHT...COULD SEE SOME IFR CONDITIONS AT KDVL/KBJI.
WINDS WILL BE FROM THE SOUTHEAST AROUND 10 TO 15 KTS. SOME
SPRINKLES/LIGHT RAIN SHOWERS ARE POSSIBLE AT KDVL/KFAR AFTER 00
UTC...BUT NOT LIKELY ENOUGH TO INCLUDE IN CURRENT TAFS.
&&
.HYDROLOGY...
ISSUED AT 320 PM CDT MON MAY 27 2013
ALL RIVER FLOOD WARNINGS HAVE BEEN CANCELLED. THE RED RIVER IS
CRESTING JUST BELOW MINOR FLOOD STAGE AT PEMBINA AND IS BEGINNING TO
SLOWLY FALL FROM A CREST RIGHT AT MINOR FLOOD STAGE AT
DRAYTON...WHILE THE BUFFALO RIVER NEAR DILWORTH HAS FALLEN BELOW
FLOOD STAGE. AREA RIVERS WILL CONTINUE TO FALL OR REMAIN STEADY OVER
THE NEXT FEW DAYS.
AN AREAL FLOOD WARNING REMAINS IN EFFECT FOR PEMBINA...WALSH...AND
EASTERN CAVALIER COUNTIES THROUGH TUESDAY. WITH NO APPRECIABLE RAIN
OVER THE PAST FEW DAYS...WATER LEVELS ACROSS THIS AREA SHOULD
CONTINUE TO GRADUALLY DECREASE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...VOELKER
LONG TERM...ROGERS/VOELKER
AVIATION...ROGERS
HYDROLOGY...MAKOWSKI