Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/05/15
AREA FORECAST DISCUSSION
NWS PUEBLO CO
236 PM MDT SUN MAY 3 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 234 PM MDT SUN MAY 3 2015
SHOWERS AND STORMS THAT HAVE DEVELOPED THIS AFTERNOON HAVE
GENERALLY BE FAIRLY SLOW MOVING AND SHORT LIVED. ISOLATED TO
SCATTERED SHOWERS AND TSTMS OVR THE AREA WL CONTINUE INTO THE
EVENING HOURS...AND DECREASING TOWARD MIDNIGHT. A COLD FRONT WL
MOVE SOUTH INTO THE SOUTHEAST PLAINS THIS EVENING...WITH THE NAM
SHOWING IT REACHING THE SRN CO BORDER EARLY MON MORNING. BEHIND
THE FRONT...SFC DEW POINTS INCREASE INTO THE 40S...AND LOW STRATUS
IS FORECAST TO DEVELOP OVR NORTHERN EL PASO COUNTY BY MIDNIGHT AND
THEN SPREADING SOUTHWARD OVERNIGHT. THE HRRR...NSSL WRF AND NAM
CONTINUE TO SHOW PCPN BEHIND THE FRONT OVR EL PASO AND TELLER
COUNTIES DURING THE LATE NIGHT HOURS...WITH MUCH OF THE REST OF
THE FORECAST AREA BEING DRY. THE HRRR SPREADS PCPN SOUTHWARD INTO
PUEBLO AND FREMONT COUNTIES AS WELL.
ON MONDAY AN UPR LOW BECOME CENTERED OVR THE CA AND AZ BORDER WITH
SOUTHERLY FLOW ALOFT OVR THE FORECAST AREA AHEAD OF THIS
SYSTEM...DRAWING MSTR NORTHWARD. WITH MOIST LOW TO MID LEVEL
SOUTHEASTERLY WINDS...KEEPING AFTERNOON SFC DEW POINTS ACRS THE SERN
PLAINS IN THE MID40S TO LOWER 50S. MOST OF THE LOW STRATUS IS
EXPECTED TO DISSIPATE BEFORE AFTERNOON. THE NAM SHOWS SHOWERS/TSTMS
DEVELOPING IN THE MID MORNING HOURS OVR THE MTNS...ESPECIALLY ALONG
THE CONTDVD...WHERE A SHORTWAVE TROF IS EXPECTED TO MOVE NORTHWARD
THRU THE AREA. PCPN WL INCREASE ACRS THE MTNS BY MIDDAY AND WL
SPREAD TO THE ADJACENT LOWER ELEVATIONS...AND THEN THROUGH THE
AFTERNOON WL BECOME WIDESPREAD ACRS MOST OF THE FORECAST AREA.
THERE WL BE THE POTENTIAL FOR LOCALIZED HEAVY RAIN. ALSO...PORTIONS
OF THE SERN PLAINS COULD SEE ONE OR TWO MARGINALLY SEVERE STORMS IN
THE AFTERNOON.
HIGH TEMPS ON MON WILL BE COOLER THAN TODAY AND SHOULD GENERALLY BE
JUST A LITTLE BELOW NORMAL. HIGH TEMPS IN THE SAN LUIS VALLEY
SHOULD BE CLOSE TO NORMAL.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 234 PM MDT SUN MAY 3 2015
...STORMY WEATHER THROUGH TUESDAY...
MONDAY NIGHT...WILL SEE SEVERAL ONGOING ROUNDS OF PRECIP AND STORMS
OVER THE AREA. THE STRONGEST OF THESE WILL LIKELY BE OVER THE ERN
PLAINS...GENERALLY E OF KLHX...AND ANOTHER AREA OVER THE PALMER DVD.
GIVEN THE ABUNDANT LLVL MOISTURE AND INCREASED SHEAR DUE TO BACKED
LLVL FLOW...CANNOT RULE OUT A STRONG TO SVR STORM OR TWO ESPECIALLY
IN THESE FAVORED AREAS. COULD SEE A BRIEF LULL IN THE PRECIP MON
EVE BEFORE PRECIP COVERAGE INCREASES LATER MON NIGHT...IN BANDS OF
CONVECTION ROTATING UP FROM THE SOUTH. WILL MAINTAIN ISOLD OR SLIGHT
CHANCE OF TS OVERNIGHT ALONG WITH MORE WIDESPREAD LIKELY POPS ACROSS
THE MTS AND PLAINS.
ON TUE...THE UPPER LOW WILL MOVE INTO THE FOUR CORNERS REGION...THEN
TRACK TO THE NE DURING THE DAY. TEMPS WILL BE COOLER...IN THE 60S
FOR THE PLAINS...DUE TO WIDESPREAD CLOUDS AND PRECIP. IT LOOKS LIKE
MUCH OF THE BEST PRECIP COVERAGE WILL BE TUE MORNING...ALTHOUGH EVEN
IF THERE ARE ANY BREAKS IN THE SHOWERS AND STORMS...THEY SHOULD PICK
UP AGAIN BY TUE AFTERNOON. SNOW LEVELS MON-TUE WILL BE PRETTY
HIGH...BUT GIVEN THE AMOUNT OF QPF...COULD SEE SOME LOCAL
SIGNIFICANT ACCUMS IN THE MTS OF SIX INCHES OR MORE...ESPECIALLY
ABOVE 12000 FEET. SO...RECREATIONISTS SHOULD BE AWARE OF WINTER
CONDITIONS FOR THE HIGH PEAKS. GIVEN ALL THE PRECIP...THE BL SHOULD
BE PRETTY STABILIZED BY TUE SO SURFACE BASED CONVECTION LOOKS
UNLIKELY. BUT...A STRONG STORM OR TWO CANNOT BE RULED OUT OVER THE
AREA AS THE UPPER LOW MOVES THROUGH NRN CO.
BY WED...SHOULD SEE THINGS WINDING DOWN AS THE FIRST UPPER LOW MOVES
OFF INTO THE DAKOTAS AND NE. WILL STILL SEE SOME WRAP AROUND PRECIP
OVER THE DVD AND NRN PORTIONS OF THE CWA. TEMPS SHOULD REBOUND NICELY
BACK INTO THE 70S OVER THE PLAINS.
THE NEXT SYSTEM WILL DROP SWD FROM THE PACNW ON WED...THEN CUTOFF
OVER CA THU-SAT...AND SLOWLY MOVE TO THE NE OVER THE WEEKEND.
GLOBAL MODELS ARE STILL IN GOOD AGREEMENT THAT THIS SYSTEM WILL
TRACK TO OUR NORTH NEXT WEEKEND...ALTHOUGH LATEST RUNS HINT THAT
THE TRACK MAY BE A BIT FARTHER SOUTH. STILL LOOKS LIKE MOST OF SE CO
WILL BE STUCK IN THE DRY SW FLOW TO THE SOUTH OF THE LOW...BUT GIVEN
THE UNCERTAINTIES WILL MAINTAIN POPS OVER THE AREA...ESPECIALLY FOR
THE MTS. TEMPS WILL BE CONSIDERABLY LOWER WITH THIS SYSTEM...AS
H7 TEMPS ARE MINUS THREE OR LOWER...SO SOME MTN SNOWS SEEM LIKE A
GOOD BET. ROSE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 234 PM MDT SUN MAY 3 2015
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES UNTIL LATE TONIGHT.
ISOLATED TO SCATTERED TSTMS MAY MOVE INTO THE VCNTY OF THE TAF
SITES THIS EVENING WITH ERRATIC GUSTY WINDS BEING THE MAIN THREAT.
LATE TONIGHT IT LOOKS LIKE AT KCOS AN MVFR OR IFR CIG WL DEVELOP
AS LOW STRATUS DEVELOPS BEHIND A COLD FRONT. ISOLD SHOWERS AND
TSTMS MAY ALSO CONTINUE AT KCOS INTO THE LATE NIGHT HOURS. KPUB
COULD ALSO SEE SOME PCPN LATE TONIGHT AND MAYBE EVEN SEE SOME LOW
STRATUS MOVE INTO THE VCNTY...HOWEVER CHANCES OF THIS OCCURRING
ARE A BIT UNCERTAIN AT THIS TIME. THE LOW STRATUS IS FORECAST TO
DISSIPATE BY MID TO LATE MORNING WITH VFR CONDITIONS EXPECTED AT
THE TAF SITES ON MONDAY. SHOWERS AND TSTMS ARE ONCE AGAIN A
POSSIBILITY AT THE TAF SITES...MAINLY IN THE AFTERNOON HOURS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...ROSE
AVIATION...28
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1255 PM EDT SUN MAY 3 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE EASTERN UNITED STATES TODAY
WILL GRADUALLY MOVE OFFSHORE ON MONDAY. A COLD FRONT IS FORECAST TO
WEAKEN AS IT DROPS SOUTHWARD ACROSS THE AREA TUESDAY THROUGH EARLY
WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK. THE HIGH WILL
EVENTUALLY SHIFT OFF THE EAST COAST NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12Z UA ANLYS VERY DRY AT 850MB AND 925MB LEVELS IN THE EASTERN
CONUS. HAVE TO CLIMB TO 700MB TO FIND SOME APPRECIABLE MOISTURE.
925MB TEMPS IN THE GREAT LAKES AROUND 18C WITH 850MB TEMPS NORTH
OF 10C. THAT WILL BE OUR AIR MASS TOMORROW.
WE ARE PLANNING NO BIG CHANGES WITH THE NEXT UPDATE. 12Z MODEL
DATA EXCEPT FOR THE GFS AND ALL OTHER MESOSCALE MODELS KEEP US DRY
INTO THIS EVENING. THE GFS HAS HAD THE HIGHEST .01" ISOHYET WET
BIAS (AMONG IT, SREF, NAM AND EC) WI 24HR DURING THE PAST MONTH
AND THE LOWEST QPF SKILL SCORE OF ALL THOSE MODELS IN THE
NORTHEAST WITH QPF OF LESS THAN .75".
THERMALLY IT IS SIMILAR TO YESTERDAY WITH LOCATIONS NW RISING
FASTER THAN FORECAST WITH SOME LOCALES LAGGING NEAR THE COAST.
OVERALL WE ARE WITHIN ABOUT 3F OF EXPECTATIONS, SO JUST SLIGHT
ADJUSTMENTS WILL BE MADE.
HIGH PRES WILL BE OVER THE SERN CONUS TODAY. SWLY FLOW WILL
INCREASE AND TEMPS WILL WARM IN RESPONSE. HIGHS ARE EXPECTED TO BE
IN THE MID TO UPPER 70S, WITH SOME LOCATIONS MAKING A RUN AT 80
DEGREES. NO PRECIP IS ANTICIPATED. THERE WILL BE SOME SCT CLOUDS
ON AN OTHERWISE BEAUTIFUL DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE AREA OF HIGH PRES WILL MOVE EWD AND OFF THE CST AND A GENLY
CLEAR SKY IS IN STORE WITH LIGHT WIND.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
THE CENTER OF SURFACE HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC
COAST ON MONDAY. SOUTHWESTERLY RETURN FLOW AROUND THE HIGH WILL DRAW
EVEN WARMER AND MORE HUMID AIR UP THE EASTERN SEABOARD. MONDAY WILL
CONTEND WITH APRIL 18TH FOR THE WARMEST DAY SO FAR THIS YEAR WITH
HIGHS 80-85 DEGREES (EXCEPT COOLER ALONG THE COAST AND IN THE
POCONOS). CONDITIONS ACROSS THE FORECAST AREA WILL BE DRY THROUGH
MONDAY NIGHT OWING TO STRONG SUBSIDENCE PRESENT BENEATH THE H8
RIDGE.
A COLD FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE AREA TUESDAY
AFTERNOON AND NIGHT. CLOUDS OVERSPREADING NORTHEAST PA AND NORTHWEST
NJ WILL RESULT IN SLIGHTLY COOLER HIGHS IN THE 70S ON TUESDAY.
FARTHER SOUTH IN THE WARM SECTOR, HIGHS TUESDAY HAVE THE POTENTIAL
TO BE CLOSE TO MONDAY`S FROM ABOUT PHILLY SOUTHWARD IF THE FRONT
AND ITS ASSOCIATED CLOUD COVER HANGS BACK TO THE NORTH. MOISTURE
WILL POOL ALONG THE FRONT AS NOTED BY PWATS INCREASING TO NEAR
1.5 INCHES AND SURFACE DEWPOINTS TO NEAR 60F BY THE AFTERNOON.
BUFKIT SOUNDINGS FROM THE 00Z GFS AND 21Z SREF SHOW MODEST
INSTABILITY (ML CAPE AROUND 500 J/KG) WHILE THE 00Z NAM DEPICTS A
CONSIDERABLY MORE UNSTABLE ENVIRONMENT (ML CAPE AOA 1000 J/KG).
WENT MORE CONSERVATIVE WITH FORECAST COVERAGE OF THUNDERSTORMS
DUE TO THE PRESENCE OF WEAK SHEAR AND LIMITED FORCING IN ADDITION
TO THE QUESTIONABLE INSTABILITY. A GENERAL WEAKENING TREND IS
EXPECTED WITH THE CONVECTION AFTER SUNSET, ALTHOUGH SHOWERS MAY
LINGER INTO THE OVERNIGHT AS SLIGHTLY BETTER LIFT ASSOCIATED WITH
AN UPPER SHORTWAVE TROUGH ARRIVES LATE.
THE FRONT MAY EITHER CONTINUE TO SAG SOUTHWARD SLOWLY OR EVEN STALL
OVER THE DELMARVA WEDNESDAY MORNING. LIFT ASSOCIATED WITH THE FRONT
ITSELF SHOULD WEAKEN AS THE BOUNDARY IS EXPECTED TO BECOME
INCREASINGLY DIFFUSE. CONSEQUENTIALLY, COVERAGE OF SHOWERS EXPECTED
TO BE RELATIVELY LOW ON WEDNESDAY. THUNDERSTORM CHANCES CONFINED TO
THE LOWER DELMARVA, WHERE THESE LOCATIONS HAVE THE BEST CHANCE OF
RESIDING IN THE WARM SECTOR TO THE SOUTH OF THE BOUNDARY. THE CAA
BEHIND THE FRONT IS NOT SIGNIFICANT, SO THE TREND OF ABOVE NORMAL
TEMPS SHOULD CONTINUE INTO WEDNESDAY. HOWEVER, WE WILL HAVE TO WATCH
FOR THE POSSIBILITY OF ONSHORE FLOW TO DEVELOP. THIS MAY PREVENT
TEMPS FROM REACHING 70F IN THE COASTAL PLAIN, ESPECIALLY THE
EASTERLY WIND BECOMES ENHANCED BY A SEABREEZE.
EXPANSIVE HIGH PRESSURE OVER THE EASTERN SEABOARD WILL PROVIDE A
MAINLY DRY PATTERN THURSDAY THROUGH SATURDAY. THE HUMIDITY IS
FORECAST TO INCREASE A BIT FRIDAY AND SATURDAY AS SOUTHERLY RETURN
FLOW DEVELOPS WITH THE SURFACE HIGH MOVING OFFSHORE. CANNOT RULE OUT
THE POSSIBILITY OF A A SHOWER DEVELOPING DURING THE AFTERNOON HOURS
FRIDAY AND SATURDAY BUT THE SUBSIDENCE INVERSION UNDERNEATH THE
RIDGE SHOULD MINIMIZE THE CONVECTIVE POTENTIAL. ABOVE NORMAL
TEMPS WILL PERSIST WITH HIGHS IN THE 70S TO NEAR 80F EACH DAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
18Z TAFS WILL BE VFR.
THIS AFTERNOON...VERY HIGH BASED (7K) FEW TO SCATTERED CUMULUS
CLOUDS EXPECTED. LIGHT WEST WINDS (AROUND 5 KNOTS) ALL TERMINALS
PRECEDING ANY SEA/BAY BREEZE FRONTAL PASSAGE.
SEA/BAY BREEZE FRONT SHOULD BE FROM LEWES THROUGH CAPE MAY COUNTY,
JUST WEST OF KACY AND KBLM AT START OF TAF PERIOD. BY 21Z SHOULD
BE WEST OF KGED AND KDOV AND THRU KMIV, MOST OF ATLC COUNTY, SERN
BURLINGTON COUNTY AND OCEAN AND MONMOUTH COUNTIES. FROM THERE THE
PROGRESS IS EXPECTED TO BE SLOWER PASSING KILG BY 22Z AND REACHING
THE DELAWARE RIVER TERMINALS AROUND 00Z. WINDS BEHIND THE FRONT
SHOULD AVERAGE SOUTH-SOUTHEAST AT AROUND 10 KNOTS.
TONIGHT...CLEAR SKIES AND WINDS BECOMING LIGHT AND VARIABLE.
AIR MASS AGAIN IS QUITE CLEAN AND WE ARE NOT ANTICIPATING ANY
FOG AT THE TERMINALS.
MONDAY...A SOUTHWEST WIND WILL DEVELOP IN THE MORNING AND
SHOULD AVERAGE CLOSE TO 10 KNOTS. SOME GUSTINESS IS LIKELY
AS THE DAY PROGRESS, MORE LIKELY IN THE AFTERNOON. THE PREDICTED
MOISTURE AT THE CUMULUS LEVEL IS SLIGHTLY MORE THAN TODAY, SO
MAYBE A FEW MORE HIGH BASED (LOOKS AROUND 7K AGAIN) CUMULUS CLOUDS
AGAIN.
OUTLOOK...
MONDAY AFTERNOON AND MONDAY NIGHT...VFR. SWLY MAY GUST TO 20 KT
LATE IN THE DAY.
TUESDAY AND TUESDAY NIGHT...PREDOMINATELY VFR. SCT SHRA AND ISO TSRA
DURING THE AFTERNOON AND NIGHT COULD YIELD LOCAL MVFR/IFR CONDITIONS.
WEDNESDAY...SHRA MAY LINGER INTO WEDNESDAY BUT MOST OF THE TERMINALS
SHOULD DRY OUT. SOME MODEL SOLUTIONS ARE INDICATING EASTERLY WINDS
TO DEVELOP. WILL HAVE TO WATCH FOR LOW CLOUDS AND MVFR CIGS TO
ACCOMPANY MARINE LAYER.
WEDNESDAY NIGHT AND THURSDAY...VFR.
&&
.MARINE...
SEAS AS OF 10 AM HAVE DROPPED TO 4.6 FEET AT BOTH BUOY9 AND 65.
IN ADDITION, THE PERIOD HAS INCREASED TO AROUND 10 SECONDS.
WITH THE DOWNWARD TREND UNDERWAY, WE WILL FINALLY PUT THIS
SMALL CRAFT ADVISORY IN THE BOOKS AND HAVE NO FURTHER EXTENSION.
WE ADJUSTED THE WINDS IN DELAWARE BAY THIS AFTERNOON AND EVE
BASED ON HRRR AND ARW MODELS AS THEY HANDLED THE UP THE BAY BREEZE
WELL YESTERDAY.
NO ADDITIONAL FLAGS ARE EXPECTED DURG THE REMAINDER OF THE NR AND
SHORT TERM PDS.
OUTLOOK...
MONDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA
CRITERIA. THE STRONGEST WINDS ARE EXPECTED MONDAY AND TUESDAY AS
HIGH PRESSURE MOVES OFFSHORE AND A S-SW FLOW AROUND 15-20 KT
ENSUES.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES NEAR 30 PERCENT, ALONG WITH OCCASIONAL WIND
GUSTS TO NEAR 20 MPH MAY ENHANCE THE FIRE WEATHER RISK LATE IN
THE DAY ON MONDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...GIGI/NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...KLEIN
AVIATION...GIGI/KLEIN/NIERENBERG
MARINE...GIGI/KLEIN/NIERENBERG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1152 AM EDT SUN MAY 3 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE EASTERN UNITED STATES TODAY
WILL GRADUALLY MOVE OFFSHORE ON MONDAY. A COLD FRONT IS FORECAST TO
WEAKEN AS IT DROPS SOUTHWARD ACROSS THE AREA TUESDAY THROUGH EARLY
WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK. THE HIGH WILL
EVENTUALLY SHIFT OFF THE EAST COAST NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12Z UA ANLYS VERY DRY AT 850MB AND 925MB LEVELS IN THE EASTERN
CONUS. HAVE TO CLIMB TO 700MB TO FIND SOME APPRECIABLE MOISTURE.
925MB TEMPS IN THE GREAT LAKES AROUND 18C WITH 850MB TEMPS NORTH
OF 10C. THAT WILL BE OUR AIR MASS TOMORROW.
WE ARE PLANNING NO BIG CHANGES WITH THE NEXT UPDATE. 12Z MODEL
DATA EXCEPT FOR THE GFS AND ALL OTHER MESOSCALE MODELS KEEP US DRY
INTO THIS EVENING. THE GFS HAS HAD THE HIGHEST .01" ISOHYET WET
BIAS (AMONG IT, SREF, NAM AND EC) WI 24HR DURING THE PAST MONTH
AND THE LOWEST QPF SKILL SCORE OF ALL THOSE MODELS IN THE
NORTHEAST WITH QPF OF LESS THAN .75".
THERMALLY IT IS SIMILAR TO YESTERDAY WITH LOCATIONS NW RISING
FASTER THAN FORECAST WITH SOME LOCALES LAGGING NEAR THE COAST.
OVERALL WE ARE WITHIN ABOUT 3F OF EXPECTATIONS, SO JUST SLIGHT
ADJUSTMENTS WILL BE MADE.
HIGH PRES WILL BE OVER THE SERN CONUS TODAY. SWLY FLOW WILL
INCREASE AND TEMPS WILL WARM IN RESPONSE. HIGHS ARE EXPECTED TO BE
IN THE MID TO UPPER 70S, WITH SOME LOCATIONS MAKING A RUN AT 80
DEGREES. NO PRECIP IS ANTICIPATED. THERE WILL BE SOME SCT CLOUDS
ON AN OTHERWISE BEAUTIFUL DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE AREA OF HIGH PRES WILL MOVE EWD AND OFF THE CST AND A GENLY
CLEAR SKY IS IN STORE WITH LIGHT WIND.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
THE CENTER OF SURFACE HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC
COAST ON MONDAY. SOUTHWESTERLY RETURN FLOW AROUND THE HIGH WILL DRAW
EVEN WARMER AND MORE HUMID AIR UP THE EASTERN SEABOARD. MONDAY WILL
CONTEND WITH APRIL 18TH FOR THE WARMEST DAY SO FAR THIS YEAR WITH
HIGHS 80-85 DEGREES (EXCEPT COOLER ALONG THE COAST AND IN THE
POCONOS). CONDITIONS ACROSS THE FORECAST AREA WILL BE DRY THROUGH
MONDAY NIGHT OWING TO STRONG SUBSIDENCE PRESENT BENEATH THE H8
RIDGE.
A COLD FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE AREA TUESDAY
AFTERNOON AND NIGHT. CLOUDS OVERSPREADING NORTHEAST PA AND NORTHWEST
NJ WILL RESULT IN SLIGHTLY COOLER HIGHS IN THE 70S ON TUESDAY.
FARTHER SOUTH IN THE WARM SECTOR, HIGHS TUESDAY HAVE THE POTENTIAL
TO BE CLOSE TO MONDAY`S FROM ABOUT PHILLY SOUTHWARD IF THE FRONT
AND ITS ASSOCIATED CLOUD COVER HANGS BACK TO THE NORTH. MOISTURE
WILL POOL ALONG THE FRONT AS NOTED BY PWATS INCREASING TO NEAR
1.5 INCHES AND SURFACE DEWPOINTS TO NEAR 60F BY THE AFTERNOON.
BUFKIT SOUNDINGS FROM THE 00Z GFS AND 21Z SREF SHOW MODEST
INSTABILITY (ML CAPE AROUND 500 J/KG) WHILE THE 00Z NAM DEPICTS A
CONSIDERABLY MORE UNSTABLE ENVIRONMENT (ML CAPE AOA 1000 J/KG).
WENT MORE CONSERVATIVE WITH FORECAST COVERAGE OF THUNDERSTORMS
DUE TO THE PRESENCE OF WEAK SHEAR AND LIMITED FORCING IN ADDITION
TO THE QUESTIONABLE INSTABILITY. A GENERAL WEAKENING TREND IS
EXPECTED WITH THE CONVECTION AFTER SUNSET, ALTHOUGH SHOWERS MAY
LINGER INTO THE OVERNIGHT AS SLIGHTLY BETTER LIFT ASSOCIATED WITH
AN UPPER SHORTWAVE TROUGH ARRIVES LATE.
THE FRONT MAY EITHER CONTINUE TO SAG SOUTHWARD SLOWLY OR EVEN STALL
OVER THE DELMARVA WEDNESDAY MORNING. LIFT ASSOCIATED WITH THE FRONT
ITSELF SHOULD WEAKEN AS THE BOUNDARY IS EXPECTED TO BECOME
INCREASINGLY DIFFUSE. CONSEQUENTIALLY, COVERAGE OF SHOWERS EXPECTED
TO BE RELATIVELY LOW ON WEDNESDAY. THUNDERSTORM CHANCES CONFINED TO
THE LOWER DELMARVA, WHERE THESE LOCATIONS HAVE THE BEST CHANCE OF
RESIDING IN THE WARM SECTOR TO THE SOUTH OF THE BOUNDARY. THE CAA
BEHIND THE FRONT IS NOT SIGNIFICANT, SO THE TREND OF ABOVE NORMAL
TEMPS SHOULD CONTINUE INTO WEDNESDAY. HOWEVER, WE WILL HAVE TO WATCH
FOR THE POSSIBILITY OF ONSHORE FLOW TO DEVELOP. THIS MAY PREVENT
TEMPS FROM REACHING 70F IN THE COASTAL PLAIN, ESPECIALLY THE
EASTERLY WIND BECOMES ENHANCED BY A SEABREEZE.
EXPANSIVE HIGH PRESSURE OVER THE EASTERN SEABOARD WILL PROVIDE A
MAINLY DRY PATTERN THURSDAY THROUGH SATURDAY. THE HUMIDITY IS
FORECAST TO INCREASE A BIT FRIDAY AND SATURDAY AS SOUTHERLY RETURN
FLOW DEVELOPS WITH THE SURFACE HIGH MOVING OFFSHORE. CANNOT RULE OUT
THE POSSIBILITY OF A A SHOWER DEVELOPING DURING THE AFTERNOON HOURS
FRIDAY AND SATURDAY BUT THE SUBSIDENCE INVERSION UNDERNEATH THE
RIDGE SHOULD MINIMIZE THE CONVECTIVE POTENTIAL. ABOVE NORMAL
TEMPS WILL PERSIST WITH HIGHS IN THE 70S TO NEAR 80F EACH DAY.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
VFR CONDS WILL PREVAIL THRU THE TAF PD WITH HIGH PRES TO THE SE
TODAY MOVG OFFSHORE TONIGHT. THE FLOW WILL BECOME SWLY BY AFTN BUT
WILL BE LESS THAN 10 KTS. ONLY SCT CLOUDS ARE ANTICIPATED. WITH
LIGHT FLOW, STILL EXPECTING ANOTHER SEA BREEZE AT KACY AND KMIV.
AT THESE LOCATIONS, WIND COULD REACH 10 KT OR SO.
OUTLOOK...
MONDAY AND MONDAY NIGHT...VFR. SWLY MAY GUST TO 20 KT LATE IN THE
DAY.
TUESDAY AND TUESDAY NIGHT...PREDOMINATELY VFR. SCT SHRA AND ISO TSRA
DURING THE AFTERNOON AND NIGHT COULD YIELD LOCAL MVFR/IFR CONDITIONS.
WEDNESDAY...SHRA MAY LINGER INTO WEDNESDAY BUT MOST OF THE TERMINALS
SHOULD DRY OUT. SOME MODEL SOLUTIONS ARE INDICATING EASTERLY WINDS
TO DEVELOP. WILL HAVE TO WATCH FOR LOW CLOUDS AND MVFR CIGS TO
ACCOMPANY MARINE LAYER.
WEDNESDAY NIGHT AND THURSDAY...VFR.
&&
.MARINE...
SEAS AS OF 10 AM HAVE DROPPED TO 4.6 FEET AT BOTH BUOY9 AND 65.
IN ADDITION, THE PERIOD HAS INCREASED TO AROUND 10 SECONDS.
WITH THE DOWNWARD TREND UNDERWAY, WE WILL FINALLY PUT THIS
SMALL CRAFT ADVISORY IN THE BOOKS AND HAVE NO FURTHER EXTENSION.
WE ADJUSTED THE WINDS IN DELAWARE BAY THIS AFTERNOON AND EVE
BASED ON HRRR AND ARW MODELS AS THEY HANDLED THE UP THE BAY BREEZE
WELL YESTERDAY.
NO ADDITIONAL FLAGS ARE EXPECTED DURG THE REMAINDER OF THE NR AND
SHORT TERM PDS.
OUTLOOK...
MONDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA
CRITERIA. THE STRONGEST WINDS ARE EXPECTED MONDAY AND TUESDAY AS
HIGH PRESSURE MOVES OFFSHORE AND A S-SW FLOW AROUND 15-20 KT
ENSUES.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES NEAR 30 PERCENT, ALONG WITH OCCASIONAL WIND
GUSTS TO NEAR 20 MPH MAY ENHANCE THE FIRE WEATHER RISK LATE IN
THE DAY ON MONDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...GIGI/NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...KLEIN
AVIATION...KLEIN/NIERENBERG
MARINE...GIGI/KLEIN/NIERENBERG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1052 AM EDT SUN MAY 3 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE EASTERN UNITED STATES TODAY
WILL GRADUALLY MOVE OFFSHORE ON MONDAY. A COLD FRONT IS FORECAST TO
WEAKEN AS IT DROPS SOUTHWARD ACROSS THE AREA TUESDAY THROUGH EARLY
WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK. THE HIGH WILL
EVENTUALLY SHIFT OFF THE EAST COAST NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO BIG CHANGES MADE WITH THIS UPDATE. 12Z SOUNDINGS HAVE HIGH
TEMPS REACHING THE 70S TODAY, BUT WITH CONTINUED AIR MASS
MODIFICATION AND SOME WAA, SOME LOW 80S ARE POSSIBLE INLAND. SINCE
THE HRRR DID PRETTY WELL WITH THE SEA BREEZE FRONT YESTERDAY, WE
ADJUSTED WINDS BASED ON ITS LATEST RUN OR TWO.
HIGH PRES WILL BE OVER THE SERN CONUS TODAY. SWLY FLOW WILL
INCREASE AND TEMPS WILL WARM IN RESPONSE. HIGHS ARE EXPECTED TO
BE IN THE MID TO UPPER 70S, WITH SOME LOCATIONS MAKING A RUN AT 80
DEGREES. NO PRECIP IS ANTICIPATED. THERE WILL BE SOME SCT CLOUDS
ON AN OTHERWISE BEAUTIFUL DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE AREA OF HIGH PRES WILL MOVE EWD AND OFF THE CST AND A GENLY
CLEAR SKY IS IN STORE WITH LIGHT WIND.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
THE CENTER OF SURFACE HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC
COAST ON MONDAY. SOUTHWESTERLY RETURN FLOW AROUND THE HIGH WILL DRAW
EVEN WARMER AND MORE HUMID AIR UP THE EASTERN SEABOARD. MONDAY WILL
CONTEND WITH APRIL 18TH FOR THE WARMEST DAY SO FAR THIS YEAR WITH
HIGHS 80-85 DEGREES (EXCEPT COOLER ALONG THE COAST AND IN THE
POCONOS). CONDITIONS ACROSS THE FORECAST AREA WILL BE DRY THROUGH
MONDAY NIGHT OWING TO STRONG SUBSIDENCE PRESENT BENEATH THE H8
RIDGE.
A COLD FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE AREA TUESDAY
AFTERNOON AND NIGHT. CLOUDS OVERSPREADING NORTHEAST PA AND NORTHWEST
NJ WILL RESULT IN SLIGHTLY COOLER HIGHS IN THE 70S ON TUESDAY.
FARTHER SOUTH IN THE WARM SECTOR, HIGHS TUESDAY HAVE THE POTENTIAL
TO BE CLOSE TO MONDAY`S FROM ABOUT PHILLY SOUTHWARD IF THE FRONT
AND ITS ASSOCIATED CLOUD COVER HANGS BACK TO THE NORTH. MOISTURE
WILL POOL ALONG THE FRONT AS NOTED BY PWATS INCREASING TO NEAR
1.5 INCHES AND SURFACE DEWPOINTS TO NEAR 60F BY THE AFTERNOON.
BUFKIT SOUNDINGS FROM THE 00Z GFS AND 21Z SREF SHOW MODEST
INSTABILITY (ML CAPE AROUND 500 J/KG) WHILE THE 00Z NAM DEPICTS A
CONSIDERABLY MORE UNSTABLE ENVIRONMENT (ML CAPE AOA 1000 J/KG).
WENT MORE CONSERVATIVE WITH FORECAST COVERAGE OF THUNDERSTORMS
DUE TO THE PRESENCE OF WEAK SHEAR AND LIMITED FORCING IN ADDITION
TO THE QUESTIONABLE INSTABILITY. A GENERAL WEAKENING TREND IS
EXPECTED WITH THE CONVECTION AFTER SUNSET, ALTHOUGH SHOWERS MAY
LINGER INTO THE OVERNIGHT AS SLIGHTLY BETTER LIFT ASSOCIATED WITH
AN UPPER SHORTWAVE TROUGH ARRIVES LATE.
THE FRONT MAY EITHER CONTINUE TO SAG SOUTHWARD SLOWLY OR EVEN STALL
OVER THE DELMARVA WEDNESDAY MORNING. LIFT ASSOCIATED WITH THE FRONT
ITSELF SHOULD WEAKEN AS THE BOUNDARY IS EXPECTED TO BECOME
INCREASINGLY DIFFUSE. CONSEQUENTIALLY, COVERAGE OF SHOWERS EXPECTED
TO BE RELATIVELY LOW ON WEDNESDAY. THUNDERSTORM CHANCES CONFINED TO
THE LOWER DELMARVA, WHERE THESE LOCATIONS HAVE THE BEST CHANCE OF
RESIDING IN THE WARM SECTOR TO THE SOUTH OF THE BOUNDARY. THE CAA
BEHIND THE FRONT IS NOT SIGNIFICANT, SO THE TREND OF ABOVE NORMAL
TEMPS SHOULD CONTINUE INTO WEDNESDAY. HOWEVER, WE WILL HAVE TO WATCH
FOR THE POSSIBILITY OF ONSHORE FLOW TO DEVELOP. THIS MAY PREVENT
TEMPS FROM REACHING 70F IN THE COASTAL PLAIN, ESPECIALLY THE
EASTERLY WIND BECOMES ENHANCED BY A SEABREEZE.
EXPANSIVE HIGH PRESSURE OVER THE EASTERN SEABOARD WILL PROVIDE A
MAINLY DRY PATTERN THURSDAY THROUGH SATURDAY. THE HUMIDITY IS
FORECAST TO INCREASE A BIT FRIDAY AND SATURDAY AS SOUTHERLY RETURN
FLOW DEVELOPS WITH THE SURFACE HIGH MOVING OFFSHORE. CANNOT RULE OUT
THE POSSIBILITY OF A A SHOWER DEVELOPING DURING THE AFTERNOON HOURS
FRIDAY AND SATURDAY BUT THE SUBSIDENCE INVERSION UNDERNEATH THE
RIDGE SHOULD MINIMIZE THE CONVECTIVE POTENTIAL. ABOVE NORMAL
TEMPS WILL PERSIST WITH HIGHS IN THE 70S TO NEAR 80F EACH DAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
VFR CONDS WILL PREVAIL THRU THE TAF PD WITH HIGH PRES TO THE SE
TODAY MOVG OFFSHORE TONIGHT. THE FLOW WILL BECOME SWLY BY AFTN BUT
WILL BE LESS THAN 10 KTS. ONLY SCT CLOUDS ARE ANTICIPATED. WITH
LIGHT FLOW, STILL EXPECTING ANOTHER SEA BREEZE AT KACY AND KMIV.
AT THESE LOCATIONS, WIND COULD REACH 10 KT OR SO.
OUTLOOK...
MONDAY AND MONDAY NIGHT...VFR. SWLY MAY GUST TO 20 KT LATE IN THE
DAY.
TUESDAY AND TUESDAY NIGHT...PREDOMINATELY VFR. SCT SHRA AND ISO TSRA
DURING THE AFTERNOON AND NIGHT COULD YIELD LOCAL MVFR/IFR CONDITIONS.
WEDNESDAY...SHRA MAY LINGER INTO WEDNESDAY BUT MOST OF THE TERMINALS
SHOULD DRY OUT. SOME MODEL SOLUTIONS ARE INDICATING EASTERLY WINDS
TO DEVELOP. WILL HAVE TO WATCH FOR LOW CLOUDS AND MVFR CIGS TO
ACCOMPANY MARINE LAYER.
WEDNESDAY NIGHT AND THURSDAY...VFR.
&&
.MARINE...
SEAS AS OF 10 AM HAVE DROPPED TO 4.6 FEET AT BOTH BUOY9 AND 65.
IN ADDITION, THE PERIOD HAS INCREASED TO AROUND 10 SECONDS.
WITH THE DOWNWARD TREND UNDERWAY, WE WILL FINALLY PUT THIS
SMALL CRAFT ADVISORY IN THE BOOKS AND HAVE NO FURTHER EXTENSION.
WE ADJUSTED THE WINDS IN DELAWARE BAY THIS AFTERNOON AND EVE
BASED ON HRRR AND ARW MODELS AS THEY HANDLED THE UP THE BAY BREEZE
WELL YESTERDAY.
NO ADDITIONAL FLAGS ARE EXPECTED DURG THE REMAINDER OF THE NR AND
SHORT TERM PDS.
OUTLOOK...
MONDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA
CRITERIA. THE STRONGEST WINDS ARE EXPECTED MONDAY AND TUESDAY AS
HIGH PRESSURE MOVES OFFSHORE AND A S-SW FLOW AROUND 15-20 KT
ENSUES.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES NEAR 30 PERCENT, ALONG WITH OCCASIONAL WIND
GUSTS TO NEAR 20 MPH MAY ENHANCE THE FIRE WEATHER RISK LATE IN
THE DAY ON MONDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...GIGI/NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...KLEIN
AVIATION...KLEIN/NIERENBERG
MARINE...GIGI/KLEIN/NIERENBERG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
920 AM EDT SUN MAY 3 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OVER THE EASTERN UNITED STATES TODAY
WILL GRADUALLY MOVE OFFSHORE ON MONDAY. A COLD FRONT IS FORECAST TO
WEAKEN AS IT DROPS SOUTHWARD ACROSS THE AREA TUESDAY THROUGH EARLY
WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK. THE HIGH WILL
EVENTUALLY SHIFT OFF THE EAST COAST NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO BIG CHANGES MADE WITH THIS UPDATE. 12Z SOUNDINGS HAVE HIGH
TEMPS REACHING THE 70S TODAY, BUT WITH CONTINUED AIR MASS
MODIFICATION AND SOME WAA, SOME LOW 80S ARE POSSIBLE INLAND. SINCE
THE HRRR DID PRETTY WELL WITH THE SEA BREEZE FRONT YESTERDAY, WE
ADJUSTED WINDS BASED ON ITS LATEST RUN OR TWO.
HIGH PRES WILL BE OVER THE SERN CONUS TODAY. SWLY FLOW WILL
INCREASE AND TEMPS WILL WARM IN RESPONSE. HIGHS ARE EXPECTED TO
BE IN THE MID TO UPPER 70S, WITH SOME LOCATIONS MAKING A RUN AT 80
DEGREES. NO PRECIP IS ANTICIPATED. THERE WILL BE SOME SCT CLOUDS
ON AN OTHERWISE BEAUTIFUL DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE AREA OF HIGH PRES WILL MOVE EWD AND OFF THE CST AND A GENLY
CLEAR SKY IS IN STORE WITH LIGHT WIND.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
THE CENTER OF SURFACE HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC
COAST ON MONDAY. SOUTHWESTERLY RETURN FLOW AROUND THE HIGH WILL DRAW
EVEN WARMER AND MORE HUMID AIR UP THE EASTERN SEABOARD. MONDAY WILL
CONTEND WITH APRIL 18TH FOR THE WARMEST DAY SO FAR THIS YEAR WITH
HIGHS 80-85 DEGREES (EXCEPT COOLER ALONG THE COAST AND IN THE
POCONOS). CONDITIONS ACROSS THE FORECAST AREA WILL BE DRY THROUGH
MONDAY NIGHT OWING TO STRONG SUBSIDENCE PRESENT BENEATH THE H8
RIDGE.
A COLD FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE AREA TUESDAY
AFTERNOON AND NIGHT. CLOUDS OVERSPREADING NORTHEAST PA AND NORTHWEST
NJ WILL RESULT IN SLIGHTLY COOLER HIGHS IN THE 70S ON TUESDAY.
FARTHER SOUTH IN THE WARM SECTOR, HIGHS TUESDAY HAVE THE POTENTIAL
TO BE CLOSE TO MONDAY`S FROM ABOUT PHILLY SOUTHWARD IF THE FRONT
AND ITS ASSOCIATED CLOUD COVER HANGS BACK TO THE NORTH. MOISTURE
WILL POOL ALONG THE FRONT AS NOTED BY PWATS INCREASING TO NEAR
1.5 INCHES AND SURFACE DEWPOINTS TO NEAR 60F BY THE AFTERNOON.
BUFKIT SOUNDINGS FROM THE 00Z GFS AND 21Z SREF SHOW MODEST
INSTABILITY (ML CAPE AROUND 500 J/KG) WHILE THE 00Z NAM DEPICTS A
CONSIDERABLY MORE UNSTABLE ENVIRONMENT (ML CAPE AOA 1000 J/KG).
WENT MORE CONSERVATIVE WITH FORECAST COVERAGE OF THUNDERSTORMS
DUE TO THE PRESENCE OF WEAK SHEAR AND LIMITED FORCING IN ADDITION
TO THE QUESTIONABLE INSTABILITY. A GENERAL WEAKENING TREND IS
EXPECTED WITH THE CONVECTION AFTER SUNSET, ALTHOUGH SHOWERS MAY
LINGER INTO THE OVERNIGHT AS SLIGHTLY BETTER LIFT ASSOCIATED WITH
AN UPPER SHORTWAVE TROUGH ARRIVES LATE.
THE FRONT MAY EITHER CONTINUE TO SAG SOUTHWARD SLOWLY OR EVEN STALL
OVER THE DELMARVA WEDNESDAY MORNING. LIFT ASSOCIATED WITH THE FRONT
ITSELF SHOULD WEAKEN AS THE BOUNDARY IS EXPECTED TO BECOME
INCREASINGLY DIFFUSE. CONSEQUENTIALLY, COVERAGE OF SHOWERS EXPECTED
TO BE RELATIVELY LOW ON WEDNESDAY. THUNDERSTORM CHANCES CONFINED TO
THE LOWER DELMARVA, WHERE THESE LOCATIONS HAVE THE BEST CHANCE OF
RESIDING IN THE WARM SECTOR TO THE SOUTH OF THE BOUNDARY. THE CAA
BEHIND THE FRONT IS NOT SIGNIFICANT, SO THE TREND OF ABOVE NORMAL
TEMPS SHOULD CONTINUE INTO WEDNESDAY. HOWEVER, WE WILL HAVE TO WATCH
FOR THE POSSIBILITY OF ONSHORE FLOW TO DEVELOP. THIS MAY PREVENT
TEMPS FROM REACHING 70F IN THE COASTAL PLAIN, ESPECIALLY THE
EASTERLY WIND BECOMES ENHANCED BY A SEABREEZE.
EXPANSIVE HIGH PRESSURE OVER THE EASTERN SEABOARD WILL PROVIDE A
MAINLY DRY PATTERN THURSDAY THROUGH SATURDAY. THE HUMIDITY IS
FORECAST TO INCREASE A BIT FRIDAY AND SATURDAY AS SOUTHERLY RETURN
FLOW DEVELOPS WITH THE SURFACE HIGH MOVING OFFSHORE. CANNOT RULE OUT
THE POSSIBILITY OF A A SHOWER DEVELOPING DURING THE AFTERNOON HOURS
FRIDAY AND SATURDAY BUT THE SUBSIDENCE INVERSION UNDERNEATH THE
RIDGE SHOULD MINIMIZE THE CONVECTIVE POTENTIAL. ABOVE NORMAL
TEMPS WILL PERSIST WITH HIGHS IN THE 70S TO NEAR 80F EACH DAY.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
VFR CONDS WILL PREVAIL THRU THE TAF PD WITH HIGH PRES TO THE SE
TODAY MOVG OFFSHORE TONIGHT. THE FLOW WILL BECOME SWLY BY AFTN BUT
WILL BE LESS THAN 10 KTS. ONLY SCT CLOUDS ARE ANTICIPATED. WITH
LIGHT FLOW, STILL EXPECTING ANOTHER SEA BREEZE AT KACY AND KMIV.
AT THESE LOCATIONS, WIND COULD REACH 10 KT OR SO.
OUTLOOK...
MONDAY AND MONDAY NIGHT...VFR. SWLY MAY GUST TO 20 KT LATE IN THE
DAY.
TUESDAY AND TUESDAY NIGHT...PREDOMINATELY VFR. SCT SHRA AND ISO TSRA
DURING THE AFTERNOON AND NIGHT COULD YIELD LOCAL MVFR/IFR CONDITIONS.
WEDNESDAY...SHRA MAY LINGER INTO WEDNESDAY BUT MOST OF THE TERMINALS
SHOULD DRY OUT. SOME MODEL SOLUTIONS ARE INDICATING EASTERLY WINDS
TO DEVELOP. WILL HAVE TO WATCH FOR LOW CLOUDS AND MVFR CIGS TO
ACCOMPANY MARINE LAYER.
WEDNESDAY NIGHT AND THURSDAY...VFR.
&&
.MARINE...
DOGGEDLY PERSISTENT 5 FOOT SEAS NOW HAVE MADE IT INTO ALL OF OUR
MARINE ZONES. WE HAVE EXTENDED THE SCA THROUGH ALL OUR WATERS FOR
THIS MORNING. SINCE WINDS ARE NOW WELL BELOW SCA THRESHOLD FOR
WINDS, WE CONVERTED THE SCA OVER TO HAZARDOUS SEAS ALL OCEAN
ZONES.
ONCE THIS SCA COMES DOWN, NO ADDITIONAL FLAGS ARE EXPECTED DURG
THE REMAINDER OF THE NR AND SHORT TERM PDS.
OUTLOOK...
MONDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA
CRITERIA. THE STRONGEST WINDS ARE EXPECTED MONDAY AND TUESDAY AS
HIGH PRESSURE MOVES OFFSHORE AND A S-SW FLOW AROUND 15-20 KT
ENSUES.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES NEAR 30 PERCENT, ALONG WITH OCCASIONAL WIND
GUSTS TO NEAR 20 MPH MAY ENHANCE THE FIRE WEATHER RISK LATE IN
THE DAY ON MONDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM EDT THIS
MORNING FOR ANZ450>455.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...GIGI/NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...KLEIN
AVIATION...KLEIN/NIERENBERG
MARINE...GIGI/KLEIN/NIERENBERG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MIAMI FL
140 PM EDT SUN MAY 3 2015
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD. WINDS
THIS AFTERNOON WILL CONTINUE TO BE OUT OF THE EAST BETWEEN 15 TO
20 KNOTS WITH HIGHER GUSTS POSSIBLE. WINDS WILL SLIGHTLY SUBSIDE
DURING THE OVERNIGHT HOURS, HOWEVER, THEY ARE EXPECTED TO INCREASE
TO 15 TO 20 KNOTS AGAIN ON MONDAY MORNING WITH HIGHER GUSTS ONCE
AGAIN POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 954 AM EDT SUN MAY 3 2015/
UPDATE...
THE CURRENT MODEL ANALYSIS SHOWS MOSTLY ZONAL FLOW ACROSS THE
FLORIDA PENINSULA WITH A VERY WEAK MID LEVEL TROUGH OVER SOUTH
FLORIDA. AT THE SURFACE, A BROAD AREA OF HIGH PRESSURE EXISTS
ACROSS THE SOUTHEAST STATES CENTERED FROM WEST VIRGINIA TO
NORTHERN GEORGIA. THE MID LEVEL TROUGH IS REFLECTED WELL ON THE
12Z MFL SOUNDING SHOWING A NORTH-NORTHEAST WIND IN THE LAYER FROM
600MB TO 450MB WITH WESTERLY FLOW ABOVE AND BELOW THAT. LOW LEVEL
FLOW IS EAST-NORTHEAST WITH THE HIGH PRESSURE CENTERED TO THE
NORTH. THE SURFACE HIGH WILL RAPIDLY SHIFT EAST TODAY IN RESPONSE
TO A COLD FRONT THAT WILL MOVE INTO THE CENTRAL PORTION OF THE
CONTINENTAL U.S. WITH THE PRESSURE GRADIENT TIGHTENING ACROSS
SOUTH FLORIDA BY EARLY THIS AFTERNOON. THIS WILL KEEP THE HIGH
RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES WITH MIAMI BEACH
OCEAN RESCUE ALREADY REPORTING STRONG CURRENTS THIS MORNING. THE
12Z SOUNDING ALSO SHOWS A VERY STABLE AIRMASS LAYER BETWEEN 850MB
AND 750MB SO THIS WILL CONTINUE TO KEEP RAIN CHANCES OUT OF THE
FORECAST ALTHOUGH THE HRRR IS INDICATING THE POSSIBILITY OF A
COUPLE OF QUICK PASSING SHOWERS. HOWEVER, IT IS ONLY DEPICTING
20-25 DBZ INTENSITY SO NOT WORTH MENTIONING AT THIS TIME AND THE
HRRR OFTEN TIMES OVER EMPHASIZES SHOWERS IN A DRY EASTERLY FLOW
REGIME. BUT STILL, SOMETHING TO MONITOR.
FOR THE MARINE FORECAST, DO NOT PLAN ANY CHANGES AT THIS TIME.
HOWEVER, THE LATEST GFS MODEL GUIDANCE IS SHOWING A TAD BIT
STRONGER WINDS OVER THE ATLANTIC WATERS THIS AFTERNOON THAN IS
CURRENTLY DEPICTED. DUE TO THIS BEING FROM THE INTERMEDIATE RUN AT
06Z AND ONLY ONE UPDATE SHOWING THIS, WILL WAIT FOR THE 12Z RUN TO
MAKE ANY DECISIONS BUT MAY NEED TO BUMP UP THE WIND TO 20 KNOTS
FROM THE CURRENT 15-20 KNOTS WHICH COULD AFFECT THE SIGNIFICANT
WAVE HEIGHTS AS WELL AND MAY NEED TO BEGIN THE SCA FOR THOSE
WATERS EARLIER THAN THE 00Z START NOW.
KOB
PREV DISCUSSION... /ISSUED 744 AM EDT SUN MAY 3 2015/
AVIATION...
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY MORNING
HOURS AND THROUGH THE AFTERNOON WITH MAINLY STABLE WEATHER CONDITIONS
ANTICIPATED. AS HIGH PRESSURE BUILDS...EAST NORTHEAST WINDS FORECAST
TO INCREASE TO THE 15 TO 20 KNOTS RANGE BY LATE MORNING WITH
HIGHER GUSTS POSSIBLE AND SUBSIDING OVERNIGHT BUT STILL REMAINING
AROUND 10-15 KTS EXCEPT AROUND 10 KNOTS AT APF AND TMB.
PREV DISCUSSION... /ISSUED 433 AM EDT SUN MAY 3 2015/
DISCUSSION...
THE REGIONAL SYNOPTIC FEATURES EARLY THIS MORNING INCLUDE A WEAK SURFACE
TROUGH JUST WEST OF THE KEYS AND EXTENDING NORTHWARD...A MID TO
UPPER LEVEL TROUGH EXTENDING INTO THE CENTRAL TO EASTERN GULF AND
A COLD FRONT ACROSS EASTERN CUBA THAT EXTENDS NORTHWARD TO A
SURFACE LOW NORTHEAST OF THE MID-ATLANTIC STATES.
FOR TODAY...HIGH PRESSURE WILL SLOWLY DEVELOP OFF THE
GEORGIA/CAROLINAS COAST WITH THE AFOREMENTIONED SURFACE TROUGH
ERODING. IN ADDITION DEEPER LAYERED MOISTURE WILL LIKELY REMAIN
ACROSS THE KEYS TODAY. WITH HIGHER PRESSURE BUILDING INTO THE
REGION THE WEST COAST SEA BREEZE WILL BE SUPPRESSED AND WITH PWAT
EXPECTED TO BE AROUND ONLY AN INCH CONVECTION IS NOT LIKELY TODAY
ALTHOUGH SOME ISOLATED SHOWER ACTIVITY IS POSSIBLE ACROSS THE
SOUTHERN TIP OF THE PENINSULA.
THERE WILL BE A HIGH RISK OF RIP CURRENTS ALONG THE ATLANTIC COAST
BEACHES TODAY AND TONIGHT WITH A LONG PERIOD NORTHEASTERLY SWELL
IN THE 2 TO 4 FOOT RANGE FORECAST TO ENTER THE ATLANTIC WATERS
EAST OF PALM BEACH COUNTY THIS MORNING...WITH THE GREATEST IMPACT
EXPECTED ACROSS THE WATERS TO THE EAST OF PALM BEACH COUNTY.
FOR MONDAY...MOISTURE AND CLOUDINESS WILL BEGIN TO RETURN TO THE
REGION. THE MID TO UPPER LEVEL TROUGH ACROSS THE GULF IS FORECAST
TO DEEPEN WITH THE FLORIDA PENINSULA TO THE EAST OF THE TROUGH
AXIS. THE LOW LEVEL FLOW WILL BECOME SOUTHERLY BRINGING DEEP
MOISTURE ACROSS CUBA NORTHWARD INTO THE REGION. MODERATE EASTERLY
WINDS WILL FAVOR SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS
MAINLY ALONG THE EASTERN THIRD OF THE PENINSULA AND THE ADJACENT
ATLANTIC WATERS.
FOR TUESDAY...PREVIOUS DISCUSSIONS HAVE ALREADY INDICATED THAT
DEEP TROPICAL MOISTURE IS FORECAST TO ENTER ON TUESDAY WITH THE MID
TO UPPER LEVEL TROUGH AXIS JUST WEST OF FLORIDA AND A BROAD LOW
LEVEL TROUGH DEVELOPING ACROSS THE FLORIDA STRAITS AND EXTENDING
INTO THE NORTHWEST BAHAMAS. THE PWAT IS FORECAST TO BE ABOUT 1.7
INCHES AND MID LEVEL TEMPERATURES FORECAST TO BE SIGNIFICANTLY
COOL FOR THIS TIME OF YEAR...ABOUT 3 DEGREES COOLER. ALL THESE
FACTORS ARE FORECAST TO BRING SCATTERED TO NUMEROUS
SHOWERS/THUNDERSTORMS TO THE REGION ON TUESDAY WITH A SYNOPTIC
PATTERN SUPPORTIVE OF LOCALLY HEAVY RAINFALL WITH FLOODING
POTENTIAL POSSIBLE IN ISOLATED AREAS.
BY WEDNESDAY THE GLOBAL MODELS START TO DIVERGE SOME IN THEIR
SOLUTIONS BUT THE GFS ENSEMBLE SHOWS BROAD FEATURES THAT SEEM LIKE
A GENERAL CONSENSUS BETWEEN THE GFS AND THE ECMWF. THE ENSEMBLE INDICATES THAT
THE UPPER LEVEL TROUGH AXIS IS FORECAST TO SHIFT EAST ACROSS THE FLORIDA
PENINSULA WITH A BROAD LOW LEVEL AND SURFACE TROUGH OFF THE EAST
CENTRAL FLORIDA COAST WITH DEEP MOISTURE EXTENDING ACROSS SOUTH
FLORIDA. SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST
WITH A SYNOPTIC PATTERN AGAIN SUPPORTIVE OF LOCALLY HEAVY
RAINFALL.
FOR THE EXTENDED FORECAST...BY THURSDAY THE ECMWF...GFS AND THE
GFS ENSEMBLE HAVE BROAD AGREEMENT THAT THE UPPER LEVEL TROUGH
WILL PERSIST NEAR THE FLORIDA PENINSULA WITH A CLOSED SURFACE LOW
FORECAST OFF THE NORTHEAST FLORIDA COAST. THE GUIDANCE GENERALLY
SUGGESTS THAT THE LOW COULD SLOWLY DRIFT TO THE NORTHWEST INTO
NEXT WEEKEND. OBVIOUSLY ITS TOO EARLY TO SPECULATE ON THIS
SCENARIO AND WHAT IF ANY IMPACT IT MIGHT HAVE FOR SOUTH FLORIDA
AND WILL HAVE TO WAIT AND SEE WHAT CONSENSUS THE GUIDANCE HAS
DURING THIS WEEK.
MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GULF WATERS FOR
WINDS TO NEAR 20 KNOTS OR JUST ABOVE THROUGH 10 AM. WINDS ARE
FORECAST TO SLOWLY DECREASE TODAY THEN INCREASE AGAIN TO 20 KNOTS
OR JUST ABOVE MAINLY ACROSS THE OFF SHORE WATERS. THEREFORE THE
SMALL CRAFT ADVISORY WILL BE ALLOWED TO EXPIRE THIS MORNING BUT A
NEW ONE WILL BE ISSUED FOR TONIGHT...STARTING AT 00Z FOR THE OFF
SHORE GULF WATERS.
WITH THE COMBINATION OF NORTHEASTERLY WINDS IN THE 15 TO 20
KNOT RANGE ACROSS THE ATLANTIC WATERS AND A LONG PERIOD
NORTHEASTERLY SWELL IN THE 2 TO 4 FOOT RANGE FORECAST TO ENTER
THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY LATER THIS MORNING...HAZARDOUS
SEAS TO NEAR 7 FEET ARE FORECAST ACROSS THE ATLANTIC WATERS WITH A
SMALL CRAFT ADVISORY IN EFFECT TODAY STARTING AT 18Z THROUGH 00Z
TUESDAY BUT MAY HAVE TO BE EXTENDED WITH LATER GUIDANCE.
THERE IS A LOT OF UNCERTAINTY IN THE EXTENDED FORECAST GIVEN THE
UNCERTAINTIES OUTLINED IN THE DISCUSSION ABOVE. SO THERE COULD BE
CONSIDERABLE CHANGES TO THE WIND AND WAVES FORECAST IN THE
EXTENDED PERIODS IN THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 69 82 73 78 / 0 20 60 70
FORT LAUDERDALE 71 82 73 80 / 10 20 70 70
MIAMI 70 82 72 81 / 10 20 70 70
NAPLES 63 86 67 86 / 10 10 20 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL MIDNIGHT EDT TONIGHT FOR FLZ168-172-
173.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT MONDAY
FOR AMZ650-651-670-671.
GM...SMALL CRAFT ADVISORY FOR WINDS FROM 8 PM THIS EVENING TO 8 AM
EDT MONDAY FOR GMZ676.
&&
$$
SHORT TERM...52/PS
LONG TERM....52/PS
AVIATION...55/CWC
AREA FORECAST DISCUSSION
NWS MIAMI FL
954 AM EDT SUN MAY 3 2015
.UPDATE...
THE CURRENT MODEL ANALYSIS SHOWS MOSTLY ZONAL FLOW ACROSS THE
FLORIDA PENINSULA WITH A VERY WEAK MID LEVEL TROUGH OVER SOUTH
FLORIDA. AT THE SURFACE, A BROAD AREA OF HIGH PRESSURE EXISTS
ACROSS THE SOUTHEAST STATES CENTERED FROM WEST VIRGINIA TO
NORTHERN GEORGIA. THE MID LEVEL TROUGH IS REFLECTED WELL ON THE
12Z MFL SOUNDING SHOWING A NORTH-NORTHEAST WIND IN THE LAYER FROM
600MB TO 450MB WITH WESTERLY FLOW ABOVE AND BELOW THAT. LOW LEVEL
FLOW IS EAST-NORTHEAST WITH THE HIGH PRESSURE CENTERED TO THE
NORTH. THE SURFACE HIGH WILL RAPIDLY SHIFT EAST TODAY IN RESPONSE
TO A COLD FRONT THAT WILL MOVE INTO THE CENTRAL PORTION OF THE
CONTINENTAL U.S. WITH THE PRESSURE GRADIENT TIGHTENING ACROSS
SOUTH FLORIDA BY EARLY THIS AFTERNOON. THIS WILL KEEP THE HIGH
RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES WITH MIAMI BEACH
OCEAN RESCUE ALREADY REPORTING STRONG CURRENTS THIS MORNING. THE
12Z SOUNDING ALSO SHOWS A VERY STABLE AIRMASS LAYER BETWEEN 850MB
AND 750MB SO THIS WILL CONTINUE TO KEEP RAIN CHANCES OUT OF THE
FORECAST ALTHOUGH THE HRRR IS INDICATING THE POSSIBILITY OF A
COUPLE OF QUICK PASSING SHOWERS. HOWEVER, IT IS ONLY DEPICTING
20-25 DBZ INTENSITY SO NOT WORTH MENTIONING AT THIS TIME AND THE
HRRR OFTEN TIMES OVER EMPHASIZES SHOWERS IN A DRY EASTERLY FLOW
REGIME. BUT STILL, SOMETHING TO MONITOR.
FOR THE MARINE FORECAST, DO NOT PLAN ANY CHANGES AT THIS TIME.
HOWEVER, THE LATEST GFS MODEL GUIDANCE IS SHOWING A TAD BIT
STRONGER WINDS OVER THE ATLANTIC WATERS THIS AFTERNOON THAN IS
CURRENTLY DEPICTED. DUE TO THIS BEING FROM THE INTERMEDIATE RUN AT
06Z AND ONLY ONE UPDATE SHOWING THIS, WILL WAIT FOR THE 12Z RUN TO
MAKE ANY DECISIONS BUT MAY NEED TO BUMP UP THE WIND TO 20 KNOTS
FROM THE CURRENT 15-20 KNOTS WHICH COULD AFFECT THE SIGNIFICANT
WAVE HEIGHTS AS WELL AND MAY NEED TO BEGIN THE SCA FOR THOSE
WATERS EARLIER THAN THE 00Z START NOW.
KOB
&&
.PREV DISCUSSION... /ISSUED 744 AM EDT SUN MAY 3 2015/
AVIATION...
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY MORNING
HOURS AND THROUGH THE AFTERNOON WITH MAINLY STABLE WEATHER CONDITIONS
ANTICIPATED. AS HIGH PRESSURE BUILDS...EAST NORTHEAST WINDS FORECAST
TO INCREASE TO THE 15 TO 20 KNOTS RANGE BY LATE MORNING WITH
HIGHER GUSTS POSSIBLE AND SUBSIDING OVERNIGHT BUT STILL REMAINING
AROUND 10-15 KTS EXCEPT AROUND 10 KNOTS AT APF AND TMB.
PREV DISCUSSION... /ISSUED 433 AM EDT SUN MAY 3 2015/
DISCUSSION...
THE REGIONAL SYNOPTIC FEATURES EARLY THIS MORNING INCLUDE A WEAK SURFACE
TROUGH JUST WEST OF THE KEYS AND EXTENDING NORTHWARD...A MID TO
UPPER LEVEL TROUGH EXTENDING INTO THE CENTRAL TO EASTERN GULF AND
A COLD FRONT ACROSS EASTERN CUBA THAT EXTENDS NORTHWARD TO A
SURFACE LOW NORTHEAST OF THE MID-ATLANTIC STATES.
FOR TODAY...HIGH PRESSURE WILL SLOWLY DEVELOP OFF THE
GEORGIA/CAROLINAS COAST WITH THE AFOREMENTIONED SURFACE TROUGH
ERODING. IN ADDITION DEEPER LAYERED MOISTURE WILL LIKELY REMAIN
ACROSS THE KEYS TODAY. WITH HIGHER PRESSURE BUILDING INTO THE
REGION THE WEST COAST SEA BREEZE WILL BE SUPPRESSED AND WITH PWAT
EXPECTED TO BE AROUND ONLY AN INCH CONVECTION IS NOT LIKELY TODAY
ALTHOUGH SOME ISOLATED SHOWER ACTIVITY IS POSSIBLE ACROSS THE
SOUTHERN TIP OF THE PENINSULA.
THERE WILL BE A HIGH RISK OF RIP CURRENTS ALONG THE ATLANTIC COAST
BEACHES TODAY AND TONIGHT WITH A LONG PERIOD NORTHEASTERLY SWELL
IN THE 2 TO 4 FOOT RANGE FORECAST TO ENTER THE ATLANTIC WATERS
EAST OF PALM BEACH COUNTY THIS MORNING...WITH THE GREATEST IMPACT
EXPECTED ACROSS THE WATERS TO THE EAST OF PALM BEACH COUNTY.
FOR MONDAY...MOISTURE AND CLOUDINESS WILL BEGIN TO RETURN TO THE
REGION. THE MID TO UPPER LEVEL TROUGH ACROSS THE GULF IS FORECAST
TO DEEPEN WITH THE FLORIDA PENINSULA TO THE EAST OF THE TROUGH
AXIS. THE LOW LEVEL FLOW WILL BECOME SOUTHERLY BRINGING DEEP
MOISTURE ACROSS CUBA NORTHWARD INTO THE REGION. MODERATE EASTERLY
WINDS WILL FAVOR SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS
MAINLY ALONG THE EASTERN THIRD OF THE PENINSULA AND THE ADJACENT
ATLANTIC WATERS.
FOR TUESDAY...PREVIOUS DISCUSSIONS HAVE ALREADY INDICATED THAT
DEEP TROPICAL MOISTURE IS FORECAST TO ENTER ON TUESDAY WITH THE MID
TO UPPER LEVEL TROUGH AXIS JUST WEST OF FLORIDA AND A BROAD LOW
LEVEL TROUGH DEVELOPING ACROSS THE FLORIDA STRAITS AND EXTENDING
INTO THE NORTHWEST BAHAMAS. THE PWAT IS FORECAST TO BE ABOUT 1.7
INCHES AND MID LEVEL TEMPERATURES FORECAST TO BE SIGNIFICANTLY
COOL FOR THIS TIME OF YEAR...ABOUT 3 DEGREES COOLER. ALL THESE
FACTORS ARE FORECAST TO BRING SCATTERED TO NUMEROUS
SHOWERS/THUNDERSTORMS TO THE REGION ON TUESDAY WITH A SYNOPTIC
PATTERN SUPPORTIVE OF LOCALLY HEAVY RAINFALL WITH FLOODING
POTENTIAL POSSIBLE IN ISOLATED AREAS.
BY WEDNESDAY THE GLOBAL MODELS START TO DIVERGE SOME IN THEIR
SOLUTIONS BUT THE GFS ENSEMBLE SHOWS BROAD FEATURES THAT SEEM LIKE
A GENERAL CONSENSUS BETWEEN THE GFS AND THE ECMWF. THE ENSEMBLE INDICATES THAT
THE UPPER LEVEL TROUGH AXIS IS FORECAST TO SHIFT EAST ACROSS THE FLORIDA
PENINSULA WITH A BROAD LOW LEVEL AND SURFACE TROUGH OFF THE EAST
CENTRAL FLORIDA COAST WITH DEEP MOISTURE EXTENDING ACROSS SOUTH
FLORIDA. SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST
WITH A SYNOPTIC PATTERN AGAIN SUPPORTIVE OF LOCALLY HEAVY
RAINFALL.
FOR THE EXTENDED FORECAST...BY THURSDAY THE ECMWF...GFS AND THE
GFS ENSEMBLE HAVE BROAD AGREEMENT THAT THE UPPER LEVEL TROUGH
WILL PERSIST NEAR THE FLORIDA PENINSULA WITH A CLOSED SURFACE LOW
FORECAST OFF THE NORTHEAST FLORIDA COAST. THE GUIDANCE GENERALLY
SUGGESTS THAT THE LOW COULD SLOWLY DRIFT TO THE NORTHWEST INTO
NEXT WEEKEND. OBVIOUSLY ITS TOO EARLY TO SPECULATE ON THIS
SCENARIO AND WHAT IF ANY IMPACT IT MIGHT HAVE FOR SOUTH FLORIDA
AND WILL HAVE TO WAIT AND SEE WHAT CONSENSUS THE GUIDANCE HAS
DURING THIS WEEK.
MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GULF WATERS FOR
WINDS TO NEAR 20 KNOTS OR JUST ABOVE THROUGH 10 AM. WINDS ARE
FORECAST TO SLOWLY DECREASE TODAY THEN INCREASE AGAIN TO 20 KNOTS
OR JUST ABOVE MAINLY ACROSS THE OFF SHORE WATERS. THEREFORE THE
SMALL CRAFT ADVISORY WILL BE ALLOWED TO EXPIRE THIS MORNING BUT A
NEW ONE WILL BE ISSUED FOR TONIGHT...STARTING AT 00Z FOR THE OFF
SHORE GULF WATERS.
WITH THE COMBINATION OF NORTHEASTERLY WINDS IN THE 15 TO 20
KNOT RANGE ACROSS THE ATLANTIC WATERS AND A LONG PERIOD
NORTHEASTERLY SWELL IN THE 2 TO 4 FOOT RANGE FORECAST TO ENTER
THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY LATER THIS MORNING...HAZARDOUS
SEAS TO NEAR 7 FEET ARE FORECAST ACROSS THE ATLANTIC WATERS WITH A
SMALL CRAFT ADVISORY IN EFFECT TODAY STARTING AT 18Z THROUGH 00Z
TUESDAY BUT MAY HAVE TO BE EXTENDED WITH LATER GUIDANCE.
THERE IS A LOT OF UNCERTAINTY IN THE EXTENDED FORECAST GIVEN THE
UNCERTAINTIES OUTLINED IN THE DISCUSSION ABOVE. SO THERE COULD BE
CONSIDERABLE CHANGES TO THE WIND AND WAVES FORECAST IN THE
EXTENDED PERIODS IN THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 69 82 73 / 10 0 20 60
FORT LAUDERDALE 80 71 82 73 / 10 10 20 70
MIAMI 81 70 82 72 / 10 10 20 70
NAPLES 87 63 86 67 / 10 10 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR FLZ168-172-173.
AM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM EDT THIS MORNING FOR
AMZ651-671.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON
TO 8 PM EDT MONDAY FOR AMZ650-651-670-671.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM EDT THIS MORNING FOR
GMZ656-657-676.
SMALL CRAFT ADVISORY FOR WINDS FROM 8 PM THIS EVENING TO 8 AM
EDT MONDAY FOR GMZ676.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
900 PM CDT MON MAY 4 2015
.UPDATE...
ISSUED AT 848 PM CDT MON MAY 4 2015
LATEST SURFACE ANALYSIS HAS A NEARLY STATIONARY FRONTAL BOUNDARY
CUTTING WEST TO EAST ACROSS CENTRAL ILLINOIS ROUGHLY FROM QUINCY
TO PARIS. THIS BOUNDARY IS FAIRLY WELL DELINEATED BY AN EXPANDING
FINE LINE OF SHOWERS AND ISOLATED THUNDERSTORMS. THE PREVIOUS
INTENSITY OF THE AREA OF STORMS PUSHING INTO WEST-CENTRAL ILLINOIS
HAS FADED WITH THE LOSS OF DIURNAL INSTABILITY WITH THE BULK OF
THE STORMS IN OUR VICINITY CURRENTLY OF THE "GARDEN VARIETY".
THE BULK OF THE GUIDANCE, ESPECIALLY RECENT RUNS OF MANY HIGH
RESOLUTION MODELS, SUGGEST THE BULK OF THE SHOWERS/STORMS THOUGH
THE NIGHT WILL EXIST ALONG/NORTH OF THE FRONTAL BOUNDARY. ALSO, A
WAVE LIFTING NORTHEAST OUT OF THE PLAINS IS EXPECTED TO HELP PUSH
THE FRONT A LITTLE FURTHER NORTH WITH TIME OVERNIGHT. THESE
FACTORS WOULD SUGGEST THE BULK OF THE UPSTREAM PRECIPITATION OVER
IOWA AND MISSOURI WOULD TRACK NORTH OF MOST OF THE FORECAST AREA.
PLAN TO UPDATE FORECAST TO REFINE POPS, MAINLY TO PUSH THE RISK
FURTHER NORTH. OTHERWISE, MINOR TWEAKS ARE NEEDED FOR THE LATEST
HOURLY TRENDS.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 245 PM CDT MON MAY 4 2015
FRONTAL BOUNDARY EXTENDING FROM SOUTHERN LAKE MICHIGAN TO NORTHERN
KANSAS WILL SINK SOUTHWARD...EVENTUALLY STALLING NEAR THE I-72
CORRIDOR LATER THIS EVENING. SHOWERS AND THUNDERSTORMS WILL DEVELOP
ALONG THE BOUNDARY...WITH MOST MODEL SOLUTIONS SUGGESTING THE
GREATEST AREAL COVERAGE OF PRECIP ACROSS THE NORTHERN HALF OF THE
KILX CWA. HRRR IS SHOWING WIDELY SCATTERED STORMS DEVELOPING OVER
THE NEXT COUPLE OF HOURS...WITH THE CONVECTION BECOMING MORE
WIDESPREAD AFTER SUNSET AS A WEAK LOW-LEVEL JET DEVELOPS. HAVE
ADJUSTED RAIN CHANCES ACCORDINGLY...WITH LIKELY POPS ALONG/NORTH OF
I-72 TAPERING DOWN TO JUST SLIGHT CHANCE ALONG/SOUTH OF I-70.
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 245 PM CDT MON MAY 4 2015
AN UPPER LEVEL RIDGE IS EXPECTED TO AMPLIFY OVER THE CENTER OF THE
NATION STARTING ON TUESDAY WHICH SHOULD PUSH THE BETTER CHANCES FOR
SHOWERS AND THUNDERSTORMS NORTH OF THE FORECAST AREA...AT LEAST INTO
THURSDAY. SHORTWAVE ENERGY IS THEN FORECAST TO EJECTS NORTH OUT OF
THE SOUTHERN PLAINS AND BRING ABOUT A CHANCE FOR MORE SHOWERS AND
THUNDERSTORMS...ESPECIALLY ACROSS OUR WEST...THURSDAY NIGHT INTO
FRIDAY. A MORE POTENT 500 MB TROF IS THEN FORECAST TO SLOWLY TRACK
OUT OF THE ROCKIES DURING THE WEEKEND BRINGING PERIODS OF SHOWERS
AND THUNDERSTORMS TO THE FORECAST AREA. MOST MODELS TRACK THIS LOW
NORTH-NORTHEAST ON SUNDAY SUGGESTING THE MORE SIGNIFICANT LIFT TO
REMAIN WEST OF OUR AREA UNTIL LATE SUNDAY OR MONDAY OF NEXT WEEK
WHEN THE SYSTEM WILL SWING A COLD FRONT THROUGH CENTRAL ILLINOIS.
UNTIL THEN...WARM TEMPERATURES TO PREVAIL WITH THE SHOWER AND STORM
CHANCES ACROSS THE FAR NORTH TOMORROW AS THE FRONT RETREATS BACK
TO THE NORTH...AND THEN RAIN CHANCES RETURN LATE THU INTO FRIDAY
AND HOLDS THROUGH EARLY NEXT WEEK BEFORE WE FINALLY GET A CHANGE
IN AIR MASS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 650 PM CDT MON MAY 4 2015
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND TRACK
ACROSS CENTRAL ILLINOIS FOR MUCH OF THE NIGHT IN THE VICINITY OF A
STALLED W-E ORIENTED FRONTAL BOUNDARY. BASED ON THE EXPECTED
POSITION OF THE FRONT, KPIA, KBMI, AND KCMI ARE THE MOST LIKELY OF
THE LOCAL TAF SITES TO BE IMPACTED. EXPECT MOSTLY VARIABLE WINDS
THROUGH THE NIGHT IN THE VICINITY OF THE FRONT, WITH WINDS
TRENDING SOUTHERLY TUESDAY AS THE FRONT PUSHES BACK NORTHWARD,
ALSO TAKING THE BULK OF THE PRECIPITATION RISK WITH IT.
PREDOMINANTLY VFR CONDITIONS ARE EXPECTED, ALTHOUGH PERIODS OF
MVFR CONDITIONS WILL DEVELOP TONIGHT IN AREAS THAT RECEIVE
STEADIER RAINFALL.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BAK
SHORT TERM...BARNES
LONG TERM...SMITH
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
654 PM CDT MON MAY 4 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 245 PM CDT MON MAY 4 2015
FRONTAL BOUNDARY EXTENDING FROM SOUTHERN LAKE MICHIGAN TO NORTHERN
KANSAS WILL SINK SOUTHWARD...EVENTUALLY STALLING NEAR THE I-72
CORRIDOR LATER THIS EVENING. SHOWERS AND THUNDERSTORMS WILL DEVELOP
ALONG THE BOUNDARY...WITH MOST MODEL SOLUTIONS SUGGESTING THE
GREATEST AREAL COVERAGE OF PRECIP ACROSS THE NORTHERN HALF OF THE
KILX CWA. HRRR IS SHOWING WIDELY SCATTERED STORMS DEVELOPING OVER
THE NEXT COUPLE OF HOURS...WITH THE CONVECTION BECOMING MORE
WIDESPREAD AFTER SUNSET AS A WEAK LOW-LEVEL JET DEVELOPS. HAVE
ADJUSTED RAIN CHANCES ACCORDINGLY...WITH LIKELY POPS ALONG/NORTH OF
I-72 TAPERING DOWN TO JUST SLIGHT CHANCE ALONG/SOUTH OF I-70.
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 245 PM CDT MON MAY 4 2015
AN UPPER LEVEL RIDGE IS EXPECTED TO AMPLIFY OVER THE CENTER OF THE
NATION STARTING ON TUESDAY WHICH SHOULD PUSH THE BETTER CHANCES FOR
SHOWERS AND THUNDERSTORMS NORTH OF THE FORECAST AREA...AT LEAST INTO
THURSDAY. SHORTWAVE ENERGY IS THEN FORECAST TO EJECTS NORTH OUT OF
THE SOUTHERN PLAINS AND BRING ABOUT A CHANCE FOR MORE SHOWERS AND
THUNDERSTORMS...ESPECIALLY ACROSS OUR WEST...THURSDAY NIGHT INTO
FRIDAY. A MORE POTENT 500 MB TROF IS THEN FORECAST TO SLOWLY TRACK
OUT OF THE ROCKIES DURING THE WEEKEND BRINGING PERIODS OF SHOWERS
AND THUNDERSTORMS TO THE FORECAST AREA. MOST MODELS TRACK THIS LOW
NORTH-NORTHEAST ON SUNDAY SUGGESTING THE MORE SIGNIFICANT LIFT TO
REMAIN WEST OF OUR AREA UNTIL LATE SUNDAY OR MONDAY OF NEXT WEEK
WHEN THE SYSTEM WILL SWING A COLD FRONT THROUGH CENTRAL ILLINOIS.
UNTIL THEN...WARM TEMPERATURES TO PREVAIL WITH THE SHOWER AND STORM
CHANCES ACROSS THE FAR NORTH TOMORROW AS THE FRONT RETREATS BACK
TO THE NORTH...AND THEN RAIN CHANCES RETURN LATE THU INTO FRIDAY
AND HOLDS THROUGH EARLY NEXT WEEK BEFORE WE FINALLY GET A CHANGE
IN AIR MASS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 650 PM CDT MON MAY 4 2015
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND TRACK
ACROSS CENTRAL ILLINOIS FOR MUCH OF THE NIGHT IN THE VICINITY OF A
STALLED W-E ORIENTED FRONTAL BOUNDARY. BASED ON THE EXPECTED
POSITION OF THE FRONT, KPIA, KBMI, AND KCMI ARE THE MOST LIKELY OF
THE LOCAL TAF SITES TO BE IMPACTED. EXPECT MOSTLY VARIABLE WINDS
THROUGH THE NIGHT IN THE VICINITY OF THE FRONT, WITH WINDS
TRENDING SOUTHERLY TUESDAY AS THE FRONT PUSHES BACK NORTHWARD,
ALSO TAKING THE BULK OF THE PRECIPITATION RISK WITH IT.
PREDOMINANTLY VFR CONDITIONS ARE EXPECTED, ALTHOUGH PERIODS OF
MVFR CONDITIONS WILL DEVELOP TONIGHT IN AREAS THAT RECEIVE
STEADIER RAINFALL.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...SMITH
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
256 PM CDT SUN MAY 3 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 250 PM CDT SUN MAY 3 2015
A WEAKENING SHORT WAVE OVER EASTERN IA AND NW IL BY MS RIVER WILL
LIFT INTO SE WI BY SUNSET AND KEEP BEST CHANCES OF SHOWERS AND
THUNDERSTORMS NORTH OF I-80 THROUGH SUNSET WITH JUST ISOLATED
SHOWERS AND POSSIBLE THUNDERSTORMS OVER THE IL RIVER VALLEY. CHANCES
OF SHOWERS AND THUNDERSTORMS WILL INCREASE DURING THE NIGHT
ESPECIALLY OVERNIGHT OVER THE IL RIVER VALLEY WITH SLIGHT CHANCES
EXTENDING AS FAR SE AT CHARLESTON/MATTOON BY SUNRISE MONDAY AS YET
ANOTHER SHORT WAVE OVER EASTERN NEBRASKA TRACKS EAST TOWARD THE
IA/IL BORDER BY 12Z/7 AM MONDAY. SPC KEEPS RISK OF SEVERE STORMS NW
OF IL OVER NORTHERN IA, SE MN AND INTO CENTRAL WI THROUGH DAYBREAK
MONDAY WHERE BETTER FORCING WILL BE AS COLD FRONT PUSHES SE INTO
CENTRAL PARTS OF WI/IA BY SUNRISE MONDAY. STAYED CLOSE TO MET/MAV
GUIDANCE LOWS TONIGHT IN THE UPPER 50S AND LOWER 60S WITH COOLEST
READINGS IN EASTERN/SE IL. BREEZY SSW WINDS 15-25 MPH THIS AFTERNOON
WILL DIMINISH SOUTH 7-14 MPH AFTER SUNSET.
&&
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN MAY 3 2015
MAIN FORECAST CHALLENGE WILL BE POSITION OF FRONTAL BOUNDARY AND
HIGHER RAIN CHANCES LATER TONIGHT THRU MONDAY NIGHT. REMNANTS OF
TODAY`S MCV SHOULD PUSH OFF TO OUR NORTHEAST PUSHING THE SHOWERS
EVEN FURTHER AWAY FROM THE FORECAST AREA THIS EVENING. WEAK UPPER
LEVEL DISTURBANCE OVER THE MISSOURI VALLEY HAS A FEW SHOWERS
ASSOCIATED WITH IT BUT THE LAST FEW RUNS OF THE RAP AND HRRR HAVE
BACKED OFF SOME ON ANY ORGANIZED SHOWER AND THUNDERSTORM THREAT WITH
THAT FEATURE. IT STILL APPEARS OUR MAIN THREAT WILL COME LATER
TONIGHT AND THRU THE MORNING HOURS OF MONDAY WITH REDEVELOPMENT
TAKING PLACE LATER TOMORROW AFTERNOON INTO THE EVENING RIGHT ALONG
THE STALLED FRONTAL BOUNDARY. HAVE TRENDED MORE TOWARDS THE HIGH
RESOLUTION MODEL SOLUTIONS FROM THE NSSL-ARW AND 4KM NAM-WRF WITH
RESPECT TO FRONTAL POSITION ON MONDAY AND ASSOCIATED PRECIP CHANCES
ALONG IT. THE HIGHER POPS WILL REMAIN ACROSS THE NORTHERN HALF OF
THE FORECAST AREA BEFORE THE BOUNDARY SHIFTS BACK NORTH LATE TUESDAY
INTO WEDNESDAY AS UPPER LEVEL RIDGING BUILDS ACROSS THE REGION.
SEVERE THREAT WILL BE TIED TO THE POSITION OF THE BOUNDARY MONDAY
AFTERNOON AND EVENING WITH THE NAM-WRF INDICATING A 40-45 KT LOW
LEVEL JET SETTING UP TONIGHT FROM NORTHERN MISSOURI NORTHEAST INTO
NORTHERN IL WITH THE STRONGER 850 MB THETA-E ADVECTION AND MOISTURE
TRANSPORT LOCATED FROM NORTHEAST MISSOURI INTO NORTHERN IL. STORMS
SHOULD DEVELOP WELL OUT TO OUR WEST AND NORTHWEST LATER THIS EVENING
AND THEN TRANSLATE EAST AND SOUTHEAST INTO OUR NORTHERN AREAS BY
LATE EVENING OR DURING THE EARLY MORNING HOURS OF MONDAY. IF A
DECENT COLD POOL DEVELOPS LATER TONIGHT...THOSE STORMS MAY TRACK
FURTHER SOUTH AND AFFECT THE POSITION OF THE SYNOPTIC SCALE BOUNDARY
IN OUR AREA ON MONDAY/MONDAY EVENING. WITH THE WEST TO EAST BOUNDARY
LOCATED ACROSS A PORTION OF THE FORECAST AREA MONDAY AFTERNOON AND
EVENING...LOOK FOR STORMS TO FIRE AGAIN ALONG THE INSTABILITY AXIS
WHICH SHOULD BE ALIGNED FROM NORTHERN MISSOURI INTO WEST CENTRAL IL
BY MID AFTERNOON. MIXED LAYER CAPES OF 1500-2000 J/KG AND EFFECTIVE
SHEAR VALUES OF 25 KTS SHOULD PROMOTE STORM ORGANIZATION WITH
ISOLATED STRONG WIND GUSTS AND HAIL POSSIBLE WITH 700-500 MB LAPSE
RATES OF 6.5-7 DEG/C DEPICTED ON SOUNDINGS TOMORROW AFTERNOON ACROSS
THE NORTH. SCATTERED STORMS SHOULD CONTINUE MONDAY NIGHT AND THEN
BEGIN TO EDGE NORTHWARD BY TUESDAY AS THE UPPER LEVEL RIDGING BEGINS
TO AMPLIFY ACROSS THE MIDWEST.
ONCE THE 500 MB RIDGE BUILDS OVER THE AREA ON TUESDAY...SHOWER AND
THUNDERSTORM CHANCES WILL SHIFT NORTH CLOSER TO THE RETREATING
SURFACE BOUNDARY. OUR NEXT THREAT WILL BE ASSOCIATED WITH A LEAD
SHORTWAVE TROF THAT IS FORECAST TO EJECT NORTHEAST INTO THE SOUTHERN
AND CENTRAL PLAINS ON THURSDAY WITH THE HIGHEST POPS...AT LEAST
INITIALLY...ACROSS THE WEST AS MODELS SUGGEST MOST OF THE STRONGER
LIFT AND INSTABILITY WILL SHIFT MORE NORTH THAN EAST. HOWEVER...OUR
AREA WILL BE UNDER A SOUTHWEST FLOW ALOFT LATE IN THE WEEK AND INTO
NEXT WEEKEND WITH A DEEPER UPPER LEVEL LOW FORECAST BY MEDIUM RANGE
MODELS TO PUSH OUT OF THE PLAINS AND INTO THE MIDWEST BY LATE IN THE
WEEKEND. UNFORTUNATELY...THIS TYPE OF A PATTERN THIS TIME OF YEAR
BRINGS DAILY CHANCES FOR SHOWERS AND STORMS BUT AT LEAST THE
TEMPERATURES WILL REMAIN ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1255 PM CDT SUN MAY 3 2015
VFR CONDITIONS GENERALLY EXPECTED TO CONTINUE ACROSS THE CENTRAL
IL AIRPORTS NEXT 24 HOURS THROUGH 18Z/1 PM MONDAY DUE TO UPPER
LEVEL RIDGE INTO THE MID MS RIVER VALLEY. SCATTERED TO BROKEN
MID/HIGH CLOUDS TO OCCUR AT TIMES THROUGH MONDAY MORNING. FEW TO
SCATTERED CUMULUS CLOUDS 5-8 KFT APPEARING THIS AFTERNOON AND
COULD GO BROKEN AT TIMES TONIGHT INTO MID MONDAY MORNING. VCSH AT
PIA THIS AFTERNOON WHILE BRUNT OF SHOWERS AND ISOLATED
THUNDERSTORMS THIS AFTERNOON STAY NORTH OF I-80 AS WEAKENING SHORT
WAVE IN EASTERN IA LIFT ACROSS NORTHERN IL AND SE WI THROUGH
SUNSET. CARRIED VCSH SHOWERS AT PIA AND BMI THIS EVENING THOUGH
BEST CHANCES AGAIN TO THE NW PER HIGH RES MODELS LIKE HRRR AND RAP.
A LITTLE BETTER CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS FROM
09Z-15Z ESPECIALLY AT NORTHERN AIRPORTS OF BMI AND PIA AS ANOTHER
SHORT WAVE TRACKS EASTWARD FROM IA INTO THE IL RIVER VALLEY BY
15Z/MON. BREEZY SSW WINDS 13-18 KTS WITH GUSTS OF 20-27 KTS THIS
AFTERNOON TO DIMINISH SOUTH CLOSER TO 10 KTS AFTER SUNSET AND
BECOME SW 10-13 KTS WITH GUSTS 15-20 KTS AFTER 15Z/MONDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...SMITH
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1256 PM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 1045 AM CDT SUN MAY 3 2015
FORECAST WAS UPDATED TWICE THIS MORNING TO ADDRESS THE SMALL
CHANCES OF SHOWERS AND ISOLATED THUNDERSTORMS OVER NORTHERN
COUNTIES TODAY AND HANDLING CLOUD COVER. HAVE 20% CHANCE OF
SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON MAINLY NW OF
I-55 WITH 30% CHANCE FAR NORTHERN COUNTIES OF KNOX, STARK AND
MARSHALL COUNTIES. SCATTERED SHOWERS OVER SE IA INTO NW IL JUST NW
OF ILX CWA WAS TRACKING ENE AHEAD OF ANOTHER WEAK SHORT WAVE OVER
CENTRAL IA THAT WILL WEAKEN A LIFT INTO NE IL THIS AFTERNOON
KEEPING BETTER CHANCES OF CONVECTION NORTH OF CENTRAL IL REST OF
TODAY. IL RIVER VALLEY WILL BE ON SOUTHERN EDGE OF THIS WEATHER
SYSTEM TO HAVE SMALL CHANCES OF CONVECTION THERE. TEMPS AT 1030 AM
HAVE WARMED INTO THE UPPER 60S TO MID 70S AND WARM HIGHS IN THE
LOWER 80S EXPECTED BY 4 PM TODAY ACROSS MUCH OF THE AREA. BREEZY
SOUTHWEST WINDS OF 15 TO 25 MPH AND PARTLY TO MOSTLY SUNNY SKIES.
&&
.SHORT TERM...(TODAY)
ISSUED AT 338 AM CDT SUN MAY 3 2015
SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN WELL OFF TO THE NORTHWEST
THIS MORNING...DRAPED FROM SD NORTHEAST THROUGH MN. THIS WILL BECOME
THE FOCUS FOR CONVECTIVE ACTIVITY LATER TODAY AS IT MOVES CLOSER TO
CENTRAL IL IN THE LATE AFTERNOON. THIS MORNING A SHORTWAVE EVIDENT
ON WATER VAPOR IMAGERY OVER CENTRAL IL CONTINUES TO PRODUCE A FEW
SHOWERS...EXPECTED TO MOVE EASTWARD AND DISSIPATE LATER THIS MORNING
IN EAST CENTRAL IL ACCORDING TO LATEST HRRR RUN. ANOTHER SHORTWAVE
OVER WEST IA IS EXPECTED TO TRACK ENE AND PASS BY THE CENTRAL IL
FORECAST AREA TO THE NORTH. WITH GENERAL SUBSIDENCE INDICATED ACROSS
THE AREA...HAVE KEPT THE FORECAST DRY LATE MORNING THROUGH LATE
AFTERNOON/EARLY EVENING ONCE THE INITIAL ROUND OF MORNING SHOWERS
PASSES THROUGH. LOW LEVEL SOUTHERLY FLOW WILL KEEP THE WARMING TREND
GOING FOR TODAY WITH HIGHS REACHING AROUND 80 DEGREES. FORECAST
SOUNDINGS INDICATE BOUNDARY LAYER MOMENTUM CAPABLE OF PRODUCING
GUSTS 20-25 MPH FROM I-70 NORTHWARD...WITH SUSTAINED SOUTHERLY WINDS
12-18 MPH.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN MAY 3 2015
NOT A LOT OF CHANGES IN THE FORECAST. MAJORITY OF FORECAST REVOLVES
AROUND A SLOWING/STALLED FRONTAL BOUNDARY ACROSS THE REGION FOR
TONIGHT AND THROUGH TOMORROW BEFORE BEING EDGED TO THE NORTH BEFORE
ANOTHER SYSTEM SPINS UP OVER THE PLAINS AND MOVES INTO THE REGION.
FOR TONIGHT, THE FRONTAL BOUNDARY SETTLING IN JUST TO THE NORTHWEST
WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FOR
THE AREA...SETTLING INTO THE NORTHERN HALF OF THE STATE AND BECOMING
HUNG UP IN QUASI ZONAL FLOW ALOFT. BEST CHANCES FOR PRECIP REMAIN
IN THE NORTHERN HALF OF THE STATE PROVIDING SOME FOCUS FOR STORM
DEVELOPMENT. MODELS HAVE TRENDED A LITTLE MORE SCATTERED IN THE QPF
FIELDS, ALTHOUGH THE NORTHERN HALF OF THE STATE STILL SEEMS PRIMED
FOR THE BEST CHANCES OF PRECIP THROUGH MONDAY NIGHT, SPECIFICALLY
THE AREAS WHERE THE BOUNDARY STALLS. SPC HAS KEPT THE NORTHERN HALF
OF THE CWA IN A MARGINAL RISK FOR STORMS INVOF THE BOUNDARY ON
MONDAY. CLUSTERS OF STORMS NEAR A WEAK BOUNDARY LOOKING BORDERLINE
AT THIS POINT, BUT IN AN AREA OF CONTINUING WARM AIR ADVECTION
PROVIDING POTENTIAL INSTABILITY JUST SOUTH OF THE BOUNDARY THAT WILL
SLOWLY BE SETTLING SOUTH INTO THE WARMER AND MORE BUOYANT AIR.
A RIDGE BEGINS TO BUILD INTO THE MIDWEST FROM THE SOUTHEAST...WITH
ENOUGH SUBSIDENCE IN THE REGION OF THE RIDGE AXIS TO ERODE SHOWER
CHANCES AT LEAST TUES NIGHT THROUGH WED NIGHT. ANOTHER PATTERN SHIFT
TAKES HOLD FOR THE LATER HALF OF THE WEEK, SETTING UP MORE OF A
SOUTHWESTERLY FLOW AND AN ACTIVE WEATHER PATTERN AGAIN AS WAVES
CONTINUE TO RIPPLE AROUND THE SWRN LOW AND INTO THE MIDWEST. A
RATHER WET FORECAST OVERALL, WITH SEVERAL DIFFERENT PATTERNS
ESTABLISHING THEMSELVES...AND KEEPING SHOWERS AND THUNDERSTORMS IN
THE OUTLOOK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1255 PM CDT SUN MAY 3 2015
VFR CONDITIONS GENERALLY EXPECTED TO CONTINUE ACROSS THE CENTRAL
IL AIRPORTS NEXT 24 HOURS THROUGH 18Z/1 PM MONDAY DUE TO UPPER
LEVEL RIDGE INTO THE MID MS RIVER VALLEY. SCATTERED TO BROKEN
MID/HIGH CLOUDS TO OCCUR AT TIMES THROUGH MONDAY MORNING. FEW TO
SCATTERED CUMULUS CLOUDS 5-8 KFT APPEARING THIS AFTERNOON AND
COULD GO BROKEN AT TIMES TONIGHT INTO MID MONDAY MORNING. VCSH AT
PIA THIS AFTERNOON WHILE BRUNT OF SHOWERS AND ISOLATED
THUNDERSTORMS THIS AFTERNOON STAY NORTH OF I-80 AS WEAKENING SHORT
WAVE IN EASTERN IA LIFT ACROSS NORTHERN IL AND SE WI THROUGH
SUNSET. CARRIED VCSH SHOWERS AT PIA AND BMI THIS EVENING THOUGH
BEST CHANCES AGAIN TO THE NW PER HIGH RES MODELS LIKE HRRR AND RAP.
A LITTLE BETTER CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS FROM
09Z-15Z ESPECIALLY AT NORTHERN AIRPORTS OF BMI AND PIA AS ANOTHER
SHORT WAVE TRACKS EASTWARD FROM IA INTO THE IL RIVER VALLEY BY
15Z/MON. BREEZY SSW WINDS 13-18 KTS WITH GUSTS OF 20-27 KTS THIS
AFTERNOON TO DIMINISH SOUTH CLOSER TO 10 KTS AFTER SUNSET AND
BECOME SW 10-13 KTS WITH GUSTS 15-20 KTS AFTER 15Z/MONDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1044 AM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 1045 AM CDT SUN MAY 3 2015
FORECAST WAS UPDATED TWICE THIS MORNING TO ADDRESS THE SMALL
CHANCES OF SHOWERS AND ISOLATED THUNDERSTORMS OVER NORTHERN
COUNTIES TODAY AND HANDLING CLOUD COVER. HAVE 20% CHANCE OF
SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON MAINLY NW OF
I-55 WITH 30% CHANCE FAR NORTHERN COUNTIES OF KNOX, STARK AND
MARSHALL COUNTIES. SCATTERED SHOWERS OVER SE IA INTO NW IL JUST NW
OF ILX CWA WAS TRACKING ENE AHEAD OF ANOTHER WEAK SHORT WAVE OVER
CENTRAL IA THAT WILL WEAKEN A LIFT INTO NE IL THIS AFTERNOON
KEEPING BETTER CHANCES OF CONVECTION NORTH OF CENTRAL IL REST OF
TODAY. IL RIVER VALLEY WILL BE ON SOUTHERN EDGE OF THIS WEATHER
SYSTEM TO HAVE SMALL CHANCES OF CONVECTION THERE. TEMPS AT 1030 AM
HAVE WARMED INTO THE UPPER 60S TO MID 70S AND WARM HIGHS IN THE
LOWER 80S EXPECTED BY 4 PM TODAY ACROSS MUCH OF THE AREA. BREEZY
SOUTHWEST WINDS OF 15 TO 25 MPH AND PARTLY TO MOSTLY SUNNY SKIES.
&&
.SHORT TERM...(TODAY)
ISSUED AT 338 AM CDT SUN MAY 3 2015
SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN WELL OFF TO THE NORTHWEST
THIS MORNING...DRAPED FROM SD NORTHEAST THROUGH MN. THIS WILL BECOME
THE FOCUS FOR CONVECTIVE ACTIVITY LATER TODAY AS IT MOVES CLOSER TO
CENTRAL IL IN THE LATE AFTERNOON. THIS MORNING A SHORTWAVE EVIDENT
ON WATER VAPOR IMAGERY OVER CENTRAL IL CONTINUES TO PRODUCE A FEW
SHOWERS...EXPECTED TO MOVE EASTWARD AND DISSIPATE LATER THIS MORNING
IN EAST CENTRAL IL ACCORDING TO LATEST HRRR RUN. ANOTHER SHORTWAVE
OVER WEST IA IS EXPECTED TO TRACK ENE AND PASS BY THE CENTRAL IL
FORECAST AREA TO THE NORTH. WITH GENERAL SUBSIDENCE INDICATED ACROSS
THE AREA...HAVE KEPT THE FORECAST DRY LATE MORNING THROUGH LATE
AFTERNOON/EARLY EVENING ONCE THE INITIAL ROUND OF MORNING SHOWERS
PASSES THROUGH. LOW LEVEL SOUTHERLY FLOW WILL KEEP THE WARMING TREND
GOING FOR TODAY WITH HIGHS REACHING AROUND 80 DEGREES. FORECAST
SOUNDINGS INDICATE BOUNDARY LAYER MOMENTUM CAPABLE OF PRODUCING
GUSTS 20-25 MPH FROM I-70 NORTHWARD...WITH SUSTAINED SOUTHERLY WINDS
12-18 MPH.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN MAY 3 2015
NOT A LOT OF CHANGES IN THE FORECAST. MAJORITY OF FORECAST REVOLVES
AROUND A SLOWING/STALLED FRONTAL BOUNDARY ACROSS THE REGION FOR
TONIGHT AND THROUGH TOMORROW BEFORE BEING EDGED TO THE NORTH BEFORE
ANOTHER SYSTEM SPINS UP OVER THE PLAINS AND MOVES INTO THE REGION.
FOR TONIGHT, THE FRONTAL BOUNDARY SETTLING IN JUST TO THE NORTHWEST
WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FOR
THE AREA...SETTLING INTO THE NORTHERN HALF OF THE STATE AND BECOMING
HUNG UP IN QUASI ZONAL FLOW ALOFT. BEST CHANCES FOR PRECIP REMAIN
IN THE NORTHERN HALF OF THE STATE PROVIDING SOME FOCUS FOR STORM
DEVELOPMENT. MODELS HAVE TRENDED A LITTLE MORE SCATTERED IN THE QPF
FIELDS, ALTHOUGH THE NORTHERN HALF OF THE STATE STILL SEEMS PRIMED
FOR THE BEST CHANCES OF PRECIP THROUGH MONDAY NIGHT, SPECIFICALLY
THE AREAS WHERE THE BOUNDARY STALLS. SPC HAS KEPT THE NORTHERN HALF
OF THE CWA IN A MARGINAL RISK FOR STORMS INVOF THE BOUNDARY ON
MONDAY. CLUSTERS OF STORMS NEAR A WEAK BOUNDARY LOOKING BORDERLINE
AT THIS POINT, BUT IN AN AREA OF CONTINUING WARM AIR ADVECTION
PROVIDING POTENTIAL INSTABILITY JUST SOUTH OF THE BOUNDARY THAT WILL
SLOWLY BE SETTLING SOUTH INTO THE WARMER AND MORE BUOYANT AIR.
A RIDGE BEGINS TO BUILD INTO THE MIDWEST FROM THE SOUTHEAST...WITH
ENOUGH SUBSIDENCE IN THE REGION OF THE RIDGE AXIS TO ERODE SHOWER
CHANCES AT LEAST TUES NIGHT THROUGH WED NIGHT. ANOTHER PATTERN SHIFT
TAKES HOLD FOR THE LATER HALF OF THE WEEK, SETTING UP MORE OF A
SOUTHWESTERLY FLOW AND AN ACTIVE WEATHER PATTERN AGAIN AS WAVES
CONTINUE TO RIPPLE AROUND THE SWRN LOW AND INTO THE MIDWEST. A
RATHER WET FORECAST OVERALL, WITH SEVERAL DIFFERENT PATTERNS
ESTABLISHING THEMSELVES...AND KEEPING SHOWERS AND THUNDERSTORMS IN
THE OUTLOOK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN MAY 3 2015
VFR CONDITIONS AND LIGHT SOUTHERLY WINDS ACROSS CENTRAL IL THIS
MORNING WITH ISOLATED -SHRA THROUGH MORNING. PARTIAL CLEARING
EXPECTED LATE MORNING THROUGH AFTERNOON WITH SSW WINDS INCREASING
TO AROUND 15 KTS WITH GUSTS 20-25 KTS. A FRONTAL BOUNDARY
APPROACHING FROM THE NORTHWEST OVERNIGHT EXPECTED TO SPREAD SCT
SHRA/ISOLD TSRA INTO CENTRAL IL AFTER 00Z. INCLUDED LOWER VFR
CEILINGS AND VCSH IN TAFS FROM KSPI-KBMI NORTHWESTWARD BEFORE
12Z...HOWEVER KDEC-KCMI SOUTHEASTWARD NOT LIKELY TO BE AFFECTED
BEFORE 12Z. ISOLD MVFR CIGS/VSBYS POSSIBLE WITH STRONGER STORMS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
656 AM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY)
ISSUED AT 338 AM CDT SUN MAY 3 2015
SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN WELL OFF TO THE NORTHWEST
THIS MORNING...DRAPED FROM SD NORTHEAST THROUGH MN. THIS WILL BECOME
THE FOCUS FOR CONVECTIVE ACTIVITY LATER TODAY AS IT MOVES CLOSER TO
CENTRAL IL IN THE LATE AFTERNOON. THIS MORNING A SHORTWAVE EVIDENT
ON WATER VAPOR IMAGERY OVER CENTRAL IL CONTINUES TO PRODUCE A FEW
SHOWERS...EXPECTED TO MOVE EASTWARD AND DISSIPATE LATER THIS MORNING
IN EAST CENTRAL IL ACCORDING TO LATEST HRRR RUN. ANOTHER SHORTWAVE
OVER WEST IA IS EXPECTED TO TRACK ENE AND PASS BY THE CENTRAL IL
FORECAST AREA TO THE NORTH. WITH GENERAL SUBSIDENCE INDICATED ACROSS
THE AREA...HAVE KEPT THE FORECAST DRY LATE MORNING THROUGH LATE
AFTERNOON/EARLY EVENING ONCE THE INITIAL ROUND OF MORNING SHOWERS
PASSES THROUGH. LOW LEVEL SOUTHERLY FLOW WILL KEEP THE WARMING TREND
GOING FOR TODAY WITH HIGHS REACHING AROUND 80 DEGREES. FORECAST
SOUNDINGS INDICATE BOUNDARY LAYER MOMENTUM CAPABLE OF PRODUCING
GUSTS 20-25 MPH FROM I-70 NORTHWARD...WITH SUSTAINED SOUTHERLY WINDS
12-18 MPH.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN MAY 3 2015
NOT A LOT OF CHANGES IN THE FORECAST. MAJORITY OF FORECAST REVOLVES
AROUND A SLOWING/STALLED FRONTAL BOUNDARY ACROSS THE REGION FOR
TONIGHT AND THROUGH TOMORROW BEFORE BEING EDGED TO THE NORTH BEFORE
ANOTHER SYSTEM SPINS UP OVER THE PLAINS AND MOVES INTO THE REGION.
FOR TONIGHT, THE FRONTAL BOUNDARY SETTLING IN JUST TO THE NORTHWEST
WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FOR
THE AREA...SETTLING INTO THE NORTHERN HALF OF THE STATE AND BECOMING
HUNG UP IN QUASI ZONAL FLOW ALOFT. BEST CHANCES FOR PRECIP REMAIN
IN THE NORTHERN HALF OF THE STATE PROVIDING SOME FOCUS FOR STORM
DEVELOPMENT. MODELS HAVE TRENDED A LITTLE MORE SCATTERED IN THE QPF
FIELDS, ALTHOUGH THE NORTHERN HALF OF THE STATE STILL SEEMS PRIMED
FOR THE BEST CHANCES OF PRECIP THROUGH MONDAY NIGHT, SPECIFICALLY
THE AREAS WHERE THE BOUNDARY STALLS. SPC HAS KEPT THE NORTHERN HALF
OF THE CWA IN A MARGINAL RISK FOR STORMS INVOF THE BOUNDARY ON
MONDAY. CLUSTERS OF STORMS NEAR A WEAK BOUNDARY LOOKING BORDERLINE
AT THIS POINT, BUT IN AN AREA OF CONTINUING WARM AIR ADVECTION
PROVIDING POTENTIAL INSTABILITY JUST SOUTH OF THE BOUNDARY THAT WILL
SLOWLY BE SETTLING SOUTH INTO THE WARMER AND MORE BUOYANT AIR.
A RIDGE BEGINS TO BUILD INTO THE MIDWEST FROM THE SOUTHEAST...WITH
ENOUGH SUBSIDENCE IN THE REGION OF THE RIDGE AXIS TO ERODE SHOWER
CHANCES AT LEAST TUES NIGHT THROUGH WED NIGHT. ANOTHER PATTERN SHIFT
TAKES HOLD FOR THE LATER HALF OF THE WEEK, SETTING UP MORE OF A
SOUTHWESTERLY FLOW AND AN ACTIVE WEATHER PATTERN AGAIN AS WAVES
CONTINUE TO RIPPLE AROUND THE SWRN LOW AND INTO THE MIDWEST. A
RATHER WET FORECAST OVERALL, WITH SEVERAL DIFFERENT PATTERNS
ESTABLISHING THEMSELVES...AND KEEPING SHOWERS AND THUNDERSTORMS IN
THE OUTLOOK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM CDT SUN MAY 3 2015
VFR CONDITIONS AND LIGHT SOUTHERLY WINDS ACROSS CENTRAL IL THIS
MORNING WITH ISOLATED -SHRA THROUGH MORNING. PARTIAL CLEARING
EXPECTED LATE MORNING THROUGH AFTERNOON WITH SSW WINDS INCREASING
TO AROUND 15 KTS WITH GUSTS 20-25 KTS. A FRONTAL BOUNDARY
APPROACHING FROM THE NORTHWEST OVERNIGHT EXPECTED TO SPREAD SCT
SHRA/ISOLD TSRA INTO CENTRAL IL AFTER 00Z. INCLUDED LOWER VFR
CEILINGS AND VCSH IN TAFS FROM KSPI-KBMI NORTHWESTWARD BEFORE
12Z...HOWEVER KDEC-KCMI SOUTHEASTWARD NOT LIKELY TO BE AFFECTED
BEFORE 12Z. ISOLD MVFR CIGS/VSBYS POSSIBLE WITH STRONGER STORMS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
339 AM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY)
ISSUED AT 338 AM CDT SUN MAY 3 2015
SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN WELL OFF TO THE NORTHWEST
THIS MORNING...DRAPED FROM SD NORTHEAST THROUGH MN. THIS WILL BECOME
THE FOCUS FOR CONVECTIVE ACTIVITY LATER TODAY AS IT MOVES CLOSER TO
CENTRAL IL IN THE LATE AFTERNOON. THIS MORNING A SHORTWAVE EVIDENT
ON WATER VAPOR IMAGERY OVER CENTRAL IL CONTINUES TO PRODUCE A FEW
SHOWERS...EXPECTED TO MOVE EASTWARD AND DISSIPATE LATER THIS MORNING
IN EAST CENTRAL IL ACCORDING TO LATEST HRRR RUN. ANOTHER SHORTWAVE
OVER WEST IA IS EXPECTED TO TRACK ENE AND PASS BY THE CENTRAL IL
FORECAST AREA TO THE NORTH. WITH GENERAL SUBSIDENCE INDICATED ACROSS
THE AREA...HAVE KEPT THE FORECAST DRY LATE MORNING THROUGH LATE
AFTERNOON/EARLY EVENING ONCE THE INITIAL ROUND OF MORNING SHOWERS
PASSES THROUGH. LOW LEVEL SOUTHERLY FLOW WILL KEEP THE WARMING TREND
GOING FOR TODAY WITH HIGHS REACHING AROUND 80 DEGREES. FORECAST
SOUNDINGS INDICATE BOUNDARY LAYER MOMENTUM CAPABLE OF PRODUCING
GUSTS 20-25 MPH FROM I-70 NORTHWARD...WITH SUSTAINED SOUTHERLY WINDS
12-18 MPH.
&&
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN MAY 3 2015
NOT A LOT OF CHANGES IN THE FORECAST. MAJORITY OF FORECAST REVOLVES
AROUND A SLOWING/STALLED FRONTAL BOUNDARY ACROSS THE REGION FOR
TONIGHT AND THROUGH TOMORROW BEFORE BEING EDGED TO THE NORTH BEFORE
ANOTHER SYSTEM SPINS UP OVER THE PLAINS AND MOVES INTO THE REGION.
FOR TONIGHT, THE FRONTAL BOUNDARY SETTLING IN JUST TO THE NORTHWEST
WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FOR
THE AREA...SETTLING INTO THE NORTHERN HALF OF THE STATE AND BECOMING
HUNG UP IN QUASI ZONAL FLOW ALOFT. BEST CHANCES FOR PRECIP REMAIN
IN THE NORTHERN HALF OF THE STATE PROVIDING SOME FOCUS FOR STORM
DEVELOPMENT. MODELS HAVE TRENDED A LITTLE MORE SCATTERED IN THE QPF
FIELDS, ALTHOUGH THE NORTHERN HALF OF THE STATE STILL SEEMS PRIMED
FOR THE BEST CHANCES OF PRECIP THROUGH MONDAY NIGHT, SPECIFICALLY
THE AREAS WHERE THE BOUNDARY STALLS. SPC HAS KEPT THE NORTHERN HALF
OF THE CWA IN A MARGINAL RISK FOR STORMS INVOF THE BOUNDARY ON
MONDAY. CLUSTERS OF STORMS NEAR A WEAK BOUNDARY LOOKING BORDERLINE
AT THIS POINT, BUT IN AN AREA OF CONTINUING WARM AIR ADVECTION
PROVIDING POTENTIAL INSTABILITY JUST SOUTH OF THE BOUNDARY THAT WILL
SLOWLY BE SETTLING SOUTH INTO THE WARMER AND MORE BUOYANT AIR.
A RIDGE BEGINS TO BUILD INTO THE MIDWEST FROM THE SOUTHEAST...WITH
ENOUGH SUBSIDENCE IN THE REGION OF THE RIDGE AXIS TO ERODE SHOWER
CHANCES AT LEAST TUES NIGHT THROUGH WED NIGHT. ANOTHER PATTERN SHIFT
TAKES HOLD FOR THE LATER HALF OF THE WEEK, SETTING UP MORE OF A
SOUTHWESTERLY FLOW AND AN ACTIVE WEATHER PATTERN AGAIN AS WAVES
CONTINUE TO RIPPLE AROUND THE SWRN LOW AND INTO THE MIDWEST. A
RATHER WET FORECAST OVERALL, WITH SEVERAL DIFFERENT PATTERNS
ESTABLISHING THEMSELVES...AND KEEPING SHOWERS AND THUNDERSTORMS IN
THE OUTLOOK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1150 PM CDT SAT MAY 2 2015
ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO MOVE ACROSS THE
AREA OVERNIGHT. SO WILL BE KEEPING VCSH IN OVERNIGHT FOR ALL
SITES. OTHERWISE, VFR AND MID LEVEL CIGS WILL BE HAD AT ALL SITES
OVERNIGHT. HRRR MODEL ENDS THE PCPN TOWARD EARLY MORNING BUT MID
LEVEL CIGS CONTINUE FOR A FEW HOURS. THEN CLOUDS WILL SCATTER OUT.
WILL HAVE HIGH CIRRUS WHICH WILL BE THE BLOW OFF FROM THE STORMS
CURRENTLY WELL WEST OF THE AREA. NOT EXPECTING TO SEE ANY OF THE
PCPN ASSOCIATED WITH THESE STORMS IN THE AREA TOMORROW, BUT MODELS
ADVECT SOME REMNANTS OF THESE STORMS INTO NORTHERN IL. WINDS WILL
BE SOUTH TO SOUTHWEST THROUGH THE PERIOD WITH STILL THINKING OF
SOME GUSTS AROUND 22-25KTS TOMORROW LATE MORNING THROUGH AFTERNOON
AFTER THE CLOUDS CLEAR AND GOOD MIXING TAKES PLACE. MAY SEE SOME
LLWS TOMORROW NIGHT BUT SOME UNCERTAINTY, SO NOT GOING TO PUT IN
TAFS AT THIS POINT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1150 PM CDT SAT MAY 2 2015
.UPDATE...
ISSUED AT 857 PM CDT SAT MAY 2 2015
ISOLATED TO SCATTERED SHOWERS ARE MOVING INTO THE AREA FROM THE
WEST AND IT APPEARS THEY WILL CONTINUE TO MOVE EAST THROUGH THE
NIGHT. MODELS CONTINUE TO SHOW THIS AREA WEAKENING AS IT MOVES
EAST, AND IR SATELLITE LOOP SEEMS TO SUPPORT THIS WITH CLOUD TOPS
WARMING ACROSS THE WHOLE AREA OF WHERE THE SHOWERS ARE. ITS ALSO
MOVING AWAY INTO A DRIER AIRMASS. HAVE TRIED TO MAKE SOME
ADJUSTMENTS TO POPS FOR REMAINDER OF THE NIGHT IN THE GRIDS. OTHER
PARAMETERS SHOULD BE OK OR RELATIVELY CLOSE TO CURRENT AND
EXPECTED CONDITIONS REMAINDER OF THE NIGHT.
OTHER SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING FURTHER WEST
IN THE PLAINS. HRRR MODEL SHOWS THESE MAKING THEIR WAY INT WESTERN
AND NORTHWESTERN IL TOMORROW MORNING. WILL BE TAKING A CLOSER LOOK
AT THIS OVER THE NEXT SEVERAL HOURS. ANOTHER UPDATE MAY BE NEEDED
LATER THIS EVENING BEFORE NEW FORECAST PACKAGE COMES OUT AT 4AM.
UPDATE TO FORECAST WILL BE COMING SHORTLY.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 255 PM CDT SAT MAY 2 2015
A WEAK SHORT WAVE OVER WESTERN IA WILL TRACK EAST TO THE IL/IA
BORDER BY MIDNIGHT AND WEAKEN AS IT MOVES ACROSS CENTRAL AND
NORTHERN IL OVERNIGHT. AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS
OVER NORTHERN MO AND SOUTHERN IA WILL CONTINUE TO TRACK EASTWARD
INTO WEST CENTRAL IL EARLY THIS EVENING BETWEEN 6-8 PM AND INTO
CENTRAL IL LATER THIS EVENING AND OVERNIGHT AS SHOWERS BECOME MORE
ISOLATED. HAVE 20-30% CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS
FROM I-55 NW AFTER SUNSET TONIGHT AND LINGERING ISOLATED LIGHT
SHOWERS UNTIL MID SUNDAY MORNING NORTH OF I-72 UNTIL WEAKENING SHORT
WAVE PASSES EAST OF IL INTO WESTERN IN BY MIDDAY SUNDAY. MID AND
HIGH CLOUDS WILL CONTINUE TO INCREASE FROM THE WEST LATE THIS
AFTERNOON AND EVENING WITH SOUTHEAST IL SEEING LESS CLOUD COVER
TONIGHT SINCE CLOSER TO HIGH PRESSURE RIDGE OVER SOUTHEAST STATES.
LOWS TONIGHT IN THE LOW TO MID 50S WITH COOLEST READINGS NEAR WABASH
RIVER WHERE LIGHTER WINDS AND LESS CLOUD COVER TONIGHT. SSW WINDS
7- 14 MPH AND GUSTS 15-20 MPH THIS AFTERNOON TO DIMINISH LESS THAN
10 MPH AFTER SUNSET AND VEER SSE.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 255 PM CDT SAT MAY 2 2015
IOWA SHORTWAVE FORECAST BY MODELS TO TRACK ACROSS THE AREA OVERNIGHT
AND INTO THE MORNING HOURS OF SUNDAY BRINGING ISOLATED SHOWERS TO
PARTS OF THE FORECAST AREA. SOUNDINGS STILL SHOWING A VERY DRY
PROFILE BELOW 725 MB (~8500 FEET) INTO SUNDAY MORNING BEFORE THE
WAVE SHIFTS OFF TO OUR EAST DURING THE MORNING. WILL KEEP SLIGHTS
GOING FOR A FEW HOURS IN THE MORNING BEFORE THE WAVE MOVES OUT OF
THE AREA.
OUR ATTENTION THEN TURNS TO A NORTHERN STREAM SHORTWAVE THAT WILL
DRAG A COLD FRONT SOUTHEAST INTO THE LOWER GREAT LAKES LATE SUNDAY
AND INTO MONDAY INCREASING THE CHANCES FOR MORE WIDESPREAD SHOWERS
AND STORMS...ESPECIALLY OVER THE NORTHERN HALF OF THE FORECAST AREA
WHERE THE BOUNDARY IS FORECAST TO BECOME STATIONARY. AFTER OUR SLIGHT
CHANCES SUNDAY MORNING...THE REST OF THE DAY LOOKS QUIET AND WARM
WITH A GUSTY SOUTH TO SOUTHWEST WIND HELPING TO PUSH AFTERNOON TEMPS
INTO THE UPPER 70S TO LOWER 80S. POPS START TO RAMP UP SUNDAY NIGHT
ACROSS THE FAR NORTHWEST AS THE BOUNDARY EDGES SLOWLY SOUTHEAST WITH
MODELS TRENDING SLOWER WITH THE FRONTAL BOUNDARY AND QPF ALONG IT.
MAY HAVE TO SLOW THE ONSET OF THE SHOWERS EVEN MORE IF THESE TRENDS
CONTINUE. BETTER LOW LEVEL JET SUPPORT AND 850 MB THETA-E ADVECTION
REMAINS OUT TO OUR NORTHWEST LATE SUNDAY NIGHT WITH MOST MODELS
SUGGESTING THAT A CLUSTER OF STORMS...AT LEAST WHAT`S LEFT OF
THEM...WILL APPROACH OUR FAR NORTHWEST COUNTIES WELL AFTER
MIDNIGHT SUNDAY NIGHT.
THE SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE TO SPREAD SLOWLY
SOUTHEAST ON MONDAY AND INTO MONDAY NIGHT WITH THE HIGHER THREAT
BEING AGAIN WHERE THE BOUNDARY IS EXPECTED TO BECOME STATIONARY...
WHICH AT THIS TIME LOOKS TO BE NORTH OF I-72. FORECAST SOUNDINGS
SHOWING MIXED LAYER CAPES OF AROUND 1500 J/KG MONDAY AFTERNOON INTO
EARLY MONDAY EVENING WITH THE STRONGER 500 MB WIND FLOW TO OUR NORTH
WITH 30-35 KTS FORECAST. SPC HAS A LARGE AREA OF MARGINAL RISK FOR
SEVERE STORMS MONDAY AFTERNOON AND EVENING STRETCHING FROM THE
SOUTHERN PLAINS UP ACROSS THE NORTHERN HALF OF OUR CWA. SEVERE
PARAMETERS BORDERLINE AT THIS TIME BUT WITH THE BOUNDARY IN THE AREA
AND FORECAST CONVECTIVE TEMPS AROUND 80...MULTI-CELL STORMS SHOULD
DEVELOP DURING THE AFTERNOON AND CONTINUE INTO THE EVENING WITH THE
POSSIBILITY FOR SOME GUSTY WINDS...HAIL AND HEAVY RAINFALL WITH SOME
OF THE MORE ORGANIZED CLUSTERS OF STORMS THAT FORM ALONG THE STALLED
FRONTAL BOUNDARY.
MODELS SUGGEST THE BOUNDARY WILL SHIFT NORTH OF THE AREA STARTING ON
TUESDAY AS UPPER LEVEL HEIGHTS BUILD IN RESPONSE TO A RATHER
VIGOROUS UPPER WAVE THAT WILL BE PUSHING ACROSS THE SOUTHERN ROCKIES
AND EVENTUALLY SWING NORTHEAST INTO THE PLAINS BY MID TO LATE IN THE
UPCOMING WORK WEEK. WILL INDICATE A BIT OF A LULL IN THE SHOWER AND
STORM CHANCES UNTIL LATE THURSDAY OR FRIDAY WHEN THE WAVE WILL
APPROACH OUR AREA. TEMPERATURES LOOK TO BE ABOVE NORMAL THRU THE
WORK WEEK WITH AFTERNOON HIGHS CLIMBING INTO THE UPPER 70S TO LOWER
80S...WHILE EARLY MORNING LOWS ONLY DROP OFF INTO THE UPPER 50S TO
LOWER 60S TUESDAY MORNING...WITH MOST OF OUR AREA SEEING LOW
TEMPERATURES IN THE LOW TO MID 60S FOR THE REMAINDER OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1150 PM CDT SAT MAY 2 2015
ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO MOVE ACROSS THE
AREA OVERNIGHT. SO WILL BE KEEPING VCSH IN OVERNIGHT FOR ALL
SITES. OTHERWISE, VFR AND MID LEVEL CIGS WILL BE HAD AT ALL SITES
OVERNIGHT. HRRR MODEL ENDS THE PCPN TOWARD EARLY MORNING BUT MID
LEVEL CIGS CONTINUE FOR A FEW HOURS. THEN CLOUDS WILL SCATTER OUT.
WILL HAVE HIGH CIRRUS WHICH WILL BE THE BLOW OFF FROM THE STORMS
CURRENTLY WELL WEST OF THE AREA. NOT EXPECTING TO SEE ANY OF THE
PCPN ASSOCIATED WITH THESE STORMS IN THE AREA TOMORROW, BUT MODELS
ADVECT SOME REMNANTS OF THESE STORMS INTO NORTHERN IL. WINDS WILL
BE SOUTH TO SOUTHWEST THROUGH THE PERIOD WITH STILL THINKING OF
SOME GUSTS AROUND 22-25KTS TOMORROW LATE MORNING THROUGH AFTERNOON
AFTER THE CLOUDS CLEAR AND GOOD MIXING TAKES PLACE. MAY SEE SOME
LLWS TOMORROW NIGHT BUT SOME UNCERTAINTY, SO NOT GOING TO PUT IN
TAFS AT THIS POINT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AUTEN
SHORT TERM...07
LONG TERM...SMITH
AVIATION...AUTEN
AREA FORECAST DISCUSSION
1152 PM CDT SAT MAY 2 2015
.UPDATE...
ISSUED AT 957 PM CDT SAT MAY 2 2015
UPDATE MADE TO THE FORECAST FOR THE EVENING CONCERNS PRECIP
UNCERTAINTIES FOR THE OVERNIGHT. THE HI-RES MODELS ALL PICK UP ON
SOME ELEVATED INSTABILITY DRIBBLING ACROSS THE FORECAST AREA
TONIGHT WHILE THE OTHER MODELS KEEP US DRY. WATER VAPOR SHOWS A
VORT MAX AND A SECONDARY SHORTWAVE PUSHING EAST OUT OF OMAHA WHICH
THE HRRR BRINGS ACROSS IOWA THROUGH THE OVERNIGHT. CERTAINLY THE
STORMS OVER EASTERN NEBRASKA HAVE HELD TOGETHER AS THEY CROSSED
INTO IOWA AND ADDITIONAL SHOWERS/STORMS ARE CURRENTLY RE-
DEVELOPING ACROSS OUR WESTERN FORECAST AREA. THE UPDATE BROUGHT
PRECIP BACK INTO THE WEST THIS EVENING INTO THE OVERNIGHT BUT JUST
HOW LONG IT WILL PERSIST IS THE QUESTION. DESPITE THE HI-RES
MODELS SOLUTION...THE STORMS OUT WEST ARE DYING THE FURTHER EAST
THEY COME AND WE ARE FORECAST TO LOSE AT LEAST SOME OF OUR
INSTABILITY OVERNIGHT. ANY SHOWERS THAT WOULD HAPPEN WOULD BE VERY
HIT OR MISS IN POCKETS OF RESIDUAL INSTABILITY WHICH ARE JUST TOO
HARD TO FORECAST AND CERTAINLY NOT WORTH PAINTING SLIGHT CHANCE
POPS ACROSS OUR ENTIRE FORECAST AREA...AT LEAST AT THIS POINT. IF
WE SEE BETTER EVIDENCE OF MORE WIDESPREAD INSTABILITY TO COINCIDE
WITH THE HRRR`S WEAK SHORTWAVE AND VORT MAX DRIFTING ACROSS THE
CWA OVERNIGHT WE MAY NEED TO ADD A LITTLE MORE WIDESPREAD SLIGHT
CHANCE POPS TO THE GRIDS. CERTAINLY AN INTERESTING AND NOT CLEAR
CUT FORECAST TONIGHT.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 310 PM CDT SAT MAY 2 2015
AREA OF SHOWERS AND A FEW THUNDERSTORMS HAS SLOWLY PROGRESSED
EASTWARD ACROSS THE SOUTHERN HALF OF IOWA TODAY. THIS ACTIVITY IS
IN AN AREA OF MID LEVEL THETA-E ADVECTION AND WARM ADVECTION AHEAD
OF A WEAK SHORTWAVE THAT IS QUITE EVIDENT IN THE WATER VAPOR
IMAGERY. THIS ACTIVITY WILL CONTINUE TO PROGRESS EASTWARD THIS
EVENING WITHOUT AND EVENTUALLY EXIT THE EAST LATER THIS EVENING AS
SUBSIDENCE INCREASES FROM THE WEST BEHIND THE WAVE. OVERNIGHT WILL
BE RELATIVELY QUIET WITH MODEST SOUTHERLY SURFACE WINDS AND
GENERALLY CLEAR TO PARTLY CLOUDY SKIES. HAVE KEPT TEMPERATURES AT
OR SLIGHTLY ABOVE GUIDANCE GIVEN THE ONGOING WARM ADVECTION
OVERNIGHT AND INCREASING MOISTURE.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 310 PM CDT SAT MAY 2 2015
ACTIVE WEATHER PATTERN SETS UP ACROSS THE REGION SUNDAY NIGHT AND
LASTS THROUGHOUT MUCH OF THE WEEK. SEVERE POTENTIAL SUNDAY LATE
AFTERNOON INTO THE EVENING OVER THE NORTH BUT NO OTHER CLEAR CUT
TIME FRAME FOR SEVERE WEATHER THE REMAINDER OF THE WEEK. LEANED
TOWARD A BLEND OF THE NAM12/ECMWF FOR TEMPS AND POPS THROUGH
TUESDAY...THEN A GFS/ECMWF BLEND THROUGH THE REST OF THE WEEK.
SUNDAY INTO TUESDAY...GOOD SURGE OF WAA ACROSS THE STATE WILL PUSH
MAX TEMPS WELL INTO THE 80S ACROSS CENTRAL IOWA. BUMPED UP MAX TEMPS
UP A COUPLE DEGREES AS WELL AS WINDS DURING THE AFTERNOON WITH THE
STRONG SOUTHWEST FLOW AND MIXING TO AROUND 900MB. BOUNDARY SAGS SOUTH
INTO NORTHERN IOWA SUNDAY EVENING AND HELPS WEAKEN THE CAP OVER
NORTHERN IOWA PAST 22Z SUNDAY. MUCAPE INCREASES TO 1500-2200 J/KG
LATE IN THE AFTERNOON INTO THE EVENING WITH DEEP LAYER SHEAR STRONG
ENOUGH TO SUPPORT UPDRAFTS FOR A CONSIDERABLE TIME FRAME. LOW LEVEL
SHEAR IS WEAK...SO MAINLY LOOKING AT ELEVATED HAIL OVER THE
NORTHERN SECTIONS OF THE FORECAST AREA WITH A SECONDARY THREAT OF
DAMAGING WINDS PER LOW VALUES OF DCAPE PRESENT. TEMPERATURES MONDAY
WILL BE COOLER WITH THE BOUNDARY STALLING ACROSS CENTRAL IOWA FROM
WEST TO EAST...BASICALLY ALONG INTERSTATE 80 TO HIGHWAY 30 CORRIDOR
THROUGH MONDAY EVENING. THUNDERSTORMS CHANCES CONTINUED SOUTH OF THE
BOUNDARY DURING THE DAY MONDAY AND BY MONDAY NIGHT INTO
TUESDAY...THE WARM FRONT SURGES BACK NORTHWARD AND HAVE LIKELY POPS
GOING ACROSS THE ENTIRE FORECAST AREA THROUGH TUESDAY MORNING WITH
FORCING AND MOISTURE TRANSPORT INTO THE STATE DURING THIS TIME.
SEVERE THREAT LOOKS MINIMAL ATTM WITH THE LACK OF SIGNIFICANT
INSTABILITY AND SHEAR PRESENT.
THE WARM FRONT CONTINUES TO SURGE NORTH INTO SOUTHERN MINNESOTA ON
TUESDAY AND PLACES THE FORECAST AREA WELL INTO THE WARM SECTOR. THE
850MB TEMPS WARM TO +12C TO +14C AND BUMPED UP MAX TEMPS
CONSIDERABLY...ESPECIALLY OVER NORTHERN IOWA FOR TUESDAY. THE
ATMOSPHERE BECOMES STABILIZED BY TUESDAY NIGHT INTO WEDNESDAY...AND
WENT COMPLETELY DRY ACROSS MUCH OF THE FORECAST AREA DURING THIS
TIME. MODELS ARE IN GOOD AGREEMENT WITH THIS DRY PERIOD.
WEDNESDAY THROUGH SATURDAY...MORE PERIODIC RAIN CHANCES DURING THIS
TIME FRAME WITH THE BEST POTENTIAL LOOK TO BE LATE WEDNESDAY INTO
THURSDAY AS A DECENT SHORTWAVE EJECTS OUT OF THE CENTRAL ROCKIES
INTO WESTERN IOWA. AFTER THURSDAY...DEPENDING ON WHICH MODEL...THERE
IS THUNDERSTORM CHANCES EACH PERIOD THROUGH NEXT WEEKEND.
&&
.AVIATION...03/06Z
ISSUED AT 1152 PM CDT SAT MAY 2 2015
INTERESTING FORECAST TONIGHT AS HI-RES MODELS HAVE PICKED UP ON MID
LEVEL INSTABILITY IN RESPONSE TO A WEAK WAVE PUSHING OUT OF NEBRASKA
AND ACROSS IOWA TONIGHT. THUNDERSTORMS HAVE DEVELOPED IN THIS AREA
AND WILL CONTINUE TO TREK EAST IN A NARROW CORRIDOR OVERNIGHT...
MAINLY AFFECTING KFOD AND KALO. AFT 21Z A FRONT WILL SLOWLY SAG
SOUTH ACROSS TAF LOCATIONS BRINGING THUNDERSTORMS CHANCES INCREASING
ACROSS NORTHERN TAFS BY EARLY TO MID EVENING AND APPROACHING KDSM BY
06Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...FAB
SHORT TERM...COGIL
LONG TERM...PODRAZIK
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
731 PM MDT MON MAY 4 2015
.UPDATE...
ISSUED AT 720 PM MDT MON MAY 4 2015
LATEST RADAR SHOWS THE TWO SEPARATE WAVES HAVE MERGED INTO ONE
OVER THE STATIONARY FRONT. MODELS INDICATE THE FRONT WILL MOVE
NORTHWARD THROUGH THE NIGHT. A CONSISTENT PLUME OF LIFT WILL
REMAIN OVER THE FRONT AS IT PROGRESSES NORTHWARD. AS IT MOVES
NORTHWARD LIFT DECLINES OVER THE NORTHEAST QUADRANT OF THE AREA.
HAVE RAINFALL CHANCES DECLINING SOME AS A RESULT.
MEANWHILE TO THE SOUTH ANOTHER WAVE WILL MOVE INTO THE AREA.
MODELS DISAGREE WITH WHETHER THIS WAVE WILL REMAIN OVER THE
SOUTHERN PART OF THE AREA OR MOVE NORTHWARD. AM MORE INCLINED TO
BELIEVE THE WAVE WILL MOVE NORTHWARD SINCE EACH OF THESE WAVES ARE
ROTATING TO THE NORTH AROUND THE UPPER LEVEL LOW TO THE WEST.
DUE TO THE SLOW MOVEMENT AND EFFICIENT RAIN PROCESSES...AM
EXPECTING MODERATE TO HEAVY RAINFALL...PRIMARILY WITH THE FIRST
WAVE TONIGHT.
UPDATE ISSUED AT 555 PM MDT MON MAY 4 2015
CURRENT RADAR SHOWS THE TWO SEPARATE WAVES OF RAINFALL MERGING
INTO ONE AS OUTFLOW BOUNDARIES FROM THE SOUTHERN WAVE OVER
SOUTHWEST KANSAS MERGE WITH THE NEARLY STATIONARY STORMS OVER THE
FRONT. CURRENT FORECAST SEEMS TO HAVE THE GENERAL TREND OF STORM
DEVELOPMENT TONIGHT HANDLED FAIRLY WELL. GENERALLY LOOKS LIKE
LOCATIONS WEST OF HIGHWAY 25 WILL HAVE THE BEST SHOT AT PROLONGED
RAINFALL TONIGHT AS TWO DIFFERENT WAVES MOVE OVER THAT PART OF THE
AREA. DUE TO THE SLOW MOVEMENT OF THE STORMS...LESS THAN 20
MPH...FLASH FLOODING WILL BE A CONCERN THROUGH THE NIGHT.
REGARDING SEVERE WEATHER...INSTABILITY DECLINES DURING THE
EARLY EVENING BUT THEN RETURNS OVERNIGHT EAST OF HIGHWAY 83. THERE
STRONG TO POSSIBLY SEVERE STORMS ARE POSSIBLE...ALTHOUGH DEEP
LAYER SHEAR IS ONLY 25KTS WHICH IS BARELY ENOUGH TO SUPPORT
SUPERCELLS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 220 PM MDT MON MAY 4 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
DEEPENING TROUGH OVER SOUTHERN CALIFORNIA WITH SW FLOW FROM THE GULF
OF ALASKA AND ACROSS THE CENTRAL/HIGH PLAINS. MOIST PLUME EXTENDS
FROM THE GREAT BASIN ACROSS THE OHIO RIVER VALLEY WITH ADDITIONAL
MOISTURE FEEDING IN THE PLAINS FROM THE GULF OF MEXICO. AT THE
SURFACE A STATIONARY FRONT EXTENDS FROM NORTHEAST KANSAS TO
SOUTHEAST COLORADO AND LIES JUST SOUTHEAST OF OUR CWA...WITH
BAROCLINIC ZONE EXTENDING NORTH INTO THE SE PART OF OUR CWA.
THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THIS FRONTAL ZONE
TOWARDS THE SOUTHEAST PART OF OUR CWA.
THIS AFTERNOON-EVENING...ALONG THIS FRONTAL ZONE ANALYSIS INDICATES
ML CAPE VALUES RANGING FROM 1500 J/KG IN THE WARM SECTOR TO 500
J/KG IN OUR SE CWA. BULK SHEER IS APPROXIMATELY 30-35KT...SO
DEPENDING ON POSITION OF FRONT (CURRENTLY ADVERTISED TO SLIDE NORTH
INTO OUR SOUTHEAST)...THERE IS THE POTENTIAL FOR A FEW STRONGER
THUNDERSTORMS...POSSIBLY SEVERE WITH LARGE HAIL/DAMAGING WINDS MAIN
THREAT. IF FRONT WERE TO LIFT NORTH AS WARM FRONT WE COULD SEE
BETTER SB/ML CAPE AND THE POSSIBILITY FOR A FEW MORE ORGANIZED CELLS
IN THE SOUTHEAST. ANALYSIS ALSO INDICATES PWAT VALUES ALREADY IN
EXCESS OF 1" OVER OUR EAST. STORM MOTIONS WILL BE ROUGHLY
TANGENTIAL/PARALLEL THIS AFTERNOON BECOMING PERPENDICULAR TO FRONTAL
ZONE THIS EVENING. AS THIS TRANSITION OCCURS THERE IS THE
FOR BACKBUILDING OR TRAINING AS VERY MOIST/UNSTABLE AIR IN THE WARM
SECTOR FEEDS NORTH. THERE COULD BE A THREAT FOR FLASH FLOODING IF
THIS SCENARIO PLAYS OUT. EITHER WAY WITH VERY MOIST AIR MASS AND
INCREASING ELEVATED INSTABILITY...THUNDERSTORMS COULD BE VERY
EFFICIENT RAINFALL PRODUCERS.
TONIGHT-TUESDAY...UPSTREAM AREAS OF MID LEVEL VORTICITY WILL ROTATE
INTO THE CWA WITH INCREASING LIFT LATE THIS EVENING INTO THE
OVERNIGHT. AS TROUGH CONTINUES TO DEEPEN OVER THE SW US AND MOVE
EAST WE WILL CONTINUE TO SEE VERY GOOD FORCING/MOISTURE ROTATES
THROUGH THE REGION. LARGE SCALE Q VECTOR FIELDS INDICATED FORCING
INCREASING THROUGH THE NIGHT AND OMEGA/MOISTURE
CONVERGENCE FIELDS SHOW SUPPORT FOR INCREASING COVERAGE/COMPLEX OF
SHOWERS THUNDERSTORMS. ELEVATED INSTABILITY TRANSITIONS NORTHWARD
AND WEAKENS...HOWEVER THERE IS ENOUGH TO KEEP THUNDER MENTION IN
PLACE THROUGH TUESDAY AFTERNOON. WHILE GUIDANCE IS IN AGREEMENT ON
GENERAL LARGE SCALE PATTERN THE MAIN DIFFERENCES ARE ON TIMING OF
POTENTIAL PERIODS OF HEAVIER PRECIP...WITH BEST PRECIP SIGNAL AND
MOISTURE PROFILES OVERLAPPING TUESDAY MORNING THROUGH TUESDAY
AFTERNOON ACROSS THE WESTERN 2/3 OF THE CWA (THOUGH ECMWF MIGHT BE A
LITTLE EAST). THERE WILL BE MODERATE/ELEVATED INSTABILITY IN PLACE
THROUGH THE DAY TUESDAY...SO STRONG TO SEVERE THUNDERSTORMS WILL
STILL BE POSSIBLE AGAIN...THOUGH SEVERE POTENTIAL MIGHT NOT BE AS
GOOD AS TODAY WITH WIDESPREAD SHOWERS AND STRATUS LIMITING SURFACE
BASED PARCELS AND ANY ACTIVITY LIKELY EMBEDDED WITH OTHER SHOWER
CLUSTERS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 124 PM MDT MON MAY 4 2015
MAIN TROUGH AXIS WILL LIFT NORTHEAST ACROSS THE AREA TUESDAY NIGHT
WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUING. AFTER
MIDNIGHT...GENERAL TREND WILL BE FOR A WEST TO EAST END OF THE
PRECIPITATION AS DRY SLOT WORKS IN BEHIND THE TROUGH. AFTER A LULL
WEDNESDAY MORNING...WRAPAROUND PRECIPITATION WILL MOVE IN FROM
COLORADO WEDNESDAY AFTERNOON AND BECOME WIDESPREAD WEDNESDAY
NIGHT. A COLD FRONT WILL ALSO MOVE THROUGH WEDNESDAY NIGHT WHICH
WILL PROVIDE A FOCUS FOR THUNDERSTORMS IN THE EVENING...BUT THE
POST FRONTAL ENVIRONMENT HAS ONLY LIMITED ELEVATED INSTABILITY AND
EXPECT ONLY ISOLATED THUNDERSTORMS THROUGH THURSDAY MORNING.
HOWEVER BY THURSDAY AFTERNOON SBCAPE INCREASES ONCE AGAIN AND A
COMBINATION OF MOIST LOW LEVEL UPSLOPE AND ANOTHER SHORTWAVE
TROUGH IN THE SOUTHWESTERLY FLOW ALOFT WILL RESULT IN THUNDERSTORM
DEVELOPMENT IN EASTERN COLORADO WHICH WILL MOVE INTO NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA THURSDAY EVENING. SEVERE THREAT WILL
DEPEND ON HOW MUCH INSTABILITY CAN DEVELOP AFTER A CLOUDY
MORNING...BUT DEEP LAYER SHEAR WOULD BE SUPPORTIVE OF ORGANIZED
UPDRAFTS THROUGH EARLY EVENING BEFORE BOUNDARY LAYER DECOUPLES
WITH NOCTURNAL COOLING.
OVERALL PATTERN CHANGES LITTLE ON FRIDAY ALTHOUGH MODELS SHOWING
ONLY MINIMAL SBCAPE AVAILABLE SO SEVERE THREAT MAY NOT BE AS
GREAT. ANOTHER STRONG UPPER LOW WILL KICK OUT OF THE DESERT
SOUTHWEST ON SATURDAY WITH A NEGATIVE TILT AND PROVIDE THE
SYNOPTIC SCALE FORCING FOR THUNDERSTORMS. THE PATTERN SUGGESTS A
SEVERE THREAT WITH MODELS SHOWING DEEP LAYER SHEAR OF OVER 50KTS
AND SUFFICIENT INSTABILITY FOR SUPERCELLS. IF CURRENT TIMING
TRENDS CONTINUE WOULD EXPECT TO SEE A DRY SLOT SATURDAY NIGHT
FOLLOWED BY WRAPAROUND PRECIPITATION CHANCES ON SUNDAY.
THE PATTERN FINALLY CHANGES BY EARLY NEXT WEEK WITH SUBTLE
SHORTWAVE RIDGING IN A ZONAL FLOW WHICH WOULD TRANSLATE TO DRY
CONDITIONS AND SEASONABLE TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 555 PM MDT MON MAY 4 2015
VFR TO LIFR CONDITIONS FOR THE TAFS. CHALLENGING SET OF TAFS DUE
TO TIMING OF THE DIFFERENT WAVES OF RAINFALL...THE CEILING
HEIGHTS AND VISIBILITY. IN GENERAL LOOKS LIKE KGLD WILL HAVE A
BETTER CHANCE FOR RECEIVING RAINFALL THAN KMCK...ESPECIALLY
PROLONGED RAINFALL. BASED TIMING OF THE STORMS FOR BOTH SITES BY
TRACKING THE SPEED OF THE CURRENT STORMS. IF STORM MOVEMENT
CHANGES THAT WILL AFFECT THE TIMING IN THE TAFS. BASED ON
OBSERVATIONS AND MODEL SOUNDINGS...LOOKS LIKE THE SECOND WAVE OF
STORMS WILL CAUSE CEILINGS TO FALL. OVERNIGHT VISIBILITIES WILL
DECLINE SOME BUT THEN IMPROVE BY MID MORNING. HAVE VC FOR KMCK DUE
TO UNCERTAINTY THERE WILL STILL BE RAINFALL AT THE SITE DURING THE
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
609 PM MDT MON MAY 4 2015
.UPDATE...
ISSUED AT 555 PM MDT MON MAY 4 2015
CURRENT RADAR SHOWS THE TWO SEPERATE WAVES OF RAINFALL MERGING
INTO ONE AS OUTFLOW BOUNDARIES FROM THE SOUTHERN WAVE OVER
SOUTHWEST KANSAS MERGE WITH THE NEARLY STATIONARY STORMS OVER THE
FRONT. CURRENT FORECAST SEEMS TO HAVE THE GENERAL TREND OF STORM
DEVELOPMENT TONIGHT HANDLED FAIRLY WELL. GENERALLY LOOKS LIKE
LOCATIONS WEST OF HIGHWAY 25 WILL HAVE THE BEST SHOT AT PROLONGED
RAINFALL TONIGHT AS TWO DIFFERENT WAVES MOVE OVER THAT PART OF THE
AREA. DUE TO THE SLOW MOVEMENT OF THE STORMS...LESS THAN 20
MPH...FLASH FLOODING WILL BE A CONCERN THROUGH THE NIGHT.
REGARDING SEVERE WEATHER...INSTABILITY DECLINES DURING THE
EARLY EVENING BUT THEN RETURNS OVERNIGHT EAST OF HIGHWAY 83. THERE
STRONG TO POSSIBLY SEVERE STORMS ARE POSSIBLE...ALTHOUGH DEEP
LAYER SHEAR IS ONLY 25KTS WHICH IS BARELY ENOUGH TO SUPPORT
SUPERCELLS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 220 PM MDT MON MAY 4 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
DEEPENING TROUGH OVER SOUTHERN CALIFORNIA WITH SW FLOW FROM THE GULF
OF ALASKA AND ACROSS THE CENTRAL/HIGH PLAINS. MOIST PLUME EXTENDS
FROM THE GREAT BASIN ACROSS THE OHIO RIVER VALLEY WITH ADDITIONAL
MOISTURE FEEDING IN THE PLAINS FROM THE GULF OF MEXICO. AT THE
SURFACE A STATIONARY FRONT EXTENDS FROM NORTHEAST KANSAS TO
SOUTHEAST COLORADO AND LIES JUST SOUTHEAST OF OUR CWA...WITH
BAROCLINIC ZONE EXTENDING NORTH INTO THE SE PART OF OUR CWA.
THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THIS FRONTAL ZONE
TOWARDS THE SOUTHEAST PART OF OUR CWA.
THIS AFTERNOON-EVENING...ALONG THIS FRONTAL ZONE ANALYSIS INDICATES
ML CAPE VALUES RANGING FROM 1500 J/KG IN THE WARM SECTOR TO 500
J/KG IN OUR SE CWA. BULK SHEER IS APPROXIMATELY 30-35KT...SO
DEPENDING ON POSITION OF FRONT (CURRENTLY ADVERTISED TO SLIDE NORTH
INTO OUR SOUTHEAST)...THERE IS THE POTENTIAL FOR A FEW STRONGER
THUNDERSTORMS...POSSIBLY SEVERE WITH LARGE HAIL/DAMAGING WINDS MAIN
THREAT. IF FRONT WERE TO LIFT NORTH AS WARM FRONT WE COULD SEE
BETTER SB/ML CAPE AND THE POSSIBILITY FOR A FEW MORE ORGANIZED CELLS
IN THE SOUTHEAST. ANALYSIS ALSO INDICATES PWAT VALUES ALREADY IN
EXCESS OF 1" OVER OUR EAST. STORM MOTIONS WILL BE ROUGHLY
TANGENTIAL/PARALLEL THIS AFTERNOON BECOMING PERPENDICULAR TO FRONTAL
ZONE THIS EVENING. AS THIS TRANSITION OCCURS THERE IS THE
FOR BACKBUILDING OR TRAINING AS VERY MOIST/UNSTABLE AIR IN THE WARM
SECTOR FEEDS NORTH. THERE COULD BE A THREAT FOR FLASH FLOODING IF
THIS SCENARIO PLAYS OUT. EITHER WAY WITH VERY MOIST AIR MASS AND
INCREASING ELEVATED INSTABILITY...THUNDERSTORMS COULD BE VERY
EFFICIENT RAINFALL PRODUCERS.
TONIGHT-TUESDAY...UPSTREAM AREAS OF MID LEVEL VORTICITY WILL ROTATE
INTO THE CWA WITH INCREASING LIFT LATE THIS EVENING INTO THE
OVERNIGHT. AS TROUGH CONTINUES TO DEEPEN OVER THE SW US AND MOVE
EAST WE WILL CONTINUE TO SEE VERY GOOD FORCING/MOISTURE ROTATES
THROUGH THE REGION. LARGE SCALE Q VECTOR FIELDS INDICATED FORCING
INCREASING THROUGH THE NIGHT AND OMEGA/MOISTURE
CONVERGENCE FIELDS SHOW SUPPORT FOR INCREASING COVERAGE/COMPLEX OF
SHOWERS THUNDERSTORMS. ELEVATED INSTABILITY TRANSITIONS NORTHWARD
AND WEAKENS...HOWEVER THERE IS ENOUGH TO KEEP THUNDER MENTION IN
PLACE THROUGH TUESDAY AFTERNOON. WHILE GUIDANCE IS IN AGREEMENT ON
GENERAL LARGE SCALE PATTERN THE MAIN DIFFERENCES ARE ON TIMING OF
POTENTIAL PERIODS OF HEAVIER PRECIP...WITH BEST PRECIP SIGNAL AND
MOISTURE PROFILES OVERLAPPING TUESDAY MORNING THROUGH TUESDAY
AFTERNOON ACROSS THE WESTERN 2/3 OF THE CWA (THOUGH ECMWF MIGHT BE A
LITTLE EAST). THERE WILL BE MODERATE/ELEVATED INSTABILITY IN PLACE
THROUGH THE DAY TUESDAY...SO STRONG TO SEVERE THUNDERSTORMS WILL
STILL BE POSSIBLE AGAIN...THOUGH SEVERE POTENTIAL MIGHT NOT BE AS
GOOD AS TODAY WITH WIDESPREAD SHOWERS AND STRATUS LIMITING SURFACE
BASED PARCELS AND ANY ACTIVITY LIKELY EMBEDDED WITH OTHER SHOWER
CLUSTERS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 124 PM MDT MON MAY 4 2015
MAIN TROUGH AXIS WILL LIFT NORTHEAST ACROSS THE AREA TUESDAY NIGHT
WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUING. AFTER
MIDNIGHT...GENERAL TREND WILL BE FOR A WEST TO EAST END OF THE
PRECIPITATION AS DRY SLOT WORKS IN BEHIND THE TROUGH. AFTER A LULL
WEDNESDAY MORNING...WRAPAROUND PRECIPITATION WILL MOVE IN FROM
COLORADO WEDNESDAY AFTERNOON AND BECOME WIDESPREAD WEDNESDAY
NIGHT. A COLD FRONT WILL ALSO MOVE THROUGH WEDNESDAY NIGHT WHICH
WILL PROVIDE A FOCUS FOR THUNDERSTORMS IN THE EVENING...BUT THE
POST FRONTAL ENVIRONMENT HAS ONLY LIMITED ELEVATED INSTABILITY AND
EXPECT ONLY ISOLATED THUNDERSTORMS THROUGH THURSDAY MORNING.
HOWEVER BY THURSDAY AFTERNOON SBCAPE INCREASES ONCE AGAIN AND A
COMBINATION OF MOIST LOW LEVEL UPSLOPE AND ANOTHER SHORTWAVE
TROUGH IN THE SOUTHWESTERLY FLOW ALOFT WILL RESULT IN THUNDERSTORM
DEVELOPMENT IN EASTERN COLORADO WHICH WILL MOVE INTO NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA THURSDAY EVENING. SEVERE THREAT WILL
DEPEND ON HOW MUCH INSTABILITY CAN DEVELOP AFTER A CLOUDY
MORNING...BUT DEEP LAYER SHEAR WOULD BE SUPPORTIVE OF ORGANIZED
UPDRAFTS THROUGH EARLY EVENING BEFORE BOUNDARY LAYER DECOUPLES
WITH NOCTURNAL COOLING.
OVERALL PATTERN CHANGES LITTLE ON FRIDAY ALTHOUGH MODELS SHOWING
ONLY MINIMAL SBCAPE AVAILABLE SO SEVERE THREAT MAY NOT BE AS
GREAT. ANOTHER STRONG UPPER LOW WILL KICK OUT OF THE DESERT
SOUTHWEST ON SATURDAY WITH A NEGATIVE TILT AND PROVIDE THE
SYNOPTIC SCALE FORCING FOR THUNDERSTORMS. THE PATTERN SUGGESTS A
SEVERE THREAT WITH MODELS SHOWING DEEP LAYER SHEAR OF OVER 50KTS
AND SUFFICIENT INSTABILITY FOR SUPERCELLS. IF CURRENT TIMING
TRENDS CONTINUE WOULD EXPECT TO SEE A DRY SLOT SATURDAY NIGHT
FOLLOWED BY WRAPAROUND PRECIPITATION CHANCES ON SUNDAY.
THE PATTERN FINALLY CHANGES BY EARLY NEXT WEEK WITH SUBTLE
SHORTWAVE RIDGING IN A ZONAL FLOW WHICH WOULD TRANSLATE TO DRY
CONDITIONS AND SEASONABLE TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 555 PM MDT MON MAY 4 2015
VFR TO LIFR CONDITIONS FOR THE TAFS. CHALLENGING SET OF TAFS DUE
TO TIMING OF THE DIFFERENT WAVES OF RAINFALL...THE CEILING
HEIGHTS AND VISIBILITY. IN GENERAL LOOKS LIKE KGLD WILL HAVE A
BETTER CHANCE FOR RECEIVING RAINFALL THAN KMCK...ESPECIALLY
PROLONGED RAINFALL. BASED TIMING OF THE STORMS FOR BOTH SITES BY
TRACKING THE SPEED OF THE CURRENT STORMS. IF STORM MOVEMENT
CHANGES THAT WILL AFFECT THE TIMING IN THE TAFS. BASED ON
OBSERVATIONS AND MODEL SOUNDINGS...LOOKS LIKE THE SECOND WAVE OF
STORMS WILL CAUSE CIELINGS TO FALL. OVERNIGHT VISIBILITIES WILL
DECLINE SOME BUT THEN IMPROVE BY MID MORNING. HAVE VC FOR KMCK DUE
TO UNCERTAINTY THERE WILL STILL BE RAINFALL AT THE SITE DURING THE
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
234 PM MDT SUN MAY 3 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 224 PM MDT SUN MAY 3 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
WESTERLY FLOW IN PLACE ACROSS THE PLAINS WITH A SHORTWAVE TROUGH
UPSTREAM OVER THE CENTRAL ROCKIES. AT THE SURFACE A TROUGH IS
CURRENTLY IN PLACE OVER THE CWA...WITH A COLD FRONT NEAR IMPERIAL
NEBRASKA EXTENDING INTO NORTHEAST COLORADO. REGIONAL RADAR SHOWS
SCATTERED THUNDERSTORM ACTIVITY ALREADY MOVING OFF THE HIGHER
TERRAIN IN COLORADO AND MOVING OFF THE PALMER DIVIDE TOWARDS THE
WESTERN PART OF OUR CWA.
THIS AFTERNOON-TONIGHT...WINDOW FOR SEVERE WEATHER APPEARS TO BE
MAINLY AHEAD OF COLD FRONT WHERE MODELS HAD BEEN ADVERTISING
MODERATE INSTABILITY DEVELOPING BY 00Z (MAINLY EAST OF SURFACE
TROUGH). SO FAR RAP ANALYSIS SHOWS ML CAPE GENERALLY AROUND 500 J/KG
LIKELY DUE TO MUCH LOWER TD VALUES AHEAD OF COLD FRONT THAN
PREVIOUSLY ANTICIPATED. HRRR/RAP HAVE BEEN SHOWING ISOLATED
DEVELOPMENT ALONG SURFACE TROUGH AXIS WHERE CAP HAS BEEN WEAKENED.
THERE IS A WINDOW FOR INCREASING SHEER AS COLD FRONT MOVES SOUTH AND
DEPENDING ON STRENGTH OF UPDRAFTS WE COULD SEE SOME ORGANIZED
CELLS...OTHERWISE IT APPEARS TO BE AN ENVIRONMENT FAVORING PULSE
TYPE THUNDERSTORMS THROUGH MOST OF THE NIGHT. DCAPE VALUES IN EXCESS
OF 1000 J/KG DO RAISE CONCERNS FOR MICROBURST POTENTIAL AHEAD OF
COLD FRONT SO EVEN WEAKER UPDRAFTS COULD PRODUCE NEAR SEVERE OR
SEVERE WINDS AS THEY COLLAPSE.
SHOWER AND THUNDERSTORM COVERAGE WILL INCREASE LATE THIS EVENING
ALONG/NORTH OF COLD FRONT WITH INCREASING MOISTURE RETURN AND
ELEVATED CAPE IN PLACE. BY LATE TONIGHT INSTABILITY BEGINS TO
WANE...WHILE LARGE SCALE FORCING STARTS TO SHIFT NORTH AND EAST OF
THE REGION. THIS IS WHERE MODELS DIVERGE WITH NAM CONTINUING TO
INDICATE AND LULL OR DRY PERIOD WHILE ECMWF/GFS INDICATE POSSIBLE
OVERRUNNING OR STRATUS/FOG/DRIZZLE DEVELOPMENT ALONG/NORTH OF THE
FRONT. TOUGH CALL AND WHILE I HEDGED TOWARD THE DRY NAM AT 12Z...I
COULD SEE IN THIS TYPE OF PATTERN A LIGHT PRECIP/DRIZZLE EVEN
EVOLVING BY MONDAY MORNING.
MONDAY...UPPER LOW OVER THE SOUTHWEST US BEGINS TO DEEPEN AND
MOVE EAST WITH BETTER LARGE SCALE FORCING SPREADING OVER THE CWA
BY LATE AFTERNOON. DEPENDING ON WHAT HAPPENS TO POSSIBLE STRATUS
DURING THE DAY WE MAY OR MAY NOT HAVE A WINDOW FOR SEVERE
THUNDERSTORMS IN THE EASTERN PART OF OUR CWA WHERE MODELS SHOW WAA
AND INCREASING TDS/INSTABILITY. FURTHER NORTH AND WEST STRATUS IS
MORE LIKELY TO LINGER...HOLDING TEMPS DOWN IN AND ANY INSTABILITY
WOULD BE ELEVATED AND WEAKER. DEPENDING ON CHOICE IN MODEL
SHOWERS/THUNDERSTORMS COULD BE POSSIBLE THROUGH THE DAY...HOWEVER
BETTER CHANCES SHOULD BE TIED TO STRONGER LARGE SCALE FORCING
LATER DURING THE DAY MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 224 PM MDT SUN MAY 3 2015
SOUTHWEST FLOW WILL PRECEDE AN UPPER TROUGH THAT WILL AFFECT THE
CENTRAL PLAINS TUESDAY THROUGH WEDNESDAY. SURFACE HIGH PRESSURE
WILL SHIFT EAST ACROSS THE CENTRAL PLAINS MONDAY NIGHT AS LOW
PRESSURE MOVES INTO COLORADO TUESDAY. LOW PRESSURE WILL REMAIN OVER
COLORADO AND WESTERN KANSAS THROUGH WEDNESDAY.
POPS WILL INCREASE FROM MONDAY EVENING TO OVERNIGHT AS BETTER
DYNAMICS AND MOISTURE MOVE NORTH INTO THE FA. PLAN TO GO WITH
CHANCE POPS ACROSS THE WESTERN PORTION OF THE FA DURING THE EVENING
WITH LIKELY POPS OVER THE SOUTHEAST ZONES CLOSER TO THE SURFACE
BOUNDARY. LIKELY POPS WILL SPREAD NORTH ACROSS THE FA OVERNIGHT AS
VERY FAVORABLE MOISTURE AND LIFT MOVE INTO THE FA. LIKELY AND
DEFINITE POPS WILL BE USED ACROSS THE ENTIRE FA TUESDAY AND TUESDAY
EVENING AS GOOD DYNAMICS AND MOISTURE CONTINUE TO STREAM NORTHWARD
ACROSS THE FA. PRECIPITABLE WATER VALUES ARE AROUND AN INCH SO WILL
INCLUDE MODERATE RAIN IN THE GRIDS TUESDAY. POPS WILL START
DECREASING TO CHANCE POPS AFTER 06Z WEDNESDAY AS THE UPPER TROUGH
STARTS TO LIFT OUT OF THE AREA. SOME LIKELY POPS WILL STILL EXIST
ACROSS THE NORTHERN FA WEDNESDAY AFTERNOON AS INSTABILITY INCREASES.
MIN TEMPERATURES MONDAY NIGHT SHOULD COOL TO THE MID 40S IN EASTERN
COLORADO AND THE MID 50S IN THE EASTERN FA. MIN TEMPERATURES TUESDAY
NIGHT WILL RANGE FROM THE LOWER TO MID 50S. MAX TEMPERATURES TUESDAY
SHOULD RANGE FROM 65 TO 70 AND 70 TO 75 WEDNESDAY.
IN THE EXTENDED...(WEDNESDAY NIGHT THROUGH SUNDAY)...THE UPPER
TROUGH LIFTS NORTHEAST WEDNESDAY NIGHT WITH SOUTHWEST FLOW FOLLOWING
THROUGH SATURDAY. THE NEXT UPPER TROUGH MOVES INTO THE PLAINS
SATURDAY NIGHT AND SUNDAY. SHORTWAVES MOVING THROUGH THE FLOW AND
INCREASING DYNAMICS WITH THE NEXT TROUGH SATURDAY NIGHT AND SUNDAY
WILL KEEP AT LEAST A CHANCE OF THUNDERSTORMS ACROSS THE FA EACH DAY.
MIN TEMPERATURES THROUGH SATURDAY NIGHT SHOULD RANGE FROM 45 TO 55.
MAX TEMPERATURES WILL GENERALLY RANGE FROM THE MID 60S TO THE MID
70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1132 AM MDT SUN MAY 3 2015
SCATTERED THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON ALONG
SURFACE TROUGH WITHIN VICINITY OF BOTH KGLD AND KMCK...WITH
BETTER COVERAGE LATE AFTERNOON AND EVENING. A COLD FRONT WILL DROP
SOUTH OVERNIGHT WITH INSTABILITY DECREASING LEADING TO TRANSITION
TO MAINLY LIGHT SHOWERS LATE...WITH A LULL IN ACTIVITY BY MONDAY
MORNING POSSIBLE. SOME GUIDANCE SHOWS LIGHT PRECIP AND LOW STRATUS
DEVELOPING NORTH OF THIS FRONT AND CONTINUING TO IMPACT BOTH KGLD
AND KMCK AFTER 11-13Z PERIOD THROUGH MIDDAY MONDAY. THERE IS QUITE
A BIT OF SPREAD IN GUIDANCE AFTER 09Z...SO CONFIDENCE IS LOW.
CONDITIONAL CLIMATOLOGY FAVORS AT LEAST IFR CIGS WITH EASTERLY
FLOW/LOW LEVEL MOISTURE INCREASING NORTH OF THE FRONT. I
INTRODUCED 2000-2500 CIG GROUPS FOR MONDAY MORNING AS A START AS I
WOULD RATHER NOT GO AS LOW AS IFR AT THIS TIME CONSIDERING LEVEL
OF CONFIDENCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
329 PM CDT Sun May 3 2015
.SHORT TERM...(This Evening through Monday)
Issued at 328 PM CDT SUN MAY 3 2015
Zonal but weak flow aloft continues over the Central Plains
between northern and southern branches with a few weak waves
moving through. Appears moderate mid-level isentropic lift
combined with one of these waves to spark overnight convection,
with another wave keeping isolated showers going in eastern Kansas
into the early afternoon. High- based nature of this activity
keeping much precip from what there is in check however. Water
vapor imagery suggesting a stronger wave rotating northeast out of
eastern New Mexico with convection firing ahead of it into
southeastern Colorado. Cold front was from northwestern Kansas
into northeastern Nebraska early this afternoon with a few cumulus
along it in central Nebraska. Dewpoints have dropped to around 40F
in southwest Kansas with thermal ridge ahead of front pushing temp
at CNK to near record levels.
Precipitation chances remain the main challenge through Monday
afternoon. Recent HRRR and RAP runs continue to attempt to produce
convection along the front, but have been too fast to do so. With
low levels rather dry to the west, the main player with convection
to the west and south could be via the New Mexico wave, or other
convective-induced waves from eastern Colorado. Isentropic upglide
looks less impressive than this morning but some is again present
and could be enough to continue or even produce convection into east
central Kansas late this evening and into much of Monday. Other
prime scenario for convection seems to be with eventual convection
generated in eastern Nebraska sinking south into northeast Kansas on
decent 850mb moisture convergence as a moderate low level jet veers
with time. This could linger well into Monday morning, and with the
earlier possibilities as well, have kept chance PoPs going into the
morning Monday, with lesser confidence in precip in the northwest
counties nearer the drier low level air. Details in precip activity
Monday afternoon will be largely impacted by the earlier activity,
but models increase low level moisture further, though NAM likely a
bit aggressive again, with CAPE possibly near 2000 J/kg ahead of any
outflow or front/effective front. Shear values again look meager to
support much severe weather but some potential remains. Have kept
highs cooler than today with more cloud/precip/moisture anticipated.
.LONG TERM...(Monday Night through Sunday)
Issued at 328 PM CDT SUN MAY 3 2015
Models continue to show an active pattern for Monday night through
Sunday as they dig another closed low into the southwestern U.S. by
the end of the work week. This causes mid level flow to remain
from the southwest while gulf moisture continues advecting north.
So there looks to be plenty of moisture available with occasional
forcing mechanisms passing overhead such that there is a chance
for precip in every period of the forecast. The one period with
the lowest chance for precip remain Tuesday. There seems to be
agreement among the models that shortwave ridge will propagate
over eastern KS with some relatively dryer air moving in.
Therefore have a dry forecast for northeast and east central
KS. North central KS may be close enough to shortwave energy
lifting north through the high plains that have kept a small
chance for the western counties for Tuesday.
The best chance for showers and thunderstorms appears to be late
Tuesday night and Wednesday as a well defined shortwave is progged
to lift across northeast KS. There are some minor differences in
timing of the vort max lifting out. Nevertheless with little or no
inhibition to convection expect showers and thunderstorms to
overspread the area and have increased POPs into the 70 to 80
percent range.
Wednesday night through Saturday does not look like it will be
constant precip, but the pattern makes it difficult to say when
chances are better than not. With occasional low amplitude waves
within the southwest flow and a moist airmass remaining in place,
the forecast has a chance for precip each day. There are even some
signs of a weak frontal boundary moving into the forecast on
Friday which may help focus moisture and provide some lift.
Otherwise think chances could be on the increase for Saturday
night and Sunday as the upper low begins to lift out of the
southern Rockies. Because the GFS is a little further north and
doesn`t have as much shortwave energy rotating through the
southern plains, have kept POPs in the chance category for now.
There should not be any big swings in temps through the period due
to the persistent pattern. If anything there may be a slight cool
down for Wednesday expecting cloud cover and precip to limit
heating. Otherwise temps should be seasonable with lows around 60
and highs in the mid 70s to near 80
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1229 PM CDT SUN MAY 3 2015
The main aviation concern for the afternoon will be the strong and
gusty southerly winds. These will diminish around sunset. Winds
likely strong enough overnight to minimize the possibility of wind
shear conditions. With the frontal system just off to the North of
the terminals, there is some suggestion that KMHK, KTOP/KFOE
terminals could at least see some VCSH or perhaps VCTS, but this
would be high based and confidence is to low at this point to
carry in the TAFs. This is something to stay tuned to though if
planning transit to or from the terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65
LONG TERM...Wolters
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1237 PM CDT Sun May 3 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 346 AM CDT SUN MAY 3 2015
Isolated thunderstorms developed this morning shortly after 06Z in
warm/moist advection within the low level jet. Vad wind profiles as
well as water vapor imagery shows a mid level wave around 700 mb
moving across central Kansas at 08Z. Latest runs of the HRRR and RAP
move the isolated convection east into Missouri by 12Z-13Z. After
this early morning round of convection, the rest of the day should
be dry with clouds gradually decreasing through the early afternoon
hours. Deep mixing today along with warm advection will yield highs
in the low to mid 80s. Main thermal axis sets up from New Mexico
through north central Kansas into northeast Nebraska today. Winds
will increase by mid morning as pressure gradient increases. Surface
front moves southeast into western Kansas this afternoon while it
moves little across Nebraska. Expect afternoon heating out west will
overcome convective inhibition for scattered storms to develop.
These will remain to the west of north central Kansas into the early
evening hours. Models eject weak waves northeast across western
Kansas into southern Nebraska overnight. Expect convection to fire
along the front in Nebraska tonight with outflow pushing south into
north central and northeast Kansas. Southerly low level jet will
help to develop scattered showers and thunderstorms overnight. Shear
is marginal 20 to 30 kts overnight with MUCAPE 800-1000 J/kg. Expect
some strong storms are possible with a few severe storms not out of
the question later this evening across north central Kansas. Hail
and winds will be the main hazards. Lows tonight will be mild with
readings in the lower 60s.
.LONG TERM...(Monday through Saturday)
Issued at 346 AM CDT SUN MAY 3 2015
A wet pattern looks to be setting up for this upcoming week with
several chances for precipitation all the way into next weekend.
By Monday, a mid-level ridge will stretch across the Southern Plains
and southeastern U.S. with a surface low centered over southwest
Kansas. Models show the associated cold front extending into north
central Kansas and southeast Nebraska, however the last few models
runs have shown this front becoming fairly stationary over northern
Kansas Monday into Monday night, limiting the southeastern extent of
precipitation chances across the CWA. As a result, have continued to
diminish PoPs across far east central Kansas through that period
with likely PoPs along the KS/NE border with the stationary
boundary. There continues to be the potential for some strong to
severe thunderstorms to develop along this stationary boundary
Monday afternoon into Monday evening as storms should be
surface-based due to little to no inhibition present. The NAM
continues to be the most aggressive with the amount of available
moisture, thus increasing the parameters for severe thunderstorms.
However, CAPE values could reach upwards of 1000-2000 J/kg with
decent low-level lapse rates. However, 0-6km bulk shear continues to
look fairly weak with most models showing upwards of only about
30kts. The main concern with any strong to severe storms will likely
be some large hail and potentially some locally heavy rain as
thunderstorms may train across north central Kansas into the evening
and overnight hours with the low-level jet looking to be parallel to
the boundary.
The mid-level ridge should stretch further northward into the
Central Plains Monday night into Tuesday, helping to push the cold
front northward into Nebraska and further limiting the precipitation
potential across the southeastern portions of the forecast area. At
this time, Tuesday looks to show the best potential for being dry
across much of the forecast area. However, focus quickly shifts to
the southwest where a mid-level trough will be beginning to lift
northeastward across the High Plains through Wednesday and into the
Northern Plains by Wednesday night. At the surface, a low pressure
system will strengthen across the High Plains but looks to become
anchored over that region through mid to late week, resulting in
persistent southerly surface winds advecting warm, moist air into
the region. The combination of this steady stream of moisture and a
frontal boundary that will likely remain hung up just west of the
forecast area through much of the remainder of the week will help to
support continued scattered shower and thunderstorm chances through
the end of the week. While there is decent model agreement with the
timing and tracking of the mid-level trough and the development of
weak embedded waves within the pattern by late week, there is less
agreement with the surface features in when the associated cold
front will become tilted enough to move into the forecast area
during the latter part of the week. Due to the low confidence in
this boundary placement, have lowered PoPs some from the consensus
blend but still have chance PoPs in for the entire forecast area
through Saturday. This fairly stationary surface pattern should
result in fairly similar temperatures throughout the week with highs
in the 70s/near 80, lows in the upper 50s/low 60s, and dewpoints in
the 50s and 60s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1229 PM CDT SUN MAY 3 2015
The main aviation concern for the afternoon will be the strong and
gusty southerly winds. These will diminish around sunset. Winds
likely strong enough overnight to minimize the possibility of wind
shear conditions. With the frontal system just off to the North of
the terminals, there is some suggestion that KMHK, KTOP/KFOE
terminals could at least see some VCSH or perhaps VCTS, but this
would be high based and confidence is to low at this point to
carry in the TAFs. This is something to stay tuned to though if
planning transit to or from the terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1211 PM CDT SUN MAY 3 2015
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1207 PM CDT SUN MAY 3 2015
AT 12Z SUNDAY AN UPPER LEVEL TROUGH/LOW WAS LOCATED JUST OFF THE
SOUTHERN CALIFORNIA COAST WITH WEAK UPPER LEVEL RIDGING OCCURRING
OVER THE SOUTHERN AND CENTRAL PLAINS. FURTHER NORTH AN UPPER LEVEL
TROUGH WAS CROSS THE NORTHERN PLAINS. AT 12Z SUNDAY A 700MB TROUGH
WAS LOCATED OVER WESTERN KANSAS WITH A THERMAL RIDGE AXIS
EXTENDING FROM SOUTHEAST COLORADO INTO THE PANHANDLE OF TEXAS. A
SURFACE COLD FRONT STRETCHED FROM EASTERN WYOMING, ACROSS
NEBRASKA, TO SOUTHWEST MINNESOTA. JUST SOUTH OF THIS COLD FRONT A
A SURFACE TROUGH EXTENDED FROM NORTH CENTRAL NEBRASKA INTO THE
TEXAS PANHANDLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT SUN MAY 3 2015
THE MAIN CONCERN FOR THE SHORT TERM IS CONVECTIVE CHANCES, COVERAGE,
AND STRENGTH FOR LATE THIS AFTERNOON INTO THE EVENING. ON THE
SYNOPTIC SCALE, A RATHER WEAK WEST-TO-EAST FLOW WAS FOUND IN THE MID
AND UPPER TROPOSPHERE, WITH 500MB FLOW AVERAGING ABOUT 15 TO 20
KNOTS ACROSS THE CENTRAL ROCKIES AND PLAINS WITH 250MB FLOW NOT MUCH
STRONGER AT 25 TO 30 KNOTS. THIS IS MORE LIKE A LATE JUNE/EARLY JULY
FLOW REGIME. AS A RESULT, THE CONVECTION THAT IS EXPECTED TO DEVELOP
LATE THIS AFTERNOON WILL BEHAVE MORE LIKE LATE JUNE/JULY STORMS:
SLOW MOVING, AND MARGINAL-AT-BEST SEVERE WEATHER PROSPECTS.
THUNDERSTORMS WILL DEVELOP IN THE DEEPLY MIXED AIRMASS THAT WILL
DEVELOP ALONG AND WEST OF THE LEE TROUGH AXIS/NEBULOUS DRYLINE. THE
CONVERGENCE WILL NOT BE ALL THAT STRONG, BUT THE LOWER TO MID
TROPOSPHERIC LAPSE RATES OF EARLY MAY WILL BE STEEP ENOUGH SUCH THAT
EVEN WEAK CONVERGENCE WILL AID IN THUNDERSTORM DEVELOPMENT ALONG THE
WEAK DRYLINE/LEE TROUGH. WHEN COMPARED AGAINST THE GFS, ECMWF, AND
WRF-ARW, THE NAM12/NMMB SURFACE DEWPOINTS APPEAR TO BE TOO AMBITIOUS
WITH MID 50S DEWPOINTS AS FAR WEST AS HIGHWAY 283 BY LATE AFTERNOON,
RESULTING IN LARGE AREA OF 2000+ J/KG SBCAPE.
THERE WILL LIKELY BE A BIT MORE MIXING THAN WHAT THE NAM12 SHOWS
WITH TEMPERATURES WARMING WELL INTO THE MID TO UPPER 80S AND THE
LACK OF ANY EASTERLY COMPONENT WIND. THAT SAID, THE EARLY RUNS OF
THE RAP13 AND HRRR APPEAR TO BE WHACKED OUT WITH SURFACE FLOW TOO
VEERED OUT/WESTERLY COMPONENT WITH DEWPOINTS TANKING INTO THE UPPER
30S TO AROUND 40F FOR ALL OF SOUTHWEST KANSAS. BELIEVE THAT
SOMETHING IN THE MIDDLE IS MORE REALISTIC IN TERMS OF WHAT WILL
REALLY PAN OUT WITH THE SURFACE SETUP LATE THIS AFTERNOON.
NEVERTHELESS, 1000 TO 1500 J/KG SBCAPE SHOULD BE REALIZED AHEAD OF
THE DEVELOPING CONVECTION THIS AFTERNOON. THE GREATEST THREAT FROM
ANY OF THE STORMS WILL BE SOME LOCALIZED DOWNBURST WIND GUSTS IN
EXCESS OF 50 KNOTS/58 MPH GIVEN THE ANTICIPATED HIGH TEMPERATURE-
DEWPOINT SPREADS APPROACHING 40F LATE THIS AFTERNOON. THE HAIL RISK
LOOKS QUITE LOW GIVEN THE POOR CAPE-SHEAR COMBINATION AND LACK OF
ANY UPPER TROPOSPHERIC FLOW TO SUPPORT MID-UPPER STORM-RELATIVE
SHEAR. THE STRONGEST STORM WILL STILL BE CAPABLE OF QUARTER TO
PERHAPS HALF-DOLLAR SIZE HAIL, THOUGH. THE FORECAST POPS OF 40 TO 50
PERCENT WILL COVER AREAS ALONG AND BETWEEN THE HIGHWAY 83 AND 283
CORRIDOR, INCLUDING SCOTT CITY, GARDEN, LIBERAL, NESS CITY,
WAKEENEY, AND HAYS. ANTICIPATED SLOW STORM MOTIONS WILL RESULT IN
LOCALIZED HEAVY RAINFALL, ESPECIALLY DURING THE EVENING WHEN UPSCALE
GROWTH OCCURS BETWEEN 00-03Z. LOSS OF DIURNAL HEATING WILL LIKELY
RESULT IN THE DEMISE OF CONVECTION BY 06Z MUCH LIKE WE HAVE SEEN
OVER THE PAST COUPLE NIGHTS OUT ALONG THE KS-CO BORDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
AN UPPER LEVEL LOW IS EXPECTED TO MOVE INTO THE DESERT SOUTHWEST
SUNDAY INTO MONDAY THEN WEAKEN INTO AN OPEN WAVE AND CURLS
NORTHEASTWARD INTO THE CENTRAL ROCKIES BY TUESDAY INTO TUESDAY
NIGHT. THIS FEATURE THEN MOVES INTO THE CENTRAL PLAINS WEDNESDAY
THEN INTO THE NORTHERN PLAINS THURSDAY. MOISTURE ABOVE WESTERN
KANSAS WILL INCREASE AS THIS FEATURE APPROACHES LEADING TO
INCREASING CLOUDS MONDAY WITH MOSTLY CLOUDY SKIES EXPECTED MONDAY
NIGHT THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY AT THE SURFACE IS
ANTICIPATED TO SPRAWL OUT ACROSS WEST CENTRAL KANSAS MONDAY THEN
SHIFT NORTHWARD MONDAY NIGHT INTO TUESDAY AS A WARM FRONT. WINDS
AHEAD OF THIS BOUNDARY WILL GENERALLY BE FROM A SOUTHERLY DIRECTION
WITH WINDS BEHIND THIS BOUNDARY FROM MORE OF A NORTHERLY DIRECTION.
A DOME OF HIGH PRESSURE WILL BE LOCATED ACROSS THE EASTERN UNITED
STATES WITH TRAJECTORIES ON THE WEST SIDE BRINGING UP COPIOUS
AMOUNTS OF MOISTURE FROM THE GULF INTO THE CENTRAL PLAINS. AS FOR
PRECIPITATION CHANCES, THUNDERSTORMS MAY BE POSSIBLE ACROSS CENTRAL
KANSAS MONDAY MORNING BUT SHOULD QUICKLY MOVE OUT OF THE CWA BY LATE
MORNING. ADDITIONAL THUNDERSTORMS ARE PROGGED TO DEVELOP ACROSS
WESTERN KANSAS IN THE AFTERNOON AND SPREAD ACROSS THE REMAINDER OF
THE AREA MONDAY NIGHT. A FEW STORMS COULD BECOME STRONG TO SEVERE
ACROSS CENTRAL KANSAS DEPENDING ON HOW MUCH HEATING OCCURS DURING
THE DAY. RAIN CHANCES BECOME LIKELY TUESDAY AS MOISTURE CONTINUES TO
BE PULLED UP FROM THE GULF AND PWAT`S SURPASS AN INCH.
MEANWHILE, AN UPPER LEVEL LOW ENTERS THE WESTERN UNITED STATES
TUESDAY THEN SLIDES SOUTHWARD INTO THE DESERT SOUTHWEST BY THURSDAY.
THIS LOW THEN CURLS NORTHEAST INTO THE CENTRAL ROCKIES FRIDAY THEN
INTO THE NORTHERN ROCKIES WEEKEND. WEAK SHORTWAVES ARE EXPECTED TO
MOVE AROUND THE PERIPHERY OF THIS SYSTEM AND TOWARDS THE CENTRAL
PLAINS FOR THE REMAINDER OF THE WEEK. THIS WILL ALLOW PRECIPITATION
CHANCES TO CONTINUE ACROSS THE AREA WITH THE BEST CHANCE OF
BENEFICIAL RAINFALL ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
AS FOR TEMPERATURES, HIGHS MONDAY LOOK TO RANGE FROM THE LOWER 70S
ACROSS WEST CENTRAL KANSAS WHERE THE FRONTAL BOUNDARY WILL BE
LOCATED TO LOWER 80S ACROSS SOUTH CENTRAL KANSAS. HIGHS TUESDAY ARE
ANTICIPATED TO BE AROUND 70 DEGREES. LOWS MONDAY NIGHT AND TUESDAY
NIGHT ARE PROGGED TO RANGE FROM AROUND 50 DEGREES ACROSS FAR WESTERN
KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
HIGHS FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND ARE EXPECTED TO
BE IN THE UPPER 70S TO LOWER 80S WITH LOWS RANGING FROM AROUND 50
DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS
CENTRAL AND SOUTH CENTRAL KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1207 PM CDT SUN MAY 3 2015
A SURFACE BOUNDARY WILL REMAIN NEARLY STATIONARY TODAY ACROSS
WESTERN KANSAS TODAY. GIVE THE LOCATION OF THIS SURFACE BOUNDARY
THE WINDS TODAY WILL AVERAGE LESS THAN 10 KNOTS. AFTER SUNSET THE
PREVAILING WINDS WILL BECOME SOUTHEAST AT 10 TO 15 KNOTS.
SCATTERED THUNDERSTORMS ARE ALSO EXPECTED TO DEVELOP ALONG AND
EAST OF THIS SURFACE BOUNDARY LATE TODAY AND THEN CONTINUE THROUGH
EARLY TONIGHT. BUFR SOUNDINGS KEEP CLOUD BASES WITH THESE STORMS
AT OR ABOVE 5000FT AGL SO VFR CONDITIONS ARE EXPECTED WITH THESE
STORMS. SOME OF THESE STORMS EARLY THIS EVENING WILL BE CAPABLE
OF PRODUCING QUARTER SIZE HAIL AND WIND GUSTS OF 50 TO 60 MPH. AT
THIS TIME THE THUNDERSTORMS WILL BE MORE LIKELY AT GCK BETWEEN 23Z
SUNDAY AND 02Z MONDAY. AT DDC AND HAY FROM 02Z TO 06Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 88 58 80 57 / 30 30 50 70
GCK 88 55 78 55 / 40 40 60 90
EHA 88 54 75 53 / 30 20 60 80
LBL 90 57 79 56 / 40 50 60 90
HYS 88 58 78 57 / 40 50 60 60
P28 86 60 81 59 / 10 20 20 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
638 AM CDT Sun May 3 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 346 AM CDT SUN MAY 3 2015
Isolated thunderstorms developed this morning shortly after 06Z in
warm/moist advection within the low level jet. Vad wind profiles as
well as water vapor imagery shows a mid level wave around 700 mb
moving across central Kansas at 08Z. Latest runs of the HRRR and RAP
move the isolated convection east into Missouri by 12Z-13Z. After
this early morning round of convection, the rest of the day should
be dry with clouds gradually decreasing through the early afternoon
hours. Deep mixing today along with warm advection will yield highs
in the low to mid 80s. Main thermal axis sets up from New Mexico
through north central Kansas into northeast Nebraska today. Winds
will increase by mid morning as pressure gradient increases. Surface
front moves southeast into western Kansas this afternoon while it
moves little across Nebraska. Expect afternoon heating out west will
overcome convective inhibition for scattered storms to develop.
These will remain to the west of north central Kansas into the early
evening hours. Models eject weak waves northeast across western
Kansas into southern Nebraska overnight. Expect convection to fire
along the front in Nebraska tonight with outflow pushing south into
north central and northeast Kansas. Southerly low level jet will
help to develop scattered showers and thunderstorms overnight. Shear
is marginal 20 to 30 kts overnight with MUCAPE 800-1000 J/kg. Expect
some strong storms are possible with a few severe storms not out of
the question later this evening across north central Kansas. Hail
and winds will be the main hazards. Lows tonight will be mild with
readings in the lower 60s.
.LONG TERM...(Monday through Saturday)
Issued at 346 AM CDT SUN MAY 3 2015
A wet pattern looks to be setting up for this upcoming week with
several chances for precipitation all the way into next weekend.
By Monday, a mid-level ridge will stretch across the Southern Plains
and southeastern U.S. with a surface low centered over southwest
Kansas. Models show the associated cold front extending into north
central Kansas and southeast Nebraska, however the last few models
runs have shown this front becoming fairly stationary over northern
Kansas Monday into Monday night, limiting the southeastern extent of
precipitation chances across the CWA. As a result, have continued to
diminish PoPs across far east central Kansas through that period
with likely PoPs along the KS/NE border with the stationary
boundary. There continues to be the potential for some strong to
severe thunderstorms to develop along this stationary boundary
Monday afternoon into Monday evening as storms should be
surface-based due to little to no inhibition present. The NAM
continues to be the most aggressive with the amount of available
moisture, thus increasing the parameters for severe thunderstorms.
However, CAPE values could reach upwards of 1000-2000 J/kg with
decent low-level lapse rates. However, 0-6km bulk shear continues to
look fairly weak with most models showing upwards of only about
30kts. The main concern with any strong to severe storms will likely
be some large hail and potentially some locally heavy rain as
thunderstorms may train across north central Kansas into the evening
and overnight hours with the low-level jet looking to be parallel to
the boundary.
The mid-level ridge should stretch further northward into the
Central Plains Monday night into Tuesday, helping to push the cold
front northward into Nebraska and further limiting the precipitation
potential across the southeastern portions of the forecast area. At
this time, Tuesday looks to show the best potential for being dry
across much of the forecast area. However, focus quickly shifts to
the southwest where a mid-level trough will be beginning to lift
northeastward across the High Plains through Wednesday and into the
Northern Plains by Wednesday night. At the surface, a low pressure
system will strengthen across the High Plains but looks to become
anchored over that region through mid to late week, resulting in
persistent southerly surface winds advecting warm, moist air into
the region. The combination of this steady stream of moisture and a
frontal boundary that will likely remain hung up just west of the
forecast area through much of the remainder of the week will help to
support continued scattered shower and thunderstorm chances through
the end of the week. While there is decent model agreement with the
timing and tracking of the mid-level trough and the development of
weak embedded waves within the pattern by late week, there is less
agreement with the surface features in when the associated cold
front will become tilted enough to move into the forecast area
during the latter part of the week. Due to the low confidence in
this boundary placement, have lowered PoPs some from the consensus
blend but still have chance PoPs in for the entire forecast area
through Saturday. This fairly stationary surface pattern should
result in fairly similar temperatures throughout the week with highs
in the 70s/near 80, lows in the upper 50s/low 60s, and dewpoints in
the 50s and 60s.
&&
.AVIATION...(For the 12Z TAFs through 12Z Monday Morning)
Issued at 638 AM CDT SUN MAY 3 2015
Isolated shra and tsra are possible at TOP and FOE terminals
through 14Z. VFR conditions are expected through the period
outside of convective activity. South to southwest winds will
increase to near 15 kts with gusts to 24kts from 14Z-00Z, then
decrease to around 10 kts. TSRA may be possible at the terminals
after 06Z. Confidence to low for timing at the terminals attm to
go with more than VCTS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...53
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 AM CDT SUN MAY 3 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT SUN MAY 3 2015
THE MAIN CONCERN FOR THE SHORT TERM IS CONVECTIVE CHANCES, COVERAGE,
AND STRENGTH FOR LATE THIS AFTERNOON INTO THE EVENING. ON THE
SYNOPTIC SCALE, A RATHER WEAK WEST-TO-EAST FLOW WAS FOUND IN THE MID
AND UPPER TROPOSPHERE, WITH 500MB FLOW AVERAGING ABOUT 15 TO 20
KNOTS ACROSS THE CENTRAL ROCKIES AND PLAINS WITH 250MB FLOW NOT MUCH
STRONGER AT 25 TO 30 KNOTS. THIS IS MORE LIKE A LATE JUNE/EARLY JULY
FLOW REGIME. AS A RESULT, THE CONVECTION THAT IS EXPECTED TO DEVELOP
LATE THIS AFTERNOON WILL BEHAVE MORE LIKE LATE JUNE/JULY STORMS:
SLOW MOVING, AND MARGINAL-AT-BEST SEVERE WEATHER PROSPECTS.
THUNDERSTORMS WILL DEVELOP IN THE DEEPLY MIXED AIRMASS THAT WILL
DEVELOP ALONG AND WEST OF THE LEE TROUGH AXIS/NEBULOUS DRYLINE. THE
CONVERGENCE WILL NOT BE ALL THAT STRONG, BUT THE LOWER TO MID
TROPOSPHERIC LAPSE RATES OF EARLY MAY WILL BE STEEP ENOUGH SUCH THAT
EVEN WEAK CONVERGENCE WILL AID IN THUNDERSTORM DEVELOPMENT ALONG THE
WEAK DRYLINE/LEE TROUGH. WHEN COMPARED AGAINST THE GFS, ECMWF, AND
WRF-ARW, THE NAM12/NMMB SURFACE DEWPOINTS APPEAR TO BE TOO AMBITIOUS
WITH MID 50S DEWPOINTS AS FAR WEST AS HIGHWAY 283 BY LATE AFTERNOON,
RESULTING IN LARGE AREA OF 2000+ J/KG SBCAPE.
THERE WILL LIKELY BE A BIT MORE MIXING THAN WHAT THE NAM12 SHOWS
WITH TEMPERATURES WARMING WELL INTO THE MID TO UPPER 80S AND THE
LACK OF ANY EASTERLY COMPONENT WIND. THAT SAID, THE EARLY RUNS OF
THE RAP13 AND HRRR APPEAR TO BE WHACKED OUT WITH SURFACE FLOW TOO
VEERED OUT/WESTERLY COMPONENT WITH DEWPOINTS TANKING INTO THE UPPER
30S TO AROUND 40F FOR ALL OF SOUTHWEST KANSAS. BELIEVE THAT
SOMETHING IN THE MIDDLE IS MORE REALISTIC IN TERMS OF WHAT WILL
REALLY PAN OUT WITH THE SURFACE SETUP LATE THIS AFTERNOON.
NEVERTHELESS, 1000 TO 1500 J/KG SBCAPE SHOULD BE REALIZED AHEAD OF
THE DEVELOPING CONVECTION THIS AFTERNOON. THE GREATEST THREAT FROM
ANY OF THE STORMS WILL BE SOME LOCALIZED DOWNBURST WIND GUSTS IN
EXCESS OF 50 KNOTS/58 MPH GIVEN THE ANTICIPATED HIGH TEMPERATURE-
DEWPOINT SPREADS APPROACHING 40F LATE THIS AFTERNOON. THE HAIL RISK
LOOKS QUITE LOW GIVEN THE POOR CAPE-SHEAR COMBINATION AND LACK OF
ANY UPPER TROPOSPHERIC FLOW TO SUPPORT MID-UPPER STORM-RELATIVE
SHEAR. THE STRONGEST STORM WILL STILL BE CAPABLE OF QUARTER TO
PERHAPS HALF-DOLLAR SIZE HAIL, THOUGH. THE FORECAST POPS OF 40 TO 50
PERCENT WILL COVER AREAS ALONG AND BETWEEN THE HIGHWAY 83 AND 283
CORRIDOR, INCLUDING SCOTT CITY, GARDEN, LIBERAL, NESS CITY,
WAKEENEY, AND HAYS. ANTICIPATED SLOW STORM MOTIONS WILL RESULT IN
LOCALIZED HEAVY RAINFALL, ESPECIALLY DURING THE EVENING WHEN UPSCALE
GROWTH OCCURS BETWEEN 00-03Z. LOSS OF DIURNAL HEATING WILL LIKELY
RESULT IN THE DEMISE OF CONVECTION BY 06Z MUCH LIKE WE HAVE SEEN
OVER THE PAST COUPLE NIGHTS OUT ALONG THE KS-CO BORDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
AN UPPER LEVEL LOW IS EXPECTED TO MOVE INTO THE DESERT SOUTHWEST
SUNDAY INTO MONDAY THEN WEAKEN INTO AN OPEN WAVE AND CURLS
NORTHEASTWARD INTO THE CENTRAL ROCKIES BY TUESDAY INTO TUESDAY
NIGHT. THIS FEATURE THEN MOVES INTO THE CENTRAL PLAINS WEDNESDAY
THEN INTO THE NORTHERN PLAINS THURSDAY. MOISTURE ABOVE WESTERN
KANSAS WILL INCREASE AS THIS FEATURE APPROACHES LEADING TO
INCREASING CLOUDS MONDAY WITH MOSTLY CLOUDY SKIES EXPECTED MONDAY
NIGHT THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY AT THE SURFACE IS
ANTICIPATED TO SPRAWL OUT ACROSS WEST CENTRAL KANSAS MONDAY THEN
SHIFT NORTHWARD MONDAY NIGHT INTO TUESDAY AS A WARM FRONT. WINDS
AHEAD OF THIS BOUNDARY WILL GENERALLY BE FROM A SOUTHERLY DIRECTION
WITH WINDS BEHIND THIS BOUNDARY FROM MORE OF A NORTHERLY DIRECTION.
A DOME OF HIGH PRESSURE WILL BE LOCATED ACROSS THE EASTERN UNITED
STATES WITH TRAJECTORIES ON THE WEST SIDE BRINGING UP COPIOUS
AMOUNTS OF MOISTURE FROM THE GULF INTO THE CENTRAL PLAINS. AS FOR
PRECIPITATION CHANCES, THUNDERSTORMS MAY BE POSSIBLE ACROSS CENTRAL
KANSAS MONDAY MORNING BUT SHOULD QUICKLY MOVE OUT OF THE CWA BY LATE
MORNING. ADDITIONAL THUNDERSTORMS ARE PROGGED TO DEVELOP ACROSS
WESTERN KANSAS IN THE AFTERNOON AND SPREAD ACROSS THE REMAINDER OF
THE AREA MONDAY NIGHT. A FEW STORMS COULD BECOME STRONG TO SEVERE
ACROSS CENTRAL KANSAS DEPENDING ON HOW MUCH HEATING OCCURS DURING
THE DAY. RAIN CHANCES BECOME LIKELY TUESDAY AS MOISTURE CONTINUES TO
BE PULLED UP FROM THE GULF AND PWAT`S SURPASS AN INCH.
MEANWHILE, AN UPPER LEVEL LOW ENTERS THE WESTERN UNITED STATES
TUESDAY THEN SLIDES SOUTHWARD INTO THE DESERT SOUTHWEST BY THURSDAY.
THIS LOW THEN CURLS NORTHEAST INTO THE CENTRAL ROCKIES FRIDAY THEN
INTO THE NORTHERN ROCKIES WEEKEND. WEAK SHORTWAVES ARE EXPECTED TO
MOVE AROUND THE PERIPHERY OF THIS SYSTEM AND TOWARDS THE CENTRAL
PLAINS FOR THE REMAINDER OF THE WEEK. THIS WILL ALLOW PRECIPITATION
CHANCES TO CONTINUE ACROSS THE AREA WITH THE BEST CHANCE OF
BENEFICIAL RAINFALL ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
AS FOR TEMPERATURES, HIGHS MONDAY LOOK TO RANGE FROM THE LOWER 70S
ACROSS WEST CENTRAL KANSAS WHERE THE FRONTAL BOUNDARY WILL BE
LOCATED TO LOWER 80S ACROSS SOUTH CENTRAL KANSAS. HIGHS TUESDAY ARE
ANTICIPATED TO BE AROUND 70 DEGREES. LOWS MONDAY NIGHT AND TUESDAY
NIGHT ARE PROGGED TO RANGE FROM AROUND 50 DEGREES ACROSS FAR WESTERN
KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
HIGHS FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND ARE EXPECTED TO
BE IN THE UPPER 70S TO LOWER 80S WITH LOWS RANGING FROM AROUND 50
DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS
CENTRAL AND SOUTH CENTRAL KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 612 AM CDT SUN MAY 3 2015
A FRONTAL BOUNDARY WILL BIFURCATE THE AREA TODAY WITH SOUTHERLY
WINDS FELT AHEAD OF THE FRONT WITH NORTHWESTERLY WINDS BEHIND THE
FRONT. THE DDC TERMINAL LOOKS TO STAY AHEAD OF THE FRONT
THROUGHOUT THE DAY WHERE AS THE GCK AND HYS TERMINALS LOOK TO BE
VERY CLOSE TO THE FRONT THIS MORNING. THIS IS THE REASON FOR THE
VRB CONDITIONS CURRENTLY IN THE TAFS. WINDS LOOK TO BE FROM A
SOUTHERLY DIRECTION BY THIS AFTERNOON AS THE AFOREMENTIONED FRONT
MOVES NORTH AS A WARM FRONT. VFR CONDITIONS WILL PREVAIL TODAY WITH
SCATTERED HIGH CLOUDS THIS MORNING. THERE IS A SLIGHT CHANCE FOR
THUNDERSTORMS AROUND THE HYS TERMINAL THIS EVENING AND A PROB30
HAS BEEN ADDED TO ACCOUNT FOR THIS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 88 58 80 57 / 30 30 50 70
GCK 88 55 78 55 / 40 40 60 90
EHA 88 54 75 53 / 30 20 60 80
LBL 90 57 79 56 / 40 50 60 90
HYS 87 58 78 57 / 40 50 60 60
P28 86 60 81 59 / 10 20 20 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS TOPEKA KS
404 AM CDT Sun May 3 2015
.SHORT TERM...(Today and Tonight)
Issued at 346 AM CDT SUN MAY 3 2015
Isolated thunderstorms developed this morning shortly after 06Z in
warm/moist advection within the low level jet. Vad wind profiles as
well as water vapor imagery shows a mid level wave around 700 mb
moving across central Kansas at 08Z. Latest runs of the HRRR and RAP
move the isolated convection east into Missouri by 12Z-13Z. After
this early morning round of convection, the rest of the day should
be dry with clouds gradually decreasing through the early afternoon
hours. Deep mixing today along with warm advection will yield highs
in the low to mid 80s. Main thermal axis sets up from New Mexico
through north central Kansas into northeast Nebraska today. Winds
will increase by mid morning as pressure gradient increases. Surface
front moves southeast into western Kansas this afternoon while it
moves little across Nebraska. Expect afternoon heating out west will
overcome convective inhibition for scattered storms to develop.
These will remain to the west of north central Kansas into the early
evening hours. Models eject weak waves northeast across western
Kansas into southern Nebraska overnight. Expect convection to fire
along the front in Nebraska tonight with outflow pushing south into
north central and northeast Kansas. Southerly low level jet will
help to develop scattered showers and thunderstorms overnight. Shear
is marginal 20 to 30 kts overnight with MUCAPE 800-1000 J/kg. Expect
some strong storms are possible with a few severe storms not out of
the question later this evening across north central Kansas. Hail
and winds will be the main hazards. Lows tonight will be mild with
readings in the lower 60s.
.LONG TERM...(Monday through Saturday)
Issued at 346 AM CDT SUN MAY 3 2015
A wet pattern looks to be setting up for this upcoming week with
several chances for precipitation all the way into next weekend.
By Monday, a mid-level ridge will stretch across the Southern Plains
and southeastern U.S. with a surface low centered over southwest
Kansas. Models show the associated cold front extending into north
central Kansas and southeast Nebraska, however the last few models
runs have shown this front becoming fairly stationary over northern
Kansas Monday into Monday night, limiting the southeastern extent of
precipitation chances across the CWA. As a result, have continued to
diminish PoPs across far east central Kansas through that period
with likely PoPs along the KS/NE border with the stationary
boundary. There continues to be the potential for some strong to
severe thunderstorms to develop along this stationary boundary
Monday afternoon into Monday evening as storms should be
surface-based due to little to no inhibition present. The NAM
continues to be the most aggressive with the amount of available
moisture, thus increasing the parameters for severe thunderstorms.
However, CAPE values could reach upwards of 1000-2000 J/kg with
decent low-level lapse rates. However, 0-6km bulk shear continues to
look fairly weak with most models showing upwards of only about
30kts. The main concern with any strong to severe storms will likely
be some large hail and potentially some locally heavy rain as
thunderstorms may train across north central Kansas into the evening
and overnight hours with the low-level jet looking to be parallel to
the boundary.
The mid-level ridge should stretch further northward into the
Central Plains Monday night into Tuesday, helping to push the cold
front northward into Nebraska and further limiting the precipitation
potential across the southeastern portions of the forecast area. At
this time, Tuesday looks to show the best potential for being dry
across much of the forecast area. However, focus quickly shifts to
the southwest where a mid-level trough will be beginning to lift
northeastward across the High Plains through Wednesday and into the
Northern Plains by Wednesday night. At the surface, a low pressure
system will strengthen across the High Plains but looks to become
anchored over that region through mid to late week, resulting in
persistent southerly surface winds advecting warm, moist air into
the region. The combination of this steady stream of moisture and a
frontal boundary that will likely remain hung up just west of the
forecast area through much of the remainder of the week will help to
support continued scattered shower and thunderstorm chances through
the end of the week. While there is decent model agreement with the
timing and tracking of the mid-level trough and the development of
weak embedded waves within the pattern by late week, there is less
agreement with the surface features in when the associated cold
front will become tilted enough to move into the forecast area
during the latter part of the week. Due to the low confidence in
this boundary placement, have lowered PoPs some from the consensus
blend but still have chance PoPs in for the entire forecast area
through Saturday. This fairly stationary surface pattern should
result in fairly similar temperatures throughout the week with highs
in the 70s/near 80, lows in the upper 50s/low 60s, and dewpoints in
the 50s and 60s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Sunday Night)
Issued at 1126 PM CDT SAT MAY 2 2015
VFR conditions expected through most of the taf period. There is a
slight chance for showers and storms towards the end of the
period, but confidence is low on timing at this point.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Hennecke
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
321 AM CDT SUN MAY 3 2015
...UPDATED SHORT TERM AND LONG TERM SECTIONS...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT SUN MAY 3 2015
THE MAIN CONCERN FOR THE SHORT TERM IS CONVECTIVE CHANCES, COVERAGE,
AND STRENGTH FOR LATE THIS AFTERNOON INTO THE EVENING. ON THE
SYNOPTIC SCALE, A RATHER WEAK WEST-TO-EAST FLOW WAS FOUND IN THE MID
AND UPPER TROPOSPHERE, WITH 500MB FLOW AVERAGING ABOUT 15 TO 20
KNOTS ACROSS THE CENTRAL ROCKIES AND PLAINS WITH 250MB FLOW NOT MUCH
STRONGER AT 25 TO 30 KNOTS. THIS IS MORE LIKE A LATE JUNE/EARLY JULY
FLOW REGIME. AS A RESULT, THE CONVECTION THAT IS EXPECTED TO DEVELOP
LATE THIS AFTERNOON WILL BEHAVE MORE LIKE LATE JUNE/JULY STORMS:
SLOW MOVING, AND MARGINAL-AT-BEST SEVERE WEATHER PROSPECTS.
THUNDERSTORMS WILL DEVELOP IN THE DEEPLY MIXED AIRMASS THAT WILL
DEVELOP ALONG AND WEST OF THE LEE TROUGH AXIS/NEBULOUS DRYLINE. THE
CONVERGENCE WILL NOT BE ALL THAT STRONG, BUT THE LOWER TO MID
TROPOSPHERIC LAPSE RATES OF EARLY MAY WILL BE STEEP ENOUGH SUCH THAT
EVEN WEAK CONVERGENCE WILL AID IN THUNDERSTORM DEVELOPMENT ALONG THE
WEAK DRYLINE/LEE TROUGH. WHEN COMPARED AGAINST THE GFS, ECMWF, AND
WRF-ARW, THE NAM12/NMMB SURFACE DEWPOINTS APPEAR TO BE TOO AMBITIOUS
WITH MID 50S DEWPOINTS AS FAR WEST AS HIGHWAY 283 BY LATE AFTERNOON,
RESULTING IN LARGE AREA OF 2000+ J/KG SBCAPE.
THERE WILL LIKELY BE A BIT MORE MIXING THAN WHAT THE NAM12 SHOWS
WITH TEMPERATURES WARMING WELL INTO THE MID TO UPPER 80S AND THE
LACK OF ANY EASTERLY COMPONENT WIND. THAT SAID, THE EARLY RUNS OF
THE RAP13 AND HRRR APPEAR TO BE WHACKED OUT WITH SURFACE FLOW TOO
VEERED OUT/WESTERLY COMPONENT WITH DEWPOINTS TANKING INTO THE UPPER
30S TO AROUND 40F FOR ALL OF SOUTHWEST KANSAS. BELIEVE THAT
SOMETHING IN THE MIDDLE IS MORE REALISTIC IN TERMS OF WHAT WILL
REALLY PAN OUT WITH THE SURFACE SETUP LATE THIS AFTERNOON.
NEVERTHELESS, 1000 TO 1500 J/KG SBCAPE SHOULD BE REALIZED AHEAD OF
THE DEVELOPING CONVECTION THIS AFTERNOON. THE GREATEST THREAT FROM
ANY OF THE STORMS WILL BE SOME LOCALIZED DOWNBURST WIND GUSTS IN
EXCESS OF 50 KNOTS/58 MPH GIVEN THE ANTICIPATED HIGH TEMPERATURE-
DEWPOINT SPREADS APPROACHING 40F LATE THIS AFTERNOON. THE HAIL RISK
LOOKS QUITE LOW GIVEN THE POOR CAPE-SHEAR COMBINATION AND LACK OF
ANY UPPER TROPOSPHERIC FLOW TO SUPPORT MID-UPPER STORM-RELATIVE
SHEAR. THE STRONGEST STORM WILL STILL BE CAPABLE OF QUARTER TO
PERHAPS HALF-DOLLAR SIZE HAIL, THOUGH. THE FORECAST POPS OF 40 TO 50
PERCENT WILL COVER AREAS ALONG AND BETWEEN THE HIGHWAY 83 AND 283
CORRIDOR, INCLUDING SCOTT CITY, GARDEN, LIBERAL, NESS CITY,
WAKEENEY, AND HAYS. ANTICIPATED SLOW STORM MOTIONS WILL RESULT IN
LOCALIZED HEAVY RAINFALL, ESPECIALLY DURING THE EVENING WHEN UPSCALE
GROWTH OCCURS BETWEEN 00-03Z. LOSS OF DIURNAL HEATING WILL LIKELY
RESULT IN THE DEMISE OF CONVECTION BY 06Z MUCH LIKE WE HAVE SEEN
OVER THE PAST COUPLE NIGHTS OUT ALONG THE KS-CO BORDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
AN UPPER LEVEL LOW IS EXPECTED TO MOVE INTO THE DESERT SOUTHWEST
SUNDAY INTO MONDAY THEN WEAKEN INTO AN OPEN WAVE AND CURLS
NORTHEASTWARD INTO THE CENTRAL ROCKIES BY TUESDAY INTO TUESDAY
NIGHT. THIS FEATURE THEN MOVES INTO THE CENTRAL PLAINS WEDNESDAY
THEN INTO THE NORTHERN PLAINS THURSDAY. MOISTURE ABOVE WESTERN
KANSAS WILL INCREASE AS THIS FEATURE APPROACHES LEADING TO
INCREASING CLOUDS MONDAY WITH MOSTLY CLOUDY SKIES EXPECTED MONDAY
NIGHT THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY AT THE SURFACE IS
ANTICIPATED TO SPRAWL OUT ACROSS WEST CENTRAL KANSAS MONDAY THEN
SHIFT NORTHWARD MONDAY NIGHT INTO TUESDAY AS A WARM FRONT. WINDS
AHEAD OF THIS BOUNDARY WILL GENERALLY BE FROM A SOUTHERLY DIRECTION
WITH WINDS BEHIND THIS BOUNDARY FROM MORE OF A NORTHERLY DIRECTION.
A DOME OF HIGH PRESSURE WILL BE LOCATED ACROSS THE EASTERN UNITED
STATES WITH TRAJECTORIES ON THE WEST SIDE BRINGING UP COPIOUS
AMOUNTS OF MOISTURE FROM THE GULF INTO THE CENTRAL PLAINS. AS FOR
PRECIPITATION CHANCES, THUNDERSTORMS MAY BE POSSIBLE ACROSS CENTRAL
KANSAS MONDAY MORNING BUT SHOULD QUICKLY MOVE OUT OF THE CWA BY LATE
MORNING. ADDITIONAL THUNDERSTORMS ARE PROGGED TO DEVELOP ACROSS
WESTERN KANSAS IN THE AFTERNOON AND SPREAD ACROSS THE REMAINDER OF
THE AREA MONDAY NIGHT. A FEW STORMS COULD BECOME STRONG TO SEVERE
ACROSS CENTRAL KANSAS DEPENDING ON HOW MUCH HEATING OCCURS DURING
THE DAY. RAIN CHANCES BECOME LIKELY TUESDAY AS MOISTURE CONTINUES TO
BE PULLED UP FROM THE GULF AND PWAT`S SURPASS AN INCH.
MEANWHILE, AN UPPER LEVEL LOW ENTERS THE WESTERN UNITED STATES
TUESDAY THEN SLIDES SOUTHWARD INTO THE DESERT SOUTHWEST BY THURSDAY.
THIS LOW THEN CURLS NORTHEAST INTO THE CENTRAL ROCKIES FRIDAY THEN
INTO THE NORTHERN ROCKIES WEEKEND. WEAK SHORTWAVES ARE EXPECTED TO
MOVE AROUND THE PERIPHERY OF THIS SYSTEM AND TOWARDS THE CENTRAL
PLAINS FOR THE REMAINDER OF THE WEEK. THIS WILL ALLOW PRECIPITATION
CHANCES TO CONTINUE ACROSS THE AREA WITH THE BEST CHANCE OF
BENEFICIAL RAINFALL ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
AS FOR TEMPERATURES, HIGHS MONDAY LOOK TO RANGE FROM THE LOWER 70S
ACROSS WEST CENTRAL KANSAS WHERE THE FRONTAL BOUNDARY WILL BE
LOCATED TO LOWER 80S ACROSS SOUTH CENTRAL KANSAS. HIGHS TUESDAY ARE
ANTICIPATED TO BE AROUND 70 DEGREES. LOWS MONDAY NIGHT AND TUESDAY
NIGHT ARE PROGGED TO RANGE FROM AROUND 50 DEGREES ACROSS FAR WESTERN
KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
HIGHS FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND ARE EXPECTED TO
BE IN THE UPPER 70S TO LOWER 80S WITH LOWS RANGING FROM AROUND 50
DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS
CENTRAL AND SOUTH CENTRAL KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1203 AM CDT SUN MAY 3 2015
THE PERSISTENT LEE TROUGH WILL REMAIN THROUGH SUNDAY...ALTHOUGH IT
WILL PUSH FARTHER EAST, WHICH WILL RESULT IN LESSER WIND
ESPECIALLY FOR GCK TERMINAL. IN FACT, GCK SHOULD SEE WIND BELOW 10
KNOTS THROUGH JUST ABOUT THE ENTIRE PERIOD...OUTSIDE OF
CONVECTION. SPEAKING OF CONVECTION, THERE IS A PRETTY HIGH
LIKELIHOOD OF STORMS LATE TOMORROW AFTERNOON/EVENING ACROSS
SOUTHWEST KANSAS, WITH THE GCK TERMINAL MOST LIKELY AFFECTED
ANYTIME AFTER 23Z OR SO.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 88 58 80 57 / 20 30 50 70
GCK 88 55 78 55 / 30 40 60 90
EHA 88 54 75 53 / 30 30 60 80
LBL 90 57 79 56 / 30 30 60 90
HYS 87 58 78 57 / 20 40 60 60
P28 86 60 81 59 / 10 10 20 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS GOODLAND KS
220 AM MDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 814 PM MDT SAT MAY 2 2015
BASED ON RADAR TRENDS OVER THE LAST COUPLE HOURS AND LATEST MODEL
DATA...HAVE LOWERED RAINFALL CHANCES ACROSS MOST OF THE AREA
EXCEPT FOR THE YUMA COUNTY AREA AND GREELEY AND WICHITA COUNTIES
WHERE RAINFALL IS OR WILL BE MOVING OVER IN THE NEXT FEW HOURS.
LATEST DATA INDICATES THE LIFT OVER THE NORTHWEST QUADRANT OF THE
IS AT ITS BEST NOW AND WILL DECLINE RATHER QUICKLY OVER THE NEXT
COUPLE OF HOURS. FURTHER SOUTH...THE TRACK OF THE 700MB SHORT
WAVE TROUGH HAS BEEN PUSHED FURTHER SOUTH FOR TONIGHT...WITH THE
MAJORITY OF THE LIFT REMAINING SOUTH OF THE AREA. STILL EXPECTING
RAINFALL CHANCES TO END BY OR SHORTLY AFTER MIDNIGHT AS THE LIFT
WITH THE SHORT WAVE TROUGH COMES TO AN END AS THE TROUGH
FILLS/MOVES OUT OF THE AREA.
UPDATE ISSUED AT 552 PM MDT SAT MAY 2 2015
MAIN CHANGE WAS TO INCREASE RAINFALL CHANCES FOR THE EVENING BASED
ON LATEST DATA. LATEST RADAR SHOWS LINE OF STORMS AHEAD OF A 700MB
SHORT WAVE TROUGH OVER EASTERN COLORADO. 700-500MB FRONTOGENESIS
STRENGTHENS RAPIDLY DURING THE EARLY EVENING AND SHIFTS EAST TO
THE CENTRAL PART OF THE AREA BY MID EVENING ACCOMPANYING THE 700MB
SHORT WAVE TROUGH. MEANWHILE ISENTROPIC LIFT STRENGTHENS
THROUGH THE FIRST HALF OF THE EVENING...WITH THE STRONGEST LIFT
WEST OF HIGHWAY 25 WHILE CONDENSATION PRESSURE DEFICITS DECLINE.
TOWARD MIDNIGHT THE LIFT DECLINES AND CONDENSATION PRESSURE
DEFICITS INCREASE AS THE SHORT WAVE TROUGH MOVES ACROSS THE EAST
HALF OF THE AREA.
WITH THIS IN MIND HAVE THE HIGHEST CHANCES FOR RAINFALL DURING THE
FIRST HALF OF THE EVENING MAINLY FOR LOCATIONS SOUTH OF I-70.
TOWARD MIDNIGHT...AS ENVIRONMENT BECOMES LESS FAVORABLE FOR
RAINFALL...HAVE RAINFALL CHANCES QUICKLY DECLINING OVER THE EAST
HALF OF THE AREA.
LOOKING AT THE SEVERE WEATHER POTENTIAL...STRONGEST STORMS STILL
REMAIN WEST OF THE AREA WHERE THE BEST FORCING IS LOCATED. HAVE
HAD SOME ISOLATED STORMS DEVELOP ALONG THE SURFACE TROUGH
EXTENDING FROM SOUTHWEST TO NORTHEAST OVER THE CENTRAL PART OF THE
AREA. HOWEVER THESE STORMS HAVE BEEN TOO FAR REMOVED FROM THE
BETTER UPPER LEVEL FORCING TO LAST VERY LONG AND HAVE BEEN FAIRLY
WEAK. AS STORMS MOVE EAST INTO THE AREA...THE LIKELIHOOD FOR
SEVERE OUTFLOW WINDS INCREASES OVER THE NEXT HOUR OR SO BEFORE THE
INVERSION DEVELOPS. OVERALL SEVERE STORMS ARE MOST LIKELY WEST OF
HIGHWAY 25 PRIOR TO 9 PM CT OR 8 PM MT. AFTER THAT THE
FORCING...SHEAR...AND INSTABILITY DECLINE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 157 PM MDT SAT MAY 2 2015
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW WESTERLY ZONAL
FLOW IN PLACE FROM THE GREAT BASIN ACROSS THE CENTRAL ROCKIES INTO
THE MISSISSIPPI VALLEY WITH EMBEDDED H5/H7 SHORTWAVE TROUGHS MOVING
THROUGH THE MEAN FLOW. AT THE SURFACE LEE TROUGH HAS DEVELOPED ACROSS
EASTERN COLORADO WITH A MEAN SURFACE TROUGH FROM THE NE PANHANDLE
AND ALONG THE COLORADO BORDER. THUNDERSTORM ACTIVITY HAS ALREADY
DEVELOPED ALONG THE CHEYENNE RIDGE AND HIGHER TERRAIN IN COLORADO.
THIS AFTERNOON-TONIGHT...RAP ANALYSIS (WHICH IS IN LINE WITH EARLIER
NAM) SHOWS 2000 J/KG OF SB CAPE IN PLACE ALONG AND AHEAD OF THE
SURFACE TROUGH...CENTERED OVER OUR CWA. CINH APPEARS TO BE
WEAKENING...HOWEVER ONLY SOME SHALLOW CU HAVE FORMED SO FAR THIS
AFTERNOON. AS MID LEVEL VORTICITY ROTATES FROM THE CENTRAL ROCKIES
INTO EASTERN COLORADO I WOULD EXPECT DEVELOPMENT TO SPREAD EAST
WHICH IS IN LINE WITH SYNOPTIC SCALE GUIDANCE. HRRR/RAP BOTH
INDICATE ISOLATED ACTIVITY DEVELOPING ALONG AND EAST OF THE SURFACE
TROUGH OVER OUR CWA WITH ADDITIONAL ACTIVITY SPREADING IN FROM THE
WEST. BULK SHEER/HELICITY ARE NOT VERY IMPRESSIVE AT THIS POINT
WHERE BETTER INSTABILITY IS IN PLACE (WEST). MOISTURE PROFILES ARE
NOT PARTICULARLY IMPRESSIVE...AND THIS COULD LIMIT COVERAGE TO
ISOLATE/SCATTERED. BETTER PRECIP SIGNAL AND INSTABILITY ARE SHOW IN
IN THE LOWER SHEER ENVIRONMENT...WHERE PULSE TYPE THUNDERSTORMS
WOULD BE MORE LIKELY. STEEP MID LEVEL LAPSE RATES AND MODERATE
INSTABILITY COULD SUPPORT STRONGER UPDRAFTS/CORES...WITH LARGE
HAIL/SEVERE WINDS POSSIBLE. DCAPE VALUES 1000-1500 J/KG AND IN
HIGHER TD DEPRESSIONS (MAINLY WEST) DO RAISE A CONCERN FOR INCREASED
MICROBURST POTENTIAL WITH SOME OF THESE STORMS. IF ANY OF THIS
ACTIVITY WAS TO MOVE INTO THE EASTERN CWA IT COULD BECOME MORE
ORGANIZED WITH INCREASING SPEED SHEER (35KT BULK EFFECTIVE SHEER
AROUND 00Z). AS THE SUN SETS AND WE LOOSE DAYTIME HEATING ANY
LINGERING ACTIVITY SHOULD QUICKLY WEAKEN AS THERE IS ELEVATED CAPE
LATE AND ONLY A WEAK LLJ IN PLACE OVERNIGHT.
SUNDAY...ANOTHER VERY WARM DAY IS EXPECTED AS SURFACE TROUGH DEEPENS
A LITTLE OVER THE CWA AND WAA INCREASES OVER THE CWA. THIS IS IN
RESPONSE TO A STRONGER SHORTWAVE TROUGH MOVING INTO THE NORTHERN
PLAINS AND A COLD FRONT DROPPING SOUTH INTO NORTHERN NEBRASKA. HIGHS
SHOULD BE SIMILAR TO TODAY WITH MOST IN THE 80S...AND A FEW
LOCATIONS APPROACHING 90 (MAINLY MCCOOK/HILL CITY). SURFACE TROUGH
WILL SHIFT JUST A LITTLE BIT EAST AND LOW LEVEL MOISTURE RETURN
COULD BRING HIGHER TD VALUES INTO NORTH CENTRAL KS. NAM MAY BE A
LITTLE HIGH...BUT EITHER WAY THIS BETTER BL MOISTURE WILL SUPPORT
HIGHER CAPE VALUES IN THE AFTERNOON IN THE 2000-2500 J/KG RANGE.
SHEER MAY ALSO BE A LITTLE BIT BETTER WHERE GOOD INSTABILITY IS IN
PLACE THAN TODAY...SO THERE MAY BE A BIGGER THREAT FOR MORE
ORGANIZE THUNDERSTORM DEVELOPMENT IF ANYTHING IS TO DEVELOP IN
THE AFTERNOON. THUNDERSTORM ACTIVITY IS SHOWN TO INITIATE
PRIMARILY ALONG SURFACE TROUGH IN THE AFTERNOON. HOWEVER WITH
DRIER MOISTURE PROFILES AGAIN IN PLACE COVERAGE COULD BE LIMITED
AT LEAST UNTIL LATER WHEN BETTER LARGE SCALE FORCING/DEEPER
MOISTURE MOVINGS IN TO THE REGION FROM THE NORTHWEST.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 219 AM MDT SUN MAY 3 2015
THERE WILL BE CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS THE TRI
STATE AREA ON WEDNESDAY AS AN UPPER LEVEL SHORTWAVE TROUGH MOVES
ACROSS THE AREA. THE NEGATIVELY TILTED FEATURE WILL BRING SOME
STEEPER LAPSE RATES ALOFT AND AREA CAPE VALUES AROUND 1000 J/KG
WEDNESDAY AFTERNOON BASED ON GFS MODEL SOUNDINGS...HOWEVER WEAK
SPEED AND DIRECTIONAL SHEAR DOES NOT SUPPORT THE DEVELOPMENT OF
STRONGER STORMS. WITH SOUTHERLY ADVECTION THROUGH MOST OF THE
PROFILE WEDNESDAY MORNING...DEEP SATURATION IS LIKELY WITH
PRECIPITABLE WATER VALUES BETWEEN 0.80 AND 1.00 INCHES.
THEREFORE...RAIN SHOWERS AND GENERAL WIDESPREAD THUNDERSTORMS ARE
EXPECTED WEDNESDAY AFTERNOON AND EVENING WITH LOCALLY HEAVY RAINFALL
POSSIBLE.
THE UPPER LEVEL TROUGH CONTINUES TO DEEPEN OVERNIGHT WEDNESDAY AND
BECOMES SEPARATED FROM THE UPPER LEVEL FLOW THURSDAY OVER THE
WESTERN CONUS. MODELS DIFFER SLIGHTLY ON THE PROGRESSION OF THE
PATTERN...BUT THE TIMING IS GENERALLY IN AGREEMENT FOR THE FEATURE
TO CONTINUE TO SPIN SLOWLY EASTWARD FOR THURSDAY THROUGH THE
BEGINNING OF NEXT WEEKEND...THUS AFFECTING THE TRI STATE AREA.
BECAUSE OF THE POSITION OF THE SLOW MOVING UPPER LEVEL
SYSTEM...THERE WILL BE CHANCES FOR SHOWERS AND THUNDERSTORMS FOR THE
ENTIRETY OF THE EXTENDED FORECAST.
SURFACE TEMPERATURES THROUGH THE PERIOD WILL REMAIN STEADY DUE TO
THE RELATIVELY UNCHANGING UPPER FLOW...WITH HIGHS IN THE MID TO
UPPER 70S AND LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1055 PM MDT SAT MAY 2 2015
VFR CONDITIONS FORECAST FOR THE 6Z TAFS. STORM ACTIVITY HAS COME TO
AN END ACROSS THE TRI-STATE AREA. LIGHT WINDS WILL CONTINUE THROUGH
THE REST OF THE NIGHT AND SUNDAY. DURING THE DAY A SURFACE TROUGH
WILL MOVE THROUGH THE AREA CAUSING THE WINDS TO TURN CLOCKWISE
THROUGH THE DAY...BECOMING NORTHEAST TO EAST BY EARLY EVENING.
DURING THE EVENING STORM COVERAGE WILL INCREASE. DID NOT PLACE A
MENTION IN THE TAFS AT THIS TIME SINCE THERE IS A POSSIBILITY THE
STORMS WILL NOT MOVE NEAR THE SITES UNTIL AFTER 6Z...WHEN CHANCES
FOR STORMS WILL INCREASE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...MK
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 PM MDT SAT MAY 2 2015
.UPDATE...
ISSUED AT 814 PM MDT SAT MAY 2 2015
BASED ON RADAR TRENDS OVER THE LAST COUPLE HOURS AND LATEST MODEL
DATA...HAVE LOWERED RAINFALL CHANCES ACROSS MOST OF THE AREA
EXCEPT FOR THE YUMA COUNTY AREA AND GREELEY AND WICHITA COUNTIES
WHERE RAINFALL IS OR WILL BE MOVING OVER IN THE NEXT FEW HOURS.
LATEST DATA INDICATES THE LIFT OVER THE NORTHWEST QUADRANT OF THE
IS AT ITS BEST NOW AND WILL DECLINE RATHER QUICKLY OVER THE NEXT
COUPLE OF HOURS. FURTHER SOUTH...THE TRACK OF THE 700MB SHORT
WAVE TROUGH HAS BEEN PUSHED FURTHER SOUTH FOR TONIGHT...WITH THE
MAJORITY OF THE LIFT REMAINING SOUTH OF THE AREA. STILL EXPECTING
RAINFALL CHANCES TO END BY OR SHORTLY AFTER MIDNIGHT AS THE LIFT
WITH THE SHORT WAVE TROUGH COMES TO AN END AS THE TROUGH
FILLS/MOVES OUT OF THE AREA.
UPDATE ISSUED AT 552 PM MDT SAT MAY 2 2015
MAIN CHANGE WAS TO INCREASE RAINFALL CHANCES FOR THE EVENING BASED
ON LATEST DATA. LATEST RADAR SHOWS LINE OF STORMS AHEAD OF A 700MB
SHORT WAVE TROUGH OVER EASTERN COLORADO. 700-500MB FRONTOGENESIS
STRENGTHENS RAPIDLY DURING THE EARLY EVENING AND SHIFTS EAST TO
THE CENTRAL PART OF THE AREA BY MID EVENING ACCOMPANYING THE 700MB
SHORT WAVE TROUGH. MEANWHILE ISENTROPIC LIFT STRENGTHENS
THROUGH THE FIRST HALF OF THE EVENING...WITH THE STRONGEST LIFT
WEST OF HIGHWAY 25 WHILE CONDENSATION PRESSURE DEFICITS DECLINE.
TOWARD MIDNIGHT THE LIFT DECLINES AND CONDENSATION PRESSURE
DEFICITS INCREASE AS THE SHORT WAVE TROUGH MOVES ACROSS THE EAST
HALF OF THE AREA.
WITH THIS IN MIND HAVE THE HIGHEST CHANCES FOR RAINFALL DURING THE
FIRST HALF OF THE EVENING MAINLY FOR LOCATIONS SOUTH OF I-70.
TOWARD MIDNIGHT...AS ENVIRONMENT BECOMES LESS FAVORABLE FOR
RAINFALL...HAVE RAINFALL CHANCES QUICKLY DECLINING OVER THE EAST
HALF OF THE AREA.
LOOKING AT THE SEVERE WEATHER POTENTIAL...STRONGEST STORMS STILL
REMAIN WEST OF THE AREA WHERE THE BEST FORCING IS LOCATED. HAVE
HAD SOME ISOLATED STORMS DEVELOP ALONG THE SURFACE TROUGH
EXTENDING FROM SOUTHWEST TO NORTHEAST OVER THE CENTRAL PART OF THE
AREA. HOWEVER THESE STORMS HAVE BEEN TOO FAR REMOVED FROM THE
BETTER UPPER LEVEL FORCING TO LAST VERY LONG AND HAVE BEEN FAIRLY
WEAK. AS STORMS MOVE EAST INTO THE AREA...THE LIKELIHOOD FOR
SEVERE OUTFLOW WINDS INCREASES OVER THE NEXT HOUR OR SO BEFORE THE
INVERSION DEVELOPS. OVERALL SEVERE STORMS ARE MOST LIKELY WEST OF
HIGHWAY 25 PRIOR TO 9 PM CT OR 8 PM MT. AFTER THAT THE
FORCING...SHEAR...AND INSTABILITY DECLINE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 157 PM MDT SAT MAY 2 2015
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW WESTERLY ZONAL
FLOW IN PLACE FROM THE GREAT BASIN ACROSS THE CENTRAL ROCKIES INTO
THE MISSISSIPPI VALLEY WITH EMBEDDED H5/H7 SHORTWAVE TROUGHS MOVING
THROUGH THE MEAN FLOW. AT THE SURFACE LEE TROUGH HAS DEVELOPED ACROSS
EASTERN COLORADO WITH A MEAN SURFACE TROUGH FROM THE NE PANHANDLE
AND ALONG THE COLORADO BORDER. THUNDERSTORM ACTIVITY HAS ALREADY
DEVELOPED ALONG THE CHEYENNE RIDGE AND HIGHER TERRAIN IN COLORADO.
THIS AFTERNOON-TONIGHT...RAP ANALYSIS (WHICH IS IN LINE WITH EARLIER
NAM) SHOWS 2000 J/KG OF SB CAPE IN PLACE ALONG AND AHEAD OF THE
SURFACE TROUGH...CENTERED OVER OUR CWA. CINH APPEARS TO BE
WEAKENING...HOWEVER ONLY SOME SHALLOW CU HAVE FORMED SO FAR THIS
AFTERNOON. AS MID LEVEL VORTICITY ROTATES FROM THE CENTRAL ROCKIES
INTO EASTERN COLORADO I WOULD EXPECT DEVELOPMENT TO SPREAD EAST
WHICH IS IN LINE WITH SYNOPTIC SCALE GUIDANCE. HRRR/RAP BOTH
INDICATE ISOLATED ACTIVITY DEVELOPING ALONG AND EAST OF THE SURFACE
TROUGH OVER OUR CWA WITH ADDITIONAL ACTIVITY SPREADING IN FROM THE
WEST. BULK SHEER/HELICITY ARE NOT VERY IMPRESSIVE AT THIS POINT
WHERE BETTER INSTABILITY IS IN PLACE (WEST). MOISTURE PROFILES ARE
NOT PARTICULARLY IMPRESSIVE...AND THIS COULD LIMIT COVERAGE TO
ISOLATE/SCATTERED. BETTER PRECIP SIGNAL AND INSTABILITY ARE SHOW IN
IN THE LOWER SHEER ENVIRONMENT...WHERE PULSE TYPE THUNDERSTORMS
WOULD BE MORE LIKELY. STEEP MID LEVEL LAPSE RATES AND MODERATE
INSTABILITY COULD SUPPORT STRONGER UPDRAFTS/CORES...WITH LARGE
HAIL/SEVERE WINDS POSSIBLE. DCAPE VALUES 1000-1500 J/KG AND IN
HIGHER TD DEPRESSIONS (MAINLY WEST) DO RAISE A CONCERN FOR INCREASED
MICROBURST POTENTIAL WITH SOME OF THESE STORMS. IF ANY OF THIS
ACTIVITY WAS TO MOVE INTO THE EASTERN CWA IT COULD BECOME MORE
ORGANIZED WITH INCREASING SPEED SHEER (35KT BULK EFFECTIVE SHEER
AROUND 00Z). AS THE SUN SETS AND WE LOOSE DAYTIME HEATING ANY
LINGERING ACTIVITY SHOULD QUICKLY WEAKEN AS THERE IS ELEVATED CAPE
LATE AND ONLY A WEAK LLJ IN PLACE OVERNIGHT.
SUNDAY...ANOTHER VERY WARM DAY IS EXPECTED AS SURFACE TROUGH DEEPENS
A LITTLE OVER THE CWA AND WAA INCREASES OVER THE CWA. THIS IS IN
RESPONSE TO A STRONGER SHORTWAVE TROUGH MOVING INTO THE NORTHERN
PLAINS AND A COLD FRONT DROPPING SOUTH INTO NORTHERN NEBRASKA. HIGHS
SHOULD BE SIMILAR TO TODAY WITH MOST IN THE 80S...AND A FEW
LOCATIONS APPROACHING 90 (MAINLY MCCOOK/HILL CITY). SURFACE TROUGH
WILL SHIFT JUST A LITTLE BIT EAST AND LOW LEVEL MOISTURE RETURN
COULD BRING HIGHER TD VALUES INTO NORTH CENTRAL KS. NAM MAY BE A
LITTLE HIGH...BUT EITHER WAY THIS BETTER BL MOISTURE WILL SUPPORT
HIGHER CAPE VALUES IN THE AFTERNOON IN THE 2000-2500 J/KG RANGE.
SHEER MAY ALSO BE A LITTLE BIT BETTER WHERE GOOD INSTABILITY IS IN
PLACE THAN TODAY...SO THERE MAY BE A BIGGER THREAT FOR MORE
ORGANIZE THUNDERSTORM DEVELOPMENT IF ANYTHING IS TO DEVELOP IN
THE AFTERNOON. THUNDERSTORM ACTIVITY IS SHOWN TO INITIATE
PRIMARILY ALONG SURFACE TROUGH IN THE AFTERNOON. HOWEVER WITH
DRIER MOISTURE PROFILES AGAIN IN PLACE COVERAGE COULD BE LIMITED
AT LEAST UNTIL LATER WHEN BETTER LARGE SCALE FORCING/DEEPER
MOISTURE MOVINGS IN TO THE REGION FROM THE NORTHWEST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 233 PM MDT SAT MAY 2 2015
UPPER LEVEL FLOW WILL BE SOUTHWEST FROM SUNDAY NIGHT THROUGH TUESDAY
AHEAD OF A LOW MOVING EAST FROM THE DESERT SOUTHWEST INTO THE
CENTRAL AND SOUTHERN ROCKIES. A SURFACE TROUGH NEAR NORTHWEST KANSAS
WILL MOVE EAST MONDAY. HIGH PRESSURE WILL BUILD INTO NORTHWEST
KANSAS MONDAY NIGHT AND TUESDAY. AN AREA OF LOW PRESSURE WILL MOVE
INTO COLORADO TUESDAY.
A SHORTWAVE SHOULD AFFECT THE FA SUNDAY EVENING AND INITIATE STORMS
NEAR THE SURFACE TROUGH OVER NORTHEAST COLORADO INTO SOUTHWEST
NEBRASKA. PLAN TO USE HIGH CHANCE POPS IN THAT AREA WITH LOWER
CHANCE POPS ELSEWHERE ACROSS THE FA. PLAN TO KEEP HIGHER CHANCE POPS
ACROSS THE NORTHERN FA AS STORMS DRIFT NORTHEAST INTO THE FA
OVERNIGHT. THERE SHOULD BE A LULL MONDAY MORNING BEHIND THE EXITING
WAVE. POPS WILL INCREASE TO HIGH CHANCE MONDAY AFTERNOON AND EVENING
AS THE NEXT SHORTWAVE COMES THROUGH. MOISTURE AND DYNAMICS LOOK
GOOD FOR MONDAY NIGHT SO WILL CONTINUE HIGH CHANCE AND LIKELY POPS.
GOOD DYNAMICS AND MOISTURE CONTINUE TO STREAM ACROSS THE FA TUESDAY
AS THE MAIN TROUGH MOVES INTO THE AREA. PRECIPITABLE WATER VALUES
ACROSS THE FA FOR TUESDAY RANGE FROM 1.0 TO 1.2 INCHES. PLAN TO
CONTINUE LIKELY AND DEFINITE POPS.
MIN TEMPERATURES THROUGH MONDAY NIGHT SHOULD COOL INTO THE MID 40S
IN EASTERN COLORADO TO THE MID 50S IN THE EASTERN FA. MAX
TEMPERATURES MONDAY SHOULD RANGE FROM THE LOWER 60S IN EASTERN
COLORADO TO THE LOWER 70S IN THE EASTERN FA.
IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)...AN UPPER LEVEL
TROUGH WILL MOVE ACROSS THE CENTRAL PLAINS TUESDAY NIGHT AND
WEDNESDAY AND THEN LIFT OUT OF THE AREA WEDNEDAY NIGHT. GOOD
DYNAMICS AND MOISTURE SUPPORT HIGH POPS THROUGH WEDNESDAY. POPS
WILL DECREASE TO CHANCE THURSDAY AND FRIDAY BEHIND THE EXITING
TROUGH WITH A COUPLE OF SHORTWAVES IN SOUTHWEST FLOW PRODUCING
STORMS. POPS WILL INCREASE AGAIN SATURDAY AS THE NEXT UPPER LEVEL
TROUGH BEGINS IMPACTING THE CENTRAL PLAINS.
MIN TEMPERATURES SHOULD RANGE FROM 45 TO 55 THROUGH FRIDAY NIGHT
WITH COOLER READINGS IN EASTERN COLORADO. MAX TEMPERATURES WILL
GENERALLY WARM TO THE 70S EACH DAY WITH SOME UPPER 60S POSSIBLE IN
EASTERN COLORADO AND NEAR 80 IN THE EASTERN FA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1055 PM MDT SAT MAY 2 2015
VFR CONDITIONS FORECAST FOR THE 6Z TAFS. STORM ACTIVITY HAS COME TO
AN END ACROSS THE TRI-STATE AREA. LIGHT WINDS WILL CONTINUE THROUGH
THE REST OF THE NIGHT AND SUNDAY. DURING THE DAY A SURFACE TROUGH
WILL MOVE THROUGH THE AREA CAUSING THE WINDS TO TURN CLOCKWISE
THROUGH THE DAY...BECOMING NORTHEAST TO EAST BY EARLY EVENING.
DURING THE EVENING STORM COVERAGE WILL INCREASE. DID NOT PLACE A
MENTION IN THE TAFS AT THIS TIME SINCE THERE IS A POSSIBILITY THE
STORMS WILL NOT MOVE NEAR THE SITES UNTIL AFTER 6Z...WHEN CHANCES
FOR STORMS WILL INCREASE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...FS
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1129 PM CDT Sat May 2 2015
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Sunday)
Issued at 404 PM CDT SAT MAY 2 2015
19Z water vapor imagery shows a shortwave moving across IA while
500MB profiler data suggests a more subtle wave has passed through
eastern KS. Meanwhile a weak mid level ridge has propagated east and
is centered over the TX big bend region with the mean westerlies
remain north along the Canadian boarder. At the surface, high
pressure over the southeast U.S. and low pressure in the northern
plains has favored continued moisture advection with southerly winds
bringing mid 50s dewpoints into the central plains.
For tonight and Sunday, large scale forcing continues to be absent
from the pattern. However models hint at the possibility for
sporadic shower activity as early as this evening. The HRRR and RAP
are the most optimistic in generating the shower activity. It
appears the evening QPF is driven by warm air advection and
isentropic upglide around 700MB. However RAP soundings suggest
moisture will be rather limited in this layer. Because of this and
the general subsidence behind the subtle wave, am not convinced
showers will redevelop across central KS this evening. There are
also signs that another subtle wave could come out of the CO Rockies
late tonight and Sunday morning with some elevated light shower
activity. There is a more organized signal in the isentropic
surfaces of a shallow layer of lift Sunday morning. With bases at 10
KFT and little if any instability above this layer, am not sure any
precip would amount to much and it end up being mainly virga. So
have maintained a dry forecast for now, but there could be some
light hit or miss precip with not much impact. Thanks for the
collaboration EAX and ICT.
Southerly winds and increased low level moisture should help keep
lows tonight around 60 degrees. Increasing clouds from the west
should also help keep overnight lows mild. With continued southerly
winds, models continue the warming trend at 850MB with good mixing.
Therefore have maintained highs in the lower and mid 80s. However if
there is elevated shower activity, the forecast may be to warm for
areas that remain cloudy.
.LONG TERM...(Sunday Night through Saturday)
Issued at 404 PM CDT SAT MAY 2 2015
Several opportunities for precipitation remain present through the
forecast, with challenges on where and when the higher chances will
be being the main challenge.
The main trend in the nearer periods is the trend for a farther
north settling of the cold front as it enters the area. Getting the
front much past the northwest counties could be difficult with
little/no additional frontogenesis from convection through Sunday
afternoon along it and west to southwest flow over it. Have
continued to taper precip chances, especially in the south into
Monday night. There continues to be at least minor potential for
severe weather and perhaps training storms near the boundary. NAM
continues to look overdone with low level moisture and thus CAPE,
but values near 2000 J/kg seem possible along the front with flow
aloft nearly parallel to the boundary with slow cell motions and PWs
near 1.5", more likely late Monday into Monday night.
The front/effective front remains on track to mix back north Tuesday
with some drier air moving in through the day, but attention then
turns to the southwest as an upper wave remains on track to push
slowly northeast through the Central Plains Tuesday night through
Wednesday night. Models are fairly consistent with better upper
forcing to the northwest and southeast, but also with widespread
convection developing to the south-southwest and translating through
late Tuesday night into Wednesday. Beyond Wednesday night, there
continues to be indications of a weak boundary near to just west of
the area with continued moisture availability into the area into
Saturday.
&&
.AVIATION...(For the 06Z TAFs through 06Z Sunday Night)
Issued at 1126 PM CDT SAT MAY 2 2015
VFR conditions expected through most of the taf period. There is a
slight chance for showers and storms towards the end of the
period, but confidence is low on timing at this point.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1036 PM CDT MON MAY 4 2015
.UPDATE...
WEAK INVERTED TROF/ELY WAVE CONTINUES ITS TREK WEST...CURRENTLY
LOCATED ROUGHLY SOUTH OF THE CAMERON/VERMILION PARISH LINE. LATEST
KLCH RADAR SHOWS ISLTD SHOWERS OVER THE COASTAL WATERS EAST OF
CAMERON ALONG WITH A NARROW BAND MOVING WEST ACRS THE SABINE
RIVER. SHOWER CHCS SHOULD DIMINISH ACRS ERN PORTIONS OF THE AREA
TONIGHT...WITH A SLT TO LOW END CHC EXPECTED MAINLY ALONG AND WEST
OF A LINE FROM LEESVILLE TO LAKE CHARLES. ADJUSTED POP/WX GRIDS
SLIGHTLY TO INCORPORATE RECENT HRRR GUIDANCE. ALSO TWEAKED HOURLY
WINDS AS WELL AS TEMP AND DEWPOINT GRIDS...ACCOUNTING FOR RECENT
OBSERVATIONS. REMAINDER OF FCST IS IN OTHERWISE DECENT SHAPE AND
UPDATES HAVE BEEN SENT. 24
&&
.PREV DISCUSSION... /ISSUED 706 PM CDT MON MAY 4 2015/
DISCUSSION...
05/00Z TAF ISSUANCE.
AVIATION...
ISLTD SHRA/TSRA AND BKN VFR CIGS ACCOMPANY A WEAK INVERTED TROF
CROSSING SRN LA AND THE NRN GULF OF MEXICO. THIS TROF WILL CROSS
THE REGION TONIGHT INTO TUESDAY MORNING...WITH THE MAIN AXIS OF
CLOUDS/SHRA SHIFTING WEST. ACTIVITY EXPECTED TO DIMINISH THIS
EVENING THEN INCREASE LATE TONIGHT...MAINLY NEAR LCH/BPT...AS
SHOWERS OR STORMS MOVE INLAND OFF THE GULF. OTHERWISE...EXPECT VFR
CONDITIONS TO PREVAIL THROUGH THE PERIOD AT LFT/ARA/AEX WITH MVFR
CIGS DEVELOPING AT LCH/BPT AFTER MIDNIGHT. SELY WINDS 5-10 KT
TONIGHT WILL STRENGTHEN 10-15 KT TUESDAY MORNING WITH GUSTS TO 25
KT AT TIMES DURING THE DAY. 24
PREV DISCUSSION... /ISSUED 350 PM CDT MON MAY 4 2015/
DISCUSSION...
NORTH-SOUTH ORIENTED INVERTED SFC TROF...OR EASTERLY
WAVE...STRETCHES ROUGHLY ALONG THE ATCHAFALAYA RIVER AND ON OUT
INTO THE CENTRAL GULF OF MEXICO AS OF 20Z. THIS FEATURE HAS
ASSISTED WITH THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER PARTS OF SOUTH AND EAST CENTRAL LOUISIANA THIS
AFTERNOON. THE WAVE IS PROGGED TO CONTINUE WWD TONIGHT...WITH A
GENERAL DECREASE IN BOTH COVERAGE AND INTENSITY OF CONVECTION EXPECTED
THIS EVENING WITH THE LOSS OF DIURNAL INSTABILITY. AN UPTICK IS
LIKELY OVER THE GULF WATERS AFTER MIDNIGHT AND TWD THE EARLY
MORNING HRS WITH THE MARINE DMAX...WITH THE NWD CELL MOTION
LEADING TO AT LEAST SOME ACTIVITY SPREADING INLAND.
POPS WERE RAISED OVER EAST TX TOMORROW AS THE WAVE ENTERS A
REGION OF INCREASED UPPER DIVERGENCE AND DEEPER MSTR...WITH
COVERAGE EXPECTED TO EXCEED THAT OBSERVED TODAY.
PATTERN THEREAFTER MARKED BY A SW TO NE RIDGE AXIS OVERHEAD...WITH
A MOIST SOUTHERLY LOW LEVEL FLOW AND SUBTLE IMPULSES EJECTING
AHEAD OF A DIGGING WRN CONUS TROF. LOW END POPS...WITH A GRADIENT
THAT GENERALLY DECREASES FROM WEST TO EAST...ALONG WITH SEASONAL
HIGHS AND ABOVE NORMAL LOWS WILL RESULT.
THE TROF IS PROGGED TO EDGE EASTWARD OVER THE WEEKEND...SLOWLY
ERODING THE RIDGE ALOFT...THEN FINALLY LIFTING OUT INTO THE
CENTRAL CONUS AND FLATTENING IT OUT EARLY NEXT WEEK. GLOBAL MODELS
ALSO PROG A FRONTAL BOUNDARY INTO THE REGION ON SUN NIGHT INTO
MON.
13
MARINE...
WINDS AND SEAS WILL INCREASE TONIGHT INTO TUESDAY AS THE PRESSURE
GRADIENT TIGHTENS WHILE AN EASTERLY WAVE MOVES WEST ACROSS THE
NORTHERN GULF. ELEVATED WINDS AND SEAS WILL CONTINUE INTO
TUESDAY NIGHT...SUBSIDING ON WEDNESDAY AS THE PRESSURE GRADIENT
RELAXES. THE CHANCE OF SHOWERS WILL INCREASE AS THE EASTERLY WAVE
MOVES ACROSS THE REGION TODAY AND TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 82 63 81 62 / 20 10 10 10
LCH 81 67 80 66 / 10 30 30 10
LFT 80 65 81 64 / 40 10 10 10
BPT 81 68 80 69 / 10 40 50 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR GMZ452-455-470-
472-475.
SMALL CRAFT EXERCISE CAUTION THROUGH LATE TUESDAY NIGHT FOR
GMZ450.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1234 PM CDT SUN MAY 3 2015
.AVIATION...HIGH PRESSURE RIDGING IN FROM JUST OFF THE CAROLINAS
PROVIDING A LIGHT ANTICYCLONIC ONSHORE FLOW. MAINLY HIGH BASED
FAIR WX CU WITH SOME ENHANCEMENT BETWEEN LCH AND LFT ON VISIBLE
IMAGERY. SHORTWAVE ENERGY AROUND BPT AND AEX DUE PARTIALLY TO
SOME UPPER DIVERGENCE AND HRRR IMPLIES ISOLD SHOWERS A
POSSIBLILITY BUT WILL LEAVE OUT OF THE TAFS AS COVERAGE WOULD BE
TOO SPARSE TO WORRY ABOUT. CONTINUED VFR.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 1058 AM CDT SUN MAY 3 2015/
DISCUSSION...
FORECAST IS GENERALLY ON TRACK THIS MORNING. LATEST HIGH
RESOLUTION MODELS POINT TWD THE POTENTIAL FOR ISOLD -RW ACROSS THE
AREA IN RESPONSE TO INCREASING MSTR...A WEAK SHORTWAVE PUSHING
EAST FROM TX...AND WEAK LL CONVERGENCE. SATELLITE IMAGERY AND A
QUICK LOOK OUTSIDE REVEALS MOSTLY FLAT CU...THOUGH SOME VERTICAL
DEPTH WAS NOTED OFF TO THE EAST/SE. KLCH/KPOE 88DS HAVE SHOWN SOME
BRIEF LIGHT SHOWERS AS WELL. WITH ALL OF THIS IN MIND...INTRODUCED
A LOW POP ALONG WITH ISOLATED SHOWERS TO THE FCST FOR TODAY.
REMAINING GRIDS LOOK FINE WITH ONLY MINOR ADJUSTMENTS MADE.
13
PREV DISCUSSION... /ISSUED 410 AM CDT SUN MAY 3 2015/
DISCUSSION...
EARLY MORNING SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER THE
TENNESSEE VALLEY KEEPING A LOW-LEVEL SRLY FLOW IN PLACE OVER THE
REGION. MEANWHILE WATER VAPOR IMAGERY SHOWS WEAK RIDGING IN PLACE
FROM THE WRN GULF UP THROUGH THE SRN PLAINS. SATELLITE IMAGERY
AND SFC OBS INDICATE LITTLE CLOUDINESS OVERHEAD ATTM...WHILE
REGIONAL 88DS ARE ACCORDINGLY PPINE.
ONE MORE DRY DAY LOOKS ON TAP FOR THE FORECAST AREA AS THE RIDGE
ALOFT HOLDS FIRM. SEASONAL TEMPS IN THE LOWER 80S SHOULD BE THE
RULE FOR THE AFTERNOON.
OVER THE EARLY PART OF THE COMING WEEK THE NEXT PACIFIC STORM
SYSTEM ALOFT MOVING ASHORE ALONG THE WEST COAST WILL GIVE A PUSH
TO THE RIDGE...EVENTUALLY SHOVING IT TO THE SERN CONUS. IN THE
MEANTIME A WEAK ERLY WAVE IS PROGGED TO SLIP PAST THE REGION ON
MONDAY...ALLOWING FOR WIDELY SCATTERED SHOWERS OR STORMS TO
DEVELOP BY AFTERNOON/EVENING.
THEREAFTER SMALL POPS...MAINLY DAYTIME...LINGER THROUGH THE
REMAINDER OF THE FORECAST AS THE PACIFIC SYSTEM GRADUALLY OPENS
AND LIFTS THROUGH THE WRN CONUS AND PLAINS STATES...USHERING IN
A SERIES OF WEAK DISTURBANCES ACROSS THE WRN GULF STATES.
MARINE...
AN ONSHORE FLOW...THOUGH SOMETIMES MORE ERLY...WILL LINGER
THROUGH THE PERIOD WITH HIGH PRESSURE CENTERED OVER THE SERN
CONUS AND OFF THE SRN ATLANTIC COAST. A TIGHTENING GRADIENT WITH
LOW PRESSURE DEVELOPING OVER THE SRN PLAINS WILL ALLOW FOR AT
LEAST CAUTION-CRITERIA WINDS BY LATE TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 82 58 82 63 / 20 10 20 10
LCH 81 61 82 66 / 20 0 20 20
LFT 82 61 81 64 / 20 10 30 20
BPT 83 63 83 67 / 20 0 10 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...11
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
340 PM EDT SUN MAY 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN MAY 3 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER
LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE
TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO
TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN
MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS
VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW
MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE
FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION.
UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50.
A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE
NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS
EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR
10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND
1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS
INTO THE MID TO UPPER 70S OVER THE WEST HALF.
THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF
THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL
SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID
TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING.
LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA
DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON
HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K-
10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH
DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE
INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY
WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE
AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE
ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER
SOUTH.
EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY
06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 300 PM EDT SUN MAY 3 2015
THE MODELS INDICATE THAT THE NRN STREAM ZONAL FLOW WILL GIVE WAY TO
RIDGING OVER THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH DEVELOPING
OVER THE WRN CONUS. BY LATE IN THE WEEK...SHORTWAVES EMERGING FROM
THE SW CONUS AND CNTRL PLAINS WILL HELP TO FLATTEN THE RIDGE AND
BRING AN INCREASING POTENTIAL FOR PCPN INTO THE WRN GREAT LAKES.
TEMPS ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH MUCH OF THE
PERIOD.
HIGH PRES WILL DOMIMATE KEEPING CONDITIONS DRY MON NIGHT THROUGH
TUE. WITH PWATS DROPPING DOWN BLO .25 INCH AND LIGHT WINDS EXPECTED
UNDER THE SFC HIGH...MIN TEMPS MON NIGHT COULD VERY WELL DROP BELOW
FREEZING AT SEVERAL OF THE TYPICAL INLAND COLD SPOTS. EXPECT TEMPS
TO REBOUND ON TUESDAY AND MAYBE BE A FEW DEGREES WARMER THAN
MONDAY/S READINGS...WITH HIGHS IN THE 60S AND LOWER 70S...WARMEST
WEST. COOLER READINGS IN THE 50S CAN BE EXPECTED NEAR THE GREAT
LAKES...ESPECIALLY NEAR LAKE MICHIGAN WITH DEVELOPING LIGHT SE FLOW
ON BACKSIDE OF SFC RIDGE AXIS.
TUE NIGHT-WED NIGHT...INCLUDED SOME LOW POPS FOR SHRA OVER MAINLY
WEST HALF (ESPECIALLY ALONG THE WI BORDER) WHICH MAY DEVELOP LATE
TUE NIGHT INTO WED ALONG AN 850 MB WARM FRONT LIFTING SLOWLY NNE
FROM THE UPPER MS VALLEY AND AHEAD OF A STRENGTHENING 850 MB JET
NOSING INTO THE WRN GREAT LAKES. TEMPS WILL BEGIN TO INCREASE WED
WITH WAA BUT THERE COULD BE SOME WAA CLOUDS AROUND TO KEEP TEMPS
DOWN A BIT. MODELS SUGGEST A LULL IN PCPN WED NIGHT AS 850 MB WARM
FRONT LIFTS NORTH OF THE AREA AND WRN GREAT LAKES REGION BECOMES
CAPPED BY WARMER/DRIER AIR ALOFT.
THU-FRI...TEMPS SHOULD REALLY CLIMB THU ALONG WITH INCREASING GULF
MOISTURE IN STRENGTHENING SRLY FLOW AHEAD OF A PLAINS SFC TROUGH
THAT WILL EDGE TOWARD THE UPPER MS VALLEY. LAYER PWATS INCREASE FROM
NEAR 1.5 INCHES WEST TO 1.25 INCHES EAST. MODELS STILL DIFFER ON
TIMING OF COLD FRONTAL PASSAGE LATE IN THE WEEK WITH THE 00Z ECMWF
12-18 HRS FASTER THAN EITHER THE 12Z GFS OR 12Z CANADIAN MODEL. 00Z
ECMWF HAS FRONT MOVING THROUGH LATE THU NIGHT AND FRI WHILE THE 12Z
GFS/CANADIAN SHOW A FRONTAL TIMING OF FRI ATFERNOON AND FRI NIGHT.
ALL MODELS SHOW INCREASING PCPN CHANCES OVER THE WEST HALF THU
AFTERNOON SPREADING INTO THE EAST HALF THU NIGHT AHEAD OF
APPROACHING FRONTAL BOUNDARY. MOST OF THE MODELS SHOW SHRA/TSRA
HANGING AROUND ON FRIDAY WITH ECMWF SHOWING FRONTAL PASSAGE TAKING
PLACE AND GFS/CANADIAN SHOWING FRONTAL BOUNDARY APPROACHING THE WRN
CWA.
FRI NIGHT-SATURDAY...MODEL DIFFERENCES WILL HAVE BIGGEST IMPACT ON
FCST TOWARD NEXT WEEKEND. IF 00Z ECMWF VERIFIES THEN FRI NIGHT AND
SAT WILL BE MOSTLY DRY AND COOLER IN WAKE OF FRONTAL PASSAGE. THE
12Z SLOWER GFS AND CANADIAN SOLN WITH FRONT WOULD WARRANT KEEPING
SHRA/TSRA CHCS IN FOR AT LEAST THE CENTRAL AND ERN FCST AREA FRI
NIGHT AND MAYBE EVEN LINGERING INTO SAT MORNING. GFS AND CANADIAN
WOULD THEN ARGUE FOR DRIER/COOLER CONDITIONS SAT AFTERNOON INTO SAT
NIGHT AS HIGH PRES BUILDS IN FM THE NW IN THE WAKE OF THE FRONTAL
PASSAGE. GIVEN POOR MODEL AGREEMENT WILL PROBABLY EMPLOY A BLEND
OF FCST GUIDANCE FOR POPS DURING THIS PERIOD.
NEXT SUNDAY...AGAIN MODEL DIFFERENCES WILL PROBABLY ARGUE FOR USING
A BLEND OF MODEL GUIDANCE BY DAY 7 FCST. THIS WOULD WARRANT A DRY
FCST FOR MUCH OF THE CWA ESPECIALLY CENTRAL AND EAST STILL UNDER
INFLUENCE OF CANADIAN HIGH PRES OVER AREA. THE ECMWF SHOWS SYSTEM
DEVELOPING OVER CENTRAL PLAINS AND TRIES TO DEVELOP PCPN ALONG THE
WI BORDER COUNTIES IN STRENGTHENING WAA PATTERN OUT AHEAD OF IT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 151 PM EDT SUN MAY 3 2015
EXPECT MAINLY VFR CEILINGS/VIS THROUGH THE PERIOD. THE ONLY
EXCEPTION WILL BE IF AND WHEN TS ENTER THE AREA. SHOWERS AND
ISOLATED TS ACTIVITY ACROSS CENTRAL MN WILL CONTINUE TO EDGE
NE...WITH ADDITIONAL SHOWERS AND TS DEVELOPMENT ALONG THE NEARING
COLD FRONT STRETCHING FROM SE ACROSS CENTRAL MANITOBA TO NEAR THE W
LAKE SUPERIOR SHORELINE...AND THROUGH CENTRAL MN. LOOK FOR THE BEST
CHANCE FOR TS DEVELOPMENT AT IWD 20-22Z. WHILE SAW WILL HAVE A
CHANCE OF TS AROUND 23Z...IT WAS LESS LIKELY...SO LEFT VCTS OUT OF
THE TAF FOR THEM. DRY HIGH PRESSURE ROLLING INTO E MT AND THE
DAKOTAS THIS AFTERNOON WILL QUICKLY BUILD IN BEHIND THE FRONT. THE
RESULT WILL BE A CLEAR/MOSTLY CLEAR BY DAYBREAK MONDAY IF NOT
EARLIER.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 339 PM EDT SUN MAY 3 2015
OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR
SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD.
A LOW OVER S HUDSON BAY WILL MOVE INTO FAR N QUEBEC TONIGHT AND DRAG
A TROUGH/COLD FRONT OVER LAKE SUPERIOR...WITH SHOWER AND
THUNDERSTORMS...AND THE POTENTIAL FOR AREAS OF FOG. FOG WILL LINGER
INTO MONDAY OVER THE E HALF OF LAKE SUPERIOR. IN THE WAKE OF THE
TROUGH...HIGH PRESSURE WILL BUILD OVER THE UPPER LAKES FROM THE W-NW
ON MONDAY. EXPECT THIS HIGH TO DRIFT INTO SE ONTARIO LATER TUESDAY
INTO WEDNESDAY...AS ANOTHER AREA OF HIGH PRESSURE MOVES INTO NW
ONTARI...AND A LOW TAKES SHAPE OVER THE PLAINS. A LOW PRESSURE
CENTER EMERGING FROM THIS TROUGH WILL MOVE THROUGH THE N PLAINS ON
THURSDAY WHILE THE ONTARIO HIGH DRIFTS ACROSS HUDSON BAY INTO
QUEBEC. THE LOW WILL DRAG A TROUGHACROSS THE UPPER GREAT LAKES
REGION THURSDAY NIGHT THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
300 PM EDT SUN MAY 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN MAY 3 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER
LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE
TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO
TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN
MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS
VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW
MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE
FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION.
UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50.
A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE
NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS
EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR
10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND
1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS
INTO THE MID TO UPPER 70S OVER THE WEST HALF.
THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF
THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL
SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID
TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING.
LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA
DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON
HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K-
10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH
DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE
INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY
WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE
AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE
ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER
SOUTH.
EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY
06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 300 PM EDT SUN MAY 3 2015
THE MODELS INDICATE THAT THE NRN STREAM ZONAL FLOW WILL GIVE WAY TO
RIDGING OVER THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH DEVELOPING
OVER THE WRN CONUS. BY LATE IN THE WEEK...SHORTWAVES EMERGING FROM
THE SW CONUS AND CNTRL PLAINS WILL HELP TO FLATTEN THE RIDGE AND
BRING AN INCREASING POTENTIAL FOR PCPN INTO THE WRN GREAT LAKES.
TEMPS ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH MUCH OF THE
PERIOD.
HIGH PRES WILL DOMIMATE KEEPING CONDITIONS DRY MON NIGHT THROUGH
TUE. WITH PWATS DROPPING DOWN BLO .25 INCH AND LIGHT WINDS EXPECTED
UNDER THE SFC HIGH...MIN TEMPS MON NIGHT COULD VERY WELL DROP BELOW
FREEZING AT SEVERAL OF THE TYPICAL INLAND COLD SPOTS. EXPECT TEMPS
TO REBOUND ON TUESDAY AND MAYBE BE A FEW DEGREES WARMER THAN
MONDAY/S READINGS...WITH HIGHS IN THE 60S AND LOWER 70S...WARMEST
WEST. COOLER READINGS IN THE 50S CAN BE EXPECTED NEAR THE GREAT
LAKES...ESPECIALLY NEAR LAKE MICHIGAN WITH DEVELOPING LIGHT SE FLOW
ON BACKSIDE OF SFC RIDGE AXIS.
TUE NIGHT-WED NIGHT...INCLUDED SOME LOW POPS FOR SHRA OVER MAINLY
WEST HALF (ESPECIALLY ALONG THE WI BORDER) WHICH MAY DEVELOP LATE
TUE NIGHT INTO WED ALONG AN 850 MB WARM FRONT LIFTING SLOWLY NNE
FROM THE UPPER MS VALLEY AND AHEAD OF A STRENGTHENING 850 MB JET
NOSING INTO THE WRN GREAT LAKES. TEMPS WILL BEGIN TO INCREASE WED
WITH WAA BUT THERE COULD BE SOME WAA CLOUDS AROUND TO KEEP TEMPS
DOWN A BIT. MODELS SUGGEST A LULL IN PCPN WED NIGHT AS 850 MB WARM
FRONT LIFTS NORTH OF THE AREA AND WRN GREAT LAKES REGION BECOMES
CAPPED BY WARMER/DRIER AIR ALOFT.
THU-FRI...TEMPS SHOULD REALLY CLIMB THU ALONG WITH INCREASING GULF
MOISTURE IN STRENGTHENING SRLY FLOW AHEAD OF A PLAINS SFC TROUGH
THAT WILL EDGE TOWARD THE UPPER MS VALLEY. LAYER PWATS INCREASE FROM
NEAR 1.5 INCHES WEST TO 1.25 INCHES EAST. MODELS STILL DIFFER ON
TIMING OF COLD FRONTAL PASSAGE LATE IN THE WEEK WITH THE 00Z ECMWF
12-18 HRS FASTER THAN EITHER THE 12Z GFS OR 12Z CANADIAN MODEL. 00Z
ECMWF HAS FRONT MOVING THROUGH LATE THU NIGHT AND FRI WHILE THE 12Z
GFS/CANADIAN SHOW A FRONTAL TIMING OF FRI ATFERNOON AND FRI NIGHT.
ALL MODELS SHOW INCREASING PCPN CHANCES OVER THE WEST HALF THU
AFTERNOON SPREADING INTO THE EAST HALF THU NIGHT AHEAD OF
APPROACHING FRONTAL BOUNDARY. MOST OF THE MODELS SHOW SHRA/TSRA
HANGING AROUND ON FRIDAY WITH ECMWF SHOWING FRONTAL PASSAGE TAKING
PLACE AND GFS/CANADIAN SHOWING FRONTAL BOUNDARY APPROACHING THE WRN
CWA.
FRI NIGHT-SATURDAY...MODEL DIFFERENCES WILL HAVE BIGGEST IMPACT ON
FCST TOWARD NEXT WEEKEND. IF 00Z ECMWF VERIFIES THEN FRI NIGHT AND
SAT WILL BE MOSTLY DRY AND COOLER IN WAKE OF FRONTAL PASSAGE. THE
12Z SLOWER GFS AND CANADIAN SOLN WITH FRONT WOULD WARRANT KEEPING
SHRA/TSRA CHCS IN FOR AT LEAST THE CENTRAL AND ERN FCST AREA FRI
NIGHT AND MAYBE EVEN LINGERING INTO SAT MORNING. GFS AND CANADIAN
WOULD THEN ARGUE FOR DRIER/COOLER CONDITIONS SAT AFTERNOON INTO SAT
NIGHT AS HIGH PRES BUILDS IN FM THE NW IN THE WAKE OF THE FRONTAL
PASSAGE. GIVEN POOR MODEL AGREEMENT WILL PROBABLY EMPLOY A BLEND
OF FCST GUIDANCE FOR POPS DURING THIS PERIOD.
NEXT SUNDAY...AGAIN MODEL DIFFERENCES WILL PROBABLY ARGUE FOR USING
A BLEND OF MODEL GUIDANCE BY DAY 7 FCST. THIS WOULD WARRANT A DRY
FCST FOR MUCH OF THE CWA ESPECIALLY CENTRAL AND EAST STILL UNDER
INFLUENCE OF CANADIAN HIGH PRES OVER AREA. THE ECMWF SHOWS SYSTEM
DEVELOPING OVER CENTRAL PLAINS AND TRIES TO DEVELOP PCPN ALONG THE
WI BORDER COUNTIES IN STRENGTHENING WAA PATTERN OUT AHEAD OF IT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 151 PM EDT SUN MAY 3 2015
EXPECT MAINLY VFR CEILINGS/VIS THROUGH THE PERIOD. THE ONLY
EXCEPTION WILL BE IF AND WHEN TS ENTER THE AREA. SHOWERS AND
ISOLATED TS ACTIVITY ACROSS CENTRAL MN WILL CONTINUE TO EDGE
NE...WITH ADDITIONAL SHOWERS AND TS DEVELOPMENT ALONG THE NEARING
COLD FRONT STRETCHING FROM SE ACROSS CENTRAL MANITOBA TO NEAR THE W
LAKE SUPERIOR SHORELINE...AND THROUGH CENTRAL MN. LOOK FOR THE BEST
CHANCE FOR TS DEVELOPMENT AT IWD 20-22Z. WHILE SAW WILL HAVE A
CHANCE OF TS AROUND 23Z...IT WAS LESS LIKELY...SO LEFT VCTS OUT OF
THE TAF FOR THEM. DRY HIGH PRESSURE ROLLING INTO E MT AND THE
DAKOTAS THIS AFTERNOON WILL QUICKLY BUILD IN BEHIND THE FRONT. THE
RESULT WILL BE A CLEAR/MOSTLY CLEAR BY DAYBREAK MONDAY IF NOT
EARLIER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT SUN MAY 3 2015
OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR
SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD.
LOW PRESSURE OVER NW ONTARIO WILL LIFT NORTHEAST TO HUDSON
BAY...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR LATE THIS AFTERNOON
AND EVENING ALONG WITH A CHANCE OF THUNDERSTORMS...AND PATCHY TO
AREAS OF FOG. LOOK FOR HIGH PRESSURE ACROSS NORTH DAKOTA TONIGHT TO
BUILD ACROSS THE UPPER GREAT LAKES MONDAY...WITH DRIER AIR LIMITING
ANY LINGERING FOG ACROSS LAKE SUPERIOR. THE HIGH WILL SLOWLY EXIT
ACROSS THE LOWER GREAT LAKES WEDNESDAY NIGHT...IN RESPONSE TO A LOW
NEARING FROM THE N AND CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY.
THE CHANCE OF THUNDERSTORMS WILL ALSO RETURN WEDNESDAY AFTERNOON
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...KF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
152 PM EDT SUN MAY 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN MAY 3 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER
LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE
TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO
TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN
MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS
VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW
MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE
FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION.
UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50.
A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE
NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS
EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR
10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND
1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS
INTO THE MID TO UPPER 70S OVER THE WEST HALF.
THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF
THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL
SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID
TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING.
LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA
DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON
HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K-
10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH
DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE
INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY
WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE
AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE
ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER
SOUTH.
EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY
06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 AM EDT SUN MAY 3 2015
ABOVE AVERAGE TEMPS WITH GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS THE FORECAST AREA THROUGH TUESDAY BEFORE OFF AND ON CHANCES
OF SHOWERS AND THUNDERSTORMS CLOSE OUT THE WEEK.
MONDAY AND TUESDAY...A SPLIT UPPER JET PATTERN WILL BE WELL IN PLACE
TO BEGIN THE PERIOD...WITH A VERY BROAD MID-LEVEL TROUGH ACROSS THE
UPPER MS VALLEY AND UPPER GREAT LAKES. THE COLD FRONT AND ASSOCIATED
CONVECTION EXPECTED TO INFLUENCE THE CWA THIS AFTERNOON AND TONIGHT
WILL CLEAR THE CWA BY 12Z MONDAY. WITH SFC HIGH PRESSURE SHIFTING
ACROSS THE CWA AND A MID-LEVEL RIDGE BUILDING ACROSS THE NORTHERN
PLAINS...DRY CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY. TEMPS
WILL BE COOLER THAN TODAY FOR BOTH MONDAY AND TUESDAY AS 850 HPA
TEMPS FALL TO 3-7C. WITH A WNW WIND MON...TEMPS WILL BE CHILLY
ACROSS PORTIONS OF THE LAKE SUPERIOR SHORELINE...ESPECIALLY EAST OF
MARQUETTE. SOME HINTS AS LINGERING LOW-LEVEL MOISTURE OVER EASTERN
LAKE SUPERIOR MAY ALSO RESULT IN SOME FOG ALONG THE SHORELINE
THROUGH MOST OF MONDAY.
TUESDAY NIGHT AND WEDNESDAY...A BROAD SFC LOW FORMING UNDER THE
SOUTHERN UPPER JET AND A MID-LEVEL TROUGH OVER THE SW STATES WILL
BEGIN TO LIFT INTO THE CENTRAL PLAINS BY THIS TIME. MEANWHILE...THE
MID-LEVEL RIDGE ACROSS THE PLAINS AND MS VALLEY WILL CONTINUE TO
BUILD WHILE DRIFTING EASTWARD. LOW-LEVEL WAA/ISENTROPIC LIFT WELL
AHEAD OF THIS LOW IS EXPECTED ACROSS WI AND THE WEST AND CENTRAL CWA
TUESDAY NIGHT INTO WEDNESDAY...AND SHOULD BE ENOUGH TO GENERATE
LIGHT RAIN ALOFT. HOW MUCH REACHES THE GROUND REMAINS IN QUESTION AS
THE LOW-LEVELS WILL BE QUITE DRY TUESDAY. BECAUSE OF THIS...ALL
MODEL SOLUTIONS SHOW A RAPID DETERIORATION OF THE PRECIP AS IT MOVES
OVER UPPER MI. HAVE OPTED TO KEEP ONLY LOW CHANCE POPS ALONG THE WI
BORDER TUESDAY NIGHT...AND ACROSS MUCH OF WESTERN AND CENTRAL UPPER
MI ON WEDNESDAY.
THURSDAY THROUGH SATURDAY...THE SFC LOW OVER THE PLAINS WILL
CONTINUE TO MEANDER TO THE NE AS THE ASSOCIATED MID-LEVEL WAVE
ATTEMPTS TO ROUND THE RIDGE. WITH MINIMAL FORCING...MUCH OF THE AREA
SHOULD REMAIN DRY WED NIGHT INTO THU MORNING. BY THE
AFTERNOON...FORCING FROM THE APPROACHING MID-LEVEL SHORTWAVE WILL BE
ENOUGH TO INDUCE SCATTERED SHOWERS AND POSSIBLY SOME THUNDERSTORMS
ACROSS THE WEST HALF OF THE CWA. WITH THE WAVE AND SFC LOW LIFTING
ACROSS THE ARROWHEAD OF MN AND NORTH OF LAKE SUPERIOR...SCATTERED
SHOWERS AND STORMS ARE EXPECTED INTO FRIDAY MORNING. COVERAGE MAY
INCREASE FRIDAY AFTERNOON AS THE SFC COLD FRONT BEGINS TO MOVE IN
FROM THE WEST. OVERALL...DO NOT SEE ANY REASON TO GO WITH ANYTHING
HIGHER THAN HIGH-END CHANCE POPS GIVEN THE OVERALL SCATTERED NATURE
OF EXPECTED PRECIP. BY SATURDAY...THE SFC COLD FRONT WILL CLEAR THE
AREA AS IT BEGINS TO STALL/WASH OUT OVER WI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 151 PM EDT SUN MAY 3 2015
EXPECT MAINLY VFR CEILINGS/VIS THROUGH THE PERIOD. THE ONLY
EXCEPTION WILL BE IF AND WHEN TS ENTER THE AREA. SHOWERS AND
ISOLATED TS ACTIVITY ACROSS CENTRAL MN WILL CONTINUE TO EDGE
NE...WITH ADDITIONAL SHOWERS AND TS DEVELOPMENT ALONG THE NEARING
COLD FRONT STRETCHING FROM SE ACROSS CENTRAL MANITOBA TO NEAR THE W
LAKE SUPERIOR SHORELINE...AND THROUGH CENTRAL MN. LOOK FOR THE BEST
CHANCE FOR TS DEVELOPMENT AT IWD 20-22Z. WHILE SAW WILL HAVE A
CHANCE OF TS AROUND 23Z...IT WAS LESS LIKELY...SO LEFT VCTS OUT OF
THE TAF FOR THEM. DRY HIGH PRESSURE ROLLING INTO E MT AND THE
DAKOTAS THIS AFTERNOON WILL QUICKLY BUILD IN BEHIND THE FRONT. THE
RESULT WILL BE A CLEAR/MOSTLY CLEAR BY DAYBREAK MONDAY IF NOT
EARLIER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT SUN MAY 3 2015
OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR
SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD.
LOW PRESSURE OVER NW ONTARIO WILL LIFT NORTHEAST TO HUDSON
BAY...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR LATE THIS AFTERNOON
AND EVENING ALONG WITH A CHANCE OF THUNDERSTORMS...AND PATCHY TO
AREAS OF FOG. LOOK FOR HIGH PRESSURE ACROSS NORTH DAKOTA TONIGHT TO
BUILD ACROSS THE UPPER GREAT LAKES MONDAY...WITH DRIER AIR LIMITING
ANY LINGERING FOG ACROSS LAKE SUPERIOR. THE HIGH WILL SLOWLY EXIT
ACROSS THE LOWER GREAT LAKES WEDNESDAY NIGHT...IN RESPONSE TO A LOW
NEARING FROM THE N AND CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY.
THE CHANCE OF THUNDERSTORMS WILL ALSO RETURN WEDNESDAY AFTERNOON
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...KF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 AM EDT SUN MAY 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN MAY 3 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER
LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE
TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO
TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN
MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS
VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW
MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE
FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION.
UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50.
A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE
NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS
EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR
10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND
1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS
INTO THE MID TO UPPER 70S OVER THE WEST HALF.
THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF
THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL
SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID
TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING.
LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA
DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON
HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K-
10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH
DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE
INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY
WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE
AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE
ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER
SOUTH.
EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY
06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 AM EDT SUN MAY 3 2015
ABOVE AVERAGE TEMPS WITH GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS THE FORECAST AREA THROUGH TUESDAY BEFORE OFF AND ON CHANCES
OF SHOWERS AND THUNDERSTORMS CLOSE OUT THE WEEK.
MONDAY AND TUESDAY...A SPLIT UPPER JET PATTERN WILL BE WELL IN PLACE
TO BEGIN THE PERIOD...WITH A VERY BROAD MID-LEVEL TROUGH ACROSS THE
UPPER MS VALLEY AND UPPER GREAT LAKES. THE COLD FRONT AND ASSOCIATED
CONVECTION EXPECTED TO INFLUENCE THE CWA THIS AFTERNOON AND TONIGHT
WILL CLEAR THE CWA BY 12Z MONDAY. WITH SFC HIGH PRESSURE SHIFTING
ACROSS THE CWA AND A MID-LEVEL RIDGE BUILDING ACROSS THE NORTHERN
PLAINS...DRY CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY. TEMPS
WILL BE COOLER THAN TODAY FOR BOTH MONDAY AND TUESDAY AS 850 HPA
TEMPS FALL TO 3-7C. WITH A WNW WIND MON...TEMPS WILL BE CHILLY
ACROSS PORTIONS OF THE LAKE SUPERIOR SHORELINE...ESPECIALLY EAST OF
MARQUETTE. SOME HINTS AS LINGERING LOW-LEVEL MOISTURE OVER EASTERN
LAKE SUPERIOR MAY ALSO RESULT IN SOME FOG ALONG THE SHORELINE
THROUGH MOST OF MONDAY.
TUESDAY NIGHT AND WEDNESDAY...A BROAD SFC LOW FORMING UNDER THE
SOUTHERN UPPER JET AND A MID-LEVEL TROUGH OVER THE SW STATES WILL
BEGIN TO LIFT INTO THE CENTRAL PLAINS BY THIS TIME. MEANWHILE...THE
MID-LEVEL RIDGE ACROSS THE PLAINS AND MS VALLEY WILL CONTINUE TO
BUILD WHILE DRIFTING EASTWARD. LOW-LEVEL WAA/ISENTROPIC LIFT WELL
AHEAD OF THIS LOW IS EXPECTED ACROSS WI AND THE WEST AND CENTRAL CWA
TUESDAY NIGHT INTO WEDNESDAY...AND SHOULD BE ENOUGH TO GENERATE
LIGHT RAIN ALOFT. HOW MUCH REACHES THE GROUND REMAINS IN QUESTION AS
THE LOW-LEVELS WILL BE QUITE DRY TUESDAY. BECAUSE OF THIS...ALL
MODEL SOLUTIONS SHOW A RAPID DETERIORATION OF THE PRECIP AS IT MOVES
OVER UPPER MI. HAVE OPTED TO KEEP ONLY LOW CHANCE POPS ALONG THE WI
BORDER TUESDAY NIGHT...AND ACROSS MUCH OF WESTERN AND CENTRAL UPPER
MI ON WEDNESDAY.
THURSDAY THROUGH SATURDAY...THE SFC LOW OVER THE PLAINS WILL
CONTINUE TO MEANDER TO THE NE AS THE ASSOCIATED MID-LEVEL WAVE
ATTEMPTS TO ROUND THE RIDGE. WITH MINIMAL FORCING...MUCH OF THE AREA
SHOULD REMAIN DRY WED NIGHT INTO THU MORNING. BY THE
AFTERNOON...FORCING FROM THE APPROACHING MID-LEVEL SHORTWAVE WILL BE
ENOUGH TO INDUCE SCATTERED SHOWERS AND POSSIBLY SOME THUNDERSTORMS
ACROSS THE WEST HALF OF THE CWA. WITH THE WAVE AND SFC LOW LIFTING
ACROSS THE ARROWHEAD OF MN AND NORTH OF LAKE SUPERIOR...SCATTERED
SHOWERS AND STORMS ARE EXPECTED INTO FRIDAY MORNING. COVERAGE MAY
INCREASE FRIDAY AFTERNOON AS THE SFC COLD FRONT BEGINS TO MOVE IN
FROM THE WEST. OVERALL...DO NOT SEE ANY REASON TO GO WITH ANYTHING
HIGHER THAN HIGH-END CHANCE POPS GIVEN THE OVERALL SCATTERED NATURE
OF EXPECTED PRECIP. BY SATURDAY...THE SFC COLD FRONT WILL CLEAR THE
AREA AS IT BEGINS TO STALL/WASH OUT OVER WI.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 740 AM EDT SUN MAY 3 2015
EXPECT VFR CONDITIONS THROUGH THIS MORNING AT ALL THE TAF SITES WITH
RELATIVELY DRY AIRMASS ASSOCIATED WITH RETREATING HIGH PRES
DOMINATING. DURING THE AFTERNOON...THE INTERACTION BETWEEN AN APPROACHING
DISTURBANCE/COLD FRONT...INCREASING LOW LEVEL MOISTURE IN A GUSTY SW
FLOW AHEAD OF THE FRONT AND DAYTIME HEATING/DESTABILIZATION WILL
RESULT IN SOME SHRA AND TSRA. THERE IS STILL SOME UNCERTAINTY ON THE
DEGREE OF LOW LEVEL MOISTENING/DESTABILIZATION...BUT DID INCLUDE A
MENTION OF SOME TS AT SAW...WHICH IS MORE LIKELY TO SEE HIGHER
INSTABILITY. MVFR CONDITIONS ARE LIKELY TO ACCOMPANY THE STRONGER
SHRA/TS. ANY STRONGER TS COULD ALSO PRODUCE VERY GUSTY WINDS. LOOK
FOR VFR CONDITIONS OVERNIGHT WITH DRYING BEHIND THE COLD FRONT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT SUN MAY 3 2015
OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR
SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD.
LOW PRESSURE OVER NW ONTARIO WILL LIFT NORTHEAST TO HUDSON
BAY...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR LATE THIS AFTERNOON
AND EVENING ALONG WITH A CHANCE OF THUNDERSTORMS...AND PATCHY TO
AREAS OF FOG. LOOK FOR HIGH PRESSURE ACROSS NORTH DAKOTA TONIGHT TO
BUILD ACROSS THE UPPER GREAT LAKES MONDAY...WITH DRIER AIR LIMITING
ANY LINGERING FOG ACROSS LAKE SUPERIOR. THE HIGH WILL SLOWLY EXIT
ACROSS THE LOWER GREAT LAKES WEDNESDAY NIGHT...IN RESPONSE TO A LOW
NEARING FROM THE N AND CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY.
THE CHANCE OF THUNDERSTORMS WILL ALSO RETURN WEDNESDAY AFTERNOON
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 AM EDT SUN MAY 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN MAY 3 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER
LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE
TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO
TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN
MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS
VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW
MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE
FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION.
UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50.
A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE
NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS
EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR
10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND
1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS
INTO THE MID TO UPPER 70S OVER THE WEST HALF.
THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF
THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL
SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID
TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING.
LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA
DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON
HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K-
10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH
DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE
INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY
WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE
AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE
ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER
SOUTH.
EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY
06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 325 AM EDT SUN MAY 3 2015
ABOVE AVERAGE TEMPS WITH GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS THE FORECAST AREA THROUGH TUESDAY BEFORE OFF AND ON CHANCES
OF SHOWERS AND THUNDERSTORMS CLOSE OUT THE WEEK.
MONDAY AND TUESDAY...A SPLIT UPPER JET PATTERN WILL BE WELL IN PLACE
TO BEGIN THE PERIOD...WITH A VERY BROAD MID-LEVEL TROUGH ACROSS THE
UPPER MS VALLEY AND UPPER GREAT LAKES. THE COLD FRONT AND ASSOCIATED
CONVECTION EXPECTED TO INFLUENCE THE CWA THIS AFTERNOON AND TONIGHT
WILL CLEAR THE CWA BY 12Z MONDAY. WITH SFC HIGH PRESSURE SHIFTING
ACROSS THE CWA AND A MID-LEVEL RIDGE BUILDING ACROSS THE NORTHERN
PLAINS...DRY CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY. TEMPS
WILL BE COOLER THAN TODAY FOR BOTH MONDAY AND TUESDAY AS 850 HPA
TEMPS FALL TO 3-7C. WITH A WNW WIND MON...TEMPS WILL BE CHILLY
ACROSS PORTIONS OF THE LAKE SUPERIOR SHORELINE...ESPECIALLY EAST OF
MARQUETTE. SOME HINTS AS LINGERING LOW-LEVEL MOISTURE OVER EASTERN
LAKE SUPERIOR MAY ALSO RESULT IN SOME FOG ALONG THE SHORELINE
THROUGH MOST OF MONDAY.
TUESDAY NIGHT AND WEDNESDAY...A BROAD SFC LOW FORMING UNDER THE
SOUTHERN UPPER JET AND A MID-LEVEL TROUGH OVER THE SW STATES WILL
BEGIN TO LIFT INTO THE CENTRAL PLAINS BY THIS TIME. MEANWHILE...THE
MID-LEVEL RIDGE ACROSS THE PLAINS AND MS VALLEY WILL CONTINUE TO
BUILD WHILE DRIFTING EASTWARD. LOW-LEVEL WAA/ISENTROPIC LIFT WELL
AHEAD OF THIS LOW IS EXPECTED ACROSS WI AND THE WEST AND CENTRAL CWA
TUESDAY NIGHT INTO WEDNESDAY...AND SHOULD BE ENOUGH TO GENERATE
LIGHT RAIN ALOFT. HOW MUCH REACHES THE GROUND REMAINS IN QUESTION AS
THE LOW-LEVELS WILL BE QUITE DRY TUESDAY. BECAUSE OF THIS...ALL
MODEL SOLUTIONS SHOW A RAPID DETERIORATION OF THE PRECIP AS IT MOVES
OVER UPPER MI. HAVE OPTED TO KEEP ONLY LOW CHANCE POPS ALONG THE WI
BORDER TUESDAY NIGHT...AND ACROSS MUCH OF WESTERN AND CENTRAL UPPER
MI ON WEDNESDAY.
THURSDAY THROUGH SATURDAY...THE SFC LOW OVER THE PLAINS WILL
CONTINUE TO MEANDER TO THE NE AS THE ASSOCIATED MID-LEVEL WAVE
ATTEMPTS TO ROUND THE RIDGE. WITH MINIMAL FORCING...MUCH OF THE AREA
SHOULD REMAIN DRY WED NIGHT INTO THU MORNING. BY THE
AFTERNOON...FORCING FROM THE APPROACHING MID-LEVEL SHORTWAVE WILL BE
ENOUGH TO INDUCE SCATTERED SHOWERS AND POSSIBLY SOME THUNDERSTORMS
ACROSS THE WEST HALF OF THE CWA. WITH THE WAVE AND SFC LOW LIFTING
ACROSS THE ARROWHEAD OF MN AND NORTH OF LAKE SUPERIOR...SCATTERED
SHOWERS AND STORMS ARE EXPECTED INTO FRIDAY MORNING. COVERAGE MAY
INCREASE FRIDAY AFTERNOON AS THE SFC COLD FRONT BEGINS TO MOVE IN
FROM THE WEST. OVERALL...DO NOT SEE ANY REASON TO GO WITH ANYTHING
HIGHER THAN HIGH-END CHANCE POPS GIVEN THE OVERALL SCATTERED NATURE
OF EXPECTED PRECIP. BY SATURDAY...THE SFC COLD FRONT WILL CLEAR THE
AREA AS IT BEGINS TO STALL/WASH OUT OVER WI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 125 AM EDT SUN MAY 3 2015
EXPECT VFR CONDITIONS THRU THIS MRNG AT ALL THE TAF SITES WITH
RELATIVELY DRY AIRMASS ASSOCIATED WITH RETREATING HI PRES
DOMINATING. DURING THE AFTN...THE INTERACTION BTWN AN APRCHG
DISTURBANCE/COLD FNT...INCRSG LLVL ABSOLUTE MSTR IN A GUSTY SW FLOW
AHEAD OF THE FNT AND DAYTIME HEATING/DESTABILIZATION WL RESULT IN
SOME SHRA AND TS. THERE IS STILL SOME UNCERTAINTY ON THE DEGREE OF
LLVL MOISTENING/DESTABILIZATION...BUT DID INCLUDE A MENTION OF SOME
TS AT SAW...WHICH IS MORE LIKELY TO SEE SUFFICIENT MOISTENING. MVFR
CONDITIONS ARE LIKELY TO ACCOMPANY THE STRONGER SHRA/TS. ANY
STRONGER TS COULD ALSO PRODUCE VERY GUSTY WINDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT SUN MAY 3 2015
OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR
SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD.
LOW PRESSURE OVER NW ONTARIO WILL LIFT NORTHEAST TO HUDSON
BAY...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR LATE THIS AFTERNOON
AND EVENING ALONG WITH A CHANCE OF THUNDERSTORMS...AND PATCHY TO
AREAS OF FOG. LOOK FOR HIGH PRESSURE ACROSS NORTH DAKOTA TONIGHT TO
BUILD ACROSS THE UPPER GREAT LAKES MONDAY...WITH DRIER AIR LIMITING
ANY LINGERING FOG ACROSS LAKE SUPERIOR. THE HIGH WILL SLOWLY EXIT
ACROSS THE LOWER GREAT LAKES WEDNESDAY NIGHT...IN RESPONSE TO A LOW
NEARING FROM THE N AND CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY.
THE CHANCE OF THUNDERSTORMS WILL ALSO RETURN WEDNESDAY AFTERNOON
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
1216 AM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 940 PM CDT SAT MAY 2 2015
THE DECAYING LINE OF SHOWERS AND THUNDERSTORMS CONTINUED TO
DIMINISH AS IT MOVES EASTWARD INTO THE CWA DURING THE EVENING.
SOME GUSTY WINDS REMAINED ACROSS AREAS WEST OF THE BRAINERD LAKES
REGION...ALTHOUGH WIND SPEED VALUES HAVE DECREASED CONSIDERABLY.
COULD STILL BE SOME GUSTY WINDS...MAINLY ACROSS THE BRAINERD LAKES
AND LEECH LAKE AREAS DURING THE REMAINDER OF THE EVENING.
OVERALL...THINK THINGS WILL QUIET DOWN FURTHER AS THE NIGHT WEARS
ON...PER HRRR AND RAP SIMULATED REFLECTIVITY AS WELL AS THE 4KM
NMM WRF. WILL CONTINUE ISOLATED TO SCATTERED MENTION FOR MUCH OF
THE AREA AS THE NIGHT WEARS ON.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 324 PM CDT SAT MAY 2 2015
A SFC LOW WAS MOVING INTO NW ONTARIO AT 19Z WITH A TRAILING COLD
FRONT SWWD INTO WESTERN ND. A SFC TROF WAS ALSO FOUND IN CENTRAL ND.
THUNDERSTORMS WERE FIRING AHEAD OF THIS TROF IN THE VCNTY OF
EMBEDDED PIECES OF ENERGY IN FAST ZONAL FLOW ALOFT. AN AREA OF SFC
FGEN WAS ALSO CO-LOCATED WITH THE STORMS. EXPECT THIS LINE OF STORMS
TO REACH NW MN BY 21Z. THE STORMS WILL CONTINUE TO MOVE EWD AND
REACH THE NW CORNER OF KOOCHICHING COUNTY BY 01Z. HOWEVER...IT IS AT
THIS POINT IN TIME WHEN THE STORMS BEGIN TO ENCOUNTER DRIER AIR THAT
HAS BEEN CAMPED OUT OVER THE FORECAST AREA. LATEST SHORT TERM HIRES
MODELS INCLUDING THE HRRR AND RAP SHOW THIS TREND AS WELL. AS THIS
INITIAL ROUND OF STORMS DISSOLVES...THE NEXT ROUND WILL BEGIN TO
DEVELOP OVER THE WESTERN HALF OF THE AREA AROUND 06Z AS THE SFC
FRONT MAKES PROGRESS EWD INTO THE REGION. A LOW LEVEL INVERSION SEEN
ON AREA FORECAST SOUNDINGS INDICATE THAT THESE STORMS WILL BE
ELEVATED IN NATURE.
ON SUNDAY...THE FRONT WILL PROGRESS SLOWLY EWD THROUGH THE DAY. SOME
WEAK THUNDERSTORMS WILL BE AROUND IN THE MORNING AS A THERMAL RIDGE
AXIS IS OVER THE REGION AND INSTABILITY IS WEAK. BY AFTERNOON...THE
FRONT PUSHES INTO NW WI WITH MAX HEATING...STORMS WILL BECOME A BIT
MORE VIGOROUS...AND BORDER ON SEVERE. SBCAPE INCREASES TO NEAR 3000
J/KG AND LI/S TO -8C PER FORECAST SOUNDINGS. SHOULD SEE SOME STORMS
NEAR SEVERE WITH LARGE HAIL AND BRIEF HEAVY RAIN AS PWATS ARE 1 TO
1.25 INCHES. MODELS COME INTO AGREEMENT WITH THIS SOLUTION AND HAVE
ROBUST QPF BY 00Z MONDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 324 PM CDT SAT MAY 2 2015
SUNDAY EVENING THE COLD FRONT MOVES SOUTHEAST AWAY FROM THE
AREA...AND WHILE I HAVE MAINTAINED SOME POPS FOR THE EVENING
HOURS...EXPECT THEY WILL ONLY BE ONGOING AT THE VERY BEGINNING OF
THE PERIOD AND EXIT QUICKLY DURING THE EVENING. A COOLER AND DRIER
AIRMASS MOVES INTO THE AREA AFTER MIDNIGHT AND WILL LINGER THROUGH
MONDAY AND MONDAY NIGHT. LOWS SUNDAY NIGHT AND MONDAY NIGHT TO FALL
INTO THE MID 30S TO MID 40S FOR MUCH OF THE AREA...WITH HIGHS MONDAY
BACK IN THE 60S TO AROUND 70.
THE UPPER LEVEL PATTERN IS EXPECTED TO SHIFT TO A LONGWAVE TROUGH
OVER THE WEST COAST AND ROCKIES...WITH WEAK RIDGING TO ZONAL FLOW
OVER THE EASTERN CONUS. THIS TROUGHINESS TO OUR WEST IS GOING TO
SENT A STRONG...SLOW MOVING UPPER LEVEL LOW SHORTWAVE ACROSS THE
UPPER MIDWEST TUESDAY THROUGH FRIDAY...WITH SOME FAIRLY HIGH CHANCES
FOR PRECIPITATION DURING THE PERIOD. TEMPERATURES WILL ALSO BE
ABOVE NORMAL WITH HIGHS IN THE 70S EVEN WITH INCREASED CLOUD COVER
AND PRECIPITATION. THIS SYSTEM TO MOVE OFF TO THE NORTHEAST BY
SATURDAY...BUT THE UPPER LEVEL PATTERN OF A TROUGH OUT WEST REMAINS
WITH WARM AIR STILL BEING FUNNELED IN OUR DIRECTION AND SOME
LINGERING PRECIPITATION CHANCES INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1212 AM CDT SUN MAY 3 2015
A COLD FRONT WILL MOVE EASTWARD ACROSS THE NORTHLAND ON SUNDAY.
ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO BE FOUND ACROSS THE
AREA OVERNIGHT...AS INCREASINGLY UNSTABLE AIR DEVELOPS ACROSS THE
REGION INTO SUNDAY. THE COLD FRONT SHOULD REACH A KBRD TO KCDD LINE
BY 15Z SUNDAY...AND KSTC TO NEAR KDLH LINE BY 18Z. THE FRONT WILL
BE THE CATALYST FOR STRONG THUNDERSTORM DEVELOPMENT ON SUNDAY...
WITH STORMS EXPECTED TO FIRE UP FROM EAST CENTRAL MINNESOTA INTO
KDLH AND THE NORTH SHORE BY MIDDAY. THE BEST CHANCE FOR STORMS WILL
BE IN WISCONSIN...ESPECIALLY FOR KHYR AND AREAS TO THE SOUTH AND
EAST. SOME VSBY AND CIG RESTRICTIONS TO MVFR WILL BE POSSIBLE IN AND
AROUND THE THUNDERSTORMS BUT OVERALL IT SHOULD BE VFR DUE TO DRY AIR
IN THE LOWER LEVELS OF THE ATMOSPHERE. CONDITIONS WILL THEN IMPROVE
FROM NW TO SE AS THE DAY WEARS ON AND INTO THE EVENING WITH SKIES
CLEARING AND GUSTY WINDS DEVELOPING FOR A TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 44 67 40 68 / 0 0 0 0
INL 38 66 38 74 / 0 0 0 0
BRD 44 70 41 70 / 0 0 0 10
HYR 44 70 40 69 / 20 0 0 10
ASX 44 67 37 69 / 10 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...DAP
SHORT TERM...GSF
LONG TERM...LE
AVIATION...GRANING
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
122 PM CDT Sun May 3 2015
.UPDATE:
Issued at 104 PM CDT Sun May 3 2015
Nudged temps up a degree or two from the metro area east. Lowered
Dps across s cntrl IL which match observed RH values already below
30%. The low RHs and fuel moisture below 10 percent will combine
with breezy conditions to create elevated fire conditions this
afternoon across s cntrl IL. Reduced going sky cover to
clear/mostly. Also reduced PoPs this aftn across NE MO and w cntrl
IL as it doesn`t appear that this threat will materialize.
2%
&&
.SHORT TERM: (Today and Tonight)
Issued at 325 AM CDT Sun May 3 2015
There is quite a bit of cloud cover early this morning across the
region courtesy of two weak short waves in the westerly flow
aloft. The first of these currently centered from northern IL into
southeast MO has been generating some spotty high-based showers
from the associated mid clouds/moisture. Present indications are
this wave and the mid level moisture will continue to push east
this morning with a few sprinkles still possible after 12z in
south central IL. The other short wave is currently centered near the
Nebraska/Iowa border into northeast KS and is more problematic. The
associated convection has generated a sizable cloud canopy which
has not been resolved by the models and will overspread a good
portion of the CWA this morning. Unclear is how it will evolve
with time - i.e. thinning, but the RAP has this wave centered through
far eastern IA at midday and the current thought is to have quite
a bit of clouds the first half of this morning then thinning and
moving east by midday into early afternoon. There are also
suggestions in the RAP, ECMWF, and a few of the hi-res WRFs that
the southwest stretching tail of this short wave could generate a
few showers across northeast MO and west central IL this afternoon
and early this evening. I have added a slight chance as a result.
Otherwise a warm day is on tap with well above normal temperatures
expected. While the morning clouds will hamper the temp rise a
bit, increasing south-southwesterly low level flow and rising low-
level temperatures should compensate and will result in highs in
the upper 70s to mid 80s across the area.
South-southwest lower trop flow will maintain a low-level warm
advection region tonight and moisture will gradually be improving.
The thermal and moisture advection combined with a plume of
relatively steep mid level lapse rates will result in a swath of
weak instability across northern parts of the CWA in advance of
the southward sinking cold front. While the front will remain well
north of the CWA at daybreak Monday, northwest steering flow will
help push at least scattered showers and thunderstorms or
thunderstorm clusters into northeast MO and west central IL late
tonight. We could also see spotty WAA generated showers well in
advance of the activity that has moved off the front, hence the low
pops all the way down to St. Louis.
Glass
.LONG TERM: (Monday through Saturday)
Issued at 325 AM CDT Sun May 3 2015
The west-east oriented cold front will ooze southward out of IA
and northern IL into northern sections of the CWA by early Monday
evening. Ongoing showers and thunderstorms at daybreak should
dissipate by midday. Heating and continued low-level moistening
in their wake will result in weak-moderate instability along the
frontal zone and the combo of a migrating impulse and good low
level convergence along the boundary should result in extensive
convective development during the later half of the afternoon
spanning from KS across northern MO/southern IA into central IL.
A broad veering southwesterly LLJ will maintain numerous
thunderstorms/clusters during the evening, with the activity
shunting a bit northward overnight in response to increasing
ridging aloft and a slight northward shift in the frontal zone.
The front will continue to shift northward on Tuesday as ridging
aloft continues to build from the lower TN Valley into the upper
MS Valley. There are some suggestions of air mass type convection
across southern portions of the CWA but I`m not sold on it and
have kept pops in the slight range and confined the coverage.
Otherwise Tuesday will be another day of above normal temps with
highs in the 80s. This warmth will persist on Wednesday and even
into Thursday with the chance of showers and thunderstorms
slowly increasing west-east over the 2 day period as the ridging
aloft shunts east and southwest flow aloft becomes more dominant
with time. The greatest threat of showers and thunderstorms in the
extended period will be Friday-Saturday with an active southwest
flow aloft, moist unstable warm sector, and slowly encroaching
cold front.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 104 PM CDT Sun May 3 2015
VFR fcst thru the prd. The region is on the backside of a large
sfc ridge that is fcst to remain anchored just off the east coast.
This will keep the area in return flow for an extended prd.
Guidance indicates that a cold front will approach the region
tonight but should stall along or near the IA/MO border. This will
limit the best precip chances to those areas and have included a
VCSH group at KUIN late tonight to account for the
threat...though not confident that precip will make it that far
south. Can`t completely rule out precip further south tonight into
Monday mrng near I70 as these types of patterns often produce
isld light precip further east and south than expected.
Specifics for KSTL:
Dry VFR fcst with sthrly flow...diurnal cu and aftn gusts.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
700 AM CDT Sun May 3 2015
.SHORT TERM: (Today and Tonight)
Issued at 325 AM CDT Sun May 3 2015
There is quite a bit of cloud cover early this morning across the
region courtesy of two weak short waves in the westerly flow
aloft. The first of these currently centered from northern IL into
southeast MO has been generating some spotty high-based showers
from the associated mid clouds/moisture. Present indications are
this wave and the mid level moisture will continue to push east
this morning with a few sprinkles still possible after 12z in
south central IL. The other short wave is currently centered near the
Nebraska/Iowa border into northeast KS and is more problematic. The
associated convection has generated a sizeable cloud canopy which
has not been resolved by the models and will overspread a good
portion of the CWA this morning. Unclear is how it will evolve
with time - i.e. thinning, but the RAP has this wave centered through
far eastern IA at midday and the current thought is to have quite
a bit of clouds the first half of this morning then thinning and
moving east by midday into early afternoon. There are also
suggestions in the RAP, ECMWF, and a few of the hi-res WRFs that
the southwest stretching tail of this short wave could generate a
few showers across northeast MO and west central IL this afternoon
and early this evening. I have added a slight chance as a result.
Otherwise a warm day is on tap with well above normal temperatures
expected. While the morning clouds will hamper the temp rise a
bit, increasing south-southwesterly low level flow and rising low-
level temperatures should compensate and will result in highs in
the upper 70s to mid 80s across the area.
South-southwest lower trop flow will maintain a low-level warm
advection region tonight and moisture will gradually be improving.
The thermal and moisture advection combined with a plume of
relatively steep mid level lapse rates will result in a swath of
weak instability across northern parts of the CWA in advance of
the southward sinking cold front. While the front will remain well
north of the CWA at daybreak Monday, northwest steering flow will
help push at least scattered showers and thunderstorms or
thunderstorm clusters into northeast MO and west central IL late
tonight. We could also see spotty WAA generated showers well in
advance of the activity that has moved off the front, hence the low
pops all the way down to St. Louis.
Glass
.LONG TERM: (Monday through Saturday)
Issued at 325 AM CDT Sun May 3 2015
The west-east oriented cold front will ooze southward out of IA
and northern IL into northern sections of the CWA by early Monday
evening. Ongoing showers and thunderstorms at daybreak should
dissipate by midday. Heating and continued low-level moistening
in their wake will result in weak-moderate instability along the
frontal zone and the combo of a migrating impulse and good low
level convergence along the boundary should result in extensive
convective development during the later half of the afternoon
spanning from KS across northern MO/southern IA into central IL.
A broad veering southwesterly LLJ will maintain numberous
thunderstorms/clusters during the evening, with the activity
shunting a bit northward overnight in response to increasing
ridging aloft and a slight northward shift in the frontal zone.
The front will continue to shift northward on Tuesday as ridging
aloft continues to build from the lower TN Valley into the upper
MS Valley. There are some suggestions of air mass type convection
across southern portions of the CWA but I`m not sold on it and
have kept pops in the slight range and confined the coverage.
Otherwise Tuesday will be another day of above normal temps with
highs in the 80s. This warmth will persist on Wednesday and even
into Thursday with the chance of showers and thunderstorms
slowly increasing west-east over the 2 day period as the ridging
aloft shunts east and southwest flow aloft becomes more dominant
with time. The greatest threat of showers and thunderstorms in the
extended period will be Friday-Saturday with an active southwest
flow aloft, moist unstable warm sector, and slowly encroaching
cold front.
Glass
&&
.AVIATION: (For the 12z TAFs through 12z Monday Morning)
Issued at 700 AM CDT Sun May 3 2015
VFR conditions to prevail through forecast period with just mid
and high clouds. Low level wind shear to diminish by mid morning
with winds mixing down to surface. Winds to pickup from the south
to southwest and gust to around 20kts at times this afternoon
before diminishing towards sunset. Some showers possible around
KUIN but will be widely scattered so no mention for now. As for
next system that will approach late tonight, did add vicinity
shower mention at KUIN, dry elsewhere.
Specifics for KSTL:
VFR conditions to prevail through forecast period with just mid
and high clouds. Low level wind shear to diminish by 14z Sunday
with winds mixing down to surface. Winds to pickup from the south
and gust to around 20kts at times this afternoon before
diminishing after 01z Monday. As for next system that will
approach late tonight, activity to remain north of metro area.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
341 AM CDT Sun May 3 2015
.SHORT TERM: (Today and Tonight)
Issued at 325 AM CDT Sun May 3 2015
There is quite a bit of cloud cover early this morning across the
region courtesy of two weak short waves in the westerly flow
aloft. The first of these currently centered from northern IL into
southeast MO has been generating some spotty high-based showers
from the associated mid clouds/moisture. Present indications are
this wave and the mid level moisture will continue to push east
this morning with a few sprinkles still possible after 12z in
south central IL. The other short wave is currently centered near the
Nebraska/Iowa border into northeast KS and is more problematic. The
associated convection has generated a sizeable cloud canopy which
has not been resolved by the models and will overspread a good
portion of the CWA this morning. Unclear is how it will evolve
with time - i.e. thinning, but the RAP has this wave centered through
far eastern IA at midday and the current thought is to have quite
a bit of clouds the first half of this morning then thinning and
moving east by midday into early afternoon. There are also
suggestions in the RAP, ECMWF, and a few of the hi-res WRFs that
the southwest stretching tail of this short wave could generate a
few showers across northeast MO and west central IL this afternoon
and early this evening. I have added a slight chance as a result.
Otherwise a warm day is on tap with well above normal temperatures
expected. While the morning clouds will hamper the temp rise a
bit, increasing south-southwesterly low level flow and rising low-
level temperatures should compensate and will result in highs in
the upper 70s to mid 80s across the area.
South-southwest lower trop flow will maintain a low-level warm
advection region tonight and moisture will gradually be improving.
The thermal and moisture advection combined with a plume of
relatively steep mid level lapse rates will result in a swath of
weak instability across northern parts of the CWA in advance of
the southward sinking cold front. While the front will remain well
north of the CWA at daybreak Monday, northwest steering flow will
help push at least scattered showers and thunderstorms or
thunderstorm clusters into northeast MO and west central IL late
tonight. We could also see spotty WAA generated showers well in
advance of the activity that has moved off the front, hence the low
pops all the way down to St. Louis.
Glass
.LONG TERM: (Monday through Saturday)
Issued at 325 AM CDT Sun May 3 2015
The west-east oriented cold front will ooze southward out of IA
and northern IL into northern sections of the CWA by early Monday
evening. Ongoing showers and thunderstorms at daybreak should
dissipate by midday. Heating and continued low-level moistening
in their wake will result in weak-moderate instability along the
frontal zone and the combo of a migrating impulse and good low
level convergence along the boundary should result in extensive
convective development during the later half of the afternoon
spanning from KS across northern MO/southern IA into central IL.
A broad veering southwesterly LLJ will maintain numberous
thunderstorms/clusters during the evening, with the activity
shunting a bit northward overnight in response to increasing
ridging aloft and a slight northward shift in the frontal zone.
The front will continue to shift northward on Tuesday as ridging
aloft continues to build from the lower TN Valley into the upper
MS Valley. There are some suggestions of air mass type convection
across southern portions of the CWA but I`m not sold on it and
have kept pops in the slight range and confined the coverage.
Otherwise Tuesday will be another day of above normal temps with
highs in the 80s. This warmth will persist on Wednesday and even
into Thursday with the chance of showers and thunderstorms
slowly increasing west-east over the 2 day period as the ridging
aloft shunts east and southwest flow aloft becomes more dominant
with time. The greatest threat of showers and thunderstorms in the
extended period will be Friday-Saturday with an active southwest
flow aloft, moist unstable warm sector, and slowly encroaching
cold front.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1128 PM CDT Sat May 2 2015
VFR flight conditions are expected to continue through Sunday.
Very light showers continue to drift southeast over parts of the
area. Shower activity should continue to diminish slowly through
the rest of the night. Showers are so light that there should be
no impact to operations if one does move over an airport. Low
level wind shear is a good possibility especially over central and
northeast Missouri as well as west central Illinois. Models are
indicating that the wind will increase to around 30kts between
400-800 ft providing +/- 20-25 kts of shear from the surface to
those altitudes. Shear values look to fall off further east/southeast.
Expect increasing south-southwest wind on Sunday morning with
gusts to around 20kts during the afternoon.
Specifics for KSTL:
VFR flight conditions are expected to continue through Sunday.
There may be a sprinkle or two through the rest of the night, but
airport operations are not expected to be affected. Some low level
wind shear still looks possible at Lambert, but values do not look
high enough to warrant a mention in the TAF at this time. Wind
will increase from the south-southwest Sunday morning with gusts
to around 20kts during the afternoon.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
905 AM MDT SUN MAY 3 2015
.UPDATE...
WEAK ECHOES ON RADAR FROM S OF KBIL THROUGH SE MT THIS MORNING
WERE MAINLY MID CLOUDS PER SURFACE OBSERVATIONS...WITH POSSIBLE
SPRINKLES. WEB CAMS SHOWED DRY CONDITIONS.
SPRINKLES/MID CLOUDS WERE BEING INDUCED BY WEAK RIGHT-REAR JET
QUADRANT UPPER DIVERGENCE WHICH WILL CONTINUE THROUGH THE EVENING
FROM THE 90 KT JET TO THE N OF THE AREA. NEW WRF SHOWED MID-LEVEL
FRONTOGENESIS OVER THE AREA OF RADAR ECHOES INTO THE AFTERNOON.
CHANCE OF SPRINKLES WILL END BY 18Z AS FRONTOGENESIS MOVES OUT.
ISENTROPIC LIFT INCREASES OVER WESTERN AREAS BY 00Z TONIGHT.
TRIMMED BACK THE SPRINKLES TO BETTER FIT THE CURRENT RADAR ECHOES
AND REMOVED POPS FROM THE NE BIGHORNS THIS MORNING. THE AFTERNOON
POPS OVER THE MOUNTAINS WERE FINE AND NO MENTION OF THUNDER MADE
SENSE GIVEN THE LOW CAPES ON THE SREF...AND RAP SOUNDINGS.
TEMPERATURES AND DEWPOINTS LOOKED GOOD TODAY. ADJUSTED SKY COVER
BASED ON CURRENT SATELLITE...AND WIND SPEEDS BASED ON LATEST
GUIDANCE. KLVM TENDS TO BECOME GUSTY WITH AN E WIND.
LOW-LEVEL SE FLOW INCREASES TONIGHT AND MON WHILE ISENTROPIC
LIFT CONTINUES OVER THE AREA. POPS WERE IN GOOD SHAPE. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND MON...
QUIET END TO THE WEEKEND EXPECTED AS A WESTERLY FLOW ALOFT WILL
CONTINUE OVER THE FORECAST AREA TODAY. SATELLITE SHOWING AN AREA
OF CLOUDS ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE STATE
WITH CLEARING JUST TO THE WEST OF OUR AREA. EXPECT THESE CLOUDS TO
MOVE EAST ALLOWING FOR PARTLY SUNNY SKIES TO DEVELOP FROM WEST TO
EAST TODAY. RADAR HAS BEEN SHOWING SOME RETURNS FROM ABOUT BIG
HORN COUNTY EAST TO THE DAKOTAS. HOWEVER...BELIEVE MOST IF NOT ALL
OF THIS IS VIRGA AS TEMPERATURE/DEWPOINT SPREADS ARE QUITE HIGH
AND CLOUD BASES ARE AROUND 11K FEET. TEMPERATURES TODAY WILL BE A
GOOD 10 DEGREES COOLER AS A RESULT OF THE FRONT THAT MOVED THROUGH
LAST EVENING. MOST AREAS WILL SEE HIGHS IN THE 60S WHICH IS NORMAL
FOR THIS TIME OF YEAR.
AN UPPER LOW AND TROUGH APPROACH THE PACIFIC NORTHWEST COAST LATE
IN THE DAY MONDAY. THIS WILL ALLOW THE FLOW TO BUCKLE SOMEWHAT
RESULTING IN WEAK RIDGING BUILDING ACROSS OUR AREA...AS WELL AS A
SOUTHWEST FLOW ALOFT. A WEAK DISTURBANCE WILL MOVE NORTHEAST OUT
OF THE GREAT BASIN AREA DURING THE AFTERNOON AND EVENING BRINGING
A SLIGHT SHOWER AND ISOLATED THUNDERSTORM CHANCE TO OUR FAR
WESTERN AREAS WITH THE BEST CHANCES OVER THE ABSAROKA/BEARTOOTH
AND BIG HORN MOUNTAINS AND ADJACENT FOOTHILLS. AS THE DISTURBANCE
MOVES EAST...THE BETTER SHOWER CHANCES WILL SHIFT ACROSS OUR
SOUTHEAST COUNTIES MONDAY NIGHT. TEMPERATURES MONDAY WILL WARM
BACK TO ABOVE NORMAL WITH READINGS IN THE 70S...EXCEPT FOR SOME
60S OUT TOWARD THE DAKOTA BORDERS. HOOLEY
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
MODELS HAVE CONTINUED THE SAME GENERAL PATTERN IN THE
LONG TERM...WETTER AND COOLER. TUESDAY THE LOW OVER THE PACIFIC
WILL BEGIN TO MOVE ALONG THE COAST AS IT DIGS SOUTH. THIS WILL
BRING MOIST SOUTHWEST FLOW INTO THE AREA. THE FLOW WILL GENERALLY
BE UNSETTLED AS SEVERAL IMPULSES OF ENERGY MOVE THROUGH THE FLOW.
THIS WILL GIVE THE AREA A SHOT AT RAIN...BUT MOSTLY IN THE
MOUNTAINS. THE BEST CHANCES FOR RAIN WILL COME TOWARDS THE WEEKEND
AS THE LOW IN THE GREAT BASIN LIFTS INTO WYOMING. THIS WILL BRING
THE GREATEST ENERGY MOVING THROUGH COINCIDENT WITH SOME DECENT
FORCING. THERE CONTINUES TO BE SOME TIMING AND PLACEMENT ISSUES
BETWEEN THE MODELS WITH THE PRECIP...SO HAVE NOT GOTTEN TOO
SPECIFIC. WITH THE INCREASED MOISTURE AND CLOUDINESS...CONTINUE
TO EXPECT TEMPERATURES TO BE NEAR NORMAL...GENERALLY IN THE 60S
FOR HIGHS. REIMER
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE TO PREVAIL OVER THE NEXT 24 HOURS.
WINDS WILL GENERALLY BE LIGHT THROUGHOUT THE DAY. SOME SHOWERS
WILL CONTINUE TO BE POSSIBLE IN THE MOUNTAINS WITH LOCALIZED
MOUNTAIN OBSCURATION. REIMER/FRIEDERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 065 045/075 050/076 047/065 045/051 040/053 041/058
1/B 11/B 12/T 54/T 34/W 44/W 55/W
LVM 066 038/074 043/075 041/062 039/047 035/049 036/059
2/W 12/T 23/T 55/T 45/W 44/W 55/W
HDN 067 043/078 045/079 046/067 044/054 040/056 040/062
1/B 21/B 12/T 43/T 34/W 33/W 44/W
MLS 066 045/073 049/076 050/067 044/059 041/060 042/060
0/B 11/N 11/B 44/T 33/W 33/W 34/W
4BQ 066 043/070 046/074 048/066 045/059 042/056 040/060
1/B 32/W 11/N 45/T 33/W 33/W 44/W
BHK 064 039/067 045/070 047/064 043/058 038/057 038/056
1/B 12/W 11/N 46/T 33/W 22/W 34/W
SHR 065 043/072 044/072 044/063 041/054 038/055 039/057
2/W 32/T 22/T 44/T 34/W 44/W 55/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
635 PM CDT MON MAY 4 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM CDT MON MAY 4 2015
A WEAK DISTURBANCE AND MID-LEVEL WARM FRONT WILL PROVIDE FOR
ADDITIONAL SHOWERS AND THUNDERSTORMS THIS EVENING AND OVERNIGHT.
THE 04.12Z NAM SEEMS TO BE HANDLING THE CURRENT SITUATION
WELL...AND THUS WAS CONSIDERED FOR THE POP FORECAST OVERNIGHT. AT
THIS POINT...BESIDES OFF AND ON SCATTERED SHOWERS...THE GREATEST
CHANCES OF POPS OVERNIGHT COME DURING THE PRE-DAWN HOURS ACROSS
OUR SOUTHERN ZONES...THEN THE ACTIVITY LIFTS NORTH THROUGH 15Z. AT
THIS POINT WILL GENERALLY KEEP CHANCES AT 50% OR LESS OVERNIGHT.
ONLY A WEAK CONVECTIVE ELEMENT IS SHOWN IN REGIONAL PROXIMITY
SOUNDINGS OVERNIGHT...SO AT MOST A FEW CG STRIKES WOULD BE
ANTICIPATED.
A WARM FRONT WILL LIFT NORTH EARLY TUESDAY...PROVIDING A FOCUS FOR
ADDITIONAL SHOWERS AND STORMS. MODELS REMAIN IN DECENT AGREEMENT
WITH TIMING SUGGESTING THE ARRIVAL EARLY TUESDAY AFTERNOON AS
DIFLUENCE ALOFT INCREASES WITH THE APPROACH OF A LEAD CENTRAL
ROCKIES SHORTWAVE. THE MODELS INDICATE SUFFICIENT DESTABILIZATION
FOR THUNDERSTORM DEVELOPMENT...BUT BULK SHEAR INDICES ARE LESS THAN
OPTIMAL FOR ORGANIZED STORM ROTATION. THUS WIDESPREAD SEVERE STORMS
ARE NOT ANTICIPATED...BUT A FEW STRONG STORMS TUESDAY AFTERNOON
CANNOT BE OVERLOOKED. THE CONTRIBUTION OF THE INSTABILITY IS SPREAD
OVER A LARGE DISTANCE OF THE TROPOSPHERE AND GIVEN THAT PWATS ARE
SHOWN TO INCREASE TO VALUES OF ABOVE THE 99TH PERCENTILE...HEAVY
RAINFALL IS ANTICIPATED UNDER ANY CONVECTIVE STORM. THE GREATEST
THREAT OF HEAVY RAINFALL WILL OCCUR BEYOND 21Z TUESDAY AFTERNOON
WHEN WARM CLOUD DEPTHS INCREASE ABOVE 6K FEET. THE INHERITED
FORECAST INCLUDED LIKELY POPS TUESDAY AFTERNOON...WHICH AT THIS
POINT THERE/S NO REASON TO DEVIATE GIVEN THE SITUATION.
TEMPERATURES WILL BE MODERATED BY THE PRESENCE OF CLOUDS AND
MOISTURE...LOWS WILL FALL INTO THE 40S TO LOWER 50S OVERNIGHT...WITH
HIGHS WARMING INTO THE 60S TO LOWER 70S TOMORROW...ESPECIALLY IF THE
SUN IS ABLE TO PEEK OUT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM CDT MON MAY 4 2015
A LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL BE DIGGING SOUTHEAST
TOWARD THE CENTRAL GREAT BASIN BY FRIDAY. IN ADVANCE OF THIS
SYSTEM...A POTENT NEGATIVELY TILTED PV ANOMALY WILL EJECT NORTHEAST
FROM THE DESERT SOUTHWEST ACROSS THE AREA TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT. THIS LEAD PV ANOMALY WILL HELP TO INCREASE
SOUTHERLY FLOW...WITH ABUNDANT LOW LEVEL GULF MOISTURE STREAMING
NORTHWARD INTO THE CENTRAL AND NORTHERN PLAINS.
THE RAIN EXPECTED DURING THE DAY TUESDAY WILL DECREASE SOMEWHAT IN
COVERAGE TUESDAY NIGHT AS THE BEST LIFT SHIFTS NORTH INTO THE
NORTHERN PLAINS. STILL CANNOT RULE OUT SHOWERS OR A FEW STORMS WITH
GOOD MOISTURE ADVECTION AND SOME LIFT PRESENT THROUGH THE
NIGHT.
THE BEST DYNAMICS ASSOCIATED WITH THE PV ANOMALY WILL CROSS THE AREA
WEDNESDAY. STILL NOT EXPECTING MUCH IN THE WAY OF DESTABILIZATION
DURING THE AFTERNOON AHEAD OF THE COLD FRONT DUE TO ABUNDANT LOW
LEVEL MOISTURE AND LOW STRATUS CLOUD COVER. THE RESULT WOULD BE
LIMITED SURFACE BASED CONVECTIVE DEVELOPMENT. THE MORE LIKELY
SCENARIO WILL BE FOR SURFACE BASED STORMS TO DEVELOP NEAR A TRIPLE
POINT ACROSS NORTHWEST KANSAS WHERE LESS LOW CLOUD COVER AND BETTER
HEATING WILL OCCUR. EXPECT THESE STORMS TO QUICKLY SPREAD NORTH AND
EAST AND BECOME MORE ELEVATED. A FEW OF THESE COULD BE SEVERE WITH
LARGE HAIL BEING THE MAIN THREAT.
STILL ON TRACK FOR A LULL IN THE PRECIPITATION LATER WEDNESDAY NIGHT
INTO THURSDAY. THEN FRIDAY INTO THE WEEKEND...THE LARGE UPPER LEVEL
LOW WILL MOVE EAST FROM THE CENTRAL GREAT BASIN TOWARD THE CENTRAL
PLAINS. ECMWF AND GEFS CONTINUE TO BE IN VERY GOOD AGREEMENT WITH
THE CLOSED LOW TRACKING SLOWLY ACROSS COLORADO AND THEN TURN
NORTHEAST AND CROSS NEBRASKA. VERY STRONG MOISTURE ADVECTION AHEAD
OF THIS SYSTEM...AND HIGH CONFIDENCE THAT RAIN WILL OCCUR FRIDAY
NIGHT INTO SATURDAY. THE GEFS AND ECMWF NOW LINGER THE SYSTEM INTO
SUNDAY...SO WILL RAISE POPS FOR THAT DAY. MONDAY SHOULD BE A DRY DAY
AS THE SYSTEM MOVES NORTHEAST AWAY FROM THE REGION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 635 PM CDT MON MAY 4 2015
MVFR CIGS ASSOCIATED WITH RAIN ALONG I-80 WILL CONTINUE FOR A FEW
MORE HOURS. ONCE THE RAIN ENDS...A PERIOD OF VFR COULD DEVELOP FOR
A FEW HOURS ALSO. THE RAP MODEL THEN SHOWS A RAPID INCREASE IN
MOISTURE WHICH IS EXPECTED TO LOWER CIGS AGAIN TO MVFR WITH AREAS
OF IFR TOWARD MORNING AS A SECOND BATCH OF RAIN MOVES UP FROM THE
SOUTH. THE MODELS SUGGEST THIS RAIN COULD LAST THROUGHOUT THE DAY
SOUTH OF VALENTINE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JACOBS
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1259 PM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 924 AM CDT SUN MAY 3 2015
JUST UPDATED TO ADD A 2-3 HOUR WINDOW OF OPPORTUNITY FOR ISOLATED
RAIN SHOWERS/WEAK THUNDERSTORMS TO SEVERAL COUNTIES MAINLY EAST OF
AN OSBORNE-CLAY CENTER-OSCEOLA LINE THIS MORNING. ALTHOUGH FORCING
IS SUBTLE...THIS RECENT UPTICK IN ELEVATED ACTIVITY APPEARS TO BE
TIED TO A SUBTLE MID LEVEL PASSING THROUGH AND GENERATING "JUST
ENOUGH" LOW-MID LEVEL THETA-E ADVECTION TO KICK THINGS OFF.
ALTHOUGH MODELS HAVE STRUGGLED TO PICK UP ON THIS...WOULD BE
SURPRISED TO SEE ANY OF THIS EASTERN ACTIVITY LINGER PAST THE
11AM-12PM HOUR...AS STILL EXPECT THE MAJORITY OF THE CWA TO REMAIN
DRY THE MAJORITY OF THE DAY.
AS FOR THE LATE AFTERNOON/EVENING/OVERNIGHT STORM
CHANCES...UNFORTUNATELY...UNCERTAINTY MAY BE HIGHER IN THE
NOW THAN IT WAS 24 HOURS AGO REGARDING HOW THIS PLAYS OUT. PER
SOME MODELS...THE OVERALL SEVERE THREAT MAY BE A BIT LESS THAN
THOUGHT 24 HOURS AGO...BUT THAT BEING SAID...GIVEN WHAT HAPPENED
YESTERDAY WITH THE GREATER-THAN-EXPECTED COVERAGE OF STRONG-
SEVERE STORMS IN THE NORTHEAST CWA...THIS PATTERN IS PRONE TO
YIELDING SURPRISES. STAY TUNED FOR PLENTY MORE THOUGHTS/UPDATED
THINKING WITH THE AFTERNOON DISCUSSION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM CDT SUN MAY 3 2015
BIGGEST CHALLENGE WILL BE DETERMINING CHANCES AND TIMING OF
SHOWERS/THUNDERSTORMS AS WELL AS THE POTENTIAL FOR STRONG STORMS.
ANOTHER CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES FOR TODAY.
SPLIT FLOW FOR TODAY...CAUGHT BETWEEN THE NORTH AND SOUTH STREAMS.
LOCAL SYNOPTIC FLOW WILL BE ZONAL...BUT TURN MORE SOUTHWEST TONIGHT
AS A NEGATIVELY TILTED BROAD UPPER LEVEL TROUGH ENTERS THE
SOUTHWESTERN UNITED STATES. AT THE SURFACE...A COLD FRONT IS ON ITS
WAY SOUTH ACROSS SOUTH DAKOTA. THE TIMING OF THIS FRONT SUGGESTS
THAT WE WILL WARM UP SIGNIFICANTLY DUE TO COMPRESSIONAL WARMING.
MODELS ARE GENERALLY NOT PICKING UP ON THIS WELL ENOUGH...SO I AM
GOING OUT ON A BIT OF A LIMB AND GOING QUITE A BIT MORE THAN GENERAL
GUIDANCE IN THE MID 80S. GOING FOR 91 FOR THE TRI-CITIES...FAVORING
THE HI RES NMM SOLUTION. BELIEVE IT OR NOT...THIS WOULD BREAK OUR
RECORD IN HASTINGS BY 2 DEGREES AND BE ONE DEGREE SHORT OF THE
RECORD HIGH IN GRAND ISLAND. THE RAP MODEL BUMPS UP TEMPERATURES
EVEN MORE IN NORTH CENTRAL KANSAS TO THE MID 90S. THESE WARMER
TEMPERATURES WOULD HAVE PUT US IN THE REALM OF APPROACHING
CRITICAL FIRE WEATHER ISSUES IF IT WERE NOT FOR THE FACT THAT WE
HAVE GREENED UP. CHANCES OF PRECIPITATION ARE NOT CERTAIN.
COVERAGE IS A BIT SPOTTY UNTIL THE CAP BREAKS IN THE EVENING.
EVENT THEN...COVERAGE IS IN QUESTION...ESPECIALLY DEPENDING ON THE
EXACT PLACEMENT OF THE FRONT WHEN STORMS FIRE. WE WILL PROBABLY
NEED A HIGHER NARROW CORRIDOR OF CATEGORICAL CHANCES OF
SHOWERS/THUNDERSTORMS...BUT AT THIS TIME...THAT IS VERY DIFFICULT
TO DETERMINE...ESPECIALLY AS THE FRONT MAY TEMPORARILY STALL FOR A
SHORT TIME TOWARD EVENING. A SECONDARY IMPULSE WITHIN MID-LEVEL
FLOW COULD BOOST CHANCES OF RAIN OVERNIGHT...PROBABLY IN OUR
SOUTH. I DO NOT GO OVER A 60 PERCENT CHANCE ANYWHERE IN THE
CWA...AND HANG AROUND 40-50 PERCENT CHANCE FOR THE TRI-CITIES. AS
FOR STRONG/SEVERE CHANCES...WE COULD GET SOME STRONG STORMS WITH
MARGINAL INSTABILITY OF 500 TO 1500 J/KG AND LOW- LEVEL WIND SHEAR
APPROACHING 30-35 IN OUR NORTH...BUT PROBABLY LOWER IN MOST OF THE
REST OF THE CWA. THIS COULD BE ENOUGH TO GIVE US SOME STRONG
STORMS WITH NICKEL SIZE HAIL AND PERHAPS A STRONG WIND GUST...BUT
THE BETTER SUPPORT FOR SEVERE WEATHER LOOKS LIKE IT SHOULD BE
EAST/NORTHEAST OF THE CWA. WENT WITH SIMILAR LOWS FOR TONIGHT
COMPARED TO THE PREVIOUS FORECAST AND STUCK WITH SUPERBLEND IN THE
50S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM CDT SUN MAY 3 2015
PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND THE MULTIPLE
CHANCES FOR THUNDERSTORMS THROUGH THE ENTIRE PERIOD.
THE UNSETTLED WEATHER PATTERN HAS SETTLED IN ACROSS THE REGION BY
THE START OF THE PERIOD MON/MON NIGHT...WITH MODELS SHOWING THE AREA
UNDER SOUTHWESTERLY FLOW ALOFT...WITH THE PARENT LOW PRESSURE OVER
SRN CALIFORNIA AND WEAK RIDGING EXTENDING NORTH FROM THE GULF COAST
INTO PORTIONS OF THE MIDWEST. MAY HAVE SOME LINGERING PRECIP ACROSS
THE AREA DURING THE MORNING HOURS FROM OVERNIGHT ACTIVITY...BUT
WOULD THINK THERE WOULD BE A LULL AT SOME POINT. HARD TO PINPOINT
EXACTLY WHERE THAT LINGERING ACTIVITY MAY BE...SO HAVE CHANCE POPS
ACROSS THE ENTIRE CWA. AT THE SFC...MODELS CONTINUE TO BE IN PRETTY
GOOD AGREEMENT SHOWING THE PLACEMENT OF THE MAIN SFC FRONT OVER SRN
PORTIONS OF THE CWA NEAR THE NEB/KS STATE LINE...WITH SOME SHOWING A
LOW PLACED IN CLOSE PROXIMITY TO THE S/SWRN CORNER OF THE CWA. THE
PLACEMENT OF THE SFC FRONT...UNCERTAINTY WITH THE AMOUNT OF SKY
COVER /LIKELY HIGH/ AND ANY LINGERING PRECIP MAKES THE HIGH TEMP
FORECAST TRICKY. MUCH OF SC NEB IS LOOKING AT ERLY WINDS NORTH OF
THE FRONT...WITH MORE SRLY WINDS ACROSS NC KS. FORECAST HIGH TEMP IS
A BLEND...AND COULD SEE CLOSE TO A 20 DEGREE GRADIENT ACROSS THE CWA
/SOME MODELS ARE MORE DRASTIC/...WITH ARND 60 IN THE NORTH TO NEAR
80 IN THE FAR SOUTH. DURING THE AFTERNOON HOURS AND INTO THE
EVENING/OVERNIGHT...THIS FRONTAL BOUNDARY WILL BE A FOCUS FOR
ADDITIONAL THUNDERSTORM DEVELOPMENT AS YET ANOTHER DISTURBANCE MAKES
ITS WAY INTO THE REGION...AIDED ALSO BY AN INCREASING LLJ. SEVERE
WEATHER REMAINS A CONCERN WITH MODEST INSTABILITY AND SUFFICIENT
DEEP LAYER SHEAR...LARGE HAIL/DAMAGING WINDS REMAIN THE PRIMARY
CONCERNS...BUT WILL HAVE TO MONITOR THE POTENTIAL FOR AN ISOLATED
TORNADO WITH THOSE MORE ERLY WINDS/INCREASED LOW LEVEL SHEAR IN THE
AREA. SPC DAY 2 OUTLOOK SLIGHT RISK AREA INCLUDES ROUGHLY THE SERN
HALF OF THE CWA.
SIMILAR TO MONDAY...TUESDAY MORNING MAY HAVE SOME LINGERING ACTIVITY
FROM OVERNIGHT...BUT MODELS SUGGEST THE OVERALL COVERAGE MAY NOT BE
AS WIDESPREAD. THE MAIN UPPER LEVEL LOW HAS SHIFTED EAST INTO THE
FOUR CORNERS REGION BY TUESDAY MORNING...AND MODELS CONTINUE TO SHOW
THE POTENTIAL FOR THE LOW TO WEAKEN SOME/FILL...AS IT COMES UNDER
INCREASING INFLUENCE OF A STRONGER UPPER LEVEL LOW MOVING INTO THE
PAC NW REGION. AT THE SFC...DURING THE DAYTIME HOURS...THE FRONTAL
BOUNDARY CONTINUING TO MEANDER AROUND CENTRAL PORTIONS OF THE CWA
LOOKS TO PUSH NORTH AS A WARM FRONT...WITH MOST MODELS SHOWING SRLY
WINDS IN PLACE ACROSS THE ENTIRE CWA DURING THE AFTERNOON. MODELS
CONTINUE TO SHOW THE BETTER THUNDERSTORMS CHANCES ACROSS WRN
PORTIONS OF THE CWA DURING THE AFTERNOON...SPREADING ACROSS THE REST
OF THE CWA OVERNIGHT AS LIFT CONTINUES TO INCREASE WITH THE
APPROACHING MAIN UPPER TROUGH/LOW...WHICH IS STARTING TO MAKE MORE
OF A PUSH ONTO THE THE PLAINS DURING THE LATE TUES NIGHT HOURS/WED
MORNING.
WED/WED NIGHT CONTINUES TO BE THE PERIOD GENERALLY SHOWN BY MODELS
WHEN THAT MAIN TROUGH AXIS /CLOSED LOW?/ MAKES ITS TREK NE THROUGH
THE REGION...AS THAT STRONGER UPPER LEVEL LOW DIGS FURTHER SOUTH
ALONG THE WEST COAST. THE HIGH CHANCE/LOW END LIKELY POPS CONTINUE
IN THE FORECAST...SIMILAR TO PERIODS PRIOR AND FOLLOWING...HARD TO
TRIM AREAS OUT OR RAISE POPS IN OTHERS WHEN SO MANY DETAILS HAVE YET
TO BE IRONED OUT. THE LOCATION OF THE SFC LOW/ASSOCIATED BOUNDARIES
LOOK TO BE PLAYING A BIGGER ROLE/FOCUS FOR CONVECTIVE DEVELOPMENT
NEAR/ACROSS THE CWA...SO AS THEIR ULTIMATE PLACEMENT BECOMES MORE
CLEAR IN THE COMING MODEL RUNS...CAN PIN DOWN BETTER DETAILS WITH
POPS AND SEVERE WEATHER POTENTIAL.
THROUGH THE REST OF THE LONG TERM PERIOD THURSDAY THROUGH
SATURDAY...ONE NOTABLE DISTURBANCE MOVES OUT...BUT SOUTHWESTERLY
FLOW REMAINS IN PLACE IN THE UPPER LEVEL AS THAT NEXT LOW PRESSURE
SYSTEM CONTINUES TO DIG FURTHER SOUTH INTO CALIFORNIA. PIECES OF
SHORTWAVE ENERGY ASSOCIATED WITH THAT LOW LOOK TO CONTINUE TO BRING
AT LEAST PERIODIC THUNDERSTORM CHANCES...KEPT THE FORECAST CLOSE TO
THE CR INIT/SUPERBLEND OUTPUT.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1247 PM CDT SUN MAY 3 2015
ALTHOUGH CONFIDENCE IS REASONABLY HIGH IN WIND TRENDS...INCLUDING
THE PASSAGE OF A FAIRLY NOTICEABLE COLD FRONT/DIRECTIONAL SHIFT LATE
THIS AFTERNOON INTO THIS EVENING...CONFIDENCE IS BELOW AVERAGE
REGARDING THE TIMING OF POTENTIAL MVFR CEILING DURING THE LATTER
HALF OF THE PERIOD...AND WITH WHAT TIME FRAME(S) CARRIES THE
HIGHEST POTENTIAL FOR SHOWER/THUNDERSTORM ACTIVITY. STARTING WITH
THESE FIRST SEVERAL HOURS THIS AFTERNOON...DRY AND VFR CONDITIONS
WILL PERSIST WITH A GENERALLY WESTERLY BREEZE LARGELY UNDER 12KT.
STARTING AT 22Z AND LASTING THROUGH 06Z...HAVE INTRODUCED A
GENERIC VICINITY THUNDERSTORM (VCTS) MENTION AS THIS SEEMS TO BE
THE MAIN 8-HOUR WINDOW OF OPPORTUNITY FOR POSSIBLE STORMS NEAR THE
TAF SITES (LATER UPDATES CAN "UPGRADE" TO TEMPO GROUPS AS
NECESSARY). SHOULD ANY STORMS DIRECTLY AFFECT KGRI/KEAR...A
PERIOD OF GUSTY WIND AND SMALL HAIL IS CERTAINLY POSSIBLE. AT
LEAST FOR NOW...HAVE NOT MENTIONED ANY PRECIPITATION DURING THE
06Z-13Z TIME FRAME...BUT FROM 13Z ONWARD HAVE INTRODUCED AN MVFR
CEILING ALONG WITH A GENERIC VICINITY SHOWERS (VCSH) MENTION.
RE-VISITING SURFACE WIND TRENDS...ONCE THE COLD FRONT TRACKS
THROUGH LATE THIS AFTERNOON/EVENING...A PREVAILING NORTH-NORTHEAST
COMPONENT SETTLES IN WITH GUST POTENTIAL AT LEAST 15-20KT THROUGH
THE REMAINDER OF THE PERIOD.
&&
.CLIMATE...
ISSUED AT 433 AM CDT SUN MAY 3 2015
PREDICTED HIGH TODAY:
HASTINGS 91
GRAND ISLAND 91
RECORD HIGH:
HASTINGS 89 (1959)
GRAND ISLAND 92 (1959)
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...HEINLEIN
LONG TERM...ADP
AVIATION...PFANNKUCH
CLIMATE...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1217 PM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
TODAY...STORMS SHOULD CONTINUE EASTWARD OUT OF THE FORECAST AREA
EARLY THIS MORNING. HIGH RES MODELS ARE IN GOOD AGREEMENT WITH
THAT. STORMS LAST EVENING DID PRODUCE SOME LARGE HAIL AND A FEW
SPOTS RECEIVED STRONG WINDS AS STORMS MIXED DOWN A STRONG LOW
LEVEL JET. AS OF AROUND 07Z RUC MODEL INITIALIZATION SHOWED WINDS
AT AROUND 1 KM AGL OF AROUND 40-50 KNOTS STRETCHING FROM WESTERN
OKLAHOMA INTO SOUTHEAST NEBRASKA AND PARTS OF IOWA. THESE WINDS
WILL DECREASE THIS MORNING. COLD FRONT AS OF 08Z STRETCHED FROM
NORTHEAST MINNESOTA BACK INTO WESTERN SOUTH DAKOTA. THAT FRONT
WILL MOVE SOUTHEAST INTO NORTHEAST NEBRASKA THIS AFTERNOON. LOOK
FOR HIGHS IN THE MID TO UPPER 80S AT MOST SPOTS TODAY WITH A FEW
HIGHS AROUND 90 POSSIBLE. THIS WILL CREATE CAPE VALUES FROM 1500
TO 2500 J/KG BY MID AFTERNOON. EXPECT CAP TO BREAK NEAR THE FRONT
BY MID/LATE AFTERNOON. SOME MODELS ALSO HINT AT THE CAP WEAKENING
FARTHER SOUTH...BUT WITH A LACK OF FOCUS AT THAT TIME WILL KEEP
HIGHEST POPS CLOSER TO THE FRONT. SOME SEVERE STORMS APPEAR
POSSIBLE...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS.
GENERALLY USED A BLEND OF SHORT RANGE GUIDANCE FOR TONIGHT WITH THE
HIGHEST WEIGHT GIVEN TO THE 00Z HIGH RES WRF-ARW MODEL. LIKE SOME OF
THE OTHER MODELS...IT DEVELOPED STORMS LATE AFTERNOON THEN MOVED
THEM SOUTH AND EAST. SOME STORMS MAY CONTINUE TO BE SEVERE IN THE
EVENING. COVERAGE SHOULD DECREASE AFTER MIDNIGHT. CONVECTION WILL
LIKELY FORCE THE FRONT DOWN AT LEAST AS FAR AS SOUTHEAST NEBRASKA
AND MAYBE INTO NORTHEAST KANSAS BY 12Z MONDAY. MOST MODELS SHOW
LIFT OCCURRING OVER THE BOUNDARY DURING THE DAY MONDAY WITH PCPN
COVERAGE INCREASING...SO HAVE POPS INCREASING TO MATCH THAT. TWO
CLUSTERS OF STORMS MAY TAKE SHAPE BY LATE AFTERNOON OR EARLY
EVENING. ONE NEAR THE NEBRASKA/SOUTH DAKOTA BORDER AND ANOTHER
LIFTING FROM NORTHERN KANSAS THROUGH OUR AREA AND TOWARD CENTRAL
IOWA MONDAY NIGHT.
TUESDAY...WE MAY SEE SOMEWHAT OF A BREAK IN THE WIDESPREAD PCPN...
AT LEAST OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. HAVE POPS
RANGING FROM 15 TO 50 PERCENT...HIGHEST IN NORTHEAST NEBRASKA.
SOUTHERLY FLOW WILL INCREASE AND HELP A WARM FRONT LIFT NORTH OF
THE AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
PATTERN WILL BE ACTIVE MUCH OF THIS PERIOD. A LARGE MID TROPOSPHERIC
TROUGH SHOULD BE OVER THE WESTERN UNITED STATES AT THE START OF THIS
PERIOD WITH EMBEDDED SHORTWAVES. ONE OF THESE WAVES WILL LIFT ACROSS
MID AMERICA WEDNESDAY/WEDNESDAY NIGHT...WHILE A CLOSED LOW STARTS TO
DIG SOUTHWARD FROM THE PACIFIC NORTHWEST. THIS WILL GENERALLY KEEP
OUR AREA IN SOUTHWEST FLOW WITH A DECENT SUPPLY OF LOW LEVEL MOISTURE
FOR SHOWERS AND STORMS TO WORK WITH. MODEL AGREEMENT STARTS TO FALL
OFF BY DAY 7...SO CONFIDENCE FALLS TO AVERAGE BY DAY 7. TEMPERATURES
AND PCPN SHOULD BE AT OR ABOVE NORMAL FOR THIS PERIOD.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1211 PM CDT SUN MAY 3 2015
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE IN
AREAL COVERAGE THIS AFTN ALONG A COLD FRONT PUSHING THRU ERN NEB.
IT IS POSSIBLE THAT A FEW STORMS MAY APPROACH OR BECOME SEVERE
LATE THIS AFTN. HAVE ADDED TEMPO GROUPS AT ALL TERMINALS FOR
POSSIBLE LATE AFTN/EARLY EVENING MVFR CONDITIONS. VFR CONDITIONS
THEN PREVAILING THIS EVENING THRU THE REST OF THE FCST PD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...PEARSON/MILLER
LONG TERM...MILLER
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
924 AM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 924 AM CDT SUN MAY 3 2015
JUST UPDATED TO ADD A 2-3 HOUR WINDOW OF OPPORTUNITY FOR ISOLATED
RAIN SHOWERS/WEAK THUNDERSTORMS TO SEVERAL COUNTIES MAINLY EAST OF
AN OSBORNE-CLAY CENTER-OSCEOLA LINE THIS MORNING. ALTHOUGH FORCING
IS SUBTLE...THIS RECENT UPTICK IN ELEVATED ACTIVITY APPEARS TO BE
TIED TO A SUBTLE MID LEVEL PASSING THROUGH AND GENERATING "JUST
ENOUGH" LOW-MID LEVEL THETA-E ADVECTION TO KICK THINGS OFF.
ALTHOUGH MODELS HAVE STRUGGLED TO PICK UP ON THIS...WOULD BE
SURPRISED TO SEE ANY OF THIS EASTERN ACTIVITY LINGER PAST THE
11AM-12PM HOUR...AS STILL EXPECT THE MAJORITY OF THE CWA TO REMAIN
DRY THE MAJORITY OF THE DAY.
AS FOR THE LATE AFTERNOON/EVENING/OVERNIGHT STORM
CHANCES...UNFORTUNATELY...UNCERTAINTY MAY BE HIGHER IN THE
NOW THAN IT WAS 24 HOURS AGO REGARDING HOW THIS PLAYS OUT. PER
SOME MODELS...THE OVERALL SEVERE THREAT MAY BE A BIT LESS THAN
THOUGHT 24 HOURS AGO...BUT THAT BEING SAID...GIVEN WHAT HAPPENED
YESTERDAY WITH THE GREATER-THAN-EXPECTED COVERAGE OF STRONG-
SEVERE STORMS IN THE NORTHEAST CWA...THIS PATTERN IS PRONE TO
YIELDING SURPRISES. STAY TUNED FOR PLENTY MORE THOUGHTS/UPDATED
THINKING WITH THE AFTERNOON DISCUSSION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM CDT SUN MAY 3 2015
BIGGEST CHALLENGE WILL BE DETERMINING CHANCES AND TIMING OF
SHOWERS/THUNDERSTORMS AS WELL AS THE POTENTIAL FOR STRONG STORMS.
ANOTHER CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES FOR TODAY.
SPLIT FLOW FOR TODAY...CAUGHT BETWEEN THE NORTH AND SOUTH STREAMS.
LOCAL SYNOPTIC FLOW WILL BE ZONAL...BUT TURN MORE SOUTHWEST TONIGHT
AS A NEGATIVELY TILTED BROAD UPPER LEVEL TROUGH ENTERS THE
SOUTHWESTERN UNITED STATES. AT THE SURFACE...A COLD FRONT IS ON ITS
WAY SOUTH ACROSS SOUTH DAKOTA. THE TIMING OF THIS FRONT SUGGESTS
THAT WE WILL WARM UP SIGNIFICANTLY DUE TO COMPRESSIONAL WARMING.
MODELS ARE GENERALLY NOT PICKING UP ON THIS WELL ENOUGH...SO I AM
GOING OUT ON A BIT OF A LIMB AND GOING QUITE A BIT MORE THAN GENERAL
GUIDANCE IN THE MID 80S. GOING FOR 91 FOR THE TRI-CITIES...FAVORING
THE HI RES NMM SOLUTION. BELIEVE IT OR NOT...THIS WOULD BREAK OUR
RECORD IN HASTINGS BY 2 DEGREES AND BE ONE DEGREE SHORT OF THE
RECORD HIGH IN GRAND ISLAND. THE RAP MODEL BUMPS UP TEMPERATURES
EVEN MORE IN NORTH CENTRAL KANSAS TO THE MID 90S. THESE WARMER
TEMPERATURES WOULD HAVE PUT US IN THE REALM OF APPROACHING
CRITICAL FIRE WEATHER ISSUES IF IT WERE NOT FOR THE FACT THAT WE
HAVE GREENED UP. CHANCES OF PRECIPITATION ARE NOT CERTAIN.
COVERAGE IS A BIT SPOTTY UNTIL THE CAP BREAKS IN THE EVENING.
EVENT THEN...COVERAGE IS IN QUESTION...ESPECIALLY DEPENDING ON THE
EXACT PLACEMENT OF THE FRONT WHEN STORMS FIRE. WE WILL PROBABLY
NEED A HIGHER NARROW CORRIDOR OF CATEGORICAL CHANCES OF
SHOWERS/THUNDERSTORMS...BUT AT THIS TIME...THAT IS VERY DIFFICULT
TO DETERMINE...ESPECIALLY AS THE FRONT MAY TEMPORARILY STALL FOR A
SHORT TIME TOWARD EVENING. A SECONDARY IMPULSE WITHIN MID-LEVEL
FLOW COULD BOOST CHANCES OF RAIN OVERNIGHT...PROBABLY IN OUR
SOUTH. I DO NOT GO OVER A 60 PERCENT CHANCE ANYWHERE IN THE
CWA...AND HANG AROUND 40-50 PERCENT CHANCE FOR THE TRI-CITIES. AS
FOR STRONG/SEVERE CHANCES...WE COULD GET SOME STRONG STORMS WITH
MARGINAL INSTABILITY OF 500 TO 1500 J/KG AND LOW- LEVEL WIND SHEAR
APPROACHING 30-35 IN OUR NORTH...BUT PROBABLY LOWER IN MOST OF THE
REST OF THE CWA. THIS COULD BE ENOUGH TO GIVE US SOME STRONG
STORMS WITH NICKEL SIZE HAIL AND PERHAPS A STRONG WIND GUST...BUT
THE BETTER SUPPORT FOR SEVERE WEATHER LOOKS LIKE IT SHOULD BE
EAST/NORTHEAST OF THE CWA. WENT WITH SIMILAR LOWS FOR TONIGHT
COMPARED TO THE PREVIOUS FORECAST AND STUCK WITH SUPERBLEND IN THE
50S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM CDT SUN MAY 3 2015
PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND THE MULTIPLE
CHANCES FOR THUNDERSTORMS THROUGH THE ENTIRE PERIOD.
THE UNSETTLED WEATHER PATTERN HAS SETTLED IN ACROSS THE REGION BY
THE START OF THE PERIOD MON/MON NIGHT...WITH MODELS SHOWING THE AREA
UNDER SOUTHWESTERLY FLOW ALOFT...WITH THE PARENT LOW PRESSURE OVER
SRN CALIFORNIA AND WEAK RIDGING EXTENDING NORTH FROM THE GULF COAST
INTO PORTIONS OF THE MIDWEST. MAY HAVE SOME LINGERING PRECIP ACROSS
THE AREA DURING THE MORNING HOURS FROM OVERNIGHT ACTIVITY...BUT
WOULD THINK THERE WOULD BE A LULL AT SOME POINT. HARD TO PINPOINT
EXACTLY WHERE THAT LINGERING ACTIVITY MAY BE...SO HAVE CHANCE POPS
ACROSS THE ENTIRE CWA. AT THE SFC...MODELS CONTINUE TO BE IN PRETTY
GOOD AGREEMENT SHOWING THE PLACEMENT OF THE MAIN SFC FRONT OVER SRN
PORTIONS OF THE CWA NEAR THE NEB/KS STATE LINE...WITH SOME SHOWING A
LOW PLACED IN CLOSE PROXIMITY TO THE S/SWRN CORNER OF THE CWA. THE
PLACEMENT OF THE SFC FRONT...UNCERTAINTY WITH THE AMOUNT OF SKY
COVER /LIKELY HIGH/ AND ANY LINGERING PRECIP MAKES THE HIGH TEMP
FORECAST TRICKY. MUCH OF SC NEB IS LOOKING AT ERLY WINDS NORTH OF
THE FRONT...WITH MORE SRLY WINDS ACROSS NC KS. FORECAST HIGH TEMP IS
A BLEND...AND COULD SEE CLOSE TO A 20 DEGREE GRADIENT ACROSS THE CWA
/SOME MODELS ARE MORE DRASTIC/...WITH ARND 60 IN THE NORTH TO NEAR
80 IN THE FAR SOUTH. DURING THE AFTERNOON HOURS AND INTO THE
EVENING/OVERNIGHT...THIS FRONTAL BOUNDARY WILL BE A FOCUS FOR
ADDITIONAL THUNDERSTORM DEVELOPMENT AS YET ANOTHER DISTURBANCE MAKES
ITS WAY INTO THE REGION...AIDED ALSO BY AN INCREASING LLJ. SEVERE
WEATHER REMAINS A CONCERN WITH MODEST INSTABILITY AND SUFFICIENT
DEEP LAYER SHEAR...LARGE HAIL/DAMAGING WINDS REMAIN THE PRIMARY
CONCERNS...BUT WILL HAVE TO MONITOR THE POTENTIAL FOR AN ISOLATED
TORNADO WITH THOSE MORE ERLY WINDS/INCREASED LOW LEVEL SHEAR IN THE
AREA. SPC DAY 2 OUTLOOK SLIGHT RISK AREA INCLUDES ROUGHLY THE SERN
HALF OF THE CWA.
SIMILAR TO MONDAY...TUESDAY MORNING MAY HAVE SOME LINGERING ACTIVITY
FROM OVERNIGHT...BUT MODELS SUGGEST THE OVERALL COVERAGE MAY NOT BE
AS WIDESPREAD. THE MAIN UPPER LEVEL LOW HAS SHIFTED EAST INTO THE
FOUR CORNERS REGION BY TUESDAY MORNING...AND MODELS CONTINUE TO SHOW
THE POTENTIAL FOR THE LOW TO WEAKEN SOME/FILL...AS IT COMES UNDER
INCREASING INFLUENCE OF A STRONGER UPPER LEVEL LOW MOVING INTO THE
PAC NW REGION. AT THE SFC...DURING THE DAYTIME HOURS...THE FRONTAL
BOUNDARY CONTINUING TO MEANDER AROUND CENTRAL PORTIONS OF THE CWA
LOOKS TO PUSH NORTH AS A WARM FRONT...WITH MOST MODELS SHOWING SRLY
WINDS IN PLACE ACROSS THE ENTIRE CWA DURING THE AFTERNOON. MODELS
CONTINUE TO SHOW THE BETTER THUNDERSTORMS CHANCES ACROSS WRN
PORTIONS OF THE CWA DURING THE AFTERNOON...SPREADING ACROSS THE REST
OF THE CWA OVERNIGHT AS LIFT CONTINUES TO INCREASE WITH THE
APPROACHING MAIN UPPER TROUGH/LOW...WHICH IS STARTING TO MAKE MORE
OF A PUSH ONTO THE THE PLAINS DURING THE LATE TUES NIGHT HOURS/WED
MORNING.
WED/WED NIGHT CONTINUES TO BE THE PERIOD GENERALLY SHOWN BY MODELS
WHEN THAT MAIN TROUGH AXIS /CLOSED LOW?/ MAKES ITS TREK NE THROUGH
THE REGION...AS THAT STRONGER UPPER LEVEL LOW DIGS FURTHER SOUTH
ALONG THE WEST COAST. THE HIGH CHANCE/LOW END LIKELY POPS CONTINUE
IN THE FORECAST...SIMILAR TO PERIODS PRIOR AND FOLLOWING...HARD TO
TRIM AREAS OUT OR RAISE POPS IN OTHERS WHEN SO MANY DETAILS HAVE YET
TO BE IRONED OUT. THE LOCATION OF THE SFC LOW/ASSOCIATED BOUNDARIES
LOOK TO BE PLAYING A BIGGER ROLE/FOCUS FOR CONVECTIVE DEVELOPMENT
NEAR/ACROSS THE CWA...SO AS THEIR ULTIMATE PLACEMENT BECOMES MORE
CLEAR IN THE COMING MODEL RUNS...CAN PIN DOWN BETTER DETAILS WITH
POPS AND SEVERE WEATHER POTENTIAL.
THROUGH THE REST OF THE LONG TERM PERIOD THURSDAY THROUGH
SATURDAY...ONE NOTABLE DISTURBANCE MOVES OUT...BUT SOUTHWESTERLY
FLOW REMAINS IN PLACE IN THE UPPER LEVEL AS THAT NEXT LOW PRESSURE
SYSTEM CONTINUES TO DIG FURTHER SOUTH INTO CALIFORNIA. PIECES OF
SHORTWAVE ENERGY ASSOCIATED WITH THAT LOW LOOK TO CONTINUE TO BRING
AT LEAST PERIODIC THUNDERSTORM CHANCES...KEPT THE FORECAST CLOSE TO
THE CR INIT/SUPERBLEND OUTPUT.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 541 AM CDT SUN MAY 3 2015
WIND WILL BE PRIMARILY OUT OF THE SOUTH BEFORE A COLD FRONT MOVES
IN BY THIS EVENING...AND SHIFTS TO THE NORTH...WHEN
SHOWERS/THUNDERSTORMS WILL BE POSSIBLE. TIMING OF ANY
THUNDERSTORMS IS SO UNCERTAIN...THAT A RATHER GENERAL VCTS WAS
INCLUDED FOR 00Z AND BEYOND.
&&
.CLIMATE...
ISSUED AT 433 AM CDT SUN MAY 3 2015
PREDICTED HIGH TODAY:
HASTINGS 91
GRAND ISLAND 91
RECORD HIGH:
HASTINGS 89 (1959)
GRAND ISLAND 92 (1959)
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...HEINLEIN
LONG TERM...ADP
AVIATION...HEINLEIN
CLIMATE...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
637 AM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
TODAY...STORMS SHOULD CONTINUE EASTWARD OUT OF THE FORECAST AREA
EARLY THIS MORNING. HIGH RES MODELS ARE IN GOOD AGREEMENT WITH
THAT. STORMS LAST EVENING DID PRODUCE SOME LARGE HAIL AND A FEW
SPOTS RECEIVED STRONG WINDS AS STORMS MIXED DOWN A STRONG LOW
LEVEL JET. AS OF AROUND 07Z RUC MODEL INITIALIZATION SHOWED WINDS
AT AROUND 1 KM AGL OF AROUND 40-50 KNOTS STRETCHING FROM WESTERN
OKLAHOMA INTO SOUTHEAST NEBRASKA AND PARTS OF IOWA. THESE WINDS
WILL DECREASE THIS MORNING. COLD FRONT AS OF 08Z STRETCHED FROM
NORTHEAST MINNESOTA BACK INTO WESTERN SOUTH DAKOTA. THAT FRONT
WILL MOVE SOUTHEAST INTO NORTHEAST NEBRASKA THIS AFTERNOON. LOOK
FOR HIGHS IN THE MID TO UPPER 80S AT MOST SPOTS TODAY WITH A FEW
HIGHS AROUND 90 POSSIBLE. THIS WILL CREATE CAPE VALUES FROM 1500
TO 2500 J/KG BY MID AFTERNOON. EXPECT CAP TO BREAK NEAR THE FRONT
BY MID/LATE AFTERNOON. SOME MODELS ALSO HINT AT THE CAP WEAKENING
FARTHER SOUTH...BUT WITH A LACK OF FOCUS AT THAT TIME WILL KEEP
HIGHEST POPS CLOSER TO THE FRONT. SOME SEVERE STORMS APPEAR
POSSIBLE...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS.
GENERALLY USED A BLEND OF SHORT RANGE GUIDANCE FOR TONIGHT WITH THE
HIGHEST WEIGHT GIVEN TO THE 00Z HIGH RES WRF-ARW MODEL. LIKE SOME OF
THE OTHER MODELS...IT DEVELOPED STORMS LATE AFTERNOON THEN MOVED
THEM SOUTH AND EAST. SOME STORMS MAY CONTINUE TO BE SEVERE IN THE
EVENING. COVERAGE SHOULD DECREASE AFTER MIDNIGHT. CONVECTION WILL
LIKELY FORCE THE FRONT DOWN AT LEAST AS FAR AS SOUTHEAST NEBRASKA
AND MAYBE INTO NORTHEAST KANSAS BY 12Z MONDAY. MOST MODELS SHOW
LIFT OCCURRING OVER THE BOUNDARY DURING THE DAY MONDAY WITH PCPN
COVERAGE INCREASING...SO HAVE POPS INCREASING TO MATCH THAT. TWO
CLUSTERS OF STORMS MAY TAKE SHAPE BY LATE AFTERNOON OR EARLY
EVENING. ONE NEAR THE NEBRASKA/SOUTH DAKOTA BORDER AND ANOTHER
LIFTING FROM NORTHERN KANSAS THROUGH OUR AREA AND TOWARD CENTRAL
IOWA MONDAY NIGHT.
TUESDAY...WE MAY SEE SOMEWHAT OF A BREAK IN THE WIDESPREAD PCPN...
AT LEAST OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. HAVE POPS
RANGING FROM 15 TO 50 PERCENT...HIGHEST IN NORTHEAST NEBRASKA.
SOUTHERLY FLOW WILL INCREASE AND HELP A WARM FRONT LIFT NORTH OF
THE AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
PATTERN WILL BE ACTIVE MUCH OF THIS PERIOD. A LARGE MID TROPOSPHERIC
TROUGH SHOULD BE OVER THE WESTERN UNITED STATES AT THE START OF THIS
PERIOD WITH EMBEDDED SHORTWAVES. ONE OF THESE WAVES WILL LIFT ACROSS
MID AMERICA WEDNESDAY/WEDNESDAY NIGHT...WHILE A CLOSED LOW STARTS TO
DIG SOUTHWARD FROM THE PACIFIC NORTHWEST. THIS WILL GENERALLY KEEP
OUR AREA IN SOUTHWEST FLOW WITH A DECENT SUPPLY OF LOW LEVEL MOISTURE
FOR SHOWERS AND STORMS TO WORK WITH. MODEL AGREEMENT STARTS TO FALL
OFF BY DAY 7...SO CONFIDENCE FALLS TO AVERAGE BY DAY 7. TEMPERATURES
AND PCPN SHOULD BE AT OR ABOVE NORMAL FOR THIS PERIOD.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 637 AM CDT SUN MAY 3 2015
A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA THIS AFTERNOON
AND EARLY EVENING. LOOK FOR GUSTY SOUTH WINDS AHEAD OF THE FRONT.
SHOWERS AND THUNDERSTORMS SHOULD DEVELOP THIS EVENING AND CONTINUE
INTO THE EARLY OVERNIGHT HOURS. A LOT OF LOW-LEVEL MOISTURE IS
FORECAST TO REMAIN BEHIND TODAY`S FRONT...THUS HAVE KEPT MVFR
CEILINGS IN THE FORECAST THROUGH 12Z MONDAY. WITH SEVERAL WEATHER
SYSTEMS EXPECTED TO MOVE THROUGH THIS COMING WEEK EXPECT UNSETTLED
WEATHER TO CONTINUE OFF AND ON THROUGH THE WORK WEEK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...PEARSON/MILLER
LONG TERM...MILLER
AVIATION...PEARSON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
543 AM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM CDT SUN MAY 3 2015
BIGGEST CHALLENGE WILL BE DETERMINING CHANCES AND TIMING OF
SHOWERS/THUNDERSTORMS AS WELL AS THE POTENTIAL FOR STRONG STORMS.
ANOTHER CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES FOR TODAY.
SPLIT FLOW FOR TODAY...CAUGHT BETWEEN THE NORTH AND SOUTH STREAMS.
LOCAL SYNOPTIC FLOW WILL BE ZONAL...BUT TURN MORE SOUTHWEST TONIGHT
AS A NEGATIVELY TILTED BROAD UPPER LEVEL TROUGH ENTERS THE
SOUTHWESTERN UNITED STATES. AT THE SURFACE...A COLD FRONT IS ON ITS
WAY SOUTH ACROSS SOUTH DAKOTA. THE TIMING OF THIS FRONT SUGGESTS
THAT WE WILL WARM UP SIGNIFICANTLY DUE TO COMPRESSIONAL WARMING.
MODELS ARE GENERALLY NOT PICKING UP ON THIS WELL ENOUGH...SO I AM
GOING OUT ON A BIT OF A LIMB AND GOING QUITE A BIT MORE THAN GENERAL
GUIDANCE IN THE MID 80S. GOING FOR 91 FOR THE TRI-CITIES...FAVORING
THE HI RES NMM SOLUTION. BELIEVE IT OR NOT...THIS WOULD BREAK OUR
RECORD IN HASTINGS BY 2 DEGREES AND BE ONE DEGREE SHORT OF THE
RECORD HIGH IN GRAND ISLAND. THE RAP MODEL BUMPS UP TEMPERATURES
EVEN MORE IN NORTH CENTRAL KANSAS TO THE MID 90S. THESE WARMER
TEMPERATURES WOULD HAVE PUT US IN THE REALM OF APPROACHING
CRITICAL FIRE WEATHER ISSUES IF IT WERE NOT FOR THE FACT THAT WE
HAVE GREENED UP. CHANCES OF PRECIPITATION ARE NOT CERTAIN.
COVERAGE IS A BIT SPOTTY UNTIL THE CAP BREAKS IN THE EVENING.
EVENT THEN...COVERAGE IS IN QUESTION...ESPECIALLY DEPENDING ON THE
EXACT PLACEMENT OF THE FRONT WHEN STORMS FIRE. WE WILL PROBABLY
NEED A HIGHER NARROW CORRIDOR OF CATEGORICAL CHANCES OF
SHOWERS/THUNDERSTORMS...BUT AT THIS TIME...THAT IS VERY DIFFICULT
TO DETERMINE...ESPECIALLY AS THE FRONT MAY TEMPORARILY STALL FOR A
SHORT TIME TOWARD EVENING. A SECONDARY IMPULSE WITHIN MID-LEVEL
FLOW COULD BOOST CHANCES OF RAIN OVERNIGHT...PROBABLY IN OUR
SOUTH. I DO NOT GO OVER A 60 PERCENT CHANCE ANYWHERE IN THE
CWA...AND HANG AROUND 40-50 PERCENT CHANCE FOR THE TRI-CITIES. AS
FOR STRONG/SEVERE CHANCES...WE COULD GET SOME STRONG STORMS WITH
MARGINAL INSTABILITY OF 500 TO 1500 J/KG AND LOW- LEVEL WIND SHEAR
APPROACHING 30-35 IN OUR NORTH...BUT PROBABLY LOWER IN MOST OF THE
REST OF THE CWA. THIS COULD BE ENOUGH TO GIVE US SOME STRONG
STORMS WITH NICKEL SIZE HAIL AND PERHAPS A STRONG WIND GUST...BUT
THE BETTER SUPPORT FOR SEVERE WEATHER LOOKS LIKE IT SHOULD BE
EAST/NORTHEAST OF THE CWA. WENT WITH SIMILAR LOWS FOR TONIGHT
COMPARED TO THE PREVIOUS FORECAST AND STUCK WITH SUPERBLEND IN THE
50S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM CDT SUN MAY 3 2015
PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND THE MULTIPLE
CHANCES FOR THUNDERSTORMS THROUGH THE ENTIRE PERIOD.
THE UNSETTLED WEATHER PATTERN HAS SETTLED IN ACROSS THE REGION BY
THE START OF THE PERIOD MON/MON NIGHT...WITH MODELS SHOWING THE AREA
UNDER SOUTHWESTERLY FLOW ALOFT...WITH THE PARENT LOW PRESSURE OVER
SRN CALIFORNIA AND WEAK RIDGING EXTENDING NORTH FROM THE GULF COAST
INTO PORTIONS OF THE MIDWEST. MAY HAVE SOME LINGERING PRECIP ACROSS
THE AREA DURING THE MORNING HOURS FROM OVERNIGHT ACTIVITY...BUT
WOULD THINK THERE WOULD BE A LULL AT SOME POINT. HARD TO PINPOINT
EXACTLY WHERE THAT LINGERING ACTIVITY MAY BE...SO HAVE CHANCE POPS
ACROSS THE ENTIRE CWA. AT THE SFC...MODELS CONTINUE TO BE IN PRETTY
GOOD AGREEMENT SHOWING THE PLACEMENT OF THE MAIN SFC FRONT OVER SRN
PORTIONS OF THE CWA NEAR THE NEB/KS STATE LINE...WITH SOME SHOWING A
LOW PLACED IN CLOSE PROXIMITY TO THE S/SWRN CORNER OF THE CWA. THE
PLACEMENT OF THE SFC FRONT...UNCERTAINTY WITH THE AMOUNT OF SKY
COVER /LIKELY HIGH/ AND ANY LINGERING PRECIP MAKES THE HIGH TEMP
FORECAST TRICKY. MUCH OF SC NEB IS LOOKING AT ERLY WINDS NORTH OF
THE FRONT...WITH MORE SRLY WINDS ACROSS NC KS. FORECAST HIGH TEMP IS
A BLEND...AND COULD SEE CLOSE TO A 20 DEGREE GRADIENT ACROSS THE CWA
/SOME MODELS ARE MORE DRASTIC/...WITH ARND 60 IN THE NORTH TO NEAR
80 IN THE FAR SOUTH. DURING THE AFTERNOON HOURS AND INTO THE
EVENING/OVERNIGHT...THIS FRONTAL BOUNDARY WILL BE A FOCUS FOR
ADDITIONAL THUNDERSTORM DEVELOPMENT AS YET ANOTHER DISTURBANCE MAKES
ITS WAY INTO THE REGION...AIDED ALSO BY AN INCREASING LLJ. SEVERE
WEATHER REMAINS A CONCERN WITH MODEST INSTABILITY AND SUFFICIENT
DEEP LAYER SHEAR...LARGE HAIL/DAMAGING WINDS REMAIN THE PRIMARY
CONCERNS...BUT WILL HAVE TO MONITOR THE POTENTIAL FOR AN ISOLATED
TORNADO WITH THOSE MORE ERLY WINDS/INCREASED LOW LEVEL SHEAR IN THE
AREA. SPC DAY 2 OUTLOOK SLIGHT RISK AREA INCLUDES ROUGHLY THE SERN
HALF OF THE CWA.
SIMILAR TO MONDAY...TUESDAY MORNING MAY HAVE SOME LINGERING ACTIVITY
FROM OVERNIGHT...BUT MODELS SUGGEST THE OVERALL COVERAGE MAY NOT BE
AS WIDESPREAD. THE MAIN UPPER LEVEL LOW HAS SHIFTED EAST INTO THE
FOUR CORNERS REGION BY TUESDAY MORNING...AND MODELS CONTINUE TO SHOW
THE POTENTIAL FOR THE LOW TO WEAKEN SOME/FILL...AS IT COMES UNDER
INCREASING INFLUENCE OF A STRONGER UPPER LEVEL LOW MOVING INTO THE
PAC NW REGION. AT THE SFC...DURING THE DAYTIME HOURS...THE FRONTAL
BOUNDARY CONTINUING TO MEANDER AROUND CENTRAL PORTIONS OF THE CWA
LOOKS TO PUSH NORTH AS A WARM FRONT...WITH MOST MODELS SHOWING SRLY
WINDS IN PLACE ACROSS THE ENTIRE CWA DURING THE AFTERNOON. MODELS
CONTINUE TO SHOW THE BETTER THUNDERSTORMS CHANCES ACROSS WRN
PORTIONS OF THE CWA DURING THE AFTERNOON...SPREADING ACROSS THE REST
OF THE CWA OVERNIGHT AS LIFT CONTINUES TO INCREASE WITH THE
APPROACHING MAIN UPPER TROUGH/LOW...WHICH IS STARTING TO MAKE MORE
OF A PUSH ONTO THE THE PLAINS DURING THE LATE TUES NIGHT HOURS/WED
MORNING.
WED/WED NIGHT CONTINUES TO BE THE PERIOD GENERALLY SHOWN BY MODELS
WHEN THAT MAIN TROUGH AXIS /CLOSED LOW?/ MAKES ITS TREK NE THROUGH
THE REGION...AS THAT STRONGER UPPER LEVEL LOW DIGS FURTHER SOUTH
ALONG THE WEST COAST. THE HIGH CHANCE/LOW END LIKELY POPS CONTINUE
IN THE FORECAST...SIMILAR TO PERIODS PRIOR AND FOLLOWING...HARD TO
TRIM AREAS OUT OR RAISE POPS IN OTHERS WHEN SO MANY DETAILS HAVE YET
TO BE IRONED OUT. THE LOCATION OF THE SFC LOW/ASSOCIATED BOUNDARIES
LOOK TO BE PLAYING A BIGGER ROLE/FOCUS FOR CONVECTIVE DEVELOPMENT
NEAR/ACROSS THE CWA...SO AS THEIR ULTIMATE PLACEMENT BECOMES MORE
CLEAR IN THE COMING MODEL RUNS...CAN PIN DOWN BETTER DETAILS WITH
POPS AND SEVERE WEATHER POTENTIAL.
THROUGH THE REST OF THE LONG TERM PERIOD THURSDAY THROUGH
SATURDAY...ONE NOTABLE DISTURBANCE MOVES OUT...BUT SOUTHWESTERLY
FLOW REMAINS IN PLACE IN THE UPPER LEVEL AS THAT NEXT LOW PRESSURE
SYSTEM CONTINUES TO DIG FURTHER SOUTH INTO CALIFORNIA. PIECES OF
SHORTWAVE ENERGY ASSOCIATED WITH THAT LOW LOOK TO CONTINUE TO BRING
AT LEAST PERIODIC THUNDERSTORM CHANCES...KEPT THE FORECAST CLOSE TO
THE CR INIT/SUPERBLEND OUTPUT.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 541 AM CDT SUN MAY 3 2015
WIND WILL BE PRIMARILY OUT OF THE SOUTH BEFORE A COLD FRONT MOVES
IN BY THIS EVENING...AND SHIFTS TO THE NORTH...WHEN
SHOWERS/THUNDERSTORMS WILL BE POSSIBLE. TIMING OF ANY
THUNDERSTORMS IS SO UNCERTAIN...THAT A RATHER GENERAL VCTS WAS
INCLUDED FOR 00Z AND BEYOND.
&&
.CLIMATE...
ISSUED AT 433 AM CDT SUN MAY 3 2015
PREDICTED HIGH TODAY:
HASTINGS 91
GRAND ISLAND 91
RECORD HIGH:
HASTINGS 89 (1959)
GRAND ISLAND 92 (1959)
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...ADP
AVIATION...HEINLEIN
CLIMATE...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
436 AM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM CDT SUN MAY 3 2015
BIGGEST CHALLENGE WILL BE DETERMINING CHANCES AND TIMING OF
SHOWERS/THUNDERSTORMS AS WELL AS THE POTENTIAL FOR STRONG STORMS.
ANOTHER CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES FOR TODAY.
SPLIT FLOW FOR TODAY...CAUGHT BETWEEN THE NORTH AND SOUTH STREAMS.
LOCAL SYNOPTIC FLOW WILL BE ZONAL...BUT TURN MORE SOUTHWEST TONIGHT
AS A NEGATIVELY TILTED BROAD UPPER LEVEL TROUGH ENTERS THE
SOUTHWESTERN UNITED STATES. AT THE SURFACE...A COLD FRONT IS ON ITS
WAY SOUTH ACROSS SOUTH DAKOTA. THE TIMING OF THIS FRONT SUGGESTS
THAT WE WILL WARM UP SIGNIFICANTLY DUE TO COMPRESSIONAL WARMING.
MODELS ARE GENERALLY NOT PICKING UP ON THIS WELL ENOUGH...SO I AM
GOING OUT ON A BIT OF A LIMB AND GOING QUITE A BIT MORE THAN GENERAL
GUIDANCE IN THE MID 80S. GOING FOR 91 FOR THE TRI-CITIES...FAVORING
THE HI RES NMM SOLUTION. BELIEVE IT OR NOT...THIS WOULD BREAK OUR
RECORD IN HASTINGS BY 2 DEGREES AND BE ONE DEGREE SHORT OF THE
RECORD HIGH IN GRAND ISLAND. THE RAP MODEL BUMPS UP TEMPERATURES
EVEN MORE IN NORTH CENTRAL KANSAS TO THE MID 90S. THESE WARMER
TEMPERATURES WOULD HAVE PUT US IN THE REALM OF APPROACHING
CRITICAL FIRE WEATHER ISSUES IF IT WERE NOT FOR THE FACT THAT WE
HAVE GREENED UP. CHANCES OF PRECIPITATION ARE NOT CERTAIN.
COVERAGE IS A BIT SPOTTY UNTIL THE CAP BREAKS IN THE EVENING.
EVENT THEN...COVERAGE IS IN QUESTION...ESPECIALLY DEPENDING ON THE
EXACT PLACEMENT OF THE FRONT WHEN STORMS FIRE. WE WILL PROBABLY
NEED A HIGHER NARROW CORRIDOR OF CATEGORICAL CHANCES OF
SHOWERS/THUNDERSTORMS...BUT AT THIS TIME...THAT IS VERY DIFFICULT
TO DETERMINE...ESPECIALLY AS THE FRONT MAY TEMPORARILY STALL FOR A
SHORT TIME TOWARD EVENING. A SECONDARY IMPULSE WITHIN MID-LEVEL
FLOW COULD BOOST CHANCES OF RAIN OVERNIGHT...PROBABLY IN OUR
SOUTH. I DO NOT GO OVER A 60 PERCENT CHANCE ANYWHERE IN THE
CWA...AND HANG AROUND 40-50 PERCENT CHANCE FOR THE TRI-CITIES. AS
FOR STRONG/SEVERE CHANCES...WE COULD GET SOME STRONG STORMS WITH
MARGINAL INSTABILITY OF 500 TO 1500 J/KG AND LOW- LEVEL WIND SHEAR
APPROACHING 30-35 IN OUR NORTH...BUT PROBABLY LOWER IN MOST OF THE
REST OF THE CWA. THIS COULD BE ENOUGH TO GIVE US SOME STRONG
STORMS WITH NICKEL SIZE HAIL AND PERHAPS A STRONG WIND GUST...BUT
THE BETTER SUPPORT FOR SEVERE WEATHER LOOKS LIKE IT SHOULD BE
EAST/NORTHEAST OF THE CWA. WENT WITH SIMILAR LOWS FOR TONIGHT
COMPARED TO THE PREVIOUS FORECAST AND STUCK WITH SUPERBLEND IN THE
50S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM CDT SUN MAY 3 2015
PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND THE MULTIPLE
CHANCES FOR THUNDERSTORMS THROUGH THE ENTIRE PERIOD.
THE UNSETTLED WEATHER PATTERN HAS SETTLED IN ACROSS THE REGION BY
THE START OF THE PERIOD MON/MON NIGHT...WITH MODELS SHOWING THE AREA
UNDER SOUTHWESTERLY FLOW ALOFT...WITH THE PARENT LOW PRESSURE OVER
SRN CALIFORNIA AND WEAK RIDGING EXTENDING NORTH FROM THE GULF COAST
INTO PORTIONS OF THE MIDWEST. MAY HAVE SOME LINGERING PRECIP ACROSS
THE AREA DURING THE MORNING HOURS FROM OVERNIGHT ACTIVITY...BUT
WOULD THINK THERE WOULD BE A LULL AT SOME POINT. HARD TO PINPOINT
EXACTLY WHERE THAT LINGERING ACTIVITY MAY BE...SO HAVE CHANCE POPS
ACROSS THE ENTIRE CWA. AT THE SFC...MODELS CONTINUE TO BE IN PRETTY
GOOD AGREEMENT SHOWING THE PLACEMENT OF THE MAIN SFC FRONT OVER SRN
PORTIONS OF THE CWA NEAR THE NEB/KS STATE LINE...WITH SOME SHOWING A
LOW PLACED IN CLOSE PROXIMITY TO THE S/SWRN CORNER OF THE CWA. THE
PLACEMENT OF THE SFC FRONT...UNCERTAINTY WITH THE AMOUNT OF SKY
COVER /LIKELY HIGH/ AND ANY LINGERING PRECIP MAKES THE HIGH TEMP
FORECAST TRICKY. MUCH OF SC NEB IS LOOKING AT ERLY WINDS NORTH OF
THE FRONT...WITH MORE SRLY WINDS ACROSS NC KS. FORECAST HIGH TEMP IS
A BLEND...AND COULD SEE CLOSE TO A 20 DEGREE GRADIENT ACROSS THE CWA
/SOME MODELS ARE MORE DRASTIC/...WITH ARND 60 IN THE NORTH TO NEAR
80 IN THE FAR SOUTH. DURING THE AFTERNOON HOURS AND INTO THE
EVENING/OVERNIGHT...THIS FRONTAL BOUNDARY WILL BE A FOCUS FOR
ADDITIONAL THUNDERSTORM DEVELOPMENT AS YET ANOTHER DISTURBANCE MAKES
ITS WAY INTO THE REGION...AIDED ALSO BY AN INCREASING LLJ. SEVERE
WEATHER REMAINS A CONCERN WITH MODEST INSTABILITY AND SUFFICIENT
DEEP LAYER SHEAR...LARGE HAIL/DAMAGING WINDS REMAIN THE PRIMARY
CONCERNS...BUT WILL HAVE TO MONITOR THE POTENTIAL FOR AN ISOLATED
TORNADO WITH THOSE MORE ERLY WINDS/INCREASED LOW LEVEL SHEAR IN THE
AREA. SPC DAY 2 OUTLOOK SLIGHT RISK AREA INCLUDES ROUGHLY THE SERN
HALF OF THE CWA.
SIMILAR TO MONDAY...TUESDAY MORNING MAY HAVE SOME LINGERING ACTIVITY
FROM OVERNIGHT...BUT MODELS SUGGEST THE OVERALL COVERAGE MAY NOT BE
AS WIDESPREAD. THE MAIN UPPER LEVEL LOW HAS SHIFTED EAST INTO THE
FOUR CORNERS REGION BY TUESDAY MORNING...AND MODELS CONTINUE TO SHOW
THE POTENTIAL FOR THE LOW TO WEAKEN SOME/FILL...AS IT COMES UNDER
INCREASING INFLUENCE OF A STRONGER UPPER LEVEL LOW MOVING INTO THE
PAC NW REGION. AT THE SFC...DURING THE DAYTIME HOURS...THE FRONTAL
BOUNDARY CONTINUING TO MEANDER AROUND CENTRAL PORTIONS OF THE CWA
LOOKS TO PUSH NORTH AS A WARM FRONT...WITH MOST MODELS SHOWING SRLY
WINDS IN PLACE ACROSS THE ENTIRE CWA DURING THE AFTERNOON. MODELS
CONTINUE TO SHOW THE BETTER THUNDERSTORMS CHANCES ACROSS WRN
PORTIONS OF THE CWA DURING THE AFTERNOON...SPREADING ACROSS THE REST
OF THE CWA OVERNIGHT AS LIFT CONTINUES TO INCREASE WITH THE
APPROACHING MAIN UPPER TROUGH/LOW...WHICH IS STARTING TO MAKE MORE
OF A PUSH ONTO THE THE PLAINS DURING THE LATE TUES NIGHT HOURS/WED
MORNING.
WED/WED NIGHT CONTINUES TO BE THE PERIOD GENERALLY SHOWN BY MODELS
WHEN THAT MAIN TROUGH AXIS /CLOSED LOW?/ MAKES ITS TREK NE THROUGH
THE REGION...AS THAT STRONGER UPPER LEVEL LOW DIGS FURTHER SOUTH
ALONG THE WEST COAST. THE HIGH CHANCE/LOW END LIKELY POPS CONTINUE
IN THE FORECAST...SIMILAR TO PERIODS PRIOR AND FOLLOWING...HARD TO
TRIM AREAS OUT OR RAISE POPS IN OTHERS WHEN SO MANY DETAILS HAVE YET
TO BE IRONED OUT. THE LOCATION OF THE SFC LOW/ASSOCIATED BOUNDARIES
LOOK TO BE PLAYING A BIGGER ROLE/FOCUS FOR CONVECTIVE DEVELOPMENT
NEAR/ACROSS THE CWA...SO AS THEIR ULTIMATE PLACEMENT BECOMES MORE
CLEAR IN THE COMING MODEL RUNS...CAN PIN DOWN BETTER DETAILS WITH
POPS AND SEVERE WEATHER POTENTIAL.
THROUGH THE REST OF THE LONG TERM PERIOD THURSDAY THROUGH
SATURDAY...ONE NOTABLE DISTURBANCE MOVES OUT...BUT SOUTHWESTERLY
FLOW REMAINS IN PLACE IN THE UPPER LEVEL AS THAT NEXT LOW PRESSURE
SYSTEM CONTINUES TO DIG FURTHER SOUTH INTO CALIFORNIA. PIECES OF
SHORTWAVE ENERGY ASSOCIATED WITH THAT LOW LOOK TO CONTINUE TO BRING
AT LEAST PERIODIC THUNDERSTORM CHANCES...KEPT THE FORECAST CLOSE TO
THE CR INIT/SUPERBLEND OUTPUT.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1257 AM CDT SUN MAY 3 2015
WIND SHEAR WILL BE A CONCERN FOR THE FIRST FEW HOURS DURING THE
OVERNIGHT...BUT SHOULD WANE FROM WEST TO EAST AS THE LOW-LEVEL JET
MOVES EAST. ANY CLOUDS SHOULD REMAIN PRIMARILY MID-HIGH LEVEL
OVERNIGHT INTO SUNDAY. AS A COLD FRONT APPROACHES FROM THE
NORTH...THERE WILL BE AN INCREASED CHANCE OF SHOWERS/T-STORMS.
&&
.CLIMATE...
ISSUED AT 433 AM CDT SUN MAY 3 2015
PREDICTED HIGH TODAY:
HASTINGS 91
GRAND ISLAND 91
RECORD HIGH:
HASTINGS 89 (1959)
GRAND ISLAND 92 (1959)
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...ADP
AVIATION...HEINLEIN
CLIMATE...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
322 AM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
TODAY...STORMS SHOULD CONTINUE EASTWARD OUT OF THE FORECAST AREA
EARLY THIS MORNING. HIGH RES MODELS ARE IN GOOD AGREEMENT WITH
THAT. STORMS LAST EVENING DID PRODUCE SOME LARGE HAIL AND A FEW
SPOTS RECEIVED STRONG WINDS AS STORMS MIXED DOWN A STRONG LOW
LEVEL JET. AS OF AROUND 07Z RUC MODEL INITIALIZATION SHOWED WINDS
AT AROUND 1 KM AGL OF AROUND 40-50 KNOTS STRETCHING FROM WESTERN
OKLAHOMA INTO SOUTHEAST NEBRASKA AND PARTS OF IOWA. THESE WINDS
WILL DECREASE THIS MORNING. COLD FRONT AS OF 08Z STRETCHED FROM
NORTHEAST MINNESOTA BACK INTO WESTERN SOUTH DAKOTA. THAT FRONT
WILL MOVE SOUTHEAST INTO NORTHEAST NEBRASKA THIS AFTERNOON. LOOK
FOR HIGHS IN THE MID TO UPPER 80S AT MOST SPOTS TODAY WITH A FEW
HIGHS AROUND 90 POSSIBLE. THIS WILL CREATE CAPE VALUES FROM 1500
TO 2500 J/KG BY MID AFTERNOON. EXPECT CAP TO BREAK NEAR THE FRONT
BY MID/LATE AFTERNOON. SOME MODELS ALSO HINT AT THE CAP WEAKENING
FARTHER SOUTH...BUT WITH A LACK OF FOCUS AT THAT TIME WILL KEEP
HIGHEST POPS CLOSER TO THE FRONT. SOME SEVERE STORMS APPEAR
POSSIBLE...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS.
GENERALLY USED A BLEND OF SHORT RANGE GUIDANCE FOR TONIGHT WITH THE
HIGHEST WEIGHT GIVEN TO THE 00Z HIGH RES WRF-ARW MODEL. LIKE SOME OF
THE OTHER MODELS...IT DEVELOPED STORMS LATE AFTERNOON THEN MOVED
THEM SOUTH AND EAST. SOME STORMS MAY CONTINUE TO BE SEVERE IN THE
EVENING. COVERAGE SHOULD DECREASE AFTER MIDNIGHT. CONVECTION WILL
LIKELY FORCE THE FRONT DOWN AT LEAST AS FAR AS SOUTHEAST NEBRASKA
AND MAYBE INTO NORTHEAST KANSAS BY 12Z MONDAY. MOST MODELS SHOW
LIFT OCCURRING OVER THE BOUNDARY DURING THE DAY MONDAY WITH PCPN
COVERAGE INCREASING...SO HAVE POPS INCREASING TO MATCH THAT. TWO
CLUSTERS OF STORMS MAY TAKE SHAPE BY LATE AFTERNOON OR EARLY
EVENING. ONE NEAR THE NEBRASKA/SOUTH DAKOTA BORDER AND ANOTHER
LIFTING FROM NORTHERN KANSAS THROUGH OUR AREA AND TOWARD CENTRAL
IOWA MONDAY NIGHT.
TUESDAY...WE MAY SEE SOMEWHAT OF A BREAK IN THE WIDESPREAD PCPN...
AT LEAST OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. HAVE POPS
RANGING FROM 15 TO 50 PERCENT...HIGHEST IN NORTHEAST NEBRASKA.
SOUTHERLY FLOW WILL INCREASE AND HELP A WARM FRONT LIFT NORTH OF
THE AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 AM CDT SUN MAY 3 2015
PATTERN WILL BE ACTIVE MUCH OF THIS PERIOD. A LARGE MID TROPOSPHERIC
TROUGH SHOULD BE OVER THE WESTERN UNITED STATES AT THE START OF THIS
PERIOD WITH EMBEDDED SHORTWAVES. ONE OF THESE WAVES WILL LIFT ACROSS
MID AMERICA WEDNESDAY/WEDNESDAY NIGHT...WHILE A CLOSED LOW STARTS TO
DIG SOUTHWARD FROM THE PACIFIC NORTHWEST. THIS WILL GENERALLY KEEP
OUR AREA IN SOUTHWEST FLOW WITH A DECENT SUPPLY OF LOW LEVEL MOISTURE
FOR SHOWERS AND STORMS TO WORK WITH. MODEL AGREEMENT STARTS TO FALL
OFF BY DAY 7...SO CONFIDENCE FALLS TO AVERAGE BY DAY 7. TEMPERATURES
AND PCPN SHOULD BE AT OR ABOVE NORMAL FOR THIS PERIOD.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1215 AM CDT SUN MAY 3 2015
LOOK FOR SCT TSRA WILL MOVE EASTWARD AWAY FROM THE TAF SITES THE
NEXT FEW HOURS. TSRA SHOULD DEVELOP ALONG A COLD FRONT NEAR KOFK
BY MID AFTERNOON THEN MOVE/DEVELOP SOUTHEAST TOWARD KOMA AND KLNK
THROUGH THE EVENING. MVFR OR LOWER CEILINGS AND VSBYS WILL BE
POSSIBLE IN THE TSRA.
OTHERWISE...LOW LEVEL WIND SHEAR EXPECTED EARLY THIS MORNING WITH
STRONG LOW LEVEL JET AROUND 1000-3000 FEET AGL.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...PEARSON/MILLER
LONG TERM...MILLER
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS ELKO NV
319 PM PDT SUN MAY 3 2015
.SYNOPSIS...WARMER THAN NORMAL CONDITIONS WILL CONTINUE THROUGH
TUESDAY...THEN MUCH COOLER FOR THE MIDDLE AND END OF NEXT WEEK
COURTESY OF A COOL LOW PRESSURE SYSTEM. THUNDERSTORMS POSSIBLE
EACH AFTERNOON...SOME OF THE STORMS WILL PRODUCE STRONG GUSTY
WINDS BUT VERY LITTLE IN THE WAY OF RAINFALL. HOWEVER BEGINNING
THURSDAY MUCH OF THE AREA WILL HAVE A GOOD SHOT OF WELCOME
PRECIPITATION.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY. RESIDUAL MOISTURE FROM
YESTERDAY RESULTING IN MORE INSTABILITY THAN PREVIOUSLY INDICATED.
BEST INSTABILITY IS LOCATED IN NORTHERN LANDER/EUREKA AND ELKO
COUNTIES. SHEAR IS MINIMAL...WITH MOST AREAS 15 TO 25KTS. THAT IS
GOOD ENOUGH FOR SOME MULTICELLUAR STORMS WITH SMALL HAIL AND GUSTY
WINDS TO 55 MPH. WOULD NOT BE SHOCKED TO SEE SOME SLIGHTLY HIGHER
GUSTS NEAR OR ABOVE 55 MPH...DUE TO FAVORABLE INVERTED V
SOUNDINGS AND DRY SUB CLOUD LAYER. JUST EAST INTO UTAH...ALREADY
HAD A GUST TO 57 MPH. THE LATEST HRRR MODEL RUNS SHOWS THIS
ACTIVITY SHIFTING NORTHWARD/NORTHEASTWARD THROUGH THE EVENING.
LIGHTNING WILL DIMINISH AFTER SUNSET...BUT SHOWERS WILL CONTINUE
THROUGH THE EVENING.
EXPECT MORE OF THE SAME MONDAY AND TUESDAY AS INSTABILITY AND
MOISTURE REMAIN. COULD BE A SLIGHT UPTICK IN CONVECTION TOMORROW
WITH ADDITIONAL STRONG STORMS POSSIBLE. TUESDAY...CONVECTION
WILL FOCUS IN CENTRAL AND EASTERN NEVADA.
ON WEDNESDAY...UPPER LEVEL TROUGH STARTS TO DIG INTO NORTHERN
NEVADA WITH A COLD FRONT SLOWING/STALLING ACROSS EASTERN NEVADA.
WITH INSTABILITY AND FRONTAL DYNAMICS...COULD SEE SOME MODERATE TO
HEAVY SHOWERS/STORMS FORM ALONG/BEHIND THAT FRONT IN EASTERN
NEVADA.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY. A STRONG UPPER LEVEL
TROUGH ACCOMPANIED BY AN UPPER LEVEL JET /H3 100 KT/ WILL DIG
SOUTHWARD FROM THE PACIFIC NORTHWEST TO NORTHERN CALIFORNIA
WEDNESDAY NIGHT. HAVE INCREASED POPS FOR A SMOOTH TRANSITION FROM
THE END OF THE SHORT TERM PERIOD INTO WEDNESDAY NIGHT.
THURSDAY...MODELS BRING THE UPPER LEVEL SYSTEM TO NORTH CENTRAL
CALIFORNIA DURING THURSDAY. BOTH THE GFS/ECMWF ARE NOW IN FAIRLY
GOOD POSITIONAL AGREEMENT. HAVE TRENDED THE POPS UP AS THE
ASSOCIATED SURFACE COLD FRONT TRANSITIONS ACROSS NORTHERN AND
CENTRAL NEVADA DURING THE DAY. SURFACE WINDS WILL BE BREEZY IN
ADVANCE AND ALONG THE SURFACE COLD FRONT ESPECIALLY OVER WHITE PINE
AND NORTHEAST NYE COUNTIES. NOT MUCH CHANGE WAS NOTED WITH THE SNOW
LEVELS AS THEY WILL REMAIN AROUND 6500-7500 FEET. WITH IS SYSTEM
INFLUENCING THE CWA...THE CLOUD COVER...PRECIPITATION AND COLD AIR
WILL RESULT IN BELOW NORMAL THURSDAY.
THURSDAY NIGHT THROUGH SATURDAY...THE GFS AND ECMWF ARE IN GOOD
AGREEMENT MOVING THE UPPER LOW ACROSS SOUTHERN NEVADA AND INTO
CENTRAL UTAH THROUGH SATURDAY. WITH THE COLD CORE OF THIS TROUGH
MOVING THROUGH THE GREAT BASIN...SCATTERED RAIN AND SNOW SHOWERS
WILL BE COMMON ALONG WITH THE POTENTIAL FOR AFTERNOON AND EVENING
THUNDER FRIDAY AND SATURDAY AFTERNOON. AFTERNOON MAX TEMPERATURES
WILL REMAIN AOB NORMAL LEVELS DURING THIS PERIOD.
SUNDAY...AS THE TROUGH SHIFTS INTO THE INTER-MOUNTAIN WEST...A SHORT
WAVE RIDGE BUILDS INTO THE GREAT BASIN SUNDAY. MID/HIGH LEVEL CLOUDS
WILL BE EVIDENT SPILLING OVER THE RIDGE WHICH WILL HOLD AFTERNOON
TEMPERATURES DOWN TO NEAR NORMAL LEVELS.
&&
.AVIATION...CONVECTION HAS FIRED UP BASICALLY ON A FROM
LANDER/EUREKA COUNTIES NORTHEASTWARD INTO SOUTHERN AND NORTHEASTERN
ELKO COUNTIES. SOME OF THE STRONGER CELLS AND ASSOCIATED OUTFLOWS
HAVE PRODUCED SURFACE WIND GUSTS FROM 35 TO 45 MPH. EXPECT THIS TO
CONTINUE INTO THIS EVENING BEFORE TRANSITIONING INTO SHOWERS LATER
TONIGHT. SIMILAR CONDITIONS ARE EXPECTED AGAIN ON MONDAY. EXPECT VFR
CONDITIONS WITH THE POSSIBILITY OF MVFR CONDITIONS NEAR THE CORES OF
THE STRONGEST STORMS.
.EQUIPMENT...THE WINNEMUCCA ASOS IS EXPERIENCING TELECOMMUNICATIONS
ISSUES AT THIS TIME. ALTHOUGH THE ASOS IS NOT TRANSMITTING
OBSERVATIONS THROUGH THE INTERNET...LANDLINE COMMUNICATIONS REMAIN
OPERATIONAL. IT IS NOT KNOWN AT THIS TIME WHEN THIS WILL BE REPAIRED.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
94/89/89
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
543 AM MDT SUN MAY 3 2015
.AVIATION...
12Z TAF CYCLE
ISO-SCT SHRA/TSRA WILL DEVELOP AROUND OR JUST AFTER 18Z TODAY.
SIMILAR STORM COVERAGE AS YDAY THOUGH SLIGHTLY MORE WIDESPREAD
ACROSS THE EAST. STORM MOTION WILL BE TOWARD THE EAST AROUND
10KTS. BASED ON HRRR OUTPUT...ANY TAF SITE MAY BE IMPACTED...
ESPECIALLY WITH GUSTY OUTFLOW WINDS UP TO 40KTS. THE STRONGER
STORMS WILL ALSO BE CAPABLE OF PEA SIZE HAIL AND BRIEF MVFR
CIGS/VSBYS. STORMS WILL LARGELY DISSIPATE AFTER SUNSET.
34
&&
.PREV DISCUSSION...335 AM MDT SUN MAY 3 2015...
.SYNOPSIS...
SLIGHTLY COOLER TODAY WEST AND CENTRAL BUT HIGHS OVERALL REMAINING
ABOVE AVERAGE BEFORE FALLING TO BELOW AVERAGE MONDAY THROUGH
THURSDAY. ISOLATED TO SCATTERED SHOWERS AND STORMS WILL DEVELOP
AGAIN TODAY OVER THE HIGHER TERRAIN AND TRACK INTO THE VALLEYS AND
PLAINS. A SLOW MOVING STORM SYSTEM WILL BRING WIDESPREAD SHOWERS AND
STORMS MONDAY THROUGH TUESDAY NIGHT. HEAVY RAIN WILL BE POSSIBLE
FROM THE CENTRAL MOUNTAIN CHAIN TO THE TEXAS BORDER...AND POTENTIAL
EXISTS FOR A FEW STRONG TO SEVERE THUNDERSTORMS TO DEVELOP BOTH
MONDAY AND TUESDAY FROM THE PECOS VALLEY TO THE TEXAS
BORDER...MAINLY OVER DE BACA...CHAVES...CURRY AND ROOSEVELT
COUNTIES. DRIER AND BREEZY TO WINDY WEATHER IS FORECAST FOR LATE IN
THE WEEK.
&&
.DISCUSSION...
SPOTTY SHOWERS AND ISOLD STORMS PERSISTING SOUTH OF I-40 EARLY THIS
MORNING...AND EXPECTING ANOTHER ROUND OF ISOLATED TO SCATTERED
SHOWERS AND STORMS TODAY...DEVELOPING OVER THE HIGHER TERRAIN AND
MOVING INTO THE LOWER ELEVATIONS THIS AFTERNOON/EVENING. HIGHS
CENTRAL AND WEST SLIDE A FEW MORE DEGREES BEFORE COOLING DOWN BELOW
AVERAGE OVER THE ENTIRE FORECAST AREA MONDAY AND TUESDAY.
A WIDESPREAD PRECIPITATION EVENT IS LOOKING MORE LIKELY FOR NORTHERN
AND CENTRAL NM MONDAY THROUGH TUESDAY NIGHT. HEAVY RAIN WILL BE
POSSIBLE FOR THE EASTERN PLAINS...WHERE SIGNIFICANT AMOUNTS COULD
RESULT IN POTENTIAL FOR AT LEAST LOCALIZED FLOODING...ESPECIALLY
ALONG AND EAST OF THE PECOS. COORDINATED WITH MAF ON POSSIBLE FLASH
FLOOD WATCH...WILL LEAVE THAT DECISION TO SUCCEEDING SHIFTS...BUT
NEW QPF AMOUNTS UPWARDS OF 2 INCHES MONDAY-TUESDAY NIGHT EAST OF THE
PECOS. IN ADDITION...SPC DAY 2 AND 3 CONVECTIVE OUTLOOKS PUT THE
EASTERN PLAINS IN A MARGINAL AREA...WITH SLIGHT RISK FOR SEVERE
STORMS FOCUSED OVER DE BACA...CHAVES...ROOSEVELT AND CURRY COUNTIES
BOTH MONDAY AND TUESDAY.
GFS IS TRENDING A BIT DRIER EARLIER...TUESDAY NIGHT...THAN IT HAD
BEEN...BUT BY WEDNESDAY THE UPPER TROUGH WILL BE EXITING AND THE
FOCUS FOR ANY CONVECTION SHOULD BE OVER THE NORTHWEST THIRD AND
PERHAPS ALONG THE EASTERN BORDER WITH TX. THEREAFTER...A LARGE AREA
OF LOW PRESSURE ALOFT WILL DEVELOP OVER THE GREAT BASIN...BUT NEW
MEXICO WILL BE ON THE DRY AND WINDY SIDE OF THE LOW AS IT EJECTS
INTO THE CENTRAL ROCKIES OVER THE UPCOMING WEEKEND. A FEW STORMS
COULD IGNITE ALONG THE FAR EASTERN PLAINS LATE IN THE WEEK AS LOW
LEVEL MOISTURE SLOSHES BACK AND FORTH.
&&
.FIRE WEATHER...
STILL LOOKING FOR ANOTHER ROUND OF SHOWERS AND A MIX OF WET AND DRY
THUNDERSTORMS THIS AFTERNOON. CONVECTIVE COVERAGE SHOULD BE SIMILAR
TO YESTERDAY...WITH PERHAPS SLIGHTLY MORE ACTIVITY ACROSS THE
CENTRAL HIGHLANDS AND EAST CENTRAL PLAINS. OTHERWISE...TEMPS ARE
EXPECTED TO BE WITHIN 5 DEGREES OF YESTERDAYS READINGS WITH MINIMUM
HUMIDITIES GENERALLY ABOVE 15 PERCENT. HUMIDITY RECOVERIES TONIGHT
WILL IMPROVE AGAIN OVER THIS MORNINGS READINGS...MAINLY ACROSS THE
EAST...AS GULF MOISTURE ADVECTS INTO THE PLAINS. RECOVERIES WILL BE
GOOD TO EXCELLENT MOST AREAS.
A PACIFIC LOW WILL APPROACH NM ON MONDAY AND CROSS THE STATE ON
TUESDAY. THE AFOREMENTIONED GULF MOISTURE PLUS LIFT AND INSTABILITY
AHEAD AND BELOW THE UPPER LOW WILL RESULT IN WIDESPREAD SHOWERS AND
THUNDERSTORMS. AREAS ACROSS THE EASTERN PLAINS MAY RECEIVE BETWEEN
ONE AND THREE INCHES OF RAINFALL. FLOODING IS POSSIBLE...AS WELL AS
SOME SEVERE STORMS IN THE AFTERNOON BOTH MONDAY AND TUESDAY.
ELSEWHERE...EXPECT STORMS...THOUGH RAINFALL AMOUNTS WILL NOT BE
QUITE AS SIGNIFICANT. TEMPERATURES WILL COOL THROUGH THIS
PERIOD...WITH ALL AREAS BETWEEN 5 AND 10 DEGREES BELOW NORMAL
TUESDAY AFTERNOON.
A WARMING AND DRYING TREND WILL FOLLOW ON WEDNESDAY AND THURSDAY AS
A DRY SLOT PUNCHES THROUGH THE STATE. HOWEVER...TEMPS WILL BE NEAR
TO JUST BELOW NORMAL. STILL LOOKING FOR A FEW SHOWERS ACROSS THE
NORTHWEST ON WEDNESDAY...BUT MOST AREAS SHOULD BE DRY ON
THURSDAY...THOUGH SOME DRYLINE ACTIVITY IS NOT OUT OF THE QUESTION.
A STRONG LEE SIDE TROUGH WILL DEVELOP ON WEDNESDAY...ALLOWING
WEST-SOUTHWESTERLY WINDS TO INCREASE ACROSS THE PLAINS. HUMIDITIES
WILL STAY ABOVE 15 PERCENT...PLUS THIS AREA IS EXPECTED TO RECEIVE
ABUNDANT RAIN ON MON/TUE...SO NO CRITICAL CONDITIONS ARE EXPECTED.
WIND SPEEDS WILL TREND UP ON THURSDAY AND FRIDAY...AS THE NEXT STORM
SYSTEM DIVES TOWARD THE GREAT BASIN AND LEE SIDE TROUGHING PERSISTS.
A STRONGER DRY SLOT WILL ALSO PUNCH IN OVER NM ON FRIDAY. THE
STRONGEST WINDS OF THE WEEK MAY ARRIVE NEXT SATURDAY AS THE SYSTEM
LIFTS AND SHIFTS EASTWARD ACROSS UTAH AND COLORADO. TEMPS LOOK TO
REMAIN NEAR TO BELOW NORMAL THRU THIS PERIOD.
VENTILATION VALUES SHOULD BE GOOD OR BETTER THROUGH THE NEXT 7 DAYS.
34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1251 PM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 1234 PM CDT SUN MAY 3 2015
FORECAST ON TRACK. NO CHANGES NEEDED.
UPDATE ISSUED AT 953 AM CDT SUN MAY 3 2015
BASED ON CURRENT RADAR TRENDS AND HIGH RESOLUTION MODEL SOLUTIONS
MAINTAINED ISOLD T THROUGH THE REMAINDER OF THE MORNING ACROSS THE
FAR SE CORNER OF THE FA. ALSO MENTIONED SOME SPRINKLES VCNTY
VALLEY CITY IN ZONE OF WEAKENING FRONTOGENETIC FORCING. ALSO
INCREASED CLOUD COVER THIS MORNING ACROSS ALL BUT THE FAR NORTH
AND SOUTH.
UPDATE ISSUED AT 648 AM CDT SUN MAY 3 2015
SOME DECENT RADAR RETURNS HAVE DEVELOPED OVER CENTRAL ND ALONG THE
700MB FRONTOGENESIS BAND...WITH A LITTLE BIT OF LIGHT RAIN
REACHING THE GROUND AT BIS. THE FRONTOGENESIS WILL BEGIN TO MOVE
INTO OUR SOUTHERN COUNTIES BY 15Z...BUT THE RAP AND HRRR HAVE
LITTLE TO NO QPF. WILL CONTINUE TO KEEP SOME MINIMAL POPS IN THE
SOUTH AND EAST THIS MORNING BUT THINK THAT IT SHOULD BE FAIRLY
QUIET.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 346 AM CDT SUN MAY 3 2015
WINDS TODAY AND TEMPERATURES THROUGHOUT THE PERIOD WILL BE THE
MAIN FORECAST ISSUES FOR THE SHORT TERM.
A SHORTWAVE TROUGH MOVING ACROSS SOUTHERN MANITOBA TODAY AND INTO
ONTARIO WILL HELP PUSH A WEAK COLD FRONT THROUGH THE CWA. WINDS
HAVE ALREADY SHIFTED TO THE NORTH ACROSS THE DEVILS LAKE BASIN AND
NORTHERN RED RIVER VALLEY. THINK THAT THE BOUNDARY WILL BE THROUGH
THE SOUTHERN AND EASTERN CWA BY THE 15 TO 18Z TIME FRAME. A FEW
LINGERING SHOWERS MAINLY OVER THE SOUTHEASTERN COUNTIES WILL BE
POSSIBLE...BUT ANY AMOUNTS WILL BE EVEN LIGHTER THAN YESTERDAY.
WINDS WILL BE THE MAIN CONCERN THIS AFTERNOON. THERE WILL BE A
FAIRLY DECENT PRESSURE GRADIENT WHICH SHOULD MAKE IT SOMEWHAT
BREEZY. MIXING UP TO AROUND 800MB OR SO IS LIKELY...BUT WINDS AT
THE TOP OF THE MIXED LAYER ARE ONLY AROUND 20 KTS. THINK THAT SOME
SUSTAINED WINDS IN THE TEENS WITH GUSTS ABOVE 20 MPH WILL BE
POSSIBLE...ENOUGH TO CAUSE SOME FIRE WEATHER HEADACHES. TEMPS
SHOULD BE COOLER THAN YESTERDAY BUT STILL PRETTY MILD...RISING
INTO THE 60S TO LOW 70S.
TONIGHT...SFC HIGH PRESSURE WILL BUILD INTO THE REGION...BRINGING
MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS SHOULD ALLOW TEMPS TO
FALL INTO THE UPPER 30S TO LOW 40S. MONDAY WILL ALSO BE VERY
QUIET UNDER NEAR ZONAL FLOW AS THE SFC HIGH BEGINS TO MOVE EAST.
WINDS SHOULD BE SHIFTING TO THE SOUTH BUT WILL REMAIN FAIRLY LIGHT
AND THINK THAT HIGHS AGAIN WILL BE IN THE 60S TO LOW 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 346 AM CDT SUN MAY 3 2015
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE MAIN EVENT WILL BE AN
UPPER TROUGH MOVING FROM THE DESERT SOUTHWEST THROUGH COLORADO AND
OUT INTO THE CENTRAL PLAINS. SFC LOW PRESSURE WILL BEGIN TO
DEVELOP TO OUR WEST AND BRING SOME HIGHER MOISTURE LEVELS AS
SOUTHERLY WINDS KICK IN. TEMPS SHOULD BE RISING AGAIN WITH MORE HIGHS
IN THE 70S FOR TUESDAY. SFC LOW PRESSURE WILL BE MOVING UP INTO
WESTERN SD TUESDAY NIGHT...WITH A WARM FRONT PUSHING INTO ND
MAINLY AFTER MIDNIGHT. CONTINUED WITH HIGH POPS FOR TUESDAY
NIGHT...AND WITH SHOWALTERS NEAR ZERO KEPT MAINLY SHOWERS WITH
ISOLATED THUNDER FOR NOW.
WEDNESDAY THROUGH SATURDAY...THE LONG TERM MODELS CONTINUE TO LOOK
WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING
UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND
NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND
PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT
INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO
THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE
SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH
MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE
IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU
TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS
WE HAVE HAD OVER THE LAST SEVERAL WEEKS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM CDT SUN MAY 3 2015
MODERATE NORTHWEST BOUNDARY LAYER WINDS ACROSS THE FA THIS AFTERNOON
WILL DIMINISH WITH NIGHTFALL. MID TO UPPER LEVEL CLOUDS ALG AND EAST
OF A ROX-RDR-JMS LINE WILL STEADILY SHIFT EASTWARD WITH VFR CONDS
PERSISTING THROUGHOUT THE PERIOD. SURFACE HIGH PRESSURE SHOULD BE
CENTERED OVER THE RRV EARLY MONDAY MORNING WITH LIGHT AND VARIABLE
WINDS AND FAIR SKIES.
&&
.FIRE WEATHER...
ISSUED AT 337 AM PM CDT SAT MAY 2 2015
THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE
WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE
FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN
SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE
CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO
NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS
CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY
DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND
ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS
THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO
THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JR/SPEICHER
AVIATION...GUST
FIRE WEATHER...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
957 AM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 953 AM CDT SUN MAY 3 2015
BASED ON CURRENT RADAR TRENDS AND HIGH RESOLUTION MODEL SOLUTIONS
MAINTAINED ISOLD T THROUGH THE REMAINDER OF THE MORNING ACROSS THE
FAR SE CORNER OF THE FA. ALSO MENTIONED SOME SPRINKLES VCNTY
VALLEY CITY IN ZONE OF WEAKENING FRONTOGENETIC FORCING. ALSO
INCREASED CLOUD COVER THIS MORNING ACROSS ALL BUT THE FAR NORTH
AND SOUTH.
UPDATE ISSUED AT 648 AM CDT SUN MAY 3 2015
SOME DECENT RADAR RETURNS HAVE DEVELOPED OVER CENTRAL ND ALONG THE
700MB FRONTOGENESIS BAND...WITH A LITTLE BIT OF LIGHT RAIN
REACHING THE GROUND AT BIS. THE FRONTOGENESIS WILL BEGIN TO MOVE
INTO OUR SOUTHERN COUNTIES BY 15Z...BUT THE RAP AND HRRR HAVE
LITTLE TO NO QPF. WILL CONTINUE TO KEEP SOME MINIMAL POPS IN THE
SOUTH AND EAST THIS MORNING BUT THINK THAT IT SHOULD BE FAIRLY
QUIET.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 346 AM CDT SUN MAY 3 2015
WINDS TODAY AND TEMPERATURES THROUGHOUT THE PERIOD WILL BE THE
MAIN FORECAST ISSUES FOR THE SHORT TERM.
A SHORTWAVE TROUGH MOVING ACROSS SOUTHERN MANITOBA TODAY AND INTO
ONTARIO WILL HELP PUSH A WEAK COLD FRONT THROUGH THE CWA. WINDS
HAVE ALREADY SHIFTED TO THE NORTH ACROSS THE DEVILS LAKE BASIN AND
NORTHERN RED RIVER VALLEY. THINK THAT THE BOUNDARY WILL BE THROUGH
THE SOUTHERN AND EASTERN CWA BY THE 15 TO 18Z TIME FRAME. A FEW
LINGERING SHOWERS MAINLY OVER THE SOUTHEASTERN COUNTIES WILL BE
POSSIBLE...BUT ANY AMOUNTS WILL BE EVEN LIGHTER THAN YESTERDAY.
WINDS WILL BE THE MAIN CONCERN THIS AFTERNOON. THERE WILL BE A
FAIRLY DECENT PRESSURE GRADIENT WHICH SHOULD MAKE IT SOMEWHAT
BREEZY. MIXING UP TO AROUND 800MB OR SO IS LIKELY...BUT WINDS AT
THE TOP OF THE MIXED LAYER ARE ONLY AROUND 20 KTS. THINK THAT SOME
SUSTAINED WINDS IN THE TEENS WITH GUSTS ABOVE 20 MPH WILL BE
POSSIBLE...ENOUGH TO CAUSE SOME FIRE WEATHER HEADACHES. TEMPS
SHOULD BE COOLER THAN YESTERDAY BUT STILL PRETTY MILD...RISING
INTO THE 60S TO LOW 70S.
TONIGHT...SFC HIGH PRESSURE WILL BUILD INTO THE REGION...BRINGING
MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS SHOULD ALLOW TEMPS TO
FALL INTO THE UPPER 30S TO LOW 40S. MONDAY WILL ALSO BE VERY
QUIET UNDER NEAR ZONAL FLOW AS THE SFC HIGH BEGINS TO MOVE EAST.
WINDS SHOULD BE SHIFTING TO THE SOUTH BUT WILL REMAIN FAIRLY LIGHT
AND THINK THAT HIGHS AGAIN WILL BE IN THE 60S TO LOW 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 346 AM CDT SUN MAY 3 2015
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE MAIN EVENT WILL BE AN
UPPER TROUGH MOVING FROM THE DESERT SOUTHWEST THROUGH COLORADO AND
OUT INTO THE CENTRAL PLAINS. SFC LOW PRESSURE WILL BEGIN TO
DEVELOP TO OUR WEST AND BRING SOME HIGHER MOISTURE LEVELS AS
SOUTHERLY WINDS KICK IN. TEMPS SHOULD BE RISING AGAIN WITH MORE HIGHS
IN THE 70S FOR TUESDAY. SFC LOW PRESSURE WILL BE MOVING UP INTO
WESTERN SD TUESDAY NIGHT...WITH A WARM FRONT PUSHING INTO ND
MAINLY AFTER MIDNIGHT. CONTINUED WITH HIGH POPS FOR TUESDAY
NIGHT...AND WITH SHOWALTERS NEAR ZERO KEPT MAINLY SHOWERS WITH
ISOLATED THUNDER FOR NOW.
WEDNESDAY THROUGH SATURDAY...THE LONG TERM MODELS CONTINUE TO LOOK
WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING
UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND
NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND
PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT
INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO
THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE
SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH
MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE
IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU
TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS
WE HAVE HAD OVER THE LAST SEVERAL WEEKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 648 AM CDT SUN MAY 3 2015
VFR CONDITIONS CONTINUE WITH ONLY SOME MID AND HIGH CLOUDS
THROUGHOUT THE PERIOD. NORTHWEST WINDS WILL PICK UP TO AROUND 15
KTS SUSTAINED WITH GUSTS ABOVE 20 KTS. WINDS WILL DIMINISH BY THIS
EVENING AND STAY UNDER 10 KTS THROUGH SUNDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 337 AM PM CDT SAT MAY 2 2015
THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE
WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE
FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN
SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE
CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO
NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS
CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY
DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND
ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS
THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO
THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JR/SPEICHER
AVIATION...JR
FIRE WEATHER...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
648 AM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 648 AM CDT SUN MAY 3 2015
SOME DECENT RADAR RETURNS HAVE DEVELOPED OVER CENTRAL ND ALONG THE
700MB FRONTOGENESIS BAND...WITH A LITTLE BIT OF LIGHT RAIN
REACHING THE GROUND AT BIS. THE FRONTOGENESIS WILL BEGIN TO MOVE
INTO OUR SOUTHERN COUNTIES BY 15Z...BUT THE RAP AND HRRR HAVE
LITTLE TO NO QPF. WILL CONTINUE TO KEEP SOME MINIMAL POPS IN THE
SOUTH AND EAST THIS MORNING BUT THINK THAT IT SHOULD BE FAIRLY
QUIET.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 346 AM CDT SUN MAY 3 2015
WINDS TODAY AND TEMPERATURES THROUGHOUT THE PERIOD WILL BE THE
MAIN FORECAST ISSUES FOR THE SHORT TERM.
A SHORTWAVE TROUGH MOVING ACROSS SOUTHERN MANITOBA TODAY AND INTO
ONTARIO WILL HELP PUSH A WEAK COLD FRONT THROUGH THE CWA. WINDS
HAVE ALREADY SHIFTED TO THE NORTH ACROSS THE DEVILS LAKE BASIN AND
NORTHERN RED RIVER VALLEY. THINK THAT THE BOUNDARY WILL BE THROUGH
THE SOUTHERN AND EASTERN CWA BY THE 15 TO 18Z TIME FRAME. A FEW
LINGERING SHOWERS MAINLY OVER THE SOUTHEASTERN COUNTIES WILL BE
POSSIBLE...BUT ANY AMOUNTS WILL BE EVEN LIGHTER THAN YESTERDAY.
WINDS WILL BE THE MAIN CONCERN THIS AFTERNOON. THERE WILL BE A
FAIRLY DECENT PRESSURE GRADIENT WHICH SHOULD MAKE IT SOMEWHAT
BREEZY. MIXING UP TO AROUND 800MB OR SO IS LIKELY...BUT WINDS AT
THE TOP OF THE MIXED LAYER ARE ONLY AROUND 20 KTS. THINK THAT SOME
SUSTAINED WINDS IN THE TEENS WITH GUSTS ABOVE 20 MPH WILL BE
POSSIBLE...ENOUGH TO CAUSE SOME FIRE WEATHER HEADACHES. TEMPS
SHOULD BE COOLER THAN YESTERDAY BUT STILL PRETTY MILD...RISING
INTO THE 60S TO LOW 70S.
TONIGHT...SFC HIGH PRESSURE WILL BUILD INTO THE REGION...BRINGING
MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS SHOULD ALLOW TEMPS TO
FALL INTO THE UPPER 30S TO LOW 40S. MONDAY WILL ALSO BE VERY
QUIET UNDER NEAR ZONAL FLOW AS THE SFC HIGH BEGINS TO MOVE EAST.
WINDS SHOULD BE SHIFTING TO THE SOUTH BUT WILL REMAIN FAIRLY LIGHT
AND THINK THAT HIGHS AGAIN WILL BE IN THE 60S TO LOW 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 346 AM CDT SUN MAY 3 2015
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE MAIN EVENT WILL BE AN
UPPER TROUGH MOVING FROM THE DESERT SOUTHWEST THROUGH COLORADO AND
OUT INTO THE CENTRAL PLAINS. SFC LOW PRESSURE WILL BEGIN TO
DEVELOP TO OUR WEST AND BRING SOME HIGHER MOISTURE LEVELS AS
SOUTHERLY WINDS KICK IN. TEMPS SHOULD BE RISING AGAIN WITH MORE HIGHS
IN THE 70S FOR TUESDAY. SFC LOW PRESSURE WILL BE MOVING UP INTO
WESTERN SD TUESDAY NIGHT...WITH A WARM FRONT PUSHING INTO ND
MAINLY AFTER MIDNIGHT. CONTINUED WITH HIGH POPS FOR TUESDAY
NIGHT...AND WITH SHOWALTERS NEAR ZERO KEPT MAINLY SHOWERS WITH
ISOLATED THUNDER FOR NOW.
WEDNESDAY THROUGH SATURDAY...THE LONG TERM MODELS CONTINUE TO LOOK
WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING
UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND
NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND
PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT
INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO
THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE
SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH
MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE
IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU
TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS
WE HAVE HAD OVER THE LAST SEVERAL WEEKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 648 AM CDT SUN MAY 3 2015
VFR CONDITIONS CONTINUE WITH ONLY SOME MID AND HIGH CLOUDS
THROUGHOUT THE PERIOD. NORTHWEST WINDS WILL PICK UP TO AROUND 15
KTS SUSTAINED WITH GUSTS ABOVE 20 KTS. WINDS WILL DIMINISH BY THIS
EVENING AND STAY UNDER 10 KTS THROUGH SUNDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 337 AM PM CDT SAT MAY 2 2015
THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE
WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE
FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN
SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE
CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO
NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS
CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY
DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND
ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS
THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO
THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/SPEICHER
AVIATION...JR
FIRE WEATHER...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1234 AM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 1234 AM CDT SUN MAY 3 2015
LATEST BOWMAN RADAR CONTINUES TO SHOW AN EXPANDING AREA OF
REFLECTIVITY`S IN SOUTHEAST MONTANA AND INTO SOUTHWEST NORTH
DAKOTA...WITH MORE ISOLATED ECHOES FARTHER NORTH. THE HRRR
COMPOSITE REFLECTIVITY SEEMS TO BE HANDLING THE CURRENT SCENARIO
WELL AND HAVE FOLLOWED A BLEND OF THE HRRR AND NAM12. THE NAM12
SHOWS A LAYER OF FRONTOGENESIS/750MB-650MB...INITIATING OVER
SOUTHWEST NORTH DAKOTA AND SHIFTING INTO SOUTH CENTRAL THROUGH 12Z
SUNDAY. VERTICAL MOTION/MAX OMEGA FIELD OCCURRING ATOP THIS LAYER
WILL RESULT IN LOWERING CLOUDS TO BETWEEN 7KFT AND 10KFT
OVERNIGHT...SUFFICIENT ENOUGH FOR PRECIPITATION TO REACH THE
GROUND. AFTER COLLABORATING WITH OUR NEIGHBORING OFFICES...HAVE
EXPANDED POPS OVERNIGHT FARTHER NORTH AND EAST...RANGING BETWEEN
ISOLATED AND SCATTERED THROUGH 15Z SUNDAY. WILL LOOK MORE INTO THE
FIRE WEATHER FORECAST AND POSSIBLE HEADLINES IN THE NEXT FORECAST.
UPDATE
ISSUED AT 1003 PM CDT SAT MAY 2 2015
RADAR RETURNS SOUTHEAST AND ACROSS THE WEST. WILL MAINTAIN SLIGHT
CHANCE SHOWERS SOUTHEAST THIS EVENING AND SOUTHWEST OVERNIGHT.
WHILE NOT MUCH WILL REACH THE GROUND SOUTHWEST LATE
TONIGHT...RADAR RETURNS VIA BOWMAN RADAR APPEAR ROBUST ENOUGH FOR
AN ISOLATED SHOWER SO WILL KEEP SOME LOW POPS IN 06-12Z.
UPDATE
ISSUED AT 825 PM CDT SAT MAY 2 2015
RED FLAG WAS ALLOWED TO EXPIRE AT 02Z. NO OTHER UPDATES AT THIS
TIME.
UPDATE
ISSUED AT 658 PM CDT SAT MAY 2 2015
COLD FRONT NEARLY THROUGH THE JAMES RIVER VALLEY...SO HAVE SCALED
BACK ON EVENING PRECIPITATION/THUNDER CHANCES A BIT...ENDING ALL
POPS OVER MY FAR SOUTHEAST BY 04Z. WINDS SHOULD TAPER OFF QUICKLY
BETWEEN NOW AND SUNSET (~01Z)...SO WILL BE ABLE TO EXPIRE THE RED
FLAG WARNING AS SCHEDULED BY 02Z.
REMAINDER OF THE FORECAST ON TRACK...SO NO MAJOR CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 245 PM CDT SAT MAY 2 2015
CURRENT SURFACE ANALYSIS PLACES COLD FRONT PUSHING THROUGH NORTH
CENTRAL INTO WESTERN NORTH DAKOTA WHILE SHOWERS AND THUNDERSTORMS
FIRE UP NEAR A PRE-FRONTAL TROUGH PUSHING OVER NORTHEAST INTO
SOUTH CENTRAL NORTH DAKOTA. UPPER LEVEL ANALYSIS PLACES WEAK SHORT
WAVE SLIDING THROUGH WEST/SOUTHWEST FLOW AHEAD OF A LOW AMPLITUDE
TROUGH PUSHING TO THE EAST OF THE ROCKIES.
FOR THE REST OF THIS AFTERNOON INTO TONIGHT...SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO DEVELOP AND PUSH TO THE EAST. MOST
ACTIVITY SHOULD SLIDE TO THE EAST OF OUR AREA EARLY THIS EVENING
PER LATEST HIGH-RES IMAGERY WHICH HAS HAD A RATHER GOOD HANDLE ON
THE TIMING OF THE STORMS. THERE REMAINS A LOW SEVERE WIND/HAIL CONCERN
GIVEN STEEP MID-LEVEL LAPSE RATES AND DRY LOW LAYERS...THOUGH WITH
WEAK FORCING AND MODEST INSTABILITY DO NOT EXPECT THIS TO BECOME
WIDESPREAD. ANOTHER WEAK WAVE PUSHES INTO THE SOUTHWEST LATE
TONIGHT WHICH MAY BRING A FEW LIGHT SHOWERS.
ON SUNDAY...QUIET WEATHER EXPECTED IN THE WAKE OF THE COLD FRONT
BRINGING NORTHWEST WINDS AND DRY CONDITIONS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 245 PM CDT SAT MAY 2 2015
THE MAIN CONCERN IN THE LONG TERM WILL BE THE ACTIVE WEATHER
PATTERN TAKING SHAPE FOR THE MIDDLE AND END OF NEXT WEEK. NEAR
TERM MODEL SOLUTIONS SUGGEST A SMALL CHANCE OF SHOWERS IN THE
SOUTHWEST PART OF THE STATE SUNDAY NIGHT INTO MONDAY...BUT ANY
RAINFALL LOOKS SPOTTY. ATTENTION THEN SHIFTS TO A LARGE TROUGH /H5
LOW WHICH WILL MOVE INTO THE WESTERN UNITED STATES. AHEAD OF THE
LOW...AN INITIAL SHORT WAVE WILL EJECT INTO THE CENTRAL AND
NORTHERN PLAINS...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS
TUESDAY NIGHT THAT CONTINUES THROUGH THURSDAY.
A BRIEF H5 RIDGE MOVES INTO THE NORTHERN PLAINS THURSDAY NIGHT AND
FRIDAY...HOWEVER THE LARGE TROUGH ACROSS THE WESTERN UNITED STATES
LIFTS INTO THE REGION FOR NEXT WEEKEND. IT APPEARS MUCH OF THE AREA
COULD RECEIVE MUCH NEEDED RAIN AS WE HEAD INTO THIS MORE ACTIVE
PATTERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM CDT SUN MAY 3 2015
A VCSH WILL CONTINUE FOR KDIK/KBIS/KJMS UNTIL AROUND 15Z-8Z SUNDAY
AS AN ISOLATED TO SCATTERED RAIN SHOWERS MOVE FROM SOUTHEAST
MONTANA ACROSS CENTRAL AND SOUTHERN NORTH DAKOTA. DESPITE THE
THREAT OF SHOWERS THROUGH SUNDAY MORNING...CIGS/VSBYS WILL REMAIN
VFR. AFTER 18Z SUNDAY...EXPECT A CLEARING SKY WHICH WILL CONTINUE
THROUGH THE REST OF THE TAF PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 825 PM CDT SAT MAY 2 2015
ON SUNDAY...NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED AS
MINIMUM RELATIVE HUMIDITY VALUES RANGE AROUND 20 TO 25 PERCENT
WHILE NORTHWEST WINDS INCREASE TO AROUND 15 TO 20 MPH. CONDITIONS
WILL BE MONITORED TO SEE IF A FIRE WEATHER HEADLINE WILL BE
NEEDED.
WETTING RAINS ARE EXPECTED OVER THE REGION TOWARDS THE MIDDLE OF
NEXT WEEK.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...JJS
LONG TERM...CK
AVIATION...KS
FIRE WEATHER...JJS/NH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1048 AM EDT SUN MAY 3 2015
.SYNOPSIS...
HIGH PRESSURE WILL GENERALLY DOMINATE THE REGION THROUGH MUCH OF
NEXT WEEK. ISOLATED SHOWERS AND OR THUNDERSTORMS WILL BE POSSIBLE
EACH AFTERNOON DURING PEAK HEATING OVER THE MOUNTAINS...WITH CHANCES
IMPROVING SLIGHT OUT OVER THE PIEDMONT BY THURSDAY AS A WEAK FRONT
SLIDES INTO THE REGION. TEMPERATURES WILL RISE TO ABOVE NORMAL
LEVELS...WITH HIGHS TOPPING OUT IN THE LOWER TO MID 80S THE LATTER
HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM EDT...TEMPERATURES ARE OFF TO A WARM START IN MOST
PLACES AS THE EXPECTED HIGH LEVEL STRATOCUMULUS FIELD HAS NOT FILLED
IN APPRECIABLY YET. STILL ANTICIPATE SOME INCREASING CLOUD COVER
BELOW A MID LEVEL CAP...BUT WARM MORNING THICKNESSES WILL REQUIRE A
ONE DEGREE BOOST IN TEMPS IN MOST PLACES. THE LATEST HRRR RUNS
CONTINUE TO FEATURE LITTLE MORE THAN ISOLD AIRMASS TYPE
SHOWERS...BUT WITH A GENERAL FOCUS ALONG THE ERN SIDE OF THE MTNS IN
DEVELOPING LIGHT UPSLOPE. VERY LITTLE CHANGE TO THE POP FORECAST IS
EXPECTED...WITH A RELATIVE FORCING MAXIMUM TOWARD 21Z WITH THE
PASSING OF AN UPPER SHORTWAVE TO THE N.
ANY AFTN/EARLY EVENING SHOWER ACTIVITY WILL WANE QUICKLY WITH SUNSET
TONIGHT. ANOTHER ROUND OF HIGH STRATOCUMULUS/LOW ALTOCU TRAPPED
UNDER THE INVERSION WILL KEEP SOME MEASURE OF CLOUDS GOING ALL
NIGHT. IN ADDITION...THE AIRMASS WILL CONTINUE TO MODIFY WITH RISING
MIN TEMPS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
AS OF 230 AM EDT SUNDAY...THE SHORT TERM FCST PERIOD INITIALIZES
MONDAY MORNING AMIDST BROAD FLAT H5 SUBTROPICAL RIDGE...WITH A WEAK
DISTURBANCE SLIDING THROUGH THE MEAN FLOW ATOP THE SOUTHERN APPS.
AT THE SURFACE...HIGH PRESSURE OFF THE CAROLINA COAST WILL CONTINUE
TO ALLOW FOR SOUTHERLY WAA ACROSS NORTHEAST GA AND THE WESTERN
CAROLINAS. STEEPENING LOW LEVEL LAPSE RATES DUE TO DIURNAL HEATING
ALONG WITH ABOVE MENTIONED UPPER IMPULSE WARRANT CHANCE LEVELS POPS
ACROSS THE HIGH TERRAIN ON MONDAY WHERE REGION OF BEST INSTABILITY
AND LEAST CIN WILL RESIDE. POPS TAPER SHARPLY TO NON MENTIONABLE
LEVEL THROUGH THE FOOTHILLS...LEADING TO A DRY FCST FOR THE PIEDMONT
AREAS DUE TO PROXIMITY OF THE PARENT SURFACE HIGH.
THE PRIMARY UPPER RIDGE AXIS WILL SHIFT OVERHEAD ON TUESDAY WHICH IS
EXPECTED TO LIMIT CONVECTION SOMEWHAT...ESPECIALLY OUTSIDE OF THE
MTNS. INSTABILITY WILL BE MAXIMIZED OVER THE HIGH TERRAIN...WHICH
COMBINED WITH WEAKER LOW LEVEL CIN DUE TO RETREATING PARENT SURFACE
HIGH...CONTINUE TO WARRANT CHANCE POPS. AS STATED ABOVE...EXPECTING
ANY CAPPING TO HOLD OUTSIDE OF THE HIGH TERRAIN THUS THE FCST
REMAINS DRY FOR TUESDAY ACROSS THESE ZONES. ANY HEAVIER
SHOWERS/THUNDERSTORMS THAT DO DEVELOP COULD PRODUCE LOCALLY HEAVY
RAINFALL AMOUNTS AS STORM MOTIONS WILL LIKELY BE LESS THAN
5-8KTS...ESPECIALLY ON TUESDAY WHEN MID LEVEL FLOW WEAKENS.
OTHERWISE...PARTLY CLOUDY SKIES WILL PREVAIL AMIDST LIGHT SOUTHERLY
FLOW. TEMPERATURES THROUGH THE PERIOD WILL EXCEED NORMAL LEVELS
WITH HIGHS TOPPING OUT IN THE LOWER 80S ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 245 AM EDT SUNDAY...THE MEDIUM RANGE FCST PERIOD INITIALIZES
WEDNESDAY MORNING WITH LITTLE TO NO CHANGES MADE TO THE PREVIOUS
FCST. HIGHLIGHTS OF THE PERIOD CONTINUE TO BE PREVAILING
SUBTROPICAL H5 RIDGE OVER EAST/CENTRAL CONUS WHILE SURFACE HIGH
PRESSURE REMAINS CENTERED OVER NEW ENGLAND. FURTHER SOUTH OVER THE
NORTHERN CARRIBEAN...A MIDLEVEL DISTURBANCE AND ASSOCIATED HYBRID
LOW WILL HAVE FORMED AND MIGRATED NORTHWARD OF THE EAST COAST OF
FLORIDA. CLOSER TO HOME...BROAD MID/UPPER LEVEL SUBSIDENCE PATTERN
IS EXPECTED TO PREVAIL INITIALLY LEADING TO A CAPPED ENVIRONMENT WITH
LITTLE IN THE WAY OF TRIGGERING AVAILABLE FOR CONVECTION ACROSS THE
PIEDMONT REGIONS. HOWEVER...OVER THE MOUNTAINS MODELS FAVOR
INCREASING INSTABILITY WITH ESE UPSLOPING FLOW PRESENT TO AID CAP
EROSION ON WEDNESDAY. THUS...SLIGHT/CHANCE LEVEL POPS ARE
FEATURED.
ON THURSDAY POPS WILL EXPAND FURTHER INTO THE NC/SC PIEDMONT AND
NORTHEAST GA AS THE ABOVE MENTIONED HYBRID LOW...AND ITS LOCATION AT
THE TIME BECOMES VITAL TO THE FCST. MODEL DISCONTINUITY AS TO ITS
LOCATION WOULD PROVIDE VASTLY DIFFERENT OUTCOMES AS IT PERTAINS TO
SENSIBLE WX FOR THE REMAINDER OF THE PERIOD. THE GFS HAS THE LOW
SETUP APPROX 2-3 HUNDRED MILES OFF THE SC COAST THURSDAY
AFTERNOON...WHILE THE ECMWF IS ABOUT THE SAME DISTANCE FURTHER OUT
TO SEA. THE GFS SOLUTION WOULD RESULT IN FLOW ON THE WESTERN FLANK
OF THE WAVE YIELDING A NORTHERLY COMPONENT OF MOTION...WHICH WOULD
AID INTRUSION OF A WEAK BACK DOOR FRONT INTO THE REGION. THE ECMWF
ON THE OTHER HAND INDICATES THE SAME BACK DOOR FRONT...ALBEIT
WEAKER. IF THE GFS VERIFIED THE FROPA COULD PROVIDE ENOUGH OF A
FOCUS FOR CONVECTION TO OCCUR OUTSIDE OF THE MTNS...THEREFORE FOR
THE FCST SLIGHT CHANCE POPS ARE MENTIONED. BOTH THE GFS/ECMWF
ILLUSTRATE A WESTWARD JAUNT OF THE LOW ON FRIDAY/SATURDAY
EFFECTIVELY KEEPING IT JUST OFF THE GA/SC COAST PER THE GFS...AND
THE SC/NC COAST PER THE ECMWF. MOISTURE WRAPPING AROUND THE LOW
SHOULD STAY JUST TO THE EAST...THEREFORE THE FCST IS DRY FOR
PIEDMONT REGIONS ALL THE WHILE FEATURING SLIGHT/CHANCE LEVEL POPS
OVER MTNS WHERE DIURNAL CONVECTION IS FAVORED. TEMPERATURES THROUGH
THE PERIOD WILL CONTINUE TO MODERATE TO 5-8 DEGREES ABOVE CLIMO.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...VFR IS EXPECTED THROUGH THE PERIOD COURTESY
OF DRY HIGH PRESSURE. WILL CONTINUE TO SEE SOME HIGH BASED STRATOCU
TRAPPED UNDER THE SUBSIDENCE INVERSION...BUT THIS SHOULD NOT BE
OPERATIONALLY SIGNIFICANT. EXPECT WINDS TO COME UP FROM THE SSE TO
SSW THROUGH EARLY AFTN AS HIGH PRESSURE MOVES OFF THE COAST. WITH
HIGH PRESSURE TO THE EAST...SOME MOISTURE RETURN WILL TAKE PLACE
FROM THE S. A CU FIELD IS EXPECTED TO DEVELOP FROM MIDDAY
ONWARD...THAT WILL PROBABLY RESULT IN A CEILING IN MOST PLACES IN
THE AFTERNOON...BUT WITH A CLOUD BASE AT 060 OR HIGHER. THE MODELS
ARE MORE SUPPORTIVE/REACTIVE WITH PRECIP OVER THE HIGHER TERRAIN
THIS AFTERNOON...SO A VICINITY SHOWER WAS INCLUDED AT KAVL.
OUTLOOK...RETURN FLOW MOISTURE WILL SLOWLY REDEVELOP THROUGH MID
WEEK...PRODUCING ISOLD TO SCATTERED DIURNAL CONVECTION EACH DAY...
MAINLY OVER THE HIGH TERRAIN.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...CDG/HG
NEAR TERM...HG
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...HG/PM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
324 PM CDT SUN MAY 3 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 323 PM CDT SUN MAY 3 2015
HAVE SEEN SCATTERED SPRINKLES/LIGHT SHOWERS DEVELOP OVER THE
WESTERN CWA ALONG ELEVATED BOUNDARY AHEAD OF THE MID LEVEL WAVE.
UPDATED GRIDS TO PROGRESS THIS ACTIVITY EASTWARD ACROSS THE AREA
THIS AFTERNOON...WITH CONVECTIVE POTENTIAL GRADUALLY INCREASING
ACROSS SOUTHEAST HALF OF THE FORECAST AREA AS THE ELEVATED FRONT
WORKS INTO MORE UNSTABLE AIR MASS. SURFACE BASED STORMS MAY BE
TOUGHER TO COME BY...AS SURFACE CONVERGENCE SOMEWHAT ILL-DEFINED
WITH BROAD AREA OF WEAK/VARIABLE FLOW AHEAD OF THE BOUNDARY...
LOCATED SOUTH OF KYKN-KFSD-KTKC LINE AT 18Z. ISOLATED SEVERE STILL
APPEAR POSSIBLE ACROSS THE SOUTHEAST...WITH RECENT HRRR MODEL RUNS
INDICATING A POTENTIAL FOR WIND THREAT ASSOCIATED WITH COLD POOL
AHEAD OF ELEVATED STORMS AS THEY TRACK ACROSS EXTREME SOUTHEAST
SD/NORTHWEST IA. NOT WHOLLY CONVINCED THIS WILL PAN OUT...BUT DOES
NOT SEEM ENTIRELY UNREASONABLE GIVEN HIGHER-BASED STORMS WITH DRIER
AIR UNDERCUTTING BEHIND SURFACE BOUNDARY...SO WILL DEFINITELY NEED
TO MONITOR THROUGH THE LATE AFTERNOON/EARLY EVENING.
OVERALL CONVECTIVE CHANCES SHOULD WANE AFTER 02Z-03Z AS THE WAVE
PASSES BY...WITH OVERNIGHT HOURS INTO EARLY MONDAY MORNING EXPECTED
TO BE DRY ACROSS THE AREA. INCREASING ISENTROPIC LIFT AHEAD OF BROAD
WAVE SHOULD BEGIN TO SPREAD PRECIP BACK INTO SOUTHERN PARTS OF THE
AREA MONDAY AFTERNOON...WITH MAIN QUESTION BEING HOW QUICKLY IT
EXPANDS TO THE NORTHEAST THE DRY LOW LEVEL EAST-NORTHEAST FLOW
FIRMLY IN PLACE. WILL HOLD GENERALLY SOUTHWEST OF KHON-KFSD-KSPW
LINE...SUPPORTED BY GREATER MODEL CONSENSUS OF NAM/ECMWF/GEM. MONDAY
SHOULD BE A COOLER DAY...WITH THICKER CLOUDS HOLDING TEMPS IN THE
60S THROUGH THE MISSOURI VALLEY...WITH LOWER 70S MORE PREVALENT TO
THE NORTHEAST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM CDT SUN MAY 3 2015
ON MONDAY NIGHT AND TUESDAY A WARM FRONT BEGINS TO LIFT NORTHWARD
THROUGH NEBRASKA...WITH INCREASING MIDLEVEL THETA E ADVECTION ACROSS
OUR AREA DURING THE PERIOD. WITH THIS WILL HAVE INCREASING
PRECIPITATION CHANCES...ESPECIALLY IN OUR SOUTH AND EAST.
INSTABILITY IS NOT ESPECIALLY IMPRESSIVE SO STAYED MAINLY WITH
ISOLATED THUNDER...ALTHOUGH IT DOES LOOK TO BE A LITTLE MORE
UNSTABLE IN OUR SOUTH ON TUESDAY AFTERNOON. HIGHS ON TUESDAY WILL
MAINLY BE UPPER 60S TO LOWER 70S...THOUGH AREAS THROUGH THE LOWER
MO RIVER VALLEY MAY APPROACH 80.
ON WEDNESDAY A MORE SIGNIFICANT VORT LOBE BEGINS TO LIFT OUT OF THE
WESTERN CONUS UPPER LEVEL TROUGH AND INTO THE CENTRAL AND NORTHERN
PLAINS. THIS WILL MOSTLY LIKELY BRING MORE SIGNIFICANT PRECIPITATION
TO THE AREA FOR LATER ON WEDNESDAY INTO WEDNESDAY NIGHT. WHILE IT
WILL BE FAIRLY UNSTABLE ON WEDNESDAY...SHEAR IS RATHER
UNIMPRESSIVE...BUT THERE WILL MOST LIKELY BE THUNDERSTORMS AROUND.
HIGHS AGAIN WILL BE RUNNING LOWER TO MID 70S. RAIN CHANCES THEN
CONTINUE INTO THURSDAY WHEN A SURFACE FRONTAL BOUNDARY SWINGS ACROSS
THE AREA AS THE UPPER LEVEL SHORTWAVE PULLS OFF INTO THE WESTERN
GREAT LAKES REGION.
MAY FINALLY BEGIN TO DRY OUT BY THURSDAY NIGHT AND FRIDAY AS HIGH
PRESSURE BEGINS TO BUILD BACK INTO THE REGION BEHIND THE EXITING
SYSTEM. SLIGHTLY COOLER AIR FILTERS INTO THE AREA FOR
FRIDAY...THOUGH STILL LOOKING AT HIGHS MID 60S TO LOWER 70S. RAIN
DOES LOOK TO RETURN BY NEXT WEEKEND HOWEVER AS ANOTHER UPPER LEVEL
LOW LIFTS OUT OF THE WESTERN CONUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 147 PM CDT SUN MAY 3 2015
CONVECTIVE CHANCES THROUGH THE AFTERNOON/EARLY EVENING...ALONG
WITH GUSTY POST-FRONTAL SURFACE WINDS...ARE PRIMARY CONCERNS FOR
THIS TAF PERIOD. CONVECTIVE THREAT SOMEWHAT ILL-DEFINED AS COOL
FRONT WORKS THROUGH MODERATELY UNSTABLE AIR MASS IN NORTHWEST IOWA
THIS AFTERNOON. SCATTERED THUNDERSTORMS STILL APPEAR POSSIBLE IN
AREAS SOUTH/EAST OF KFSD AND WILL MAINTAIN DRY FORECAST FOR KFSD
AS THIS POINT...THOUGH POTENTIAL FOR ISOLATED ELEVATED SHRA/TSRA
FOR AN HOUR OR TWO IN THE LATE AFTERNOON. GREATER CHANCE FOR THE
KSUX AREA IN THE EARLY EVENING AS ELEVATED FRONT WORKS THROUGH THE
AREA. LATE AFTERNOON/EVENING THUNDERSTORM ACTIVITY COULD PRODUCE
VARIABLE GUSTY WINDS...POSSIBLY IN EXCESS OF 40KT...THOUGH LOWER
CONFIDENCE IN TIMING/LOCATION OF WIND THREAT PRECLUDES MENTION IN
TAFS AT THIS TIME.
POST-FRONTAL WINDS GUSTING 20-30KT MORE WIDESPREAD AND EXPECTED TO
PERSIST INTO THE EVENING BEFORE DIMINISHING AFTER DARK.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JH
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
147 PM CDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 147 PM CDT SUN MAY 3 2015
HAVE SEEN SCATTERED SPRINKLES/LIGHT SHOWERS DEVELOP OVER THE
WESTERN CWA ALONG ELEVATED BOUNDARY AHEAD OF THE MID LEVEL WAVE.
UPDATED GRIDS TO PROGRESS THIS ACTIVITY EASTWARD ACROSS THE AREA
THIS AFTERNOON...WITH CONVECTIVE POTENTIAL GRADUALLY INCREASING
ACROSS SOUTHEAST HALF OF THE FORECAST AREA AS THE ELEVATED FRONT
WORKS INTO MORE UNSTABLE AIR MASS. SURFACE BASED STORMS MAY BE
TOUGHER TO COME BY...AS SURFACE CONVERGENCE SOMEWHAT ILL-DEFINED
WITH BROAD AREA OF WEAK/VARIABLE FLOW AHEAD OF THE BOUNDARY...
LOCATED SOUTH OF KYKN-KFSD-KTKC LINE AT 18Z. ISOLATED SEVERE STILL
APPEAR POSSIBLE ACROSS THE SOUTHEAST...WITH RECENT HRRR MODEL RUNS
INDICATING A GREATER POTENTIAL FOR WIND THREAT ASSOCIATED WITH
EXPANDING COLD POOL AHEAD OF ELEVATED STORMS AS THEY TRACK ACROSS
EXTREME SOUTHEAST SD/NORTHWEST IA.
OTHERWISE FORECAST APPEARS FAIRLY WELL ON TRACK. POST-FRONTAL WINDS
BECAME STRONGER THAN ANTICIPATED WITH INITIAL DEEPER MIXING ACROSS
NORTHWEST PARTS OF THE CWA IN THE LATE MORNING...BUT SEEM TO HAVE
TAMED DOWN CLOSER TO EXPECTED RANGES NOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN MAY 3 2015
CONCERNS THIS TODAY AND TONIGHT DEAL WITH CONVECTION CHANCES THIS
AFTERNOON ALONG WITH POST FRONTAL FIRE DANGER. EARLY THIS
MORNING...LOW LVL JET CONTINUES TO VEER AND PUSH CONVECTION EASTWARD
AND AWAY FROM THE CWA INTO CENTRAL IOWA. THERE REMAINS AN OUTSIDE
CHANCE FOR A FEW SHOWERS TO POPUP OVER THE EASTERN ZONES...BUT
LOOKING LESS LIKELY.
THE MAIN STORY TODAY WILL BE FOCUSED ON A FRONTAL BOUNDARY DROPPING
SOUTHEAST THROUGH THE AREA THIS EVENING. EARLY THIS MORNING...THE
FRONT WAS DRAPED ACROSS CENTRAL SOUTH DAKOTA...ALLOWING LOW TO MID
50 DEW POINTS TO POOL AHEAD OF IT. THIS FRONT WILL SLOWLY PRESS
SOUTHEAST STRETCHING FROM WORTHINGTON TO YANKTON BY 4PM. MODELS
CONTINUE TO SHOW MODEST DESTABILIZATION THROUGH THE DAY...WITH
UPWARDS OF 1500-2000 J/KG MLCAPE VALUES DEVELOPING ALONG AND BEHIND
THE BOUNDARY BY LATE AFTERNOON. THERE WILL LIKELY BE TWO MAIN
FORCING MECHANISMS THIS AFTERNOON...INCREASING FRONTAL CONVERGENCE
LATE THIS AFTERNOON ACROSS THE NORTHEASTERN HALF OF THE FRONT IN
MN...AND A SHORTWAVE ROTATING ACROSS NEBRASKA. WHILE DIFFICULT TO
PICKUP IN WV IMAGERY...THIS SHORTWAVE WAS BEGINNING TO ENTER THE
WESTERN PLAINS EARLY THIS MORNING...EVIDENT BY VEERING NPN/VWP. THE
DIFFICULTY THUS FAR...IS ASSESSING THE STRENGTH OF THIS
SHORTWAVE...WHICH MODELS HAVE BEEN STRUGGLING WITH.
SOUNDINGS INDICATE A RELATIVELY CAPPED ENVIRONMENT...WHICH SHOULD
HOLD OFF SFC BASED CONVECTION UNTIL MID-LATE AFTERNOON...WHEN
CONVERGENCE ALONG THE BOUNDARY OVER CENTRAL MN SHOULD BE SUFFICIENT.
LATEST GUIDANCE SUGGESTS THIS BOUNDARY MAY SURGE A BIT FASTER OVER
NORTHERN AND CENTRAL MINNESOTA WITH RATHER HIGH PRESSURE RISES
ACROSS THE WESTERN DAKOTAS. THIS IN RETURN COULD LIMIT THE
CONVECTIVE POTENTIAL OVER OUR SW MN COUNTIES. HOWEVER...FURTHER
SOUTHWEST ALONG THE LINE...INTO FAR SE SD...NW IA...AND NE...INITIAL
ISOLATED CONVECTION MAY BE MORE POST FRONTAL AND ELEVATED IN
NATURE...DEVELOPING ALONG A SECONDARY 925:850 CONVERGENCE ZONE.
MORE ISOLATED TO PERHAPS SCATTERED SFC BASED CONVECTION COULD
DEVELOP ONCE FORCING ALOFT CATCHES UP TO THE SFC FRONT TOWARD 00Z.
AT THIS POINT...FORCING ASSOCIATED WITH THE SHORTWAVE MAY BE THE
MORE DOMINATE FOCUS FOR CONVECTION AS OPPOSED TO THE FRONT...WITH
THE BEST CHANCES FOR THUNDER ALONG A YANKTON TO SPENCER LINE. THAT
SAID...WOULD NOT BE SURPRISED IF CONVECTION IS JUST NOT THAT
WIDESPREAD.
AGAIN...INSTABILITY IS MODERATE...BUT SHEAR PROFILE SEEMS MARGINAL
FOR THE EVENT. BEST SHEAR IS ACTUALLY IN THE POST FRONTAL
ENVIRONMENT. THAT SAID...WOULD ANTICIPATE FAIRLY ISOLATED TO
AT MOST SCATTERED CONVECTION...WITH ISOLATED SVR STORMS.
RELATIVELY STEEP LAPSE RATES...AND POCKET OF MID-LVL DRY AIR WOULD
SUPPORT DAMAGING WIND THREAT. CAPE PROFILE FAIRLY ELONGATED...BUT
SKINNY IN NATURE. WITH THE RELATIVELY LOW SHEAR
ENVIRONMENT...LOOKING AT A MARGINAL HAIL THREAT. TORNADIC THREAT
APPEARS LOW...GIVEN POOR 0-1KM SHEAR...AND RATHER HIGH LCLS.
THE SHORTWAVE WILL MOVE QUICKLY EASTWARD IN THE EVENING...WITH
CONVECTION PUSHING THE ELEVATED MOISTURE LAYER SOUTH OF THE CWA.
DEPENDING ON THE CLEARING...LOOKING AT LOWS IN THE 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN MAY 3 2015
WHILE STRONGER RIDGING WILL ATTEMPT TO BECOME REESTABLISHED ACROSS
THE NORTHERN PLAINS ON MONDAY...WILL HAVE TO DEAL WITH LIFT
ASSOCIATED WITH EXITING UPPER JET ENTRANCE REGION PULLING ACROSS THE
AREA MONDAY INTO MONDAY EVENING. THE MORNING HOURS WILL SEE MAIN
BOUNDARY AT LOWER LEVELS CONTINUING THE PUSH TO AREAS BETWEEN I-80
AND I-70...WITH FAIRLY STRONG PUSH OF LOWER LEVEL DRY AIR THROUGH
MUCH OF THE CWA. MID LEVEL MOISTURE SHOULD STALL ACROSS THE AREA...
BUT NO MORE THAN A MINIMAL THREAT OF A MID BASED SHOWER ALONG THE
EXTREME SOUTHERN BORDER THROUGH THE MORNING. INSTABILITY DISPLACED
WELL SOUTHWARD TO PRECLUDE ANY THUNDER MENTION...BUT THIS SHOULD
START TO CHANGE DURING THE AFTERNOON AS STRONGER UPPER FORCING WILL
COMBINE WITH INCREASE IN ISENTROPIC LIFT TO BULGE PRECIPITATION BACK
NORTHWARD THROUGH THE MISSOURI RIVER CORRIDOR ALONG WITH WEAK
ELEVATED INSTABILITY FOR AN ISOLATED THUNDER MENTION.
GOING THROUGH MONDAY NIGHT AND TUESDAY...LARGER SCALE BROAD
ISENTROPIC LIFT WILL SPREAD GRADUALLY NORTHWARD TO THE NORTH OF
STRONG SURFACE WARM FRONT LIFTING GRADUALLY NORTH OF I-80. MOST
SOLUTIONS DO SUGGEST THAT MAY SEE A MIDDAY MINIMA IN QG SUPPORT FOR
PRECIP WITH RIDGING STRENGTHENING ALOFT TO EAST...AND AHEAD OF NEXT
LOBE EJECTING FROM SOUTHERN ROCKIES CLOSED LOW PUSHING TOWARD
WESTERN CWA. HOWEVER...WITH PERSISTENT ISENTROPIC LIFT...EXPECT AT
LEAST A SCATTERING OF SHOWERS TO BE PRESENT. INSTABILITY IS JUST TO
THE WEAK SIDE OF NEUTRAL...SO THUNDER WILL BE FAR FROM PREDOMINANT
IN COVERAGE...AND HAVE GENERALLY KEPT A CATEGORY OR TWO BELOW ANY
PRECIP MENTION.
ON TUESDAY NIGHT...COULD ACTUALLY SEE A DECREASE IN COVERAGE OF
PRECIP CYCLING NORTHWARD THROUGH THE EASTERN CWA...WITH MAIN
ISENTROPIC BAND LIFTING NORTH OF THE CWA...AND LULL AHEAD OF
MOISTURE CONVEYOR LOBE WHICH WILL WRAP RAPIDLY NORTH AND EASTWARD
TOWARD THE MISSOURI VALLEY BY LATE NIGHT. THE MAIN DYNAMIC FORCING
WILL SWING NORTHEASTWARD LATER WEDNESDAY AND WEDNESDAY NIGHT AS
UPPER LOW LIFTS FROM COLORADO THROUGH THE DAKOTAS...AND SHOULD FOCUS
PERIOD OF MOST SIGNIFICANT RAINFALL ACROSS THE AREA. INSTABILITY
JUST A BIT STRONGER...BUT DEEP LAYER SHEAR IS QUITE MINIMAL...SO
PROSPECT OF SEVERE STORMS MINIMAL WITH WAVE OUT OF PHASE WITH
DIURNAL CYCLE AS WELL. THURSDAY WILL SEE THE LOW LEVEL BOUNDARY
PUSHING EASTWARD ACROSS THE CWA AS UPPER LOW LIFTS NORTH OF THE
REGION. DEPENDING ON TIMING OF BOUNDARY...DEGREE OF POTENTIAL
WARMING AHEAD...MAY SEE SEVERE PARAMETERS FALL OUT A BIT STRONGER
NEAR FRONTAL ZONE. MUCH OF THE TUESDAY TO THURSDAY PERIOD WILL HAVE
QUITE A BIT OF CLOUDINESS AND MOISTURE...WITH LOWER DIURNAL RANGE.
STILL SHOULD SEE TEMPS AT OR ABOVE NORMAL WITH UPPER 60S TO MID 70S
COMMON FOR HIGHS...AND 50S TO AROUND 60 FOR LOWS.
THE END OF THE LONGER RANGE FOR THURSDAY THROUGH SATURDAY CONTINUES
TO ADVERTISE SOME SIGNIFICANT DIFFERENCES IN DETAILS...WHILE A
LARGER SCALE AGREEMENT OF WESTERN TROUGHING TO EASTERN PLAINS
RIDGING REMAINS IN PLAY. ECMWF/CANADIAN SUGGEST A BIT MORE SOUTHWARD
AND QUICKER PUSH TO BAROCLINIC ZONE BY THURSDAY NIGHT AND FRIDAY
RESULTING IN A DRIER PERIOD PERHAPS LASTING INTO SATURDAY...AND
WOULD NOT BE SURPRISED TO HAVE THINGS SHAKE OUT IN THAT MANNER.
ANOTHER FAIRLY STRONG LOBE WILL BE MOVING IN JUST BEYOND THE END OF
THE FORECAST PERIOD...AND MAY HAVE SOMEWHAT SLIGHTLY BETTER SHEAR
AND INSTABILITY AT HAND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 147 PM CDT SUN MAY 3 2015
CONVECTIVE CHANCES THROUGH THE AFTERNOON/EARLY EVENING...ALONG
WITH GUSTY POST-FRONTAL SURFACE WINDS...ARE PRIMARY CONCERNS FOR
THIS TAF PERIOD. CONVECTIVE THREAT SOMEWHAT ILL-DEFINED AS COOL
FRONT WORKS THROUGH MODERATELY UNSTABLE AIR MASS IN NORTHWEST IOWA
THIS AFTERNOON. SCATTERED THUNDERSTORMS STILL APPEAR POSSIBLE IN
AREAS SOUTH/EAST OF KFSD AND WILL MAINTAIN DRY FORECAST FOR KFSD
AS THIS POINT...THOUGH POTENTIAL FOR ISOLATED ELEVATED SHRA/TSRA
FOR AN HOUR OR TWO IN THE LATE AFTERNOON. GREATER CHANCE FOR THE
KSUX AREA IN THE EARLY EVENING AS ELEVATED FRONT WORKS THROUGH THE
AREA. LATE AFTERNOON/EVENING THUNDERSTORM ACTIVITY COULD PRODUCE
VARIABLE GUSTY WINDS...POSSIBLY IN EXCESS OF 40KT...THOUGH LOWER
CONFIDENCE IN TIMING/LOCATION OF WIND THREAT PRECLUDES MENTION IN
TAFS AT THIS TIME.
POST-FRONTAL WINDS GUSTING 20-30KT MORE WIDESPREAD AND EXPECTED TO
PERSIST INTO THE EVENING BEFORE DIMINISHING AFTER DARK.
&&
.FIRE WEATHER...
ISSUED AT 358 AM CDT SUN MAY 3 2015
HIGH TO VERY HIGH FIRE DANGER EXPECTED TODAY...PRIMARILY ALONG
AND WEST OF A MARSHALL TO YANKTON LINE. THE DRIVING FORCE BEHIND
TODAYS HIGH FIRE DANGER WILL BE STRONG POST FRONTAL WINDS UP TO 20
KNOTS AT TIMES. THE AIR IMMEDIATELY BEHIND THE INCOMING FRONTAL
BOUNDARY WILL NOT BE ALL THAT DRY...SO RH VALUES WILL ONLY FALL TO
AROUND 25 TO 30 PERCENT. THUS...NOT ANTICIPATING RED FLAG WARNING
CONDITIONS BUT ANY BURNING SHOULD BE DONE WITH CAUTION.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...JH
SHORT TERM...DUX
LONG TERM...CHAPMAN
AVIATION...JH
FIRE WEATHER...DUX
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
836 PM CDT Mon May 4 2015
.UPDATE...
Convection continues to the west of the CWA. One batch of storms
is lifting slowly northeast across the South Plains from Lamesa to
near Snyder. A few showers and thunderstorms extend to the south
and southeast from this complex, generally along and north of the
Colorado River. Farther south, a persistent, right-moving
supercell continues to parallel I-10 near Ft. Stockton, with
additional development to its west. Given the proximity of this
storm to Crockett County, a Tornado Watch was issued through 2 AM.
Surface based instability is a bit more limited east of the Pecos
River, so the thinking is that this storm should weaken as it
moves into Crockett County. However, the HRRR has shown a tendency
for additional development in the Big Bend area overnight. There
is also the potential for additional thunderstorms to move into
the Big Country and Concho Valley late tonight and early Tuesday.
If this occurs, it may limit the severe weather potential for
tomorrow afternoon/evening. Will have to wait and see how this
plays out.
Johnson
&&
.PREV DISCUSSION... /ISSUED 629 PM CDT MON MAY 4 2015/
AVIATION...
/00Z TAFS/
Flight conditions will deteriorate at all terminals through the
next 24 hours. Ceilings will drop into the 1500 to 2500 feet
range after 04z at all TAF sites, with southern terminals dropping
to around 800 feet after 08z. Southeast winds gusting over 20
knots are likely area- wide tonight, with these gusts increasing
to near 30 knots tomorrow afternoon across the northern terminals,
and near/over 20 knots farther south. Showers and thunderstorms
may develop at any time during the TAF cycle. For now, have
inserted VCTS at KABI and KSJT for the next couple of hours based
on radar trends..
PREV DISCUSSION... /ISSUED 353 PM CDT Mon May 4 2015/
SHORT TERM...
(Tonight-Tuesday Night)
The main weather concerns for the short term will be the isolated
threat of severe thunderstorms this afternoon and a little more
widespread threat for severe weather Tuesday.
Thunderstorms have already developed this afternoon across much of
west central Texas. So far, storms have been of the single cell
pulse variety and staying below severe levels. We may see an
isolated storm or two produce severe hail this afternoon/evening.
However, the bigger threat for severe weather today will be
farther west over the Permian Basin. We may see a few storms cross
into our western counties this evening...so have kept
precipitation chances going overnight. For tomorrow...an upper
trough over eastern New Mexico will head northeast across west
Texas as the dryline heads east toward our area. Increased cloud
cover may limit instability slightly. However, with decent shear
across the area, expect more organized convection to develop
tomorrow afternoon with a slightly higher threat for severe
weather. Think the best chance for severe storms will be across
the northern and western parts of the area. Storms should continue
into the evening hours.
LONG TERM...
(Wednesday-Monday)
Unsettled weather will continue through the majority of the
extended period, with showers and thunderstorms possible through
next weekend.
The short-wave trough will lift northeast of the area on
Wednesday, while another significant upper trough develops across
the western states. We`ll remain in southwest flow aloft ahead of
this system through Friday, with periodic disturbances moving
across the area. The dryline will remain west of the area on
Wednesday but will mix east into far western counties Thursday
and Friday. Showers and thunderstorms are expected to develop
just about anywhere on Wednesday due to a weaker CAP, with a few
strong to severe storms possible during the late afternoon and
evening hours.
Scattered strong to severe thunderstorms will remain a possibility
Thursday and Friday ahead of the upper trough to our west, with a
continued chance for severe storms next weekend as the upper
trough moves across the Plains.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 62 74 64 80 66 / 30 50 60 40 40
San Angelo 63 76 65 82 66 / 30 30 40 30 30
Junction 64 77 66 80 67 / 20 40 40 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
826 PM CDT MON MAY 4 2015
.UPDATE... /UPDATE FOR NEW TOR WATCH VAL VERDE COUNTY/
ISOLATED SEVERE STORMS WILL CONTINUE TO BE A THREAT FOR VAL VERDE
COUNTY. RECENT CELL TRENDS ARE ON THE WAY DOWN OVER SOUTHERN
TERRELL COUNTY...BUT THE PAST FEW RUNS OF THE HRRR AND THE TX TECH
WRF STILL SUGGEST REGENERATION AND A FAVORABLE SHEAR ENVIRONMENT
FOR AN ISOLATED SUPERCELL OR TWO TOWARD MIDNIGHT. THE REST OF THE
FORECAST LOOKS IN GOOD SHAPE.
&&
.PREV DISCUSSION... /ISSUED 651 PM CDT MON MAY 4 2015/
UPDATE...UPDATE FOR 00Z AVIATION BELOW.
AVIATION...VFR CONDITIONS ONGOING EARLY THIS EVENING ACROSS
SOUTH-CENTRAL TEXAS. ISOLATED SHRAS CONTINUE ACROSS VAL VERDE
COUNTY...NEAR DRT. STRONGER TSTMS TO THE NORTHWEST MAY MOVE EAST
INTO NORTHERN VAL VERDE COUNTY THORUGH THE EVENING. WILL MONITOR
RADAR TRENDS...AND SHOULD TSTMS TREND FURTHER SOUTH MAY HAVE TO
AMEND TO INCLUDE MENTION AT DRT.
OTHERWISE...MOIST LOW LEVEL SOUTH TO SOUTHEAST FLOW WILL
CONTINUE...LEADING TO MVFR CEILINGS RE-DEVELOPING 03-06Z AND IFR
CEILINGS 07-10Z. CEILINGS FORECAST TO RISE BACK INTO MVFR RANGE
14-16Z...POTENTIALLY VFR MID AFTERNOON ON TUE.
SE WINDS AROUND 15 KTS THIS EVENING DIMINISHING TO AROUND 10 KTS
AT SAT/SSF/AUS OVERNIGHT.
PREV DISCUSSION... /ISSUED 239 PM CDT MON MAY 4 2015/
SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
UPPER AIR ANALYSIS THIS MORNING SHOWED A RIDGE EXTENDING FROM THE
CENTRAL GULF COAST TO THE CENTRAL PLAINS...A TROUGH OVER THE WEST
COAST AND SPLIT FLOW DEVELOPING OVER WEST TEXAS. THE 250MB JET
EXTENDED FROM THE BOTTOM OF THE WEST COAST TROUGH CURVING
ANTICYCLONICALLY ACROSS NORTHERN MEXICO THROUGH WEST TEXAS DOWN
TOWARD SOUTH PADRE ISLAND. AT THE SURFACE...HIGH PRESSURE WAS
CENTERED TO THE EAST AND WINDS WERE FROM THE SOUTHEAST. LOW LEVEL
MOISTURE HAS INCREASED OVER THE LAST 24 HOURS WITH DEW POINT
TEMPERATURES 3 TO 10 DEGREES HIGHER. THE LARGER INCREASES ARE
ACROSS THE NORTH. DURING THIS PERIOD THE WEST COAST UPPER TROUGH
WILL RIDE UP OVER THE RIDGE TO THE CENTRAL PLAINS. THIS WILL BRING
SOUTHWESTERLY FLOW OVER TEXAS...BUT IT WILL WEAKEN AS THE TROUGH
MOVES TO THE NORTHEAST. CHANCES FOR THUNDERSTORMS WILL MOVE INTO
THE REGION FROM THE WEST TONIGHT AND SPREAD ACROSS THE AREA
TUESDAY. POPS WILL BE LOW END CHANCE. STORMS ARE LIKELY TO
INITIATE ALONG THE DRYLINE OUT WEST. CAPE WILL BE SUFFICIENT TO
PRODUCE STRONG TO SEVERE STORMS OUT WEST AND SPC HAS OUR WESTERN
AREAS IN THE MARGINAL TO SLIGHT RISK FOR TUESDAY. DEEP LAYER SHEAR
MAY BE SUFFICIENT TO SUPPORT A FEW SUPERCELLS.
LONG TERM (WEDNESDAY THROUGH MONDAY)...
THE UPPER LEVEL PATTERN WILL BE SOMEWHAT STATIC THROUGH THE MIDDLE
OF THE WEEK AS A LARGE AMPLITUDE RIDGE AND TROUGH DEVELOP...THE
RIDGE IN THE EAST AND THE TROUGH IN THE WEST. THIS WILL KEEP
SOUTHWESTERLY FLOW OVER TEXAS. THIS WILL LEAD TO AN EXTENDED
PERIOD OF SLIGHT TO LOW END CHANCE POPS WEDNESDAY THROUGH FRIDAY.
THE UPPER PATTERN WILL BECOME SLOWLY PROGRESSIVE OVER THE WEEKEND
AS THE WESTERN TROUGH MOVES TOWARD THE MIDDLE OF THE COUNTRY.
MODELS ARE IN GOOD AGREEMENT ON THE TROUGH MOVING ACROSS TEXAS
SUNDAY NIGHT AND MONDAY. THIS WILL BRING HIGHER RAIN CHANCES FOR
THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 65 82 69 84 70 / 10 30 40 40 20
AUSTIN BERGSTROM INTL AIRPORT 63 82 68 83 69 / 10 30 40 30 20
NEW BRAUNFELS MUNI AIRPORT 64 82 68 84 70 / 10 30 30 30 20
BURNET MUNI AIRPORT 63 80 67 82 68 / 10 40 40 30 30
DEL RIO INTL AIRPORT 68 81 70 84 70 / 40 40 30 30 30
GEORGETOWN MUNI AIRPORT 63 81 68 82 69 / 10 40 50 40 30
HONDO MUNI AIRPORT 66 81 69 84 70 / 20 30 30 30 30
SAN MARCOS MUNI AIRPORT 64 81 69 82 69 / 10 30 40 30 20
LA GRANGE - FAYETTE REGIONAL 62 82 69 84 71 / 10 30 30 30 20
SAN ANTONIO INTL AIRPORT 66 82 69 84 70 / 10 30 30 30 20
STINSON MUNI AIRPORT 67 83 70 85 71 / 10 20 30 30 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
322 PM MDT SUN MAY 3 2015
.SYNOPSIS...
AFTER THREE DAYS OF VERY WARM TEMPERATURES...THE BORDERLAND WILL SEE
A COOLER STRETCH OF WEATHER AS A SERIES OF UPPER LOWS TRACK ACROSS
THE SOUTHERN U.S. MOISTURE AND INSTABILITY WILL CONTINUE TONIGHT
AND MONDAY...ALLOWING ISOLATED THUNDERSTORMS THROUGH MONDAY NIGHT.
LOW LEVEL MOISTURE BEGINS DECREASING TUESDAY...THOUGH A SLIGHT
CHANCE OF THUNDERSTORMS WILL CONTINUE EAST OF EL PASO. WEDNESDAY
THROUGH SATURDAY SHOULD SEE PLENTY OF SUNSHINE...WITH HIGHS
REMAINING NEAR NORMAL.
&&
.DISCUSSION...
LOOKS LIKE WE ARE ENTERING A COOLER PHASE OF WEATHER THOUGH NOT MUCH
WETTER. WV IMAGERY SHOWING DEEPER LAYERED MOISTURE NOW OFF TO OUR
EAST AS LARGE DRY SLOT WITH PW`S OF AROUND .4 TO .6 INCHES MOVES
OVER THE AREA. HOWEVER IMAGERY DOES APPEAR TO SHOW SEVERAL WEAK
DISTURBANCES TRACKING ACROSS THE BAJA TO FAR SOUTHERN ARIZONA AND
SOUTHERN NEW MEXICO...ASSOCIATED WITH STRONG 130 KT JET. THE
COMBINATION OF THE MODERATE MOISTURE AND DISTURBANCES SHOULD BE
ENOUGH TO CONTINUE ISOLATED SHOWERS/THUNDERSTORMS TONIGHT AND MONDAY
ACROSS THE CWA. VISIBLE SATELLITE SHOWS CONSIDERABLE CU GROWTH WITH
NICE AMOUNT OF TCU/CB. LIGHTNING LOOKS TO BE LIMITED TO MOSTLY
DEMING WEST AND ALSO OVER HUDSPETH CO AT THIS TIME. EXPECT THESE
ISOLATED TSTMS TO CONTINUE MONDAY...PERHAPS BECOMING SCATTERED OVER
THE MOUNTAINS. HRRR SHOWING DCAPES OF 700-900 J/KG...COMBINED WITH
DEW POINT DEPRESSIONS OF 50-55 DEG...WILL GIVE SOME WIND GUST
POTENTIAL OF 45 TO 55 MPH NEAR ANY SHOWERS TONIGHT. LARGE
DEPRESSIONS SHOULD LIMIT ANY RAINFALL AMOUNTS TO QUITE MODEST
TOTALS.
TUESDAY...MODELS SHOW WHAT LITTLE LOW LEVEL MOISTURE REMAINS...TO
BEGIN SCOURING OUT FROM THE WEST AS UPPER LOW PASSES THROUGH NEW
MEXICO. LEFT LOW POPS IN FAR EAST IN CASE MOISTURE REMAINS INTO
HEATING PERIOD. FLOW TURNS SOUTHWEST WEDNESDAY INTO SATURDAY AHEAD
OF A BROAD UPPER TROUGH SLOWLY MOVING ONSHORE OF THE WEST COAST.
PATTERN LOOKS LIKE IT SHOULD BE WARM...BUT MODELS NEVER REALLY
DEVELOP STRONG LEE SIDE TROUGHING TO DEVELOP WARM SOUTHWEST WINDS.
SO HIGH TEMPS LOOK TO REMAIN AROUND NORMAL LAST HALF OF THE WEEK.
NICE DAYS WITH SEASONABLE TEMPS AND YET NOT MUCH IN THE WAY OF
WINDS.
&&
.AVIATION...VALID 04/00Z-05/00Z...
VFR CONDS THRU PD. P6SM SCT-BKN080-100 BKN150-200 WITH ISOLD TO SCT
VRB25G40KT -TSRA BKN070-090 THRU 04Z AND AGAIN AFT 18Z. GENERALLY W
TO SW WINDS UNDER 12KTS THRU 20Z...THEN INCREASING TO 12-18G25KTS.
&&
.FIRE WEATHER...
AN UPPER LEVEL TROUGH WILL BE LIFTING OUT OF THE SOUTHWEST OVER THE
NEXT COUPLE OF DAYS. THIS WILL BRING ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS TO THE REGION. THERE WILL BE SOME DRY LIGHTNING
POSSIBLE AS TEMP-DEW POINT SPREAD WILL BE AROUND 50 DEGREES INTO THE
EARLY EVENING AND AROUND 45 DEGREES ON MONDAY. WINDS WILL ALSO START
TO INCREASE MONDAY AFTERNOON OUT OF THE SOUTHWEST AT 15 TO 20 MPH.
TEMPERATURES WILL COOL DOWN ON THE BACK SIDE OF THIS SYSTEM INTO THE
UPPER 70S TO LOWER 80S BUT RELATIVE HUMIDITIES WILL STAY AT OR BELOW
15 PERCENT FOR MOST LOWLAND LOCATIONS THROUGH THE UPCOMING WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 62 86 60 82 58 / 10 10 20 0 0
SIERRA BLANCA 57 83 54 82 54 / 20 10 40 0 0
LAS CRUCES 53 83 51 81 50 / 10 10 20 0 0
ALAMOGORDO 56 83 54 81 53 / 10 20 30 0 0
CLOUDCROFT 45 63 42 60 40 / 20 50 50 30 0
TRUTH OR CONSEQUENCES 53 81 50 79 50 / 10 20 20 10 0
SILVER CITY 48 75 46 72 45 / 10 20 30 20 0
DEMING 51 83 48 81 48 / 10 10 20 0 0
LORDSBURG 52 81 48 80 48 / 10 20 20 10 0
WEST EL PASO METRO 61 85 60 82 59 / 10 10 20 0 0
DELL CITY 55 85 54 81 52 / 20 20 40 20 0
FORT HANCOCK 58 87 56 83 55 / 20 10 30 0 0
LOMA LINDA 58 81 58 79 56 / 10 10 30 0 0
FABENS 57 86 55 82 54 / 10 10 30 0 0
SANTA TERESA 57 85 55 82 54 / 10 10 20 0 0
WHITE SANDS HQ 60 82 58 81 57 / 10 20 20 0 0
JORNADA RANGE 52 83 50 81 48 / 10 20 20 0 0
HATCH 53 83 50 82 49 / 10 20 20 0 0
COLUMBUS 55 81 54 81 53 / 10 10 20 0 0
OROGRANDE 59 84 57 82 57 / 10 20 30 0 0
MAYHILL 51 72 48 70 46 / 20 50 50 30 0
MESCALERO 49 72 45 70 43 / 20 50 50 30 0
TIMBERON 50 71 47 69 45 / 20 50 50 20 0
WINSTON 44 71 44 73 41 / 20 30 40 30 0
HILLSBORO 50 80 48 79 46 / 10 20 20 20 0
SPACEPORT 50 82 48 81 48 / 10 20 30 0 0
LAKE ROBERTS 44 74 44 71 42 / 10 30 30 30 0
HURLEY 47 76 47 75 44 / 10 10 20 20 0
CLIFF 46 80 42 78 42 / 10 20 20 30 0
MULE CREEK 42 78 39 75 39 / 20 20 20 30 0
FAYWOOD 49 77 47 76 46 / 10 10 20 20 0
ANIMAS 51 80 48 81 49 / 10 20 20 0 0
HACHITA 49 81 47 81 48 / 10 10 20 0 0
ANTELOPE WELLS 49 80 46 80 48 / 10 10 20 0 0
CLOVERDALE 48 78 47 77 47 / 10 10 10 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
HEFNER/GRZYWACZ
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1154 AM CDT SUN MAY 3 2015
.AVIATION...
18Z TAF CYCLE
AN UPPER LOW WILL APPROACH THE PANHANDLES FROM THE WEST THROUGH
MONDAY AND A FRONTAL BOUNDARY WILL PUSH INTO THE NORTHWEST SECTIONS
OF THE PANHANDLES TONIGHT AND MONDAY. CONVECTION WILL DEVELOP AND
MOVE EAST OUT OF NEW MEXICO THIS AFTERNOON AND TONIGHT OR DEVELOP
ACROSS MAINLY THE WESTERN HALF OF THE PANHANDLES. WILL MENTION VCTS
AT ALL THREE TAF SITES FOR NOW BETWEEN ABOUT 00Z MONDAY AND 08Z
MONDAY WITH VFR CONDITIONS. LIGHT MOSTLY WEST AND SOUTHWEST WINDS 5
TO 15 KNOTS WILL INCREASE FROM THE SOUTH 10 TO 20 KNOTS WITH SOME
HIGHER GUSTS POSSIBLE AFTER 20Z TODAY...THEN DIMINISHING TO AROUND 5
TO 15 KNOTS FROM THE SOUTH AND SOUTHEAST AFTER 00Z MONDAY.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 618 AM CDT SUN MAY 3 2015/
AVIATION...
MORE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING ACROSS
MUCH OF THE PANHANDLES. BUT WILL NOT MENTION THUNDERSTORMS AT THE TAF
SITES AS THE COVERAGE WILL NOT BE WIDESPREAD ENOUGH TO MENTION AT
THIS TIME. SKIES WILL REMAIN VFR...UNLESS A TAF SITE TAKES A DIRECT
HIT FROM A THUNDERSTORM...THEN CONDITIONS WILL LIKELY DROP INTO THE
MVFR RANGE. GUSTY SOUTHERLY WINDS WILL GRADUALLY DECREASE WITH SUNSET.
PREV DISCUSSION... /ISSUED 520 AM CDT SUN MAY 3 2015/
DISCUSSION...
NO SIGNIFICANT CHANGES WERE NEEDED TO THE PREVIOUS FORECAST. CURRENT
WATER VAPOR AND RAP ANALYSIS SHOW AN UPPER LOW CURRENTLY OFF THE
CALIFORNIA COAST MOVING EASTWARD. THIS WILL BE THE IMPETUS FOR
WIDESPREAD POTENTIALLY HEAVY RAINFALL EARLY NEXT WEEK ACROSS THE
ENTIRE FORECAST AREA.
BROAD BUT WEAK UPPER LEVEL RIDGING IS PRESENT OVER THE SOUTH-CENTRAL
UNITED STATES AND WILL HAVE LESS INFLUENCE ON OUR WEATHER AS IT
CONTINUES TO WEAKEN AND SHIFT EASTWARD. INITIAL PRECIPITATION
CHANCES WILL BE TIED TO DIURNAL CYCLE AND OROGRAPHIC EFFECTS OF THE
HIGH TERRAIN IN NEW MEXICO WITH CONVECTION BECOMING FAIRLY NUMEROUS
THERE BY EARLY/MID AFTERNOON. MEAN WESTERLY FLOW WILL REMAIN RATHER
WEAK RESULTING IN SLOW EASTWARD PROGRESSION OF THIS CONVECTION.
FURTHER EAST ONTO THE NEW MEXICO PLAINS AND ACROSS AT LEAST THE
WESTERN PORTION OF THE PANHANDLES...DEEP MIXING DURING THE AFTERNOON
SHOULD BE SUFFICIENT FOR SCATTERED HIGH BASED CONVECTION TO DEVELOP.
DEEP DRY SUB-CLOUD LAYER WILL LIMIT PRECIPITATION AMOUNTS BUT COULD
RESULT IN STRONG WIND GUSTS WITH THE MOST ROBUST CONVECTION.
CONVECTION SHOULD SLOWLY WEAKEN DURING THE EVENING AND EARLY SUNDAY
NIGHT.
UPPER FLOW BECOMES INCREASINGLY DIFLUENT ON MONDAY AS THE UPPER LOW
APPROACHES. EVEN EARLY IN THE DAY SUFFICIENT LARGE SCALE FORCING
AND MOISTURE ADVECTION IS PRESENT TO JUSTIFY AT LEAST LOW
PRECIPITATION PROBABILITIES PRIMARILY ACROSS THE WESTERN HALF OF THE
AREA. 00Z RAOB FROM COASTAL TEXAS OFFICES STILL LACK DEEP MOISTURE
BUT LATEST SATELLITE DERIVED TPW SHOWS INCREASING MOISTURE ACROSS
THE WESTERN GULF. MODEL GUIDANCE IS INSISTENT ON A SURGE OF LOW
LEVEL MOISTURE AND ABOVE CLIMO PWAT VALUES INTO THE AREA BY LATE
MONDAY WITH STRENGTHENING LEE TROUGH AND SOUTHERLY WINDS. THIS
INCREASE IN MOISTURE COMBINED WITH THE ABOVE MENTIONED LARGE SCALE
FORCING SHOULD RESULT IN WIDESPREAD RAIN. SPATIAL AND TEMPORAL
DETAILS OF HEAVY RAIN AND POTENTIAL FLOODING ARE STILL A BIT UNCLEAR
BUT THE PATTERN FITS THESE THREATS. ONE TO THREE INCHES SEEMS LIKELY.
THE MAJORITY OF THE RAINFALL WILL OCCUR MONDAY NIGHT THROUGH THE
FIRST HALF OF TUESDAY.
SEVERE THUNDERSTORM POTENTIAL SHOULD BE MOST LIKELY...ALBEIT STILL
RELATIVELY LOW AND MARGINAL...MONDAY AFTERNOON AND EVENING
COINCIDENT WITH LOW LEVEL MOISTURE SURGE BENEATH STEEPENING MID
LEVEL LAPSE RATES. THIS SHOULD YIELD AT LEAST MARGINAL INSTABILITY
AND DEEPER/STRONGER CONVECTION THAN THE PREVIOUS DAY. EFFECTIVE
SHEAR MAY BE MARGINAL FOR STORM ORGANIZATION THOUGH. SIGNIFICANT
CONVECTIVE OVERTURNING SHOULD WEAKEN MID LEVEL LAPSE RATES ON
TUESDAY PRECLUDING A NOTEWORTHY SEVERE WEATHER THREAT ALTHOUGH
IF POCKETS OF INSTABILITY CAN DEVELOP SOME STRONG TO SEVERE
THUNDERSTORMS WOULD BE POSSIBLE. ONE OF THE FEW CHANGES THAT WERE
MADE TO THE FORECAST WAS TO LOWER HIGH TEMPERATURES ON TUESDAY TO
ACCOUNT FOR WIDESPREAD CLOUDS AND PRECIPITATION THAT WILL LIKELY
LIMIT THE MAGNITUDE OF DIURNAL HEATING.
AS UPPER LOW/OPENING WAVE DEPARTS...WEAK SHORTWAVE RIDGING WILL
BRIEFLY INFLUENCE THE AREA RESULTING IN A MOSTLY DRY DAY AND
TEMPERATURES RETURNING TO THE UPPER 70S AND LOWER 80S. A DEEP CLOSED
LOW WILL EVOLVE ALONG THE WEST COAST BY THURSDAY AND WITH
STRENGTHENING MEAN SOUTHWESTERLY FLOW LEE TROUGHING WILL
PERSIST/STRENGTHEN. MULTIPLE DAYS OF DRYLINE CONVECTION MAY OCCUR
FROM LATE WEEK THROUGH THE WEEKEND WITH HIGHEST PRECIPITATION
PROBABILITIES ACROSS THE EASTERN HALF OF THE AREA. SPREAD IN THE
ENSEMBLE AND UNCERTAINTY WITH TIMING OF SMALL LEAD WAVES AND
EASTWARD PROGRESSION OF UPPER LOW MAKES IT DIFFICULT TO DELINEATE
WHEN THE HIGHEST PROBABILITY OF PRECIPITATION WILL BE. SUBSEQUENT
FORECASTS WILL REFINE THESE DETAILS.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/14
AREA FORECAST DISCUSSION
NWS AMARILLO TX
520 AM CDT SUN MAY 3 2015
.DISCUSSION...
NO SIGNIFICANT CHANGES WERE NEEDED TO THE PREVIOUS FORECAST. CURRENT
WATER VAPOR AND RAP ANALYSIS SHOW AN UPPER LOW CURRENTLY OFF THE
CALIFORNIA COAST MOVING EASTWARD. THIS WILL BE THE IMPETUS FOR
WIDESPREAD POTENTIALLY HEAVY RAINFALL EARLY NEXT WEEK ACROSS THE
ENTIRE FORECAST AREA.
BROAD BUT WEAK UPPER LEVEL RIDGING IS PRESENT OVER THE SOUTH-CENTRAL
UNITED STATES AND WILL HAVE LESS INFLUENCE ON OUR WEATHER AS IT
CONTINUES TO WEAKEN AND SHIFT EASTWARD. INITIAL PRECIPITATION
CHANCES WILL BE TIED TO DIURNAL CYCLE AND OROGRAPHIC EFFECTS OF THE
HIGH TERRAIN IN NEW MEXICO WITH CONVECTION BECOMING FAIRLY NUMEROUS
THERE BY EARLY/MID AFTERNOON. MEAN WESTERLY FLOW WILL REMAIN RATHER
WEAK RESULTING IN SLOW EASTWARD PROGRESSION OF THIS CONVECTION.
FURTHER EAST ONTO THE NEW MEXICO PLAINS AND ACROSS AT LEAST THE
WESTERN PORTION OF THE PANHANDLES...DEEP MIXING DURING THE AFTERNOON
SHOULD BE SUFFICIENT FOR SCATTERED HIGH BASED CONVECTION TO DEVELOP.
DEEP DRY SUB-CLOUD LAYER WILL LIMIT PRECIPITATION AMOUNTS BUT COULD
RESULT IN STRONG WIND GUSTS WITH THE MOST ROBUST CONVECTION.
CONVECTION SHOULD SLOWLY WEAKEN DURING THE EVENING AND EARLY SUNDAY
NIGHT.
UPPER FLOW BECOMES INCREASINGLY DIFLUENT ON MONDAY AS THE UPPER LOW
APPROACHES. EVEN EARLY IN THE DAY SUFFICIENT LARGE SCALE FORCING
AND MOISTURE ADVECTION IS PRESENT TO JUSTIFY AT LEAST LOW
PRECIPITATION PROBABILITIES PRIMARILY ACROSS THE WESTERN HALF OF THE
AREA. 00Z RAOB FROM COASTAL TEXAS OFFICES STILL LACK DEEP MOISTURE
BUT LATEST SATELLITE DERIVED TPW SHOWS INCREASING MOISTURE ACROSS
THE WESTERN GULF. MODEL GUIDANCE IS INSISTENT ON A SURGE OF LOW
LEVEL MOISTURE AND ABOVE CLIMO PWAT VALUES INTO THE AREA BY LATE
MONDAY WITH STRENGTHENING LEE TROUGH AND SOUTHERLY WINDS. THIS
INCREASE IN MOISTURE COMBINED WITH THE ABOVE MENTIONED LARGE SCALE
FORCING SHOULD RESULT IN WIDESPREAD RAIN. SPATIAL AND TEMPORAL
DETAILS OF HEAVY RAIN AND POTENTIAL FLOODING ARE STILL A BIT UNCLEAR
BUT THE PATTERN FITS THESE THREATS. ONE TO THREE INCHES SEEMS LIKELY.
THE MAJORITY OF THE RAINFALL WILL OCCUR MONDAY NIGHT THROUGH THE
FIRST HALF OF TUESDAY.
SEVERE THUNDERSTORM POTENTIAL SHOULD BE MOST LIKELY...ALBEIT STILL
RELATIVELY LOW AND MARGINAL...MONDAY AFTERNOON AND EVENING
COINCIDENT WITH LOW LEVEL MOISTURE SURGE BENEATH STEEPENING MID
LEVEL LAPSE RATES. THIS SHOULD YIELD AT LEAST MARGINAL INSTABILITY
AND DEEPER/STRONGER CONVECTION THAN THE PREVIOUS DAY. EFFECTIVE
SHEAR MAY BE MARGINAL FOR STORM ORGANIZATION THOUGH. SIGNIFICANT
CONVECTIVE OVERTURNING SHOULD WEAKEN MID LEVEL LAPSE RATES ON
TUESDAY PRECLUDING A NOTEWORTHY SEVERE WEATHER THREAT ALTHOUGH
IF POCKETS OF INSTABILITY CAN DEVELOP SOME STRONG TO SEVERE
THUNDERSTORMS WOULD BE POSSIBLE. ONE OF THE FEW CHANGES THAT WERE
MADE TO THE FORECAST WAS TO LOWER HIGH TEMPERATURES ON TUESDAY TO
ACCOUNT FOR WIDESPREAD CLOUDS AND PRECIPITATION THAT WILL LIKELY
LIMIT THE MAGNITUDE OF DIURNAL HEATING.
AS UPPER LOW/OPENING WAVE DEPARTS...WEAK SHORTWAVE RIDGING WILL
BRIEFLY INFLUENCE THE AREA RESULTING IN A MOSTLY DRY DAY AND
TEMPERATURES RETURNING TO THE UPPER 70S AND LOWER 80S. A DEEP CLOSED
LOW WILL EVOLVE ALONG THE WEST COAST BY THURSDAY AND WITH
STRENGTHENING MEAN SOUTHWESTERLY FLOW LEE TROUGHING WILL
PERSIST/STRENGTHEN. MULTIPLE DAYS OF DRYLINE CONVECTION MAY OCCUR
FROM LATE WEEK THROUGH THE WEEKEND WITH HIGHEST PRECIPITATION
PROBABILITIES ACROSS THE EASTERN HALF OF THE AREA. SPREAD IN THE
ENSEMBLE AND UNCERTAINTY WITH TIMING OF SMALL LEAD WAVES AND
EASTWARD PROGRESSION OF UPPER LOW MAKES IT DIFFICULT TO DELINEATE
WHEN THE HIGHEST PROBABILITY OF PRECIPITATION WILL BE. SUBSEQUENT
FORECASTS WILL REFINE THESE DETAILS.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 84 59 75 57 64 / 20 30 50 80 80
BEAVER OK 89 60 82 60 66 / 20 30 40 70 80
BOISE CITY OK 84 56 75 54 65 / 30 30 60 80 70
BORGER TX 87 60 78 59 65 / 20 30 50 80 80
BOYS RANCH TX 87 59 78 58 66 / 30 40 60 80 80
CANYON TX 85 59 75 57 65 / 20 30 60 80 80
CLARENDON TX 84 60 76 59 65 / 10 30 30 70 80
DALHART TX 85 56 76 55 66 / 40 30 60 80 80
GUYMON OK 87 58 79 58 65 / 30 30 60 80 80
HEREFORD TX 85 58 76 57 65 / 30 30 60 80 80
LIPSCOMB TX 85 60 79 60 65 / 20 30 30 70 80
PAMPA TX 83 58 76 57 63 / 20 30 40 80 80
SHAMROCK TX 83 60 77 60 66 / 10 20 30 70 80
WELLINGTON TX 85 61 78 61 68 / 5 20 30 60 80
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/17
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT MON MAY 4 2015
.UPDATE...
ISSUED AT 948 PM CDT MON MAY 4 2015
HAVE MADE SOME CHANGES TO THE MORNING RAIN CHANCES...HAVE
INCREASED THEM NORTHWARD INTO THE I-90 CORRIDOR BUT SLIGHTLY
OFFSET HIGHER IN WI.
HAVE BEEN WATCHING RUN AFTER RUN OF THE HRRR AND RAP MODELS COME
IN THIS EVENING WITH CONSISTENT LIGHT PRECIPITATION FORECAST OVER
THE I-90 CORRIDOR BY SUNRISE. WHILE THIS ADDED TO THE
CONFIDENCE...WAS WAITING TO SEE ANOTHER MODEL PLATFORM INDICATE
THE SAME TO LEND MORE CONFIDENCE TO THE FORECAST. THE 05.00Z NAM
HAS NOW MADE THIS SAME CHANGE NORTHWARD. THIS IS IN RESPONSE TO
FAIRLY STRONG 600-800MB FRONTOGENESIS ROTATING NORTHEAST TONIGHT
FROM DES MOINES TO GREEN BAY ON THE NORTH SIDE OF THE SHORTWAVE
JUST EAST OF OMAHA PER RADAR. THE EASTERLY DRY FLOW BELOW 5-8KFT
WILL EVAPORATE SOME OF THE PRECIPITATION...BUT HAVE DECIDED TO
INCREASE TO MID-RANGE RAIN CHANCES /50 PERCENT/ IN THE EARLY
MORNING TO BEGIN A TREND.
UPDATE ISSUED AT 648 PM CDT MON MAY 4 2015
HAVE INCREASED THE RAIN CHANCES EARLY THIS EVENING ACROSS THE FAR
SOUTH BASED ON RADAR AND SURFACE OBSERVATIONS OF VERY LIGHT RAIN.
CLEARLY A NORTHERN EDGE TO THE DEFORMATION AREA IS SEEN ON THE
RADAR AT THIS TIME WITH PLENTY OF ECHO AND RAIN DEVELOPMENT AHEAD
OF THE SHORTWAVE TROUGH HEADING E-NE FROM NEBRASKA.
MODEL GUIDANCE DOES SHOW MID-LEVEL FRONTOGENESIS CURRENTLY
ASSOCIATED WITH THE RAIN BAND ACROSS IOWA SHIFTING NORTHEASTWARD
INTO THE FORECAST AREA TOWARD KGRB. INTERESTINGLY...THE RAP TAKES
THIS FEATURE TO I-90 BY MORNING AND LATEST RAP AND HRRR MODELS
ARE PRODUCING PRECIPITATION IN THAT CORRIDOR. 04.18Z NAM AND GFS WILL
HAVE NO PART OF IT WITH MUCH WEAKER FORCING. INTERESTING TO SEE NO
PRECIPITATION SPLASHING NORTH OF THE GFS RAIN SCHIELD...THIS DUE
TO NO CONVECTIVE INSTABILITY FOR THE MODEL TO DRIBBLE OUT ITS
SUMMER SPLASHES.
CURRENT FORECAST DOES HAVE RAIN CHANCES NORTH TO I-90 BY MORNING
/20 PERCENT/ AND WILL CONTINUE TO MONITOR/ADJUST THIS AS THE
EVENING PROGRESSES. CERTAINLY THE LOW-LEVEL DRY EASTERLY FLOW WILL
NEED TO BE OVERCOME BY STRONGER FORCING SUGGESTED IN THE RAP TO
GET RAINFALL TO I-90.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 339 PM CDT MON MAY 4 2015
AT 3 PM...A STATIONARY FRONT WAS LOCATED FROM CHICAGO TO KANSAS
CITY. NORTH OF THIS FRONT...DEW POINTS ARE IN THE 60S AS FAR NORTH
AS CENTRAL IOWA AND NORTHERN ILLINOIS. NORTH OF THIS AREA...NORTH
AND NORTHEAST WINDS HAVE LOWERED DEW POINTS INTO THE 30S AND 40S.
FOR TONIGHT AND TUESDAY MORNING...A SHORT WAVE TROUGH...CURRENTLY
LOCATED OVER NEBRASKA...WILL MOVE EAST NORTHEAST THROUGH
IOWA...AND SOUTHERN WISCONSIN ON TUESDAY. WHILE THE 925 AND 850 MB
MOISTURE TRANSPORT WILL BE WEAK...STRONG 900 TO 500 MB
FRONTOGENESIS WILL PRODUCE SHOWERS AND THUNDERSTORMS MAINLY SOUTH
OF INTERSTATE 90 FROM LATE THIS EVENING THROUGH TUESDAY MORNING.
WITH BOTH THE 0-3 KM AND 0-6 KM SHEAR BEING VERY WEAK AND MOST
UNSTABLE CAPE LESS THAN 500 J/KG...NOT ANTICIPATING ANY SEVERE
WEATHER.
ON TUESDAY AFTERNOON...SUBSIDENCE IN THE WAKE OF THE SHORT TROUGH
WILL DEVELOP ACROSS THE AREA. BOTH THE ARW AND NMM SUGGEST THAT
THE AREA WILL BECOME DRY. MEANWHILE MANY OF THE DETERMINISTIC RUNS
SUGGEST THAT SOME PRECIPITATION WILL LINGER INTO THE AFTERNOON. WAS
VERY TEMPTED TO LEAN TOWARD THE MESO MODELS. HOWEVER CONSENSUS WAS
MORE TOWARD THE DETERMINISTIC RUNS...SO WENT TOWARD THEM.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 339 PM CDT MON MAY 4 2015
FROM TUESDAY NIGHT INTO WEDNESDAY...THE 04/12Z MODELS CONTINUE TO
SHOW THAT A SHORT WAVE RIDGE WILL MOVE AHEAD OF THE LONG WAVE
TROUGH. THIS WILL HELP THE WARM FRONT TO ADVANCE NORTHWARD ACROSS
THE AREA. WITH THE BEST 925 MB AND 850 MB MOISTURE ADVANCING
QUICKLY NORTH THROUGH THE AREA...NOT AS SEEING MUCH CONVERGENCE
OUTSIDE OF THE WARM FRONT ITSELF. AS A RESULT...THERE WILL BE THE
POTENTIAL FOR SOME DRY WEATHER IN THE WARM SECTOR OF THIS SYSTEM
ON WEDNESDAY MORNING AND POSSIBLY WEDNESDAY AFTERNOON. THIS IS HIGHLY
DEPENDENT ON THE LOCATION OF THE COLD FRONT. WITH WEAK 0-3 KM AND
0-6 KM SHEAR...NO SEVERE WEATHER IS ANTICIPATED WITH THE PASSAGE
OF THE WARM FRONT THROUGH THE REGION.
ON THURSDAY NIGHT AND FRIDAY...THE COLD FRONT WILL FINALLY MOVE
EAST THROUGH THE REGION. MOST UNSTABLE CAPES AHEAD OF THIS FRONT
WILL CLIMB INTO THE 1500 TO 2500 J/KG RANGE. WHILE THE 0-6 KM
SHEAR REMAINS WEAK...THE 0-3 KM SHEAR DOES CLIMB UP TO 30
KNOTS....SO MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME DAMAGING
WINDS.
ON SUNDAY NIGHT AND MONDAY...ANOTHER LOW PRESSURE SYSTEM WILL MOVE
THROUGH THE REGION. AT THIS TIME...IT LOOKS LIKE THE WARM SECTOR
WILL REMAIN SOUTHEAST OF THE AREA. THIS WILL GREATLY LIMIT THE
0-6 KM SHEAR AND INSTABILITY ACROSS THE REGION. THUS NOT
ANTICIPATING ANY SEVERE WEATHER AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1056 PM CDT MON MAY 4 2015
VFR CONDITIONS EXPECTED THROUGH THE CYCLE. HOWEVER...AS A WEATHER
SYSTEM MOVES THROUGH IOWA AND INTO SOUTHERN WI...RAIN SHOWERS
COULD MAKE THERE WAY INTO THE AIRFIELDS...ESPECIALLY KLSE. THIS
MAY PROVIDE SOME LOWERING TO THE FORECAST CIGS IN THE 09-15Z
WINDOW. HOWEVER...AT THIS TIME...THE FORECAST IS FOR THE DRY
EASTERLY FLOW TO HELP KEEP CIGS MORE ELEVATED AND IN THE LOWER VFR
CATEGORY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
948 PM CDT MON MAY 4 2015
.UPDATE...
ISSUED AT 948 PM CDT MON MAY 4 2015
HAVE MADE SOME CHANGES TO THE MORNING RAIN CHANCES...HAVE
INCREASED THEM NORTHWARD INTO THE I-90 CORRIDOR BUT SLIGHTLY
OFFSET HIGHER IN WI.
HAVE BEEN WATCHING RUN AFTER RUN OF THE HRRR AND RAP MODELS COME
IN THIS EVENING WITH CONSISTENT LIGHT PRECIPITATION FORECAST OVER
THE I-90 CORRIDOR BY SUNRISE. WHILE THIS ADDED TO THE
CONFIDENCE...WAS WAITING TO SEE ANOTHER MODEL PLATFORM INDICATE
THE SAME TO LEND MORE CONFIDENCE TO THE FORECAST. THE 05.00Z NAM
HAS NOW MADE THIS SAME CHANGE NORTHWARD. THIS IS IN RESPONSE TO
FAIRLY STRONG 600-800MB FRONTOGENESIS ROTATING NORTHEAST TONIGHT
FROM DES MOINES TO GREEN BAY ON THE NORTH SIDE OF THE SHORTWAVE
JUST EAST OF OMAHA PER RADAR. THE EASTERLY DRY FLOW BELOW 5-8KFT
WILL EVAPORATE SOME OF THE PRECIPITATION...BUT HAVE DECIDED TO
INCREASE TO MID-RANGE RAIN CHANCES /50 PERCENT/ IN THE EARLY
MORNING TO BEGIN A TREND.
UPDATE ISSUED AT 648 PM CDT MON MAY 4 2015
HAVE INCREASED THE RAIN CHANCES EARLY THIS EVENING ACROSS THE FAR
SOUTH BASED ON RADAR AND SURFACE OBSERVATIONS OF VERY LIGHT RAIN.
CLEARLY A NORTHERN EDGE TO THE DEFORMATION AREA IS SEEN ON THE
RADAR AT THIS TIME WITH PLENTY OF ECHO AND RAIN DEVELOPMENT AHEAD
OF THE SHORTWAVE TROUGH HEADING E-NE FROM NEBRASKA.
MODEL GUIDANCE DOES SHOW MID-LEVEL FRONTOGENESIS CURRENTLY
ASSOCIATED WITH THE RAIN BAND ACROSS IOWA SHIFTING NORTHEASTWARD
INTO THE FORECAST AREA TOWARD KGRB. INTERESTINGLY...THE RAP TAKES
THIS FEATURE TO I-90 BY MORNING AND LATEST RAP AND HRRR MODELS
ARE PRODUCING PRECIPITATION IN THAT CORRIDOR. 04.18Z NAM AND GFS WILL
HAVE NO PART OF IT WITH MUCH WEAKER FORCING. INTERESTING TO SEE NO
PRECIPITATION SPLASHING NORTH OF THE GFS RAIN SCHIELD...THIS DUE
TO NO CONVECTIVE INSTABILITY FOR THE MODEL TO DRIBBLE OUT ITS
SUMMER SPLASHES.
CURRENT FORECAST DOES HAVE RAIN CHANCES NORTH TO I-90 BY MORNING
/20 PERCENT/ AND WILL CONTINUE TO MONITOR/ADJUST THIS AS THE
EVENING PROGRESSES. CERTAINLY THE LOW-LEVEL DRY EASTERLY FLOW WILL
NEED TO BE OVERCOME BY STRONGER FORCING SUGGESTED IN THE RAP TO
GET RAINFALL TO I-90.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 339 PM CDT MON MAY 4 2015
AT 3 PM...A STATIONARY FRONT WAS LOCATED FROM CHICAGO TO KANSAS
CITY. NORTH OF THIS FRONT...DEW POINTS ARE IN THE 60S AS FAR NORTH
AS CENTRAL IOWA AND NORTHERN ILLINOIS. NORTH OF THIS AREA...NORTH
AND NORTHEAST WINDS HAVE LOWERED DEW POINTS INTO THE 30S AND 40S.
FOR TONIGHT AND TUESDAY MORNING...A SHORT WAVE TROUGH...CURRENTLY
LOCATED OVER NEBRASKA...WILL MOVE EAST NORTHEAST THROUGH
IOWA...AND SOUTHERN WISCONSIN ON TUESDAY. WHILE THE 925 AND 850 MB
MOISTURE TRANSPORT WILL BE WEAK...STRONG 900 TO 500 MB
FRONTOGENESIS WILL PRODUCE SHOWERS AND THUNDERSTORMS MAINLY SOUTH
OF INTERSTATE 90 FROM LATE THIS EVENING THROUGH TUESDAY MORNING.
WITH BOTH THE 0-3 KM AND 0-6 KM SHEAR BEING VERY WEAK AND MOST
UNSTABLE CAPE LESS THAN 500 J/KG...NOT ANTICIPATING ANY SEVERE
WEATHER.
ON TUESDAY AFTERNOON...SUBSIDENCE IN THE WAKE OF THE SHORT TROUGH
WILL DEVELOP ACROSS THE AREA. BOTH THE ARW AND NMM SUGGEST THAT
THE AREA WILL BECOME DRY. MEANWHILE MANY OF THE DETERMINISTIC RUNS
SUGGEST THAT SOME PRECIPITATION WILL LINGER INTO THE AFTERNOON. WAS
VERY TEMPTED TO LEAN TOWARD THE MESO MODELS. HOWEVER CONSENSUS WAS
MORE TOWARD THE DETERMINISTIC RUNS...SO WENT TOWARD THEM.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 339 PM CDT MON MAY 4 2015
FROM TUESDAY NIGHT INTO WEDNESDAY...THE 04/12Z MODELS CONTINUE TO
SHOW THAT A SHORT WAVE RIDGE WILL MOVE AHEAD OF THE LONG WAVE
TROUGH. THIS WILL HELP THE WARM FRONT TO ADVANCE NORTHWARD ACROSS
THE AREA. WITH THE BEST 925 MB AND 850 MB MOISTURE ADVANCING
QUICKLY NORTH THROUGH THE AREA...NOT AS SEEING MUCH CONVERGENCE
OUTSIDE OF THE WARM FRONT ITSELF. AS A RESULT...THERE WILL BE THE
POTENTIAL FOR SOME DRY WEATHER IN THE WARM SECTOR OF THIS SYSTEM
ON WEDNESDAY MORNING AND POSSIBLY WEDNESDAY AFTERNOON. THIS IS HIGHLY
DEPENDENT ON THE LOCATION OF THE COLD FRONT. WITH WEAK 0-3 KM AND
0-6 KM SHEAR...NO SEVERE WEATHER IS ANTICIPATED WITH THE PASSAGE
OF THE WARM FRONT THROUGH THE REGION.
ON THURSDAY NIGHT AND FRIDAY...THE COLD FRONT WILL FINALLY MOVE
EAST THROUGH THE REGION. MOST UNSTABLE CAPES AHEAD OF THIS FRONT
WILL CLIMB INTO THE 1500 TO 2500 J/KG RANGE. WHILE THE 0-6 KM
SHEAR REMAINS WEAK...THE 0-3 KM SHEAR DOES CLIMB UP TO 30
KNOTS....SO MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME DAMAGING
WINDS.
ON SUNDAY NIGHT AND MONDAY...ANOTHER LOW PRESSURE SYSTEM WILL MOVE
THROUGH THE REGION. AT THIS TIME...IT LOOKS LIKE THE WARM SECTOR
WILL REMAIN SOUTHEAST OF THE AREA. THIS WILL GREATLY LIMIT THE
0-6 KM SHEAR AND INSTABILITY ACROSS THE REGION. THUS NOT
ANTICIPATING ANY SEVERE WEATHER AT THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 648 PM CDT MON MAY 4 2015
VFR CONDITIONS ARE FORECAST AT THE TAF SITES. A VIGOROUS WEATHER
SYSTEM MOVING THROUGH IOWA AND ILLINOIS WILL SPREAD RAIN INTO
AREAS SOUTH OF THE TAF AIRFIELDS. BY SUNRISE...THERE MAY BE SOME
LOWER CIGS IN THE HIGH MVFR CATEGORY WITH -SHRA. FOR NOW...THE
FORECAST HAS THE DRIER EASTERLY FLOW WINNING OUT AND THE CIGS
REMAINING VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
648 PM CDT MON MAY 4 2015
.UPDATE...
ISSUED AT 648 PM CDT MON MAY 4 2015
HAVE INCREASED THE RAIN CHANCES EARLY THIS EVENING ACROSS THE FAR
SOUTH BASED ON RADAR AND SURFACE OBSERVATIONS OF VERY LIGHT RAIN.
CLEARLY A NORTHERN EDGE TO THE DEFORMATION AREA IS SEEN ON THE
RADAR AT THIS TIME WITH PLENTY OF ECHO AND RAIN DEVELOPMENT AHEAD
OF THE SHORTWAVE TROUGH HEADING E-NE FROM NEBRASKA.
MODEL GUIDANCE DOES SHOW MID-LEVEL FRONTOGENESIS CURRENTLY
ASSOCIATED WITH THE RAIN BAND ACROSS IOWA SHIFTING NORTHEASTWARD
INTO THE FORECAST AREA TOWARD KGRB. INTERESTINGLY...THE RAP TAKES
THIS FEATURE TO I-90 BY MORNING AND LATEST RAP AND HRRR MODELS
ARE PRODUCING PRECIPITATION IN THAT CORRIDOR. 04.18Z NAM AND GFS WILL
HAVE NO PART OF IT WITH MUCH WEAKER FORCING. INTERESTING TO SEE NO
PRECIPITATION SPLASHING NORTH OF THE GFS RAIN SCHIELD...THIS DUE
TO NO CONVECTIVE INSTABILITY FOR THE MODEL TO DRIBBLE OUT ITS
SUMMER SPLASHES.
CURRENT FORECAST DOES HAVE RAIN CHANCES NORTH TO I-90 BY MORNING
/20 PERCENT/ AND WILL CONTINUE TO MONITOR/ADJUST THIS AS THE
EVENING PROGRESSES. CERTAINLY THE LOW-LEVEL DRY EASTERLY FLOW WILL
NEED TO BE OVERCOME BY STRONGER FORCING SUGGESTED IN THE RAP TO
GET RAINFALL TO I-90.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 339 PM CDT MON MAY 4 2015
AT 3 PM...A STATIONARY FRONT WAS LOCATED FROM CHICAGO TO KANSAS
CITY. NORTH OF THIS FRONT...DEW POINTS ARE IN THE 60S AS FAR NORTH
AS CENTRAL IOWA AND NORTHERN ILLINOIS. NORTH OF THIS AREA...NORTH
AND NORTHEAST WINDS HAVE LOWERED DEW POINTS INTO THE 30S AND 40S.
FOR TONIGHT AND TUESDAY MORNING...A SHORT WAVE TROUGH...CURRENTLY
LOCATED OVER NEBRASKA...WILL MOVE EAST NORTHEAST THROUGH
IOWA...AND SOUTHERN WISCONSIN ON TUESDAY. WHILE THE 925 AND 850 MB
MOISTURE TRANSPORT WILL BE WEAK...STRONG 900 TO 500 MB
FRONTOGENESIS WILL PRODUCE SHOWERS AND THUNDERSTORMS MAINLY SOUTH
OF INTERSTATE 90 FROM LATE THIS EVENING THROUGH TUESDAY MORNING.
WITH BOTH THE 0-3 KM AND 0-6 KM SHEAR BEING VERY WEAK AND MOST
UNSTABLE CAPE LESS THAN 500 J/KG...NOT ANTICIPATING ANY SEVERE
WEATHER.
ON TUESDAY AFTERNOON...SUBSIDENCE IN THE WAKE OF THE SHORT TROUGH
WILL DEVELOP ACROSS THE AREA. BOTH THE ARW AND NMM SUGGEST THAT
THE AREA WILL BECOME DRY. MEANWHILE MANY OF THE DETERMINISTIC RUNS
SUGGEST THAT SOME PRECIPITATION WILL LINGER INTO THE AFTERNOON. WAS
VERY TEMPTED TO LEAN TOWARD THE MESO MODELS. HOWEVER CONSENSUS WAS
MORE TOWARD THE DETERMINISTIC RUNS...SO WENT TOWARD THEM.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 339 PM CDT MON MAY 4 2015
FROM TUESDAY NIGHT INTO WEDNESDAY...THE 04/12Z MODELS CONTINUE TO
SHOW THAT A SHORT WAVE RIDGE WILL MOVE AHEAD OF THE LONG WAVE
TROUGH. THIS WILL HELP THE WARM FRONT TO ADVANCE NORTHWARD ACROSS
THE AREA. WITH THE BEST 925 MB AND 850 MB MOISTURE ADVANCING
QUICKLY NORTH THROUGH THE AREA...NOT AS SEEING MUCH CONVERGENCE
OUTSIDE OF THE WARM FRONT ITSELF. AS A RESULT...THERE WILL BE THE
POTENTIAL FOR SOME DRY WEATHER IN THE WARM SECTOR OF THIS SYSTEM
ON WEDNESDAY MORNING AND POSSIBLY WEDNESDAY AFTERNOON. THIS IS HIGHLY
DEPENDENT ON THE LOCATION OF THE COLD FRONT. WITH WEAK 0-3 KM AND
0-6 KM SHEAR...NO SEVERE WEATHER IS ANTICIPATED WITH THE PASSAGE
OF THE WARM FRONT THROUGH THE REGION.
ON THURSDAY NIGHT AND FRIDAY...THE COLD FRONT WILL FINALLY MOVE
EAST THROUGH THE REGION. MOST UNSTABLE CAPES AHEAD OF THIS FRONT
WILL CLIMB INTO THE 1500 TO 2500 J/KG RANGE. WHILE THE 0-6 KM
SHEAR REMAINS WEAK...THE 0-3 KM SHEAR DOES CLIMB UP TO 30
KNOTS....SO MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME DAMAGING
WINDS.
ON SUNDAY NIGHT AND MONDAY...ANOTHER LOW PRESSURE SYSTEM WILL MOVE
THROUGH THE REGION. AT THIS TIME...IT LOOKS LIKE THE WARM SECTOR
WILL REMAIN SOUTHEAST OF THE AREA. THIS WILL GREATLY LIMIT THE
0-6 KM SHEAR AND INSTABILITY ACROSS THE REGION. THUS NOT
ANTICIPATING ANY SEVERE WEATHER AT THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 648 PM CDT MON MAY 4 2015
VFR CONDITIONS ARE FORECAST AT THE TAF SITES. A VIGOROUS WEATHER
SYSTEM MOVING THROUGH IOWA AND ILLINOIS WILL SPREAD RAIN INTO
AREAS SOUTH OF THE TAF AIRFIELDS. BY SUNRISE...THERE MAY BE SOME
LOWER CIGS IN THE HIGH MVFR CATEGORY WITH -SHRA. FOR NOW...THE
FORECAST HAS THE DRIER EASTERLY FLOW WINNING OUT AND THE CIGS
REMAINING VFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...BAUMGARDT
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 327 PM CDT SUN MAY 3 2015
TIMING AND INTENSITY OF THUNDERSTORMS ARE THE MAIN CONCERNS DURING
THIS PART OF THE FORECAST.
A COLD FRONT MOVED INTO EXTREME NORTHWEST WISCONSIN THIS
AFTERNOON AND RADAR AND LIGHTNING DETECTION DATA INDICATED A LINE
OF THUNDERSTORMS AHEAD OF THE FRONT ACROSS THE FAR NORTHWEST PART
OF THE STATE...ALONG WITH WIDESPREAD CONVECTION IN UPPER
MICHIGAN...AT 1945Z. LOCAL MESOANALYSIS GRAPHICS WERE SHOWING
1000+J/KG OF MUCAPE IN NORTH CENTRAL WISCONSIN WITH LITTLE TO NO
CIN SINCE ABOUT 16Z. BY 19Z MUCAPE VALUES ACROSS MOST OF THE REST
OF THE AREA WERE MAINLY IN THE 250-1000J/KG RANGE...WITH LESS THAN
250J/KG GENERALLY EAST OF A LINE FROM ABOUT WAUSAUKEE TO OSHKOSH.
WOULD EXPECT STORMS TO CONTINUE AS THE FRONT REACHES THE UNSTABLE
AIR IN THE NORTHERN PART OF THE STATE. 12Z MODELS GENERALLY
SHOWED QPF SPREADING ACROSS THE ENTIRE AREA BETWEEN 18Z AND 00Z
MONDAY. BUT MESOSCALE MODELS...ARW/HRRR...DID NOT HAVE
PRECIPITATION REACHING NORTH CENTRAL WISCONSIN UNTIL SHORTLY
BEFORE 00Z MONDAY WITH ONLY ISOLATED SMALL VALUES OF QPF ACROSS
THE REST OF THE AREA. MESO MODELS APPEARED TO BE DOING A BETTER
JOB OF HANDLING THE SITUATION SO HAVE SLOWED THE PROGRESSION OF
THE CONVECTION ACROSS THE AREA.
SPC HAS KEPT THE MAJORITY OF THE AREA IN A SLIGHT RISK FOR SEVERE
STORMS THIS AFTERNOON AND EVENING. WBZ HEIGHTS AT 20Z RANGED FROM LESS
THAN 7500FT IN NORTH CENTRAL WISCONSIN TO MORE THAN 9000FT IN EAST
CENTRAL WISCONSIN. 0-6KM SHEAR ACROSS THE NORTH WAS MAINLY
25-35KTS. THERE IS NOT QUITE AS MUCH INSTABILITY AS MODELS SHOWED
YESTERDAY...SHEAR WAS NOT ALL THAT IMPRESSIVE AND THERE IS NOT A
LOT OF UPPER SUPPORT AVAILABLE...SO STRENGTH OF THE STORMS IS A
BIT UNCERTAIN.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 327 PM CDT SUN MAY 3 2015
THE TRAILING END OF THE COLD FRONT WILL STALL OVER NORTHERN
ILLINOIS AND SERVE AS A WEAK FOCAL POINT FOR SHOWERS DURING THE
FIRST HALF OF THE WEEK AS IT GRADUALLY PUSHES NORTH-NORTHEAST OVER
WISCONSIN AND WASHES OUT. MEANWHILE...A BROAD SFC-500MB HIGH
PRESSURE RIDGE WILL SPREAD IN FROM THE WEST AS THE WEEK
PROGRESSES. THE RIDGE AXIS WILL MOVE EAST OF WISCONSIN BY THE END
OF THE WORK WEEK. GFS AND ECMWF MODELS ARE IN AGREEMENT THAT
WISCONSIN WILL THEN REMAIN UNDER THE UNSTABLE WEST SIDE OF THE
RIDGE THROUGH THE WEEKEND...ENABLING GULF MOISTURE TO ADVECT INTO
WISCONSIN FROM THE SOUTHWEST...ALONG WITH A DISTURBANCE OR TWO.
ML.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 104 PM CDT SUN MAY 3 2015
CONDITIONS WERE VFR ACROSS THE AREA AT MIDDAY AS A COLD FRONT WAS
JUST ENTERING THE NORTHWEST CORNER OF WISCONSIN. CONFIDENCE HAS
WANED WITH REGARD TO FORECAST OF CONVECTION ACROSS THE AREA THIS
AFTERNOON INTO MONDAY MORNING. ONLY MADE MINOR ADJUSTMENTS TO
TIMING FROM THE PREVIOUS FORECAST FOR NOW. THE MOST UNSTABLE
CONDITIONS APPEARED TO BE ACROSS NORTH CENTRAL WISCONSIN WHERE
MUCAPE VALUES WERE 500+ J/KG WITH LITTLE TO NO CIN THERE...BUT NO
CONVECTION WAS YET EVIDENT IN THAT AREA. SHOWERS AND ISOLATED
THUNDERSTORMS WERE CONFINED TO MINNESOTA AND EASTERN LAKE SUPERIOR
AT 1745Z. MOST OF THE 12Z MODELS SHOWED QPF WITH THE FRONT GREATLY
EXPANDING DURING THE AFTERNOON TO COVER THE ENTIRE AREA. A QUICK
LOOK AT THE 16Z HRRR INDICATED ISOLATED-SCATTERED LIGHT QPF UNTIL
A MORE SOLID AREA OF PRECIPITATION REACHES NORTH CENTRAL
WISCONSIN. THIS LOOKS LIKE ITS ON TRACK...AT LEAST RIGHT NOW...SO
MAINLY VFR AND DRY THE REST OF THE DAY IF IT REMAINS ON TRACK.
CANNOT RULE OUT CONVECTIVE DEVELOPMENT WITH SPC DAY 1 SEVERE
OUTLOOK INCLUDING MUCH OF THE AREA IN A SLIGHT RISK FOR
SEVERE...WITH POSSIBLE DAMAGING WINDS AND LARGE HAIL THIS
AFTERNOON AND TONIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MG
LONG TERM......ML
AVIATION.......MG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
104 PM CDT SUN MAY 3 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND MONDAY
ISSUED AT 338 AM CDT SUN MAY 3 2015
THUNDERSTORM TIMING TODAY INTO TONIGHT AS WELL AS POTENTIAL OF
SEVERE STORMS THE PRIMARY ISSUE FOR THIS PERIOD.
RADARS THIS MORNING SHOW SCATTERED SHOWERS AND STORMS OVER
MINNESOTA AHEAD OF THE COLD FRONT AND ANOTHER CLUSTER OF SHOWERS
AND STORMS OVER IOWA ASSOCIATED WITH A WEAK SHORT WAVE DRIFTING IN
THE WEST TO SOUTHWEST FLOW. THIS IOWA SHORT WAVE TROUGH IS
PROGGED TO STAY SOUTH BUT DID NOTICE SOME MID LEVEL CLOUDS
GRADUALLY DRIFTING NORTHEASTWARD INTO SOUTHWEST WISCONSIN. PROGS
OVERALL KEEP THIS CONVECTION SOUTH BUT A FEW DO EXTEND SOME LIGHT
AMOUNTS INTO PARTS OF CENTRAL AND EAST CENTRAL WISCONSIN LATER
THIS MORNING.
OTHERWISE THE BRUNT OF THE CONVECTION TODAY WILL BE WITH THE
CONVERGENCE GENERATED ALONG THE COLD FRONT. UPPER JET SUPPORT
WELL NORTH OF THE AREA. WILL HAVE AN EARLIER START TIME OF THE
CONVECTION AROUND MID DAY FOR NORTH CENTRAL DUE TO POSSIBLE EARLY
MORNING MINNESOTA CONVECTION MAY HOLD TOGETHER AND REACH THIS
AREA.
STRONGEST STORMS WILL LIKELY ARRIVE MID TO LATE AFTERNOON OVER
NORTH CENTRAL WISCONSIN AND CENTRAL WISCONSIN DURING PEAK HEATING
PERIOD. SPC CONTINUES TO PLACE MUCH OF CENTRAL AND NORTH CENTRAL
IN A SLIGHT RISK. SOME MODEL ISSUES WITH RESPECT TO AVAILABLE
INSTABILITY DUE TO SURFACE DEWPOINTS TRENDS...NAM PRODUCES UP TO
2000 J/KG CAPES LATE THIS AFTERNOON OVER CENTRAL AND NORTH CENTRAL
WISCONSIN WHILE THE GFS FORECAST SOUNDINGS ARE BETWEEN 100O TO
1500. SOME LOWER TO MID 50S NOTED OVER THE CENTRAL PLAINS AND
ANTICIPATE SIMILAR VALUES LATER TODAY ALONG AND JUST AHEAD OF THE
COLD FRONT. CAPES OF 1000 TO 1500 J/KG WILL BE WORKING WITH AN
INCREASINGLY SHEARED ENVIRONMENT DUE TO THE MID LEVEL WESTERLY
FLOW. BY THE TIME THE STORMS REACH EAST CENTRAL WISCONSIN LATER
THIS EVENING...INSTABILITY DUE TO DAYTIME HEATING WILL
DIMINISH...BUT THE WESTERLY MID LEVEL WINDS WILL WORK INTO THE
AREA AS THE COLD FRONT PASSES. THE LINGERING SHEARED ENVIRONMENT
MAY BE ENOUGH TO MAINTAIN A FEW NEAR SEVERE STORMS THIS EVENING
OVER EAST CENTRAL WISCONSIN.
SHOWERS AND STORMS WILL BE ON THE DECREASE AFTER MIDNIGHT AND
TOWARD MONDAY MORNING AFTER FROPA. HIGH PRESSURE WILL BUILD INTO
NORTHWEST WISCONSIN MONDAY FOR SUNNY SKIES ACROSS THE NORTH. SINCE
THE COLD FRONT STALLS OVER NORTHERN OR CENTRAL ILLINOIS...CLOUDS
MAY HANG AROUND OVER EAST CENTRAL WISCONSIN. NORTHEAST WINDS OFF
THE LAKE MAY ALSO CONTRIBUTE TO LOWER LEVEL CLOUDS MONDAY. DUE TO
CLOUDS SUNDAY NIGHT...AND A WARM START MONDAY MORNING AND
DECREASING CLOUDS MONDAY...FORECAST MAX TEMPERATURES MAY REBOUND
INTO AT LEAST THE LOWER 70S AWAY FROM LAKE MICHIGAN AND THE BAY.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
ISSUED AT 338 AM CDT SUN MAY 3 2015
AMPLIFIED MEAN FLOW TO PERSIST THRU MUCH OF THE WEEK WITH A BROAD
UPR TROF OVER THE WRN CONUS AND AN UPR RDG OVER THE SE CONUS. THIS
PATTERN WOULD BRING A PREVAILING SW FLOW TO THE CNTRL CONUS
(INCLUDING WI) WHICH WL KEEP TEMPS ABOVE NORMAL AND ALLOW GULF
MOISTURE TO EASILY FLOW NWD. AN ACTIVE WEATHER PERIOD IS EXPECTED
FOR NE WI AS A WRMFNT MOVES THRU THE AREA LATE TUE INTO WED...
FOLLOWED BY A WEAKENING SHORTWAVE TROF/SFC CDFNT LATE IN THE WEEK.
THE EXPECTED PCPN SHOULD HELP TO ALLEVIATE THE DRY CONDITIONS/FIRE
DANGER OVER THE REGION.
THE SFC HI WL SLOWLY SHIFT TOWARD NE SECTIONS OF THE GREAT LAKES
TUE NGT...BUT KEEP A DRY E-NE WIND OVER THE FCST AREA. MEANWHILE...
WL BE WATCHING THE STALLED BOUNDARY TO OUR SOUTH WHICH MAY EDGE A
BIT NORTH IN RESPONSE TO AN INCREASING LOW-LEVEL JET OVER THE
PLAINS. NRN WI TO REMAIN MOSTLY CLEAR THRU THE NGT...HOWEVER EXPECT
CNTRL/E-CNTRL WI TO BECOME PARTLY TO MOSTLY CLOUDY OVRNGT AND
CANNOT RULE OUT A FEW LIGHT SHWRS REACHING OUR SRN TIER OF COUNTIES
TOWARD DAYBREAK AS ADDITIONAL SHWRS/TSTMS MOVE ALONG THE FRONTAL
BOUNDARY. MIN TEMPS TO RANGE FROM THE LWR TO MID 30S NEAR THE MI
BORDER...TO THE LWR TO MID 40 SOUTH.
MODELS SEEM CONVINCED NOW THAT THE STALLED BOUNDARY WL BEGIN TO
STEADILY LIFT NORTH AS A WRMFNT ON TUE IN RESPONSE TO A SIGNIFICANT
SHORTWAVE TROF MOVING NEWD THRU THE SRN ROCKIES. THE FNT IS EXPECTED
TO STRETCH ROUGHLY FROM SRN MN E-SE THRU THE WI/IL BORDER BY 00Z WED
WITH CONVERGENCE ALONG THE FNT/GULF MOISTURE LIFTING OVER THE FNT
LEADING TO MORE SHWR/TSTM ACTIVITY. MAY NEED TO BRING POPS NORTH A
TIER OF COUNTIES...LEAVING ONLY FAR NRN WI DRY THRU THE DAYLIGHT
HOURS. MORE CLOUDS/HIGHER POPS WL LEAD TO A COOLER DAY WITH MAX
TEMPS RANGING FROM THE LWR 60S SOUTH (COOLER LAKESIDE)...TO NEAR 70
DEGS ALONG THE MI BORDER.
CHC OF SHWRS/TSTMS WL CONT ACROSS NE WI TUE NGT AS THE WRMFNT SLOWLY
LIFTS NORTH INTO SRN WI. AS THE SHORTWAVE TROF MOVES TOWARD THE
CNTRL PLAINS ON WED...THE WRMFNT WL CONT TO LIFT NWD THRU WI AND
ESSENTIALLY BE NORTH OF THE FCST AREA BY LATE WED. ANTICIPATE AT
LEAST A CHC OF SHWRS/TSTMS TO ACCOMPANY THE WRMFNT...BUT BELIEVE
THE PCPN WL HAVE A TENDENCY OF BECOMING MORE ISOLATED IN NATURE
ACROSS CNTRL/E-CNTRL WI WED AFTERNOON AS THE MAIN FOCUS SHIFTS
NORTH WITH THE FNT AND THERE IS A LACK OF ANY TRIGGER IN THE SOUTH.
WED WL FEEL MORE LIKE A SUMMER DAY WITH MAX TEMPS RANGING FROM
AROUND 70 DEGS NORTH...UPR 70S CNTRL WI (COOLER NEAR LAKE MI) AND
DEW POINTS CLIMBING INTO THE 50S.
THE SHORTWAVE TROF IS PROGGED TO MOVE THRU THE CNTRL PLAINS WED
NGT AND BEGIN TO WEAKEN IN THE PROCESS. BY THU...WHAT IS LEFT OF
THE TROF WL REACH THE UPR MS VALLEY WITH A CDFNT EXTENDED SW THRU
THE CNTRL PLAINS. PCPN CHCS APPEAR MINIMAL WED NGT INTO THU
MORNING...HOWEVER AS BETTER MID-LEVEL FORCING/INCREASING
INSTABILITY BECOME MORE PREVALENT THU AFTERNOON...PCPN CHCS LOOK
TO BE ON THE INCREASE ONCE AGAIN. GUSTY SOUTH WINDS ON THU WL CONT
TO PUMP GULF MOISTURE INTO WI WITH DEW POINTS EXPECTED TO BE IN
THE MID TO UPR 50S. COMBINE THESE DEW POINTS WITH MAX TEMPS IN THE
75-80 DEG RANGE (AWAY FROM LAKE MI) AND WE WL HAVE A SUMMER FEEL
TO THE AIR MASS.
PCPN CHCS WL CONT THU NGT AS STRONGER WAA SURGES THRU WI AHEAD OF
THE ADVANCING CDFNT. THIS CDFNT IS FCST TO PUSH INTO WI ON FRI AND
SET THE STAGE FOR ADDITIONAL SHWRS/TSTMS. TOO EARLY TO DETERMINE
THE STRENGTH OF THESE STORMS...BUT WITH THE MODELS SHOWING LITTLE
IN THE WAY OF MID OR UPR SUPPORT...THIS WOULD LIMIT THE SEVERE
RISK. MAX TEMPS ON FRI SHOULD BE A FEW DEGS COOLER THAN THU DUE TO
THICKER CLOUDS/HIGHER CHC OF PCPN.
JUST LIKE ITS PREDECESSOR...THIS CDFNT IS FCST TO SAG SOUTH AND
EVENTUALLY STALL SOMEWHERE IN THE VICINITY OF THE WI/IL BORDER
NEXT WEEKEND. THE EXACT LOCATION OF THIS BOUNDARY WL ULTIMATELY
DETERMINE THE NRN EXTENT OF ANY PCPN IN THE VICINITY OF
CNTRL/E-CNTRL WI. FOR THE MOST PART...NRN WI REMAIN DRY NEXT SAT
AS HI PRES OVER SRN CANADA FEEDS DRIER AIR INTO NRN SECTIONS OF
THE GREAT LAKES. SAT WL ALSO BE COOLER BEHIND THE INITIAL CDFNT
WITH MAX TEMPS RANGING ONLY IN THE MID 50S LAKESIDE...TO THE LWR
70S OVER CNTRL WI.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 104 PM CDT SUN MAY 3 2015
CONDITIONS WERE VFR ACROSS THE AREA AT MIDDAY AS A COLD FRONT WAS
JUST ENTERING THE NORTHWEST CORNER OF WISCONSIN. CONFIDENCE HAS
WANED WITH REGARD TO FORECAST OF CONVECTION ACROSS THE AREA THIS
AFTERNOON INTO MONDAY MORNING. ONLY MADE MINOR ADJUSTMENTS TO
TIMING FROM THE PREVIOUS FORECAST FOR NOW. THE MOST UNSTABLE
CONDITIONS APPEARED TO BE ACROSS NORTH CENTRAL WISCONSIN WHERE
MUCAPE VALUES WERE 500+ J/KG WITH LITTLE TO NO CIN THERE...BUT NO
CONVECTION WAS YET EVIDENT IN THAT AREA. SHOWERS AND ISOLATED
THUNDERSTORMS WERE CONFINED TO MINNESOTA AND EASTERN LAKE SUPERIOR
AT 1745Z. MOST OF THE 12Z MODELS SHOWED QPF WITH THE FRONT GREATLY
EXPANDING DURING THE AFTERNOON TO COVER THE ENTIRE AREA. A QUICK
LOOK AT THE 16Z HRRR INDICATED ISOLATED-SCATTERED LIGHT QPF UNTIL
A MORE SOLID AREA OF PRECIPITATION REACHES NORTH CENTRAL
WISCONSIN. THIS LOOKS LIKE ITS ON TRACK...AT LEAST RIGHT NOW...SO
MAINLY VFR AND DRY THE REST OF THE DAY IF IT REMAINS ON TRACK.
CANNOT RULE OUT CONVECTIVE DEVELOPMENT WITH SPC DAY 1 SEVERE
OUTLOOK INCLUDING MUCH OF THE AREA IN A SLIGHT RISK FOR
SEVERE...WITH POSSIBLE DAMAGING WINDS AND LARGE HAIL THIS
AFTERNOON AND TONIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......KALLAS
AVIATION.......MG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1224 PM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 321 AM CDT SUN MAY 3 2015
REGIONAL RADARS THIS MORNING SHOWING SOME CONVECTIVE ACTIVITY OVER
CENTRAL AND WESTERN IOWA. THIS IS OCCURRING ON THE NOSE OF THE LOW
LEVEL JET AND AHEAD OF A SHORT WAVE TROUGH MOVING ACROSS NORTHERN
NEBRASKA. THE 03.03Z RAP INDICATES THIS WAVE WILL CONTINUE TO
TRACK EASTWARD ACROSS NORTHERN IOWA THROUGH THE MORNING WITH THE
LOW LEVEL JET VEERING TO THE EAST TO REMAIN AHEAD OF THE WAVE. THE
RAP...03.04Z HRRR AND THE 03.00Z HI-RES ARW AND NMM ALL SUGGEST
THERE IS A CHANCE THAT SOME OF THE ACTIVITY WITH THIS WAVE COULD
GET INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN AND HAVE ADDED IN
A SMALL CHANCE FOR THIS THROUGH ABOUT THE MIDDLE OF THE MORNING.
THE MAIN CONVECTIVE SHOW WILL COME LATE THIS AFTERNOON INTO THE
EVENING. THE 03.00Z MODELS HAVE REMAIN FAIRLY CONSISTENT TAKING
THE MAIN SHORT WAVE TROUGH...CURRENTLY OVER SASKATCHEWAN...ALMOST
DUE EAST WITH A SLIGHT POSITIVE TILT AND THE PV ADVECTION IN THE
500-300 MB LAYER REMAINING NORTH OF THE AREA. AS THIS WAVE MOVES
EAST...IT WILL PUSH A COLD FRONT INTO THE AREA LATE THIS AFTERNOON
AND THEN ACROSS THE REGION TONIGHT. BUFKIT SOUNDINGS FROM THE
03.00Z NAM INDICATE A PRETTY DEEP MIXED LAYER...UP TO ABOUT 850
MB...AHEAD OF THE FRONT THAT COULD BRING DOWN SOME DRIER AIR AND
KEEP THE DEW POINTS CAPPED IN THE MID 50S. WITH 925 MB
TEMPERATURES RISING ABOUT 2 TO 3C OVER SATURDAY...EXPECT THE
SURFACE TEMPERATURES TO BE WARMER THAN SATURDAY WITH MIDDLE 80S
FOR MUCH OF THE AREA. THE COMBINATION OF THESE TEMPS AND DEW
POINTS SHOULD YIELD ML CAPES AROUND 1500 J/KG OR SO ALONG AND
AHEAD OF THE FRONT. THE FORECAST SOUNDINGS ALSO SHOW A WEAK CAP
IN THE WARM SECTOR AHEAD OF THE FRONT AND WITH MINIMAL HEIGHT
FALLS...IT WILL TAKE THE THERMODYNAMIC FORCING WITH THE FRONT TO
BREAK THE CAP. THE FRONTOGENESIS WITH THE FRONT LOOKS TO BE
MODERATE IN STRENGTH IN THE 1000-850 MB AND THEN WEAK FROM 850 MB
UP THROUGH 500 MB. THIS SHOULD BE ENOUGH TO BREAK THE WEAK CAP AND
ALLOW CONVECTION TO FORM ALONG THE FRONT. THERE IS GOOD CLUSTERING
AMONG THE HI-RES MESO MODELS...THE 03.00Z NAM12 AND 03.00Z NESTED
NAM THAT THE FRONT SHOULD START TO APPROACH LATE THIS AFTERNOON
WITH THE CONVECTION FIRST IMPACTING THE NORTHERN PARTS OF THE AREA
IN THE 21Z-24Z WINDOW AND THEN DEVELOPING SOUTHWEST ALONG THE
FRONT VERY LATE IN THE AFTERNOON INTO THE EARLY EVENING. THIS
ACTIVITY SHOULD REMAIN STRONG INTO THE MIDDLE OF THE EVENING
BEFORE THE CAPE QUICKLY DWINDLES WITH JUST GENERAL CONVECTION
EXPECTED FOR CENTRAL AND SOUTHWEST WISCONSIN. THE SEVERE THREAT IS
STILL PRESENT FROM ABOUT 4 PM THROUGH 10 PM WITH LARGE HAIL
LOOKING TO BE THE MAIN THREAT AS GOOD MID LEVEL LAPSE RATES SHOULD
AID IN THE HAIL PRODUCTION. NOT EXPECTING THE HAIL TO BE OVERLY
LARGE AS A GENERAL LACK OF SHEAR WILL KEEP THE UPDRAFT ROTATION
SUBDUED. WHAT SHEAR THERE IS WILL BE IN THE 0-3KM LAYER AND IS
EXPECTED TO BE ON THE ORDER OF 25 TO 30 KNOTS...WHICH SHOULD BE
ENOUGH TO PRODUCE SOME WIND GUSTS BUT MAY NOT BE ENOUGH TO KEEP
THE GUST FRONTS CLOSE TO THE STORMS.
THE MODELS NOW SUGGEST THE FRONT MAY NOT PUSH AS FAR SOUTH AS
PREVIOUSLY INDICATED BEFORE STALLING OUT MONDAY. THE GENERAL MODEL
CONSENSUS NOW SHOWS THE FRONT STALLING OVER SOUTHERN IOWA INSTEAD
OF NORTHERN MISSOURI. THIS CLOSER PROXIMITY TO THE AREA COULD
ALLOW SOME OF THE SHOWERS AND STORMS EXPECTED TO OCCUR NORTH OF
THE FRONT TO CONTINUE OVER NORTHEAST IOWA INTO SOUTHWEST WISCONSIN
MONDAY AFTERNOON AND EVENING. THE UPPER LEVEL PATTERN WILL START
TO SHIFT TO MORE OF A SOUTHWEST FLOW AND BEGIN TO PUSH THE FRONT
BACK TO THE NORTH LATE MONDAY NIGHT RESULTING IN A NORTHWARD
EXPANSION OF THE RAIN CHANCES OVER ALL OF SOUTHEAST MINNESOTA AND
MUCH OF WESTERN AND CENTRAL WISCONSIN. MOST OF THE AREA WILL THEN
HAVE A CHANCE FOR RAIN TUESDAY AS THE FRONT MOVES BACK INTO
THE AREA AND COULD POSSIBLY BE ACCOMPANIED BY A SHORT WAVE TROUGH
ALOFT IN THE SOUTHWEST FLOW.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 AM CDT SUN MAY 3 2015
THE SOUTHWEST FLOW ALOFT LOOKS TO CONTINUE THROUGH THE PERIOD AS
THE MAIN RIDGE REMAINS OVER THE EASTERN CONUS AND A LARGE UPPER
LEVEL LOW SINKS SLOWLY SOUTH OVER THE WESTERN CONUS. WITH THIS
FLOW PATTERN...SEVERAL PIECES OF ENERGY ARE EXPECTED TO COME OUT
AND ACROSS THE UPPER MIDWEST. IT LOOKS AS IF IT WILL TAKE UNTIL
SOMETIME WEDNESDAY OR WEDNESDAY NIGHT FOR THE RETREATING FRONT TO
GET NORTH OF THE AREA. ONCE THIS HAPPENS...A COLD FRONT AND
SURFACE LOW PRESSURE WILL START TO APPROACH FROM THE WEST WITH
WHAT SHOULD BE A STRONGER SHORT WAVE TROUGH ALOFT. THIS FRONT WILL
THEN MOVE ACROSS THE AREA IN THE END OF THE WORK WEEK WITH IT
POSSIBLY BECOME STALLED OUT JUST TO THE SOUTH OF THE AREA INTO THE
START OF THE WEEKEND. WITH THIS MESSY PATTERN...WILL CARRY RAIN
CHANCES EACH DAY...ALTHOUGH WOULD NOT BE SURPRISED TO SEE A DRY
PERIOD OR TWO...ESPECIALLY ONCE THE RETURNING FRONT GETS PAST THE
AREA. HOWEVER...CONFIDENCE ON THIS IS TOO LOW TO WORK INTO THE
FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1224 PM CDT SUN MAY 3 2015
VFR CONDITIONS EXPECTED THROUGH THIS AFTERNOON BEFORE A COLD FRONT
ENTERS THE AREA EARLY THIS EVENING. EXPECTING A LINE OF
THUNDERSTORMS TO ACCOMPANY THE FRONT...MAKING PASSAGE THROUGH KRST
IN THE 23Z-03Z TIME FRAME...AND IN THE 01Z-05Z TIME FRAME AT KLSE.
EXPECT DETERIORATING CONDITIONS WITH THE SHRA/TS ACTIVITY WITH
CIGS/VSBY TEMPORARILY DIPPING INTO THE MVFR/IFR RANGE. THERE
REMAINS THE POSSIBILITY THAT A FEW OF THE STORMS WILL BE CAPABLE
OF PRODUCING STRONG GUSTY WINDS IN EXCESS OF 50KT AND HAIL TO THE
SIZE OF QUARTERS. LOOK FOR THE FRONT AND SHRA/TS ACTIVITY TO CLEAR
SOUTHEAST OF THE AREA IN THE 07-09Z TIME FRAME WITH A RETURN TO
VFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
630 AM CDT SUN MAY 3 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 321 AM CDT SUN MAY 3 2015
REGIONAL RADARS THIS MORNING SHOWING SOME CONVECTIVE ACTIVITY OVER
CENTRAL AND WESTERN IOWA. THIS IS OCCURRING ON THE NOSE OF THE LOW
LEVEL JET AND AHEAD OF A SHORT WAVE TROUGH MOVING ACROSS NORTHERN
NEBRASKA. THE 03.03Z RAP INDICATES THIS WAVE WILL CONTINUE TO
TRACK EASTWARD ACROSS NORTHERN IOWA THROUGH THE MORNING WITH THE
LOW LEVEL JET VEERING TO THE EAST TO REMAIN AHEAD OF THE WAVE. THE
RAP...03.04Z HRRR AND THE 03.00Z HI-RES ARW AND NMM ALL SUGGEST
THERE IS A CHANCE THAT SOME OF THE ACTIVITY WITH THIS WAVE COULD
GET INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN AND HAVE ADDED IN
A SMALL CHANCE FOR THIS THROUGH ABOUT THE MIDDLE OF THE MORNING.
THE MAIN CONVECTIVE SHOW WILL COME LATE THIS AFTERNOON INTO THE
EVENING. THE 03.00Z MODELS HAVE REMAIN FAIRLY CONSISTENT TAKING
THE MAIN SHORT WAVE TROUGH...CURRENTLY OVER SASKATCHEWAN...ALMOST
DUE EAST WITH A SLIGHT POSITIVE TILT AND THE PV ADVECTION IN THE
500-300 MB LAYER REMAINING NORTH OF THE AREA. AS THIS WAVE MOVES
EAST...IT WILL PUSH A COLD FRONT INTO THE AREA LATE THIS AFTERNOON
AND THEN ACROSS THE REGION TONIGHT. BUFKIT SOUNDINGS FROM THE
03.00Z NAM INDICATE A PRETTY DEEP MIXED LAYER...UP TO ABOUT 850
MB...AHEAD OF THE FRONT THAT COULD BRING DOWN SOME DRIER AIR AND
KEEP THE DEW POINTS CAPPED IN THE MID 50S. WITH 925 MB
TEMPERATURES RISING ABOUT 2 TO 3C OVER SATURDAY...EXPECT THE
SURFACE TEMPERATURES TO BE WARMER THAN SATURDAY WITH MIDDLE 80S
FOR MUCH OF THE AREA. THE COMBINATION OF THESE TEMPS AND DEW
POINTS SHOULD YIELD ML CAPES AROUND 1500 J/KG OR SO ALONG AND
AHEAD OF THE FRONT. THE FORECAST SOUNDINGS ALSO SHOW A WEAK CAP
IN THE WARM SECTOR AHEAD OF THE FRONT AND WITH MINIMAL HEIGHT
FALLS...IT WILL TAKE THE THERMODYNAMIC FORCING WITH THE FRONT TO
BREAK THE CAP. THE FRONTOGENESIS WITH THE FRONT LOOKS TO BE
MODERATE IN STRENGTH IN THE 1000-850 MB AND THEN WEAK FROM 850 MB
UP THROUGH 500 MB. THIS SHOULD BE ENOUGH TO BREAK THE WEAK CAP AND
ALLOW CONVECTION TO FORM ALONG THE FRONT. THERE IS GOOD CLUSTERING
AMONG THE HI-RES MESO MODELS...THE 03.00Z NAM12 AND 03.00Z NESTED
NAM THAT THE FRONT SHOULD START TO APPROACH LATE THIS AFTERNOON
WITH THE CONVECTION FIRST IMPACTING THE NORTHERN PARTS OF THE AREA
IN THE 21Z-24Z WINDOW AND THEN DEVELOPING SOUTHWEST ALONG THE
FRONT VERY LATE IN THE AFTERNOON INTO THE EARLY EVENING. THIS
ACTIVITY SHOULD REMAIN STRONG INTO THE MIDDLE OF THE EVENING
BEFORE THE CAPE QUICKLY DWINDLES WITH JUST GENERAL CONVECTION
EXPECTED FOR CENTRAL AND SOUTHWEST WISCONSIN. THE SEVERE THREAT IS
STILL PRESENT FROM ABOUT 4 PM THROUGH 10 PM WITH LARGE HAIL
LOOKING TO BE THE MAIN THREAT AS GOOD MID LEVEL LAPSE RATES SHOULD
AID IN THE HAIL PRODUCTION. NOT EXPECTING THE HAIL TO BE OVERLY
LARGE AS A GENERAL LACK OF SHEAR WILL KEEP THE UPDRAFT ROTATION
SUBDUED. WHAT SHEAR THERE IS WILL BE IN THE 0-3KM LAYER AND IS
EXPECTED TO BE ON THE ORDER OF 25 TO 30 KNOTS...WHICH SHOULD BE
ENOUGH TO PRODUCE SOME WIND GUSTS BUT MAY NOT BE ENOUGH TO KEEP
THE GUST FRONTS CLOSE TO THE STORMS.
THE MODELS NOW SUGGEST THE FRONT MAY NOT PUSH AS FAR SOUTH AS
PREVIOUSLY INDICATED BEFORE STALLING OUT MONDAY. THE GENERAL MODEL
CONSENSUS NOW SHOWS THE FRONT STALLING OVER SOUTHERN IOWA INSTEAD
OF NORTHERN MISSOURI. THIS CLOSER PROXIMITY TO THE AREA COULD
ALLOW SOME OF THE SHOWERS AND STORMS EXPECTED TO OCCUR NORTH OF
THE FRONT TO CONTINUE OVER NORTHEAST IOWA INTO SOUTHWEST WISCONSIN
MONDAY AFTERNOON AND EVENING. THE UPPER LEVEL PATTERN WILL START
TO SHIFT TO MORE OF A SOUTHWEST FLOW AND BEGIN TO PUSH THE FRONT
BACK TO THE NORTH LATE MONDAY NIGHT RESULTING IN A NORTHWARD
EXPANSION OF THE RAIN CHANCES OVER ALL OF SOUTHEAST MINNESOTA AND
MUCH OF WESTERN AND CENTRAL WISCONSIN. MOST OF THE AREA WILL THEN
HAVE A CHANCE FOR RAIN TUESDAY AS THE FRONT MOVES BACK INTO
THE AREA AND COULD POSSIBLY BE ACCOMPANIED BY A SHORT WAVE TROUGH
ALOFT IN THE SOUTHWEST FLOW.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 AM CDT SUN MAY 3 2015
THE SOUTHWEST FLOW ALOFT LOOKS TO CONTINUE THROUGH THE PERIOD AS
THE MAIN RIDGE REMAINS OVER THE EASTERN CONUS AND A LARGE UPPER
LEVEL LOW SINKS SLOWLY SOUTH OVER THE WESTERN CONUS. WITH THIS
FLOW PATTERN...SEVERAL PIECES OF ENERGY ARE EXPECTED TO COME OUT
AND ACROSS THE UPPER MIDWEST. IT LOOKS AS IF IT WILL TAKE UNTIL
SOMETIME WEDNESDAY OR WEDNESDAY NIGHT FOR THE RETREATING FRONT TO
GET NORTH OF THE AREA. ONCE THIS HAPPENS...A COLD FRONT AND
SURFACE LOW PRESSURE WILL START TO APPROACH FROM THE WEST WITH
WHAT SHOULD BE A STRONGER SHORT WAVE TROUGH ALOFT. THIS FRONT WILL
THEN MOVE ACROSS THE AREA IN THE END OF THE WORK WEEK WITH IT
POSSIBLY BECOME STALLED OUT JUST TO THE SOUTH OF THE AREA INTO THE
START OF THE WEEKEND. WITH THIS MESSY PATTERN...WILL CARRY RAIN
CHANCES EACH DAY...ALTHOUGH WOULD NOT BE SURPRISED TO SEE A DRY
PERIOD OR TWO...ESPECIALLY ONCE THE RETURNING FRONT GETS PAST THE
AREA. HOWEVER...CONFIDENCE ON THIS IS TOO LOW TO WORK INTO THE
FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 630 AM CDT SUN MAY 3 2015
MAIN AVIATION CONCERNS ARE THUNDERSTORMS AT BOTH RST/LSE TAF
SITES LATE THIS AFTERNOON INTO THIS EVENING. LATEST 11Z SURFACE
ANALYSIS SHOWS COLD FRONT EXTENDING FROM SOUTHERN ONTARIO INTO
SOUTHERN SOUTH DAKOTA. COLD FRONT IS EXPECTED TO PUSH EAST INTO
WESTERN WISCONSIN AND SOUTHEAST MINNESOTA LATE THIS AFTERNOON AND
EVENING. DUE TO DAYTIME HEATING OUT AHEAD OF THE COLD
FRONT...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG
AND BEHIND THE FRONT AFTER 21Z TODAY. THE LATEST MODEL TRENDS HAVE
SLOWED THE PROGRESSION OF THE FRONT/DEVELOPMENT OF CONVECTION AND
HAVE DELAYED THE ONSET OF CONVECTION AT THE RST/LSE TAF SITES
BEGINNING AROUND 00Z AT RST AND 01Z LSE. COLD FRONT...AND
ASSOCIATED CONVECTION...WILL MOVE SOUTH OF THE TAF SITES BY 04-06Z
MONDAY. FEW OF THE THUNDERSTORMS MAY BECOME SEVERE...HOWEVER
CONFIDENCE IN THE EXACT PLACEMENT/LOCATION OF ANY SEVERE
THUNDERSTORMS IS LOW. WIND GUST OF UP TO 60 MPH AND LARGE HAIL ARE
POSSIBLE WITH THE THUNDERSTORMS FROM 21Z TODAY TO 04Z MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1213 PM MDT SUN MAY 3 2015
.UPDATE...
ISSUED AT 1156 AM MDT SUN MAY 3 2015
CLOUDS ARE ALREADY STARTING TO INCREASE ACROSS MUCH OF THE AREA
PER RECENT WATER VAPOR SATELLITE IMAGERY. POTENTIAL FOR SHOWERS
AND THUNDERSTORMS LIKELY TO INCREASE CONSIDERABLY OVER THE NEXT
FEW HOURS...ESPECIALLY ALONG/EAST OF THE LARAMIE RANGE. A WEAK
SURFACE BOUNDARY WAS EVIDENT NORTHEAST OF CHEYENNE ON THE 18Z
RADAR LOOP. AS THIS FEATURE SHIFTS SOUTHWEST...HIGH-RES MODELS
TURN LLVL WINDS NORTHEAST AND UPSLOPE BY 18-19Z. THIS IS ALREADY
REFLECTED IN SURFACE OBS OVER WESTERN NE. THE LAST COUPLE RUNS OF
THE HRRR HAVE BEEN CONSISTENT WITH SHOWERS/TSTMS BECOMING FAIRLY
WIDESPREAD AFTER 21Z OVER FAR SOUTHEAST WY...SO DECIDED TO BUMP
POPS UP TO CATEGORICAL. ONLY OTHER CHANGE WAS TO INCREASE HIGHS
A FEW DEGREES OVER THE PLAINS. WE ARE ALREADY 67F IN CHEYENNE AT
NOON. ANOTHER DEGREE OR TWO OF WARMING IS POSSIBLE BEFORE CLOUDS
AND PCPN HELP TO COOL THINGS DOWN.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 300 AM MDT SUN MAY 3 2015
STARTING OFF THIS MORNING...SURFACE ANALYSIS SHOWING A FRONTAL
BOUNDARY LAYING WEST TO EAST ACROSS NORTHERN WYOMING...VERY SLOWLY
MOVING SOUTH THIS MORNING. LOOKS TO LAY ALONG THE LARAMIE RANGE BY
18Z OR SO TODAY WITH NORTHEASTERLY WINDS BEHIND THE FRONT FOR
AREAS EAST OF THE LARAMIE RANGE. MEANWHILE...THE UPPER LEVEL LOW
THAT HAS BEEN SENDING US PIECES OF ENERGY THE PAST COUPLE DAYS
CONTINUES OVER THE DESERT SOUTHWEST.
BEST FOCUS FOR SHOWERS AND THUNDERSTORMS TODAY LOOKS TO BE WEST
AND SOUTH OF THIS FRONT...BASICALLY ALONG AND WEST OF THE LARAMIE
RANGE. BUT IT AL DEPENDS ON WHERE THIS FRONT ULTIMATELY ENDS UP BY
EARLY AFTERNOON. SHOULD IT HAPPEN TO TAKE A LITTLE LONGER TO GET
TO THE LARAMIE RANGE...SHOWERS AND STORMS COULD BE FURTHER EAST.
A LITTLE MORE UNSTABLE TODAY OVER YESTERDAY WITH NAM SHOWING A
POCKET OF 850MB CAPE AROUND 1000 J/KG NEAR LARAMIE OVER TO
SARATOGA AND 700MB CAPES AROUND 600 J/KG. LIFTED INDICES NEAR
-4C...SO DO BELIEVE THE STRONGEST STORMS WILL BE IN THIS AREA.
LOCATIONS BEHIND THE FRONT WILL MOST LIKELY EXPERIENCE COOLER
TEMPERATURES IN THE NORTHEAST FLOW...SO DID NOT STRAY TOO MUCH
FROM THE LOW CHANCE POPS WE HAD GOING EAST OF I-25. DID INCREASE
POPS THOUGH OUT WEST AS MODELS ARE IN GREAT AGREEMENT WITH THE
LARAMIE RANGE...CARBON AND ALBANY COUNTIES SEEING DECENT RAINFALL
THIS AFTERNOON.
SHOWERS AND THUNDERSTORMS COULD LAST INTO THE LATE EVENING HOURS
TONIGHT WITH THE FRONTAL BOUNDARY IN THE AREA AND FAIRLY GOOD
UPSLOPING WINDS.
SOME DIFFERENCES IN GFS AND ECMWF ON WHAT IS GOING TO HAPPEN
MONDAY. BOTH ARE SHOWING SOME ENERGY MOVING NORTH FORM THE DESERT
SOUTHWEST TO INTERACT WITH THE STALLED FRONTAL BOUNDARY. GFS KEEPS
HIGHER POPS WEST...WHILE ECMWF SHOWS THE SOUTH LARAMIE RANGE AND
POINTS SOUTH SEEING MOST OF THE POPS. WENT MORE WITH THE ECMWF/NAM
SOLUTION WITH THE HIGHER POPS ACROSS THE SOUTH AND EAST.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 300 AM MDT SUN MAY 3 2015
THE MODELS ARE STILL SHOWING A RATHER UNSETTLED EXTENDED PERIOD.
ON WED THE SHORTWAVE TROUGH WILL BE LOCATED OVER CENTRAL NEBRASKA.
GOOD LLVL MOISTURE IS INDICATED BY THE GFS WITH DEWPOINTS IN THE
MID 40S TO LOW 50S ACROSS THE PLAINS AND PW VALUES ARE QUITE HIGH
FOR EARLY MAY (0.75-1.0 INCHES). WITH MORE SUNSHINE ON WED
COMPARED TO PREVIOUS DAYS...THERE WILL BE BETTER INSTABILITY. SO
SCATTERED TO NUMEROUS SHOWERS AND TSTMS WILL DEVELOP BY WED
AFTN...SOME WITH HEAVY RAIN. WHILE THE MODELS YESTERDAY WERE
SHOWING A BRIEF BREAK IN THE PRECIP ON THURS...THIS IS REALLY NO
LONGER THE CASE. AN UPPER LOW WILL BE CUT OFF ACROSS NORTHERN
CALIFORNIA WITH EAST TO SOUTHEAST WINDS ACROSS THE CWA. THE GFS
INDICATES ANOTHER AFTN OF DECENT CAPE (600-800 J/KG) SO DID RAISE
POPS SOME INTO THE 30-40 PERCENT RANGE BY THURS EVENING. IT WILL
LIKELY BECOME EVEN WETTER AS WE HEAD INTO FRI. THE UPPER LOW MOVES
EASTWARD INTO THE GREAT BASIN ON FRI WITH UPPER LEVEL DIFFLUENCE
INCREASING ACROSS SOUTHEAST WY. THERE IS ALSO GOOD LLVL
UPSLOPE WITH A SFC HIGH OVER THE NORTHERN PLAINS...SO THE
POTENTIAL EXISTS FOR SOME PRETTY HIGH RAINFALL AMOUNTS FROM FRI
AFTN INTO SAT. BOTH THE GFS AND ECMWF SHOW WIDESPREAD QPF AMOUNTS
OF 0.5-1.5 INCHES. WILL ALSO HAVE TO MONITOR THE POTENTIAL FOR
SOME STRONG TO SVR STORMS AS THE EVENT DRAWS CLOSER...ALTHOUGH AT
THIS TIME THE THREAT LOOKS MARGINAL WITH LIMITED INSTABILITY (MORE
OF A STRATIFORM EVENT WITH EMBEDDED CONVECTIVE CELLS).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1213 PM MDT SUN MAY 3 2015
CONCERNS ARE TWO-FOLD FOR THIS TAF CYCLE. THE INITIAL CONCERN WILL
BE DEVELOPING CONVECTION NR KRWL AND KLAR AND PROBABLY GETTING
INTO KCYS AFTER 20Z. FAVORED VCTS AT ALL THESE SITES UNTIL
INDIVIDUAL CELLS CAN BE IDENTIFIED AND TIMED. PANHANDLE SITES WILL
SEE LESS OF A CHANCE TO SEE THIS THUNDERSTORM ACTIVITY...ALTHOUGH
KBFF MAY GET INTO IT AFTER 22Z. LATEST MODELS SUGGEST THIS
ACTIVITY WILL LINGER INTO THE OVERNIGHT AND MORNING HOURS AS WELL
AND EXPECT AVIATION CONDITIONS TO WORSEN AFTER 03-06Z AS WINDS
TURN UPSLOPE FLOPPING AROUND TO THE SOUTHEAST. THIS IS A FAVORABLE
DIRECTION FOR THE DEVELOPMENT OF LOW STRATUS/FG. ALSO EXPECT
ANOTHER BAND OF SHOWERS TO LIFT NORTH ACROSS PRIMARILY PANHANDLE
SITES AFTER 06Z. ANY STRATUS OR FOG THAT DOES EXIST WILL LIKELY
LIFT IF THESE SHOWERS MATERIALIZE. FOR NOW HAVE TRENDED CONDITIONS
DOWNWARD AFTER 06Z TO ACCOUNT FOR THIS ACTIVITY.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MDT SUN MAY 3 2015
DAILY CHANCES FOR WETTING RAINS FOR MOST LOCATIONS AS A COLD FRONT
MOVE SOUTH OUT OF MONTANA AND STALLS NEAR THE LARAMIE RANGE. THIS
FRONT WILL INTERACT WITH ENERGY FROM A DISTURBANCE OVER THE FOUR
CORNERS AREA AND WILL FOCUS SHOWERS AND THUNDERSTORMS ACROSS
SOUTHEAST WYOMING. COOLER TEMPERATURES AND WETTING RAINS WILL AID
IN ONGOING GREENUP OF FUELS...SO NO FIRE WEATHER CONCERNS ARE
ANTICIPATED THROUGH MUCH OF THE UPCOMING WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...GCC
LONG TERM...ZF
AVIATION...CAH
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
400 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* RAIN CONTINUES THROUGH THE MORNING. A FEW CLAPS OF THUNDER ARE
NOT OUT OF THE QUESTION THROUGH DAYBREAK.
* EAST WINDS INCREASE TO 10-11 KT THIS MORNING AND AFTERNOON.
* IFR CIGS ARE EXPECTED BY 12Z AND NOT EXPECTING CIGS TO LIFT TO
MVFR UNTIL THIS EVENING IF NOT LATER.
* ANOTHER CHANCE OF SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN.
JEE
//DISCUSSION...UPDATED 06Z...
THE MESSY PATTERN CONTINUES. A SWATH OF SHOWERS AND A FEW
THUNDERSTORMS ARE SLOWLY PUSHING NORTHEAST AND WILL IMPACT ALL OF
THE TERMINALS. LIGHTNING STRIKES ARE FEW AND FAR BTWN SO KEPT
VCTS GOING THROUGH 12Z. IT IS STILL RATHER DRY OUT THERE DESPITE
THE RAIN...SO MVFR CIGS ARE ADVANCING SLOWLY. ALL GUIDANCE MEMBERS
INDICATE THE IFR CIGS TO OUR WEST WILL INFILTRATE THE TERMINALS
EARLY THIS MORNING. THE FRONT CURRENTLY OVER CENTRAL IL WILL
REMAIN SOUTH OF THE TERMINALS TODAY...WHICH SHOULD ME WE ARE
LOCKED INTO IFR CIGS UNTIL THE FRONT LIFTS NORTH WEDNESDAY
MORNING. WINDS WILL BE OUT OF THE EAST AS WELL.
GUIDANCE ALSO HINTS AT ANOTHER ROUND OF SHOWERS AND PERHAPS A
THUNDERSTORM THIS AFTERNOON SO PUT A PROB30 IN AS CONFIDENCE IS
NOT OVERLY HIGH GIVEN HOW MESSY THE PATTERN IS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN SHOWERS THROUGH THIS MORNING AND ONLY A FEW
LIGHTNING STRIKES THROUGH DAYBREAK. MEDIUM-LOW CONFIDENCE IN
OCCURRENCE AND COVERAGE OF -SHRA AND TSRA THIS AFTN.
* MEDIUM-HIGH CONFIDENCE IN VSBY...STRONGER DOWNPOURS COULD LOWER
VSBY TO 2SM.
* MEDIUM-HIGH CONFIDENCE IN CIGS DROPPING TO IFR THIS MORNING.
MEDIUM CONFIDENCE IN CIGS LIFTING TO MVFR THIS EVENING AS THEY
COULD REMAIN IFR OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SLIGHT CHANCE TSRA. MAINLY VFR. SOUTHEAST WINDS.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...CHANCE TSRA. MAINLY VFR. SOUTH WINDS.
SATURDAY...CHANCE OF TSRA WITH BRIEF MVFR...THOUGH MAINLY VFR.
SOUTHWEST WINDS BECOMING EAST-NORTHEAST.
SUNDAY...CHANCE OF TSRA. BRIEF MVFR POSSIBLE. SOUTHEAST WINDS.
RATZER
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
333 AM CDT TUE MAY 5 2015
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
A FRONTAL BOUNDARY IS ORIENTED WEST-EAST ACROSS CENTRAL IL THIS
MORNING WITH PRECIPITATION IN ISENTROPIC ASCENT REGION LARGELY TO
THE NORTH OF THE BOUNDARY. MODELS INDICATE THE BOUNDARY AND
PRECIPITATION WILL SHIFT SLOWLY NORTHWARD TODAY. WEAK DISTURBANCES
MOVING ALONG THE BOUNDARY WILL PRODUCE SOME ENHANCEMENTS IN
CONVECTIVE SHOWER COVERAGE IN THE VICINITY...EARLY THIS MORNING FROM
AROUND THE ILLINOIS RIVER NORTHWESTWARD...AND LATE IN THE AFTERNOON
NORTH OF THE I-74 CORRIDOR. FOR THE MOST PART...CONVECTION SHOULD BE
WEAK AT THIS POINT WITH ONLY WEAK MID-LEVEL INSTABILITY REMAINING
THROUGH THE NIGHT...AND 0-6KM BULK SHEAR UP TO 25-30 KTS THIS
MORNING DIMINISHING SUBSTANTIALLY FOR THE AFTERNOON. 1000-1500
JOULES OF SURFACE-BASED CAPE SHOULD BE ABLE TO DEVELOP WITH
AFTERNOON HEATING ALONG/NORTH OF I-72 AND CAN`T RULE OUT ISOLATED
THUNDERSTORMS SOUTHWARD TO I-72 AS A RESULT.
&&
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
ONGOING CONVECTION ALONG THE BOUNDARY OVER NORTHERN ILLINOIS THIS
MORNING NOT ONLY DRIVING THE WEATHER THROUGHOUT THE DAY, BUT INTO
THE OVERNIGHT AS WELL. GFS AND NAM CONTINUE TO KEEP A BIT OF PRECIP
PRETTY FAR SOUTH, AS FAR SOUTH AS A LINE FROM HAVANA TO BLOOMINGTON.
HOWEVER, THE RAP/RUC AND THE HRRR ARE PUSHING THE AREA OF CONVECTION
WELL TO THE NORTH THROUGH THE MORNING WITH THE BOUNDARY. WHEN THE
SECONDARY WAVE RIPPLES THROUGH THE REGION AFTER 00Z, IT WOULD BE
DISPLACED NORTH OF THE FA. THE 4KM WRF HAS JUST THAT SOLUTION,
STARTING MORE IN LINE WITH THE RAP/RUC AND HRRR...AND KEEPING THE FA
DRY AFTER 00Z, BUT A LITTLE MORE GENEROUS WITH SOME ISOLATED
INSTABILITY SHOWERS. HAVE KEPT ISO TS IN THE NORTH, MAINLY ALONG
AND NORTH OF I-74 FOR THE EARLY EVENING.
HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION LATER TONIGHT,
SOUTHERLY WINDS PUSHING THE FRONT BACK TO THE NORTH AND OUT OF THE
FORECAST AREA THROUGH WED NIGHT. FORECAST REMAINS ROUGHLY THE SAME
BEYOND DAY 3... PRECIP CHANCES SLOWLY EDGING BACK INTO WEST CENTRAL
ILLINOIS FOR THURSDAY AS AN UPPER LEVEL WAVE PUSHES OUT OF THE SW.
THE ENERGY IS PART OF A GENERAL PATTERN SHIFT TO MORE SOUTHWESTERLY
FLOW WITH THE UPPER LEVEL TROF DIGGING BACK IN OVER THE SWRN CONUS.
THE SFC LOW MOVES OUT INTO THE UPPER MIDWEST AND INTO CANADA BY THE
END OF THE WEEK, BUT IN SHIFTING TO MORE SOUTHWESTERLY FLOW ALOFT,
OPENS THE DOOR TO A SERIES OF SHORTWAVES THAT KEEP THE FORECAST WET
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND. TEMPS RATHER
WARM THROUGH THE FORECAST WITH OVERCAST AND RAINY SKIES KEEPING THE
OVERNIGHT LOWS UP A BIT, BUT LIKELY NOT NEARLY AS WARM AS THE TREND
IN THE GUIDANCE. HAVE KNOCKED THEM DOWN A COUPLE DEGREES. SOUTHERLY
FLOW AND A RELATIVELY WARM AIRMASS KEEPING THE HIGHS A BIT ABOVE
NORMS, EVEN WITH THE PASSAGE OF THE FIRST LOW SKIRTING TO THE
NW...THE MID LEVELS REMAIN WARM UNTIL THE MAIN TROF OVER THE SW
LIFTS INTO AND OUT OF THE GREAT LAKES. COOLER AIR IN THE MIDLEVELS
IS ONLY AROUND FOR 36 HOURS DAY 7/8 BEFORE THE WARM AIRMASS
REESTABLISHES ITSELF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1144 PM CDT MON MAY 4 2015
FAIRLY SMALL AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS IS STILL
MAKING ITS WAY ACROSS CENTRAL ILLINOIS, AND THIS AREA IS ONLY A
THREAT AT KBMI AND KCMI FOR A FEW MORE HOURS. MORE WIDESPREAD
SHOWERS/STORMS ARE UPSTREAM FROM THE CENTRAL ILLINOIS TERMINAL
AREA. RECENT SHORT RANGE/HIGH RESOLUTION MODEL GUIDANCE, SUPPORTED
BY RADAR LOOPS, SUGGESTS THAT MUCH OF THIS PRECIPITATION WILL PASS
TO THE NORTH OF THE LOCAL TERMINALS. KPIA AND KBMI STAND THE BEST
CHANCE OF BEING IMPACTED BY THIS UPSTREAM PRECIPITATION FOR
SEVERAL MORE HOURS, WHILE KSPI, KDEC, AND KCMI WILL BE MOSTLY DRY.
OUTSIDE OF ANY APPRECIABLE RAINFALL AREAS, WHICH WILL BRIEFLY
PRODUCE MVFR CONDITIONS, VFR CONDITIONS SHOULD PREVAIL. MOST OF
THE REST OF THE NIGHT SHOULD SEE VARIABLE WINDS WITH A NEARLY
STATIONARY BOUNDARY IN THE VICINITY. EXPECT WINDS TO TREND
SOUTHWESTERLY TUESDAY MORNING AS THE FRONT SHIFTS BACK NORTH.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
332 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* -SHRA IS MOVING IN AND WILL PERSIST THROUGH THE MORNING. A FEW
CLAPS OF THUNDER ARE NOT OUT OF THE QUESTION THROUGH DAYBREAK.
* EAST WINDS INCREASE TO 10-11 KT THIS MORNING AND AFTERNOON.
* IFR CIGS ARE EXPECTED BY 12Z AND NOT EXPECTING CIGS TO LIFT TO
MVFR UNTIL THIS EVENING IF NOT LATER.
* ANOTHER CHANCE OF SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN.
JEE
//DISCUSSION...UPDATED 06Z...
THE MESSY PATTERN CONTINUES. A SWATH OF SHOWERS AND A FEW
THUNDERSTORMS ARE SLOWLY PUSHING NORTHEAST AND WILL IMPACT ALL OF
THE TERMINALS. LIGHTNING STRIKES ARE FEW AND FAR BTWN SO KEPT
VCTS GOING THROUGH 12Z. IT IS STILL RATHER DRY OUT THERE DESPITE
THE RAIN...SO MVFR CIGS ARE ADVANCING SLOWLY. ALL GUIDANCE MEMBERS
INDICATE THE IFR CIGS TO OUR WEST WILL INFILTRATE THE TERMINALS
EARLY THIS MORNING. THE FRONT CURRENTLY OVER CENTRAL IL WILL
REMAIN SOUTH OF THE TERMINALS TODAY...WHICH SHOULD ME WE ARE
LOCKED INTO IFR CIGS UNTIL THE FRONT LIFTS NORTH WEDNESDAY
MORNING. WINDS WILL BE OUT OF THE EAST AS WELL.
GUIDANCE ALSO HINTS AT ANOTHER ROUND OF SHOWERS AND PERHAPS A
THUNDERSTORM THIS AFTERNOON SO PUT A PROB30 IN AS CONFIDENCE IS
NOT OVERLY HIGH GIVEN HOW MESSY THE PATTERN IS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN SHOWERS THROUGH THIS MORNING AND ONLY A FEW
LIGHTNING STRIKES THROUGH DAYBREAK. MEDIUM-LOW CONFIDENCE IN
OCCURRENCE AND COVERAGE OF -SHRA AND TSRA THIS AFTN.
* MEDIUM-HIGH CONFIDENCE IN VSBY...STRONGER DOWNPOURS COULD LOWER
CIGS TO 2SM.
* MEDIUM-HIGH CONFIDENCE IN CIGS DROPPING TO IFR THIS MORNING.
MEDIUM CONFIDENCE IN CIGS LIFTING TO MVFR THIS EVENING AS THEY
COULD REMAIN IFR OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SLIGHT CHANCE TSRA. MAINLY VFR. SOUTHEAST WINDS.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...CHANCE TSRA. MAINLY VFR. SOUTH WINDS.
SATURDAY...CHANCE OF TSRA WITH BRIEF MVFR...THOUGH MAINLY VFR.
SOUTHWEST WINDS BECOMING EAST-NORTHEAST.
SUNDAY...CHANCE OF TSRA. BRIEF MVFR POSSIBLE. SOUTHEAST WINDS.
RATZER
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1151 PM CDT MON MAY 4 2015
.UPDATE...
ISSUED AT 848 PM CDT MON MAY 4 2015
LATEST SURFACE ANALYSIS HAS A NEARLY STATIONARY FRONTAL BOUNDARY
CUTTING WEST TO EAST ACROSS CENTRAL ILLINOIS ROUGHLY FROM QUINCY
TO PARIS. THIS BOUNDARY IS FAIRLY WELL DELINEATED BY AN EXPANDING
FINE LINE OF SHOWERS AND ISOLATED THUNDERSTORMS. THE PREVIOUS
INTENSITY OF THE AREA OF STORMS PUSHING INTO WEST-CENTRAL ILLINOIS
HAS FADED WITH THE LOSS OF DIURNAL INSTABILITY WITH THE BULK OF
THE STORMS IN OUR VICINITY CURRENTLY OF THE "GARDEN VARIETY".
THE BULK OF THE GUIDANCE, ESPECIALLY RECENT RUNS OF MANY HIGH
RESOLUTION MODELS, SUGGEST THE BULK OF THE SHOWERS/STORMS THOUGH
THE NIGHT WILL EXIST ALONG/NORTH OF THE FRONTAL BOUNDARY. ALSO, A
WAVE LIFTING NORTHEAST OUT OF THE PLAINS IS EXPECTED TO HELP PUSH
THE FRONT A LITTLE FURTHER NORTH WITH TIME OVERNIGHT. THESE
FACTORS WOULD SUGGEST THE BULK OF THE UPSTREAM PRECIPITATION OVER
IOWA AND MISSOURI WOULD TRACK NORTH OF MOST OF THE FORECAST AREA.
PLAN TO UPDATE FORECAST TO REFINE POPS, MAINLY TO PUSH THE RISK
FURTHER NORTH. OTHERWISE, MINOR TWEAKS ARE NEEDED FOR THE LATEST
HOURLY TRENDS.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 245 PM CDT MON MAY 4 2015
FRONTAL BOUNDARY EXTENDING FROM SOUTHERN LAKE MICHIGAN TO NORTHERN
KANSAS WILL SINK SOUTHWARD...EVENTUALLY STALLING NEAR THE I-72
CORRIDOR LATER THIS EVENING. SHOWERS AND THUNDERSTORMS WILL DEVELOP
ALONG THE BOUNDARY...WITH MOST MODEL SOLUTIONS SUGGESTING THE
GREATEST AREAL COVERAGE OF PRECIP ACROSS THE NORTHERN HALF OF THE
KILX CWA. HRRR IS SHOWING WIDELY SCATTERED STORMS DEVELOPING OVER
THE NEXT COUPLE OF HOURS...WITH THE CONVECTION BECOMING MORE
WIDESPREAD AFTER SUNSET AS A WEAK LOW-LEVEL JET DEVELOPS. HAVE
ADJUSTED RAIN CHANCES ACCORDINGLY...WITH LIKELY POPS ALONG/NORTH OF
I-72 TAPERING DOWN TO JUST SLIGHT CHANCE ALONG/SOUTH OF I-70.
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 245 PM CDT MON MAY 4 2015
AN UPPER LEVEL RIDGE IS EXPECTED TO AMPLIFY OVER THE CENTER OF THE
NATION STARTING ON TUESDAY WHICH SHOULD PUSH THE BETTER CHANCES FOR
SHOWERS AND THUNDERSTORMS NORTH OF THE FORECAST AREA...AT LEAST INTO
THURSDAY. SHORTWAVE ENERGY IS THEN FORECAST TO EJECTS NORTH OUT OF
THE SOUTHERN PLAINS AND BRING ABOUT A CHANCE FOR MORE SHOWERS AND
THUNDERSTORMS...ESPECIALLY ACROSS OUR WEST...THURSDAY NIGHT INTO
FRIDAY. A MORE POTENT 500 MB TROF IS THEN FORECAST TO SLOWLY TRACK
OUT OF THE ROCKIES DURING THE WEEKEND BRINGING PERIODS OF SHOWERS
AND THUNDERSTORMS TO THE FORECAST AREA. MOST MODELS TRACK THIS LOW
NORTH-NORTHEAST ON SUNDAY SUGGESTING THE MORE SIGNIFICANT LIFT TO
REMAIN WEST OF OUR AREA UNTIL LATE SUNDAY OR MONDAY OF NEXT WEEK
WHEN THE SYSTEM WILL SWING A COLD FRONT THROUGH CENTRAL ILLINOIS.
UNTIL THEN...WARM TEMPERATURES TO PREVAIL WITH THE SHOWER AND STORM
CHANCES ACROSS THE FAR NORTH TOMORROW AS THE FRONT RETREATS BACK
TO THE NORTH...AND THEN RAIN CHANCES RETURN LATE THU INTO FRIDAY
AND HOLDS THROUGH EARLY NEXT WEEK BEFORE WE FINALLY GET A CHANGE
IN AIR MASS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1144 PM CDT MON MAY 4 2015
FAIRLY SMALL AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS IS STILL
MAKING ITS WAY ACROSS CENTRAL ILLINOIS, AND THIS AREA IS ONLY A
THREAT AT KBMI AND KCMI FOR A FEW MORE HOURS. MORE WIDESPREAD
SHOWERS/STORMS ARE UPSTREAM FROM THE CENTRAL ILLINOIS TERMINAL
AREA. RECENT SHORT RANGE/HIGH RESOLUTION MODEL GUIDANCE, SUPPORTED
BY RADAR LOOPS, SUGGESTS THAT MUCH OF THIS PRECIPITATION WILL PASS
TO THE NORTH OF THE LOCAL TERMINALS. KPIA AND KBMI STAND THE BEST
CHANCE OF BEING IMPACTED BY THIS UPSTREAM PRECIPITATION FOR
SEVERAL MORE HOURS, WHILE KSPI, KDEC, AND KCMI WILL BE MOSTLY DRY.
OUTSIDE OF ANY APPRECIABLE RAINFALL AREAS, WHICH WILL BRIEFLY
PRODUCE MVFR CONDITIONS, VFR CONDTIONS SHOULD PREVAIL. MOST OF THE
REST OF THE NIGHT SHOULD SEE VARIABLE WINDS WITH A NEARLY
STATIONARY BOUNDARY IN THE VICINITY. EXPECT WINDS TO TREND
SOUTHWESTERLY TUESDAY MORNING AS THE FRONT SHIFTS BACK NORTH.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BAK
SHORT TERM...BARNES
LONG TERM...SMITH
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
228 AM MDT TUE MAY 5 2015
.UPDATE...
ISSUED AT 1023 PM MDT MON MAY 4 2015
UPDATED FORECAST TO REFLECT THE DIMINISHED CHANCES FOR RAINFALL
FOR THE WESTERN HALF OR SO OF THE AREA THROUGH THE REST OF THE
NIGHT. WAS VERY CONFIDENT EARLIER THAT THE LINE OF STORMS WOULD
MOVE ACROSS THE ENTIRE AREA...WITH SOME WEAKENING OVER THE EAST
PART OF THE AREA. HOWEVER OVER THE LAST HOUR OR SO THE LINE OF
STORMS HAS ALMOST COMPLETELY DISSIPATED.
LOOKING AT RUC THETA-E AT 850MB...THERE IS DRIER AIR OVER THE
WESTERN HALF OF THE AREA. AM THINKING THIS IS WHY THE STORMS DIED
OVER THE WEST INSTEAD OF THE EAST WHICH HAS HIGHER THETA-E AND
BETTER CAPE.
LOOKING SOUTHWARD NUMEROUS SHOWERS AND SOME T-STORMS CONTINUE
TO MOVE UP FROM THE SOUTH IN THE HIGHER THETA-E AIR. LIFT DOES
DECLINE OVER THE EAST OVERNIGHT SO HAVE RAINFALL CHANCES TRENDING
ACCORDINGLY. DOES LOOK LIKE THE EAST HALF WILL HAVE A MUCH BETTER
CHANCE FOR RAINFALL DUE TO THE HIGHER THETA-E AIR PRESENT.
MEANWHILE PATCHY FOG IS EXPECTED OVER THE NORTHERN HALF OR SO OF
THE AREA OVERNIGHT INTO TUESDAY MORNING. LOOKS LIKE THE FOG WILL
BE NORTH OF THE SLOWLY ADVANCING SURFACE BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 220 PM MDT MON MAY 4 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
DEEPENING TROUGH OVER SOUTHERN CALIFORNIA WITH SW FLOW FROM THE GULF
OF ALASKA AND ACROSS THE CENTRAL/HIGH PLAINS. MOIST PLUME EXTENDS
FROM THE GREAT BASIN ACROSS THE OHIO RIVER VALLEY WITH ADDITIONAL
MOISTURE FEEDING IN THE PLAINS FROM THE GULF OF MEXICO. AT THE
SURFACE A STATIONARY FRONT EXTENDS FROM NORTHEAST KANSAS TO
SOUTHEAST COLORADO AND LIES JUST SOUTHEAST OF OUR CWA...WITH
BAROCLINIC ZONE EXTENDING NORTH INTO THE SE PART OF OUR CWA.
THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THIS FRONTAL ZONE
TOWARDS THE SOUTHEAST PART OF OUR CWA.
THIS AFTERNOON-EVENING...ALONG THIS FRONTAL ZONE ANALYSIS INDICATES
ML CAPE VALUES RANGING FROM 1500 J/KG IN THE WARM SECTOR TO 500
J/KG IN OUR SE CWA. BULK SHEER IS APPROXIMATELY 30-35KT...SO
DEPENDING ON POSITION OF FRONT (CURRENTLY ADVERTISED TO SLIDE NORTH
INTO OUR SOUTHEAST)...THERE IS THE POTENTIAL FOR A FEW STRONGER
THUNDERSTORMS...POSSIBLY SEVERE WITH LARGE HAIL/DAMAGING WINDS MAIN
THREAT. IF FRONT WERE TO LIFT NORTH AS WARM FRONT WE COULD SEE
BETTER SB/ML CAPE AND THE POSSIBILITY FOR A FEW MORE ORGANIZED CELLS
IN THE SOUTHEAST. ANALYSIS ALSO INDICATES PWAT VALUES ALREADY IN
EXCESS OF 1" OVER OUR EAST. STORM MOTIONS WILL BE ROUGHLY
TANGENTIAL/PARALLEL THIS AFTERNOON BECOMING PERPENDICULAR TO FRONTAL
ZONE THIS EVENING. AS THIS TRANSITION OCCURS THERE IS THE
FOR BACKBUILDING OR TRAINING AS VERY MOIST/UNSTABLE AIR IN THE WARM
SECTOR FEEDS NORTH. THERE COULD BE A THREAT FOR FLASH FLOODING IF
THIS SCENARIO PLAYS OUT. EITHER WAY WITH VERY MOIST AIR MASS AND
INCREASING ELEVATED INSTABILITY...THUNDERSTORMS COULD BE VERY
EFFICIENT RAINFALL PRODUCERS.
TONIGHT-TUESDAY...UPSTREAM AREAS OF MID LEVEL VORTICITY WILL ROTATE
INTO THE CWA WITH INCREASING LIFT LATE THIS EVENING INTO THE
OVERNIGHT. AS TROUGH CONTINUES TO DEEPEN OVER THE SW US AND MOVE
EAST WE WILL CONTINUE TO SEE VERY GOOD FORCING/MOISTURE ROTATES
THROUGH THE REGION. LARGE SCALE Q VECTOR FIELDS INDICATED FORCING
INCREASING THROUGH THE NIGHT AND OMEGA/MOISTURE
CONVERGENCE FIELDS SHOW SUPPORT FOR INCREASING COVERAGE/COMPLEX OF
SHOWERS THUNDERSTORMS. ELEVATED INSTABILITY TRANSITIONS NORTHWARD
AND WEAKENS...HOWEVER THERE IS ENOUGH TO KEEP THUNDER MENTION IN
PLACE THROUGH TUESDAY AFTERNOON. WHILE GUIDANCE IS IN AGREEMENT ON
GENERAL LARGE SCALE PATTERN THE MAIN DIFFERENCES ARE ON TIMING OF
POTENTIAL PERIODS OF HEAVIER PRECIP...WITH BEST PRECIP SIGNAL AND
MOISTURE PROFILES OVERLAPPING TUESDAY MORNING THROUGH TUESDAY
AFTERNOON ACROSS THE WESTERN 2/3 OF THE CWA (THOUGH ECMWF MIGHT BE A
LITTLE EAST). THERE WILL BE MODERATE/ELEVATED INSTABILITY IN PLACE
THROUGH THE DAY TUESDAY...SO STRONG TO SEVERE THUNDERSTORMS WILL
STILL BE POSSIBLE AGAIN...THOUGH SEVERE POTENTIAL MIGHT NOT BE AS
GOOD AS TODAY WITH WIDESPREAD SHOWERS AND STRATUS LIMITING SURFACE
BASED PARCELS AND ANY ACTIVITY LIKELY EMBEDDED WITH OTHER SHOWER
CLUSTERS.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 227 AM MDT TUE MAY 5 2015
A HIGH AMPLITUDE TROUGH WITH A CLOSED LOW WILL AFFECT THE TRI STATE
AREA TO START THE LONG TERM FORECAST PERIOD FRIDAY...WHICH WILL
BRING INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS MUCH OF
THE FORECAST AREA FOR THE DURATION OF THE FORECAST PERIOD.
GFS/ECMWF/CANADIAN FORECASTS ALL INDICATE THE SLOW MOVING TROUGH
WILL AFFECT THE REGION FOR THE DURATION OF THE COMING WEEKEND. THE
TROUGH TAKES A NEGATIVE TILT SATURDAY IN THE GFS/ECMWF
FORECASTS...WHICH WILL STEEPEN LAPSE RATES ALOFT AND INCREASE CAPE
VALUES. A STRONGER JET MAY ALSO BE IN THE AREA TO HELP DESTABILIZE
THE ENVIRONMENT...BUT MODEL GUIDANCE DIFFERS AS TO THE ACTUAL
STRENGTH. GFS FORECAST HAS AN UPPER LEVEL JET APPROACHING 80KTS
OVER THE FORECAST AREA...WHICH IS PLENTY STRONG TO GIVE 0-6 KM BULK
SHEAR VALUES APPROACHING 50 KTS. LOWER LEVEL HODOGRAPHS ALSO HAVE
GOOD CURVATURE WITH 0-3 KM HELICITY APPROACHING CRITICAL VALUES FOR
TORNADOES. HOWEVER...ECMWF/CANADIAN MODELS ARE NOT AS ENTHUSIASTIC
AND HAVE BETTER JET LOCATED TO THE EAST OF OUR AREA.
THEREFORE...SEVERE THUNDERSTORM THREAT LOOKS TO BE POSSIBLE BUT NOT
DEFINITE AT THIS POINT.
HEAVY RAIN IS POSSIBLE SATURDAY NIGHT FOR MANY LOCATIONS DUE TO VERY
SATURATED MODEL SOUNDINGS AND CAPE IN THE PROFILE TO CONTINUE TO
DRIVE CONVECTION INTO THE EVENING. ALONG AN ADVANCING WARM
FRONT...AN MCS IS LIKELY TO DEVELOP AND BE PERSISTENT WITH THE
ENHANCEMENT OF THE LOWER NOCTURNAL JET. SHOWERS AND STORMS WILL
TAPER OFF TOWARDS SUNDAY MORNING. SCATTERED THUNDERSTORMS MAY
CONTINUE INTO THE AFTERNOON HOURS WITH THE UPPER LEVEL TROUGH
LINGERING IN THE AREA...BUT THE BASE OF THE TROUGH WILL PASS OVER
THE HIGH PLAINS MONDAY AND WILL EFFECTIVELY END THE HIGHER
PRECIPITATION THREAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM MDT MON MAY 4 2015
MVFR TO IFR CONDITIONS FORECAST FOR THE 6Z TAFS. EXPECT CONDITIONS
AT KMCK TO REMAIN UNCHANGED UNTIL CLOSE TO MID MORNING. MEANWHILE
AT KGLD CEILINGS HAVE FLUCTUATED FROM IFR TO VFR OVER THE PAST
HOUR OR SO. EXPECT IFR CEILING IN THE NEXT HOUR. FOR BOTH SITES CEILINGS
SHOULD INCREASE TO MVFR DURING THE LATE MORNING...THEN FALL TO IFR
AGAIN IN THE EARLY EVENING.
THE SHOWERS SHOULD REMAIN SOUTH OF KMCK FOR THE REST OF THE NIGHT
AND THROUGH MOST OF THE DAY. DURING THE LATE AFTERNOON THERE MAY
BE A SHORT WINDOW FOR STORMS TO MOVE NEAR THE SITE...BUT WILL
WAIT FOR LATER TAFS TO ADDRESS THIS.
KGLD SHOULD REMAIN RAIN FREE TONIGHT. DURING THE LATE MORNING AND
THROUGH THE AFTERNOON RAIN CHANCES WILL INCREASE...WITH THE BEST
CHANCES DURING THE MID TO LATE AFTERNOON. BY EARLY EVENING THE
CHANCES FOR RAIN WILL BEGIN TO DECLINE.
EXPECT VISIBILITY REDUCTION FOR BOTH SITES DURING THE
OVERNIGHT HOURS. VISIBILITY SHOULD IMPROVE DURING THE MID TO LATE
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...MK
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS WICHITA KS
313 AM CDT TUE MAY 5 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 307 AM CDT TUE MAY 5 2015
LINGERING SHOWERS AND THUNDERSTORMS CONTINUE ALONG A QUASI
STATIONARY BOUNDARY SITUATED JUST NORTH OF INTERSTATE 70 AT THIS
TIME. LATEST SHORT TERM HI-RES MODELS SUGGEST THIS BOUNDARY WILL
SLOWLY LIFT BACK TO THE NORTH THIS MORNING TOWARDS NEB...TAKING MOST
OF THE SHOWER ACTIVITY NORTH WITH IT. THIS WILL LEAD TO DRY
CONDITIONS FOR THE DAYTIME HOURS ACROSS THE FORECAST AREA...AS A
WARM ELEVATED MIXED LAYER CAPS OFF ANY PRECIP CHANCE WITH LESS
INSTABILITY THIS AFTERNOON.
THE MAIN DRYLINE AND CONVERGENCE FOR STORM CHANCES LOOKS TO SHIFT
INTO WESTERN KS FOR THIS AFTERNOON INTO THIS EVENING. THINK SHOWERS
AND THUNDERSTORMS WILL DEVELOP ALONG THIS DRYLINE AND MAKE SLOW
PROGRESS TO THE EAST...AS AN INITIAL SHORTWAVE ROTATES NORTH ACROSS
WESTERN KS LATE THIS AFTERNOON.
BUT EXPECT ANOTHER MORE POTENT SHORTWAVE TO ROTATE NORTH OUT OF SRN
NM DURING THE EVENING WITH THIS SHORTWAVE LIFTING NORTHEAST
ACROSS THE FORECAST AREA FOR THE LATE EVENING AND OVERNIGHT HOURS.
LIFT ASSOCIATED WITH THIS SHORTWAVE WILL LEAD TO SHOWERS INITIALLY
DEVELOPING IN OK...WITH THE STORMS MOVING NORTH INTO THE AREA
DURING THE LATE EVENING HOURS. AS THIS IMPULSE MOVES ACROSS THE
AREA...WIDESPREAD SHOWERS AND SOME EMBEDDED THUNDERSTORMS WILL
BLOSSOM ACROSS MOST OF THE FORECAST AREA FOR THE OVERNIGHT HOURS
AS THE UPPER LEVEL DIFFLUENCE INCREASES. PREVIOUS SHIFTS ADJUSTED
THE POP TIMING WITH CATEGORICAL POPS MAINLY AFTER 06Z...WITH
LIKELY POPS FOR THE EVENING HOURS. THIS LOOKS OKAY.
SOME UNCERTAINTY ON HOW EARLY WED WILL PLAY OUT...AS REMNANT SHOWERS
AND EMBEDDED THUNDER WILL STILL BE ACROSS CENTRAL KS FOR THE MORNING
HOURS. LOTS OF REMNANT CLOUD COVER WILL ALSO BE AROUND...AS
INSTABILITY INCREASES AND THE DRYLINE PUSHES EAST CLOSER TO THE
FORECAST AREA FOR WED AFTERNOON. IF AIRMASS CAN RECOVER...LATEST
NAM/WRF AND GFS SHOW A VERY UNSTABLE AIRMASS WILL BE IN PLACE ACROSS
SOUTH CENTRAL KS...WITH DEEP LAYER BULK SHEAR INCREASING TO AROUND
30-40 KTS. WEAKLY CAPPED ENVIRONMENT WILL BE IN PLACE..SO EXPECT
DISCRETE STORMS TO DEVELOP ALONG THIS DRYLINE FOR WED
AFTERNOON....WITH STORMS EXPECTED TO BECOME SUPERCELLS GIVEN THE
DIRECTIONAL SHEAR. THIS CERTAINLY LOOKS LIKE A SEVERE WEATHER THREAT
WITH LARGE HAIL AND DAMAGING WINDS THE MAIN CONCERN.
DRYLINE IS EXPECTED TO RETREAT BACK TO THE WEST DURING THE NIGHTTIME
HOURS ON WED...SO NOT ENTIRELY SURE HOW LONG THE CONVECTION WILL
CONTINUE INTO WED NIGHT...AS SOME WARMER AIR ALOFT WILL EFFECTIVELY
SHUT DOWN THE CONVECTION.
THE DRYLINE WILL AGAIN COME INTO PLAY ON THU...AS THE BOUNDARY
BECOMES MORE OF A COLD FRONT AND AGAIN PUSHES INTO PORTIONS OF
CENTRAL KS FOR THU AFTERNOON AS A NORTHERN STREAM SYSTEM HELPS PUSH
IT FURTHER EAST.
INSTABILITY AND SHEAR SUGGESTS ANOTHER ROUND OF SEVERE WEATHER MAY
OCCUR ALONG THIS BOUNDARY FOR PORTIONS OF THE FORECAST AREA FOR THU
AFTERNOON/EVENING...AS SUPERCELLS WILL AGAIN BE POSSIBLE. WILL HAVE
TO KEEP AN EYE ON THIS SEVERE WEATHER THREAT...AS AN AREA OF LOW
PRESSURE IN THE OK PANHANDLE MAY SETUP A TRIPLE POINT ACROSS SOUTH
CENTRAL KS...WITH SURFACE WINDS BACKING ACROSS SRN KS AND BETTER LOW
LEVEL TURNING FOR A POSSIBLE INCREASED TORNADO THREAT. STAY TUNED.
KETCHAM
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 307 AM CDT TUE MAY 5 2015
THE ACTIVE PATTERN LOOKS TO CONTINUE FOR FRI AND SAT...AS THE MAIN
SURFACE BOUNDARY BECOMES STATIONARY ACROSS SOUTHERN KS ON FRI
AFTERNOON. THE MID LEVEL BAROCLINIC ZONE WILL ALSO REMAIN CO-
LOCATED WITH THE SURFACE BOUNDARY AS WELL....WITH SHOWER AND
THUNDERSTORMS EXPECTED TO REDEVELOP ACROSS SOUTHERN KS AS THE LOW
LEVEL JET INCREASES OVER THE TOP OF THE BOUNDARY. THIS HAS ALL THE
SIGNS OF A SEVERE WEATHER PRODUCING COMPLEX OF STORMS (MCS)
DEVELOPING LATE FRI NIGHT ACROSS SRN KS...CONSIDERING THE AMOUNT OF
INSTABILITY THAT WILL BE AROUND AND BULK SHEAR OF 40 KTS.
HOW SAT WILL PLAY OUT WILL DEPEND ON WHERE THE MCS LATE FRI NIGHT
GOES AND ANY OUTFLOW BOUNDARY IT PUSHES OUT. MEDIUM RANGE MODELS
SUGGEST THAT A VIGOROUS SHORTWAVE IS EXPECTED TO LIFT NORTHEAST OUT
OF THE SOUTHERN PLAINS ON SAT EVENING AND WILL PUSH ANY KIND OF
BOUNDARY/WARM FRONT BACK NORTH ACROSS THE AREA FOR SAT NIGHT...WHICH
WILL LEAD TO ANOTHER CHANCE OF SEVERE STORMS FOR SAT NIGHT AS WELL.
WILL CERTAINLY HAVE TO KEEP AN EYE ON WATER ISSUES GOING INTO THE
WEEKEND...AS MOST OF THE CONVECTION WILL BE VERY EFFECTIVE RAINFALL
PRODUCERS FOR HEAVY RAINFALL AND POSSIBLE FLOODING CONCERNS.
KETCHAM
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1150 PM CDT MON MAY 4 2015
STORMS HAVE BEEN A BIT SLOWER TO EXIT CENTRAL KS THAN ANTICIPATED...
BUT SHORT TERM MODELS ARE STILL ADAMANT THAT PRECIPITATION WILL
PUSH NORTH EARLY IN THE FORECAST. LATEST RAP IS A BIT DIFFERENT
KEEPING OUTFLOW/SURFACE BOUNDARY QUASISTATIONARY BUT STILL MOVING
PRECIPITATION TO THE NORTH. THIS SEEMS PLAUSIBLE BASED ON RADAR
TRENDS. FOCUS THEN TURNS TO TIMING OF CONVECTION TOMORROW.
OUTFLOW BOUNDARY MIGHT FOCUS INITIAL UPDRAFTS...BUT INABILITY TO
ACCURATELY FORECAST ITS LOCATION PRECLUDES AN EARLY MENTION IN
TAFS. WILL STICK WITH HIGHER PROBABILITY OF JUST PRIOR TO 0000
UTC AT KRSL/KHUT AND AFTER 0000 UTC AT KSLN/KHUT. HAVE KEPT KCNU
DRY FOR NOW...BUT ROGUE CELL COULD AFFECT KCNU DURING PK HEATING.
-HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 77 62 77 65 / 10 90 60 40
HUTCHINSON 76 61 76 63 / 10 90 50 50
NEWTON 74 60 75 62 / 10 90 60 40
ELDORADO 79 62 75 64 / 10 90 70 40
WINFIELD-KWLD 77 63 76 65 / 10 90 60 40
RUSSELL 75 59 78 60 / 40 80 50 50
GREAT BEND 73 59 78 62 / 50 80 40 40
SALINA 78 61 76 65 / 10 90 50 50
MCPHERSON 75 61 75 63 / 10 90 50 50
COFFEYVILLE 78 63 75 65 / 10 80 80 40
CHANUTE 79 62 75 64 / 10 70 80 30
IOLA 78 62 75 64 / 10 70 80 30
PARSONS-KPPF 79 63 75 65 / 10 70 80 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1149 PM MDT MON MAY 4 2015
.UPDATE...
ISSUED AT 1023 PM MDT MON MAY 4 2015
UPDATED FORECAST TO REFLECT THE DIMINISHED CHANCES FOR RAINFALL
FOR THE WESTERN HALF OR SO OF THE AREA THROUGH THE REST OF THE
NIGHT. WAS VERY CONFIDENT EARLIER THAT THE LINE OF STORMS WOULD
MOVE ACROSS THE ENTIRE AREA...WITH SOME WEAKENING OVER THE EAST
PART OF THE AREA. HOWEVER OVER THE LAST HOUR OR SO THE LINE OF
STORMS HAS ALMOST COMPLETELY DISSIPATED.
LOOKING AT RUC THETA-E AT 850MB...THERE IS DRIER AIR OVER THE
WESTERN HALF OF THE AREA. AM THINKING THIS IS WHY THE STORMS DIED
OVER THE WEST INSTEAD OF THE EAST WHICH HAS HIGHER THETA-E AND
BETTER CAPE.
LOOKING SOUTHWARD NUMEROUS SHOWERS AND SOME T-STORMS CONTINUE
TO MOVE UP FROM THE SOUTH IN THE HIGHER THETA-E AIR. LIFT DOES
DECLINE OVER THE EAST OVERNIGHT SO HAVE RAINFALL CHANCES TRENDING
ACCORDINGLY. DOES LOOK LIKE THE EAST HALF WILL HAVE A MUCH BETTER
CHANCE FOR RAINFALL DUE TO THE HIGHER THETA-E AIR PRESENT.
MEANWHILE PATCHY FOG IS EXPECTED OVER THE NORTHERN HALF OR SO OF
THE AREA OVERNIGHT INTO TUESDAY MORNING. LOOKS LIKE THE FOG WILL
BE NORTH OF THE SLOWLY ADVANCING SURFACE BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 220 PM MDT MON MAY 4 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
DEEPENING TROUGH OVER SOUTHERN CALIFORNIA WITH SW FLOW FROM THE GULF
OF ALASKA AND ACROSS THE CENTRAL/HIGH PLAINS. MOIST PLUME EXTENDS
FROM THE GREAT BASIN ACROSS THE OHIO RIVER VALLEY WITH ADDITIONAL
MOISTURE FEEDING IN THE PLAINS FROM THE GULF OF MEXICO. AT THE
SURFACE A STATIONARY FRONT EXTENDS FROM NORTHEAST KANSAS TO
SOUTHEAST COLORADO AND LIES JUST SOUTHEAST OF OUR CWA...WITH
BAROCLINIC ZONE EXTENDING NORTH INTO THE SE PART OF OUR CWA.
THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THIS FRONTAL ZONE
TOWARDS THE SOUTHEAST PART OF OUR CWA.
THIS AFTERNOON-EVENING...ALONG THIS FRONTAL ZONE ANALYSIS INDICATES
ML CAPE VALUES RANGING FROM 1500 J/KG IN THE WARM SECTOR TO 500
J/KG IN OUR SE CWA. BULK SHEER IS APPROXIMATELY 30-35KT...SO
DEPENDING ON POSITION OF FRONT (CURRENTLY ADVERTISED TO SLIDE NORTH
INTO OUR SOUTHEAST)...THERE IS THE POTENTIAL FOR A FEW STRONGER
THUNDERSTORMS...POSSIBLY SEVERE WITH LARGE HAIL/DAMAGING WINDS MAIN
THREAT. IF FRONT WERE TO LIFT NORTH AS WARM FRONT WE COULD SEE
BETTER SB/ML CAPE AND THE POSSIBILITY FOR A FEW MORE ORGANIZED CELLS
IN THE SOUTHEAST. ANALYSIS ALSO INDICATES PWAT VALUES ALREADY IN
EXCESS OF 1" OVER OUR EAST. STORM MOTIONS WILL BE ROUGHLY
TANGENTIAL/PARALLEL THIS AFTERNOON BECOMING PERPENDICULAR TO FRONTAL
ZONE THIS EVENING. AS THIS TRANSITION OCCURS THERE IS THE
FOR BACKBUILDING OR TRAINING AS VERY MOIST/UNSTABLE AIR IN THE WARM
SECTOR FEEDS NORTH. THERE COULD BE A THREAT FOR FLASH FLOODING IF
THIS SCENARIO PLAYS OUT. EITHER WAY WITH VERY MOIST AIR MASS AND
INCREASING ELEVATED INSTABILITY...THUNDERSTORMS COULD BE VERY
EFFICIENT RAINFALL PRODUCERS.
TONIGHT-TUESDAY...UPSTREAM AREAS OF MID LEVEL VORTICITY WILL ROTATE
INTO THE CWA WITH INCREASING LIFT LATE THIS EVENING INTO THE
OVERNIGHT. AS TROUGH CONTINUES TO DEEPEN OVER THE SW US AND MOVE
EAST WE WILL CONTINUE TO SEE VERY GOOD FORCING/MOISTURE ROTATES
THROUGH THE REGION. LARGE SCALE Q VECTOR FIELDS INDICATED FORCING
INCREASING THROUGH THE NIGHT AND OMEGA/MOISTURE
CONVERGENCE FIELDS SHOW SUPPORT FOR INCREASING COVERAGE/COMPLEX OF
SHOWERS THUNDERSTORMS. ELEVATED INSTABILITY TRANSITIONS NORTHWARD
AND WEAKENS...HOWEVER THERE IS ENOUGH TO KEEP THUNDER MENTION IN
PLACE THROUGH TUESDAY AFTERNOON. WHILE GUIDANCE IS IN AGREEMENT ON
GENERAL LARGE SCALE PATTERN THE MAIN DIFFERENCES ARE ON TIMING OF
POTENTIAL PERIODS OF HEAVIER PRECIP...WITH BEST PRECIP SIGNAL AND
MOISTURE PROFILES OVERLAPPING TUESDAY MORNING THROUGH TUESDAY
AFTERNOON ACROSS THE WESTERN 2/3 OF THE CWA (THOUGH ECMWF MIGHT BE A
LITTLE EAST). THERE WILL BE MODERATE/ELEVATED INSTABILITY IN PLACE
THROUGH THE DAY TUESDAY...SO STRONG TO SEVERE THUNDERSTORMS WILL
STILL BE POSSIBLE AGAIN...THOUGH SEVERE POTENTIAL MIGHT NOT BE AS
GOOD AS TODAY WITH WIDESPREAD SHOWERS AND STRATUS LIMITING SURFACE
BASED PARCELS AND ANY ACTIVITY LIKELY EMBEDDED WITH OTHER SHOWER
CLUSTERS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 124 PM MDT MON MAY 4 2015
MAIN TROUGH AXIS WILL LIFT NORTHEAST ACROSS THE AREA TUESDAY NIGHT
WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUING. AFTER
MIDNIGHT...GENERAL TREND WILL BE FOR A WEST TO EAST END OF THE
PRECIPITATION AS DRY SLOT WORKS IN BEHIND THE TROUGH. AFTER A LULL
WEDNESDAY MORNING...WRAPAROUND PRECIPITATION WILL MOVE IN FROM
COLORADO WEDNESDAY AFTERNOON AND BECOME WIDESPREAD WEDNESDAY
NIGHT. A COLD FRONT WILL ALSO MOVE THROUGH WEDNESDAY NIGHT WHICH
WILL PROVIDE A FOCUS FOR THUNDERSTORMS IN THE EVENING...BUT THE
POST FRONTAL ENVIRONMENT HAS ONLY LIMITED ELEVATED INSTABILITY AND
EXPECT ONLY ISOLATED THUNDERSTORMS THROUGH THURSDAY MORNING.
HOWEVER BY THURSDAY AFTERNOON SBCAPE INCREASES ONCE AGAIN AND A
COMBINATION OF MOIST LOW LEVEL UPSLOPE AND ANOTHER SHORTWAVE
TROUGH IN THE SOUTHWESTERLY FLOW ALOFT WILL RESULT IN THUNDERSTORM
DEVELOPMENT IN EASTERN COLORADO WHICH WILL MOVE INTO NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA THURSDAY EVENING. SEVERE THREAT WILL
DEPEND ON HOW MUCH INSTABILITY CAN DEVELOP AFTER A CLOUDY
MORNING...BUT DEEP LAYER SHEAR WOULD BE SUPPORTIVE OF ORGANIZED
UPDRAFTS THROUGH EARLY EVENING BEFORE BOUNDARY LAYER DECOUPLES
WITH NOCTURNAL COOLING.
OVERALL PATTERN CHANGES LITTLE ON FRIDAY ALTHOUGH MODELS SHOWING
ONLY MINIMAL SBCAPE AVAILABLE SO SEVERE THREAT MAY NOT BE AS
GREAT. ANOTHER STRONG UPPER LOW WILL KICK OUT OF THE DESERT
SOUTHWEST ON SATURDAY WITH A NEGATIVE TILT AND PROVIDE THE
SYNOPTIC SCALE FORCING FOR THUNDERSTORMS. THE PATTERN SUGGESTS A
SEVERE THREAT WITH MODELS SHOWING DEEP LAYER SHEAR OF OVER 50KTS
AND SUFFICIENT INSTABILITY FOR SUPERCELLS. IF CURRENT TIMING
TRENDS CONTINUE WOULD EXPECT TO SEE A DRY SLOT SATURDAY NIGHT
FOLLOWED BY WRAPAROUND PRECIPITATION CHANCES ON SUNDAY.
THE PATTERN FINALLY CHANGES BY EARLY NEXT WEEK WITH SUBTLE
SHORTWAVE RIDGING IN A ZONAL FLOW WHICH WOULD TRANSLATE TO DRY
CONDITIONS AND SEASONABLE TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM MDT MON MAY 4 2015
MVFR TO IFR CONDITIONS FORECAST FOR THE 6Z TAFS. EXPECT CONDITIONS
AT KMCK TO REMAIN UNCHANGED UNTIL CLOSE TO MID MORNING. MEANWHILE
AT KGLD CEILINGS HAVE FLUCTUATED FROM IFR TO VFR OVER THE PAST
HOUR OR SO. EXPECT IFR CEILING IN THE NEXT HOUR. FOR BOTH SITES CEILINGS
SHOULD INCREASE TO MVFR DURING THE LATE MORNING...THEN FALL TO IFR
AGAIN IN THE EARLY EVENING.
THE SHOWERS SHOULD REMAIN SOUTH OF KMCK FOR THE REST OF THE NIGHT
AND THROUGH MOST OF THE DAY. DURING THE LATE AFTERNOON THERE MAY
BE A SHORT WINDOW FOR STORMS TO MOVE NEAR THE SITE...BUT WILL
WAIT FOR LATER TAFS TO ADDRESS THIS.
KGLD SHOULD REMAIN RAIN FREE TONIGHT. DURING THE LATE MORNING AND
THROUGH THE AFTERNOON RAIN CHANCES WILL INCREASE...WITH THE BEST
CHANCES DURING THE MID TO LATE AFTERNOON. BY EARLY EVENING THE
CHANCES FOR RAIN WILL BEGIN TO DECLINE.
EXPECT VISIBILITY REDUCTION FOR BOTH SITES DURING THE
OVERNIGHT HOURS. VISIBILITY SHOULD IMPROVE DURING THE MID TO LATE
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS WICHITA KS
1153 PM CDT MON MAY 4 2015
...UPDATED FOR 06Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 839 PM CDT MON MAY 4 2015
CURRENT THINKING BASED ON QUICK LOOK AT 00Z DATA AND RECENT HI RES
MODELS SUG STORMS MAY HANG ON A BIT LONGER...BUT SHOULD DIMINISH
SHORTLY AFTER MIDNIGHT. APPEARS THAT 30-35KT 850MB JET IS
IMPINGING ON THE 850MB BOUNDARY THAT EXTENDS FROM NORTHEAST TO
SOUTHWEST ACROSS THE STATE. SEVERE THUNDERSTORM WATCH WILL EXPIRE
ON SCHEDULE AS STORMS HAVE CONTINUED TO SHOW A SLOW WEAKENING
TREND.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 312 PM CDT MON MAY 4 2015
DEEP MOIST CONVECTION IS EXPECTED TO DEVELOP THIS AFTERNOON AND
EVENING ALONG A STALLED FRONTAL BOUNDARY ACROSS CENTRAL KS WHERE THE
HIGHEST POPS WILL BE MAINTAINED. OTHER MORE ISOLATED DIURNALLY
DRIVEN ACTIVITY WILL BE POSSIBLE THROUGH EARLY EVENING ACROSS
SOUTHERN KANSAS. SOME OF THE HIGHER RESOLUTION MODEL GUIDANCE IS
SUGGESTING THAT OUTFLOW WILL FORCE THE BOUNDARY FURTHER SOUTH AND
TRENDED POPS UP SLIGHTLY ACROSS PORTIONS OF SOUTH CENTRAL AND
SOUTHEAST KS TO ACCOUNT FOR THIS SCENARIO. BY 07-09Z THE WARM
FRONT IS EXPECTED TO LIFT NORTH BRINGING AN END TO ANY LINGERING
PRECIPITATION.
MUCH OF TUESDAY MAY BE DRY BUT MAINTAINED MID POPS ACROSS PORTIONS
OF CENTRAL AND SOUTH CENTRAL KANSAS AS ANY ACTIVITY DEVELOPING
ACROSS SW KS MAY DRIFT NORTHEAST ACROSS THE AREA LATER IN THE DAY
AND THE AIRMASS IS PROGGED TO REMAIN WEAKLY CAPPED. BETTER CHANCES
FOR MORE WIDESPREAD PRECIPITATION WILL ARRIVE LATE TUE NIGHT INTO
EARLY WED AS A VIGOROUS SHORTWAVE TROUGH EMERGES OVER THE CENTRAL
HIGH PLAINS. THIS WAS HANDLED WELL IN THE PREVIOUS FORECAST AND
THE PRIMARY CHANGE WAS TO SLOW POPS WITH THE HIGHEST PROBABILITIES
ARRIVING AFTER 06Z ACROSS THE FORECAST AREA.
WED-THU...THE DEEP LAYER SHEAR IS PROGGED TO INCREASE ON WED AS THE
FOCUS FOR DEEP MOIST CONVECTION IS EXPECTED TO DEVELOP ALONG HWY 281
ALONG A DRYLINE. MAINTAINED MID POPS WED NIGHT INTO THU AS THE
AIRMASS IS PROGGED TO REMAIN UNSTABLE WITH A CONTINUATION OF
SOUTHWEST MID/UPPER FLOW. TIMING ANY SHORTWAVE TROUGHS LIFTING OUT
OF THE SOUTHWEST BECOMES CHALLENGING AT THIS POINT.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 312 PM CDT MON MAY 4 2015
A MID/UPPER TROUGH OVER THE SOUTHWEST AT THE BEGINNING OF
THE PERIOD IS PROGGED TO MOVE EAST/NORTHEAST INTO THE SOUTHERN
AND CENTRAL ROCKIES OVER THE WEEKEND. RICH MOISTURE IS PROGGED TO
REMAIN ENTRENCHED ACROSS THE SOUTHERN AND CENTRAL PLAINS STATES
WHERE MULTIPLE ROUNDS OF DEEP MOIST CONVECTION ARE EXPECTED LATE
IN THE WEEK AND INTO THE WEEKEND. MAINTAINED MID POPS THROUGH MUCH
OF THE PERIOD WITH SEASONABLY MILD TEMPERATURES ANTICIPATED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1150 PM CDT MON MAY 4 2015
STORMS HAVE BEEN A BIT SLOWER TO EXIT CENTRAL KS THAN ANTICIPATED...
BUT SHORT TERM MODELS ARE STILL ADAMANT THAT PRECIPITATION WILL
PUSH NORTH EARLY IN THE FORECAST. LATEST RAP IS A BIT DIFFERENT
KEEPING OUTFLOW/SURFACE BOUNDARY QUASISTATIONARY BUT STILL MOVING
PRECIPITATION TO THE NORTH. THIS SEEMS PLAUSIBLE BASED ON RADAR
TRENDS. FOCUS THEN TURNS TO TIMING OF CONVECTION TOMORROW.
OUTFLOW BOUNDARY MIGHT FOCUS INITIAL UPDRAFTS...BUT INABILITY TO
ACCURATELY FORECAST ITS LOCATION PRECLUDES AN EARLY MENTION IN
TAFS. WILL STICK WITH HIGHER PROBABILITY OF JUST PRIOR TO 0000
UTC AT KRSL/KHUT AND AFTER 0000 UTC AT KSLN/KHUT. HAVE KEPT KCNU
DRY FOR NOW...BUT ROGUE CELL COULD AFFECT KCNU DURING PK HEATING.
-HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 62 77 63 77 / 20 20 90 60
HUTCHINSON 62 76 61 77 / 40 20 90 50
NEWTON 61 74 59 73 / 20 10 90 60
ELDORADO 61 79 63 76 / 10 10 90 70
WINFIELD-KWLD 61 77 62 76 / 10 20 90 60
RUSSELL 59 75 59 78 / 70 50 80 50
GREAT BEND 59 73 59 78 / 90 60 80 40
SALINA 61 78 61 77 / 90 20 90 50
MCPHERSON 61 75 60 74 / 50 20 90 50
COFFEYVILLE 59 78 63 74 / 10 20 80 80
CHANUTE 60 79 63 75 / 10 10 70 80
IOLA 60 78 63 73 / 10 10 70 80
PARSONS-KPPF 59 79 63 75 / 10 20 70 80
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1030 PM MDT MON MAY 4 2015
.UPDATE...
ISSUED AT 1023 PM MDT MON MAY 4 2015
UPDATED FORECAST TO REFLECT THE DIMINISHED CHANCES FOR RAINFALL
FOR THE WESTERN HALF OR SO OF THE AREA THROUGH THE REST OF THE
NIGHT. WAS VERY CONFIDENT EARLIER THAT THE LINE OF STORMS WOULD
MOVE ACROSS THE ENTIRE AREA...WITH SOME WEAKENING OVER THE EAST
PART OF THE AREA. HOWEVER OVER THE LAST HOUR OR SO THE LINE OF
STORMS HAS ALMOST COMPLETELY DISSIPATED.
LOOKING AT RUC THETA-E AT 850MB...THERE IS DRIER AIR OVER THE
WESTERN HALF OF THE AREA. AM THINKING THIS IS WHY THE STORMS DIED
OVER THE WEST INSTEAD OF THE EAST WHICH HAS HIGHER THETA-E AND
BETTER CAPE.
LOOKING SOUTHWARD NUMEROUS SHOWERS AND SOME T-STORMS CONTINUE
TO MOVE UP FROM THE SOUTH IN THE HIGHER THETA-E AIR. LIFT DOES
DECLINE OVER THE EAST OVERNIGHT SO HAVE RAINFALL CHANCES TRENDING
ACCORDINGLY. DOES LOOK LIKE THE EAST HALF WILL HAVE A MUCH BETTER
CHANCE FOR RAINFALL DUE TO THE HIGHER THETA-E AIR PRESENT.
MEANWHILE PATCHY FOG IS EXPECTED OVER THE NORTHERN HALF OR SO OF
THE AREA OVERNIGHT INTO TUESDAY MORNING. LOOKS LIKE THE FOG WILL
BE NORTH OF THE SLOWLY ADVANCING SURFACE BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 220 PM MDT MON MAY 4 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
DEEPENING TROUGH OVER SOUTHERN CALIFORNIA WITH SW FLOW FROM THE GULF
OF ALASKA AND ACROSS THE CENTRAL/HIGH PLAINS. MOIST PLUME EXTENDS
FROM THE GREAT BASIN ACROSS THE OHIO RIVER VALLEY WITH ADDITIONAL
MOISTURE FEEDING IN THE PLAINS FROM THE GULF OF MEXICO. AT THE
SURFACE A STATIONARY FRONT EXTENDS FROM NORTHEAST KANSAS TO
SOUTHEAST COLORADO AND LIES JUST SOUTHEAST OF OUR CWA...WITH
BAROCLINIC ZONE EXTENDING NORTH INTO THE SE PART OF OUR CWA.
THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THIS FRONTAL ZONE
TOWARDS THE SOUTHEAST PART OF OUR CWA.
THIS AFTERNOON-EVENING...ALONG THIS FRONTAL ZONE ANALYSIS INDICATES
ML CAPE VALUES RANGING FROM 1500 J/KG IN THE WARM SECTOR TO 500
J/KG IN OUR SE CWA. BULK SHEER IS APPROXIMATELY 30-35KT...SO
DEPENDING ON POSITION OF FRONT (CURRENTLY ADVERTISED TO SLIDE NORTH
INTO OUR SOUTHEAST)...THERE IS THE POTENTIAL FOR A FEW STRONGER
THUNDERSTORMS...POSSIBLY SEVERE WITH LARGE HAIL/DAMAGING WINDS MAIN
THREAT. IF FRONT WERE TO LIFT NORTH AS WARM FRONT WE COULD SEE
BETTER SB/ML CAPE AND THE POSSIBILITY FOR A FEW MORE ORGANIZED CELLS
IN THE SOUTHEAST. ANALYSIS ALSO INDICATES PWAT VALUES ALREADY IN
EXCESS OF 1" OVER OUR EAST. STORM MOTIONS WILL BE ROUGHLY
TANGENTIAL/PARALLEL THIS AFTERNOON BECOMING PERPENDICULAR TO FRONTAL
ZONE THIS EVENING. AS THIS TRANSITION OCCURS THERE IS THE
FOR BACKBUILDING OR TRAINING AS VERY MOIST/UNSTABLE AIR IN THE WARM
SECTOR FEEDS NORTH. THERE COULD BE A THREAT FOR FLASH FLOODING IF
THIS SCENARIO PLAYS OUT. EITHER WAY WITH VERY MOIST AIR MASS AND
INCREASING ELEVATED INSTABILITY...THUNDERSTORMS COULD BE VERY
EFFICIENT RAINFALL PRODUCERS.
TONIGHT-TUESDAY...UPSTREAM AREAS OF MID LEVEL VORTICITY WILL ROTATE
INTO THE CWA WITH INCREASING LIFT LATE THIS EVENING INTO THE
OVERNIGHT. AS TROUGH CONTINUES TO DEEPEN OVER THE SW US AND MOVE
EAST WE WILL CONTINUE TO SEE VERY GOOD FORCING/MOISTURE ROTATES
THROUGH THE REGION. LARGE SCALE Q VECTOR FIELDS INDICATED FORCING
INCREASING THROUGH THE NIGHT AND OMEGA/MOISTURE
CONVERGENCE FIELDS SHOW SUPPORT FOR INCREASING COVERAGE/COMPLEX OF
SHOWERS THUNDERSTORMS. ELEVATED INSTABILITY TRANSITIONS NORTHWARD
AND WEAKENS...HOWEVER THERE IS ENOUGH TO KEEP THUNDER MENTION IN
PLACE THROUGH TUESDAY AFTERNOON. WHILE GUIDANCE IS IN AGREEMENT ON
GENERAL LARGE SCALE PATTERN THE MAIN DIFFERENCES ARE ON TIMING OF
POTENTIAL PERIODS OF HEAVIER PRECIP...WITH BEST PRECIP SIGNAL AND
MOISTURE PROFILES OVERLAPPING TUESDAY MORNING THROUGH TUESDAY
AFTERNOON ACROSS THE WESTERN 2/3 OF THE CWA (THOUGH ECMWF MIGHT BE A
LITTLE EAST). THERE WILL BE MODERATE/ELEVATED INSTABILITY IN PLACE
THROUGH THE DAY TUESDAY...SO STRONG TO SEVERE THUNDERSTORMS WILL
STILL BE POSSIBLE AGAIN...THOUGH SEVERE POTENTIAL MIGHT NOT BE AS
GOOD AS TODAY WITH WIDESPREAD SHOWERS AND STRATUS LIMITING SURFACE
BASED PARCELS AND ANY ACTIVITY LIKELY EMBEDDED WITH OTHER SHOWER
CLUSTERS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 124 PM MDT MON MAY 4 2015
MAIN TROUGH AXIS WILL LIFT NORTHEAST ACROSS THE AREA TUESDAY NIGHT
WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUING. AFTER
MIDNIGHT...GENERAL TREND WILL BE FOR A WEST TO EAST END OF THE
PRECIPITATION AS DRY SLOT WORKS IN BEHIND THE TROUGH. AFTER A LULL
WEDNESDAY MORNING...WRAPAROUND PRECIPITATION WILL MOVE IN FROM
COLORADO WEDNESDAY AFTERNOON AND BECOME WIDESPREAD WEDNESDAY
NIGHT. A COLD FRONT WILL ALSO MOVE THROUGH WEDNESDAY NIGHT WHICH
WILL PROVIDE A FOCUS FOR THUNDERSTORMS IN THE EVENING...BUT THE
POST FRONTAL ENVIRONMENT HAS ONLY LIMITED ELEVATED INSTABILITY AND
EXPECT ONLY ISOLATED THUNDERSTORMS THROUGH THURSDAY MORNING.
HOWEVER BY THURSDAY AFTERNOON SBCAPE INCREASES ONCE AGAIN AND A
COMBINATION OF MOIST LOW LEVEL UPSLOPE AND ANOTHER SHORTWAVE
TROUGH IN THE SOUTHWESTERLY FLOW ALOFT WILL RESULT IN THUNDERSTORM
DEVELOPMENT IN EASTERN COLORADO WHICH WILL MOVE INTO NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA THURSDAY EVENING. SEVERE THREAT WILL
DEPEND ON HOW MUCH INSTABILITY CAN DEVELOP AFTER A CLOUDY
MORNING...BUT DEEP LAYER SHEAR WOULD BE SUPPORTIVE OF ORGANIZED
UPDRAFTS THROUGH EARLY EVENING BEFORE BOUNDARY LAYER DECOUPLES
WITH NOCTURNAL COOLING.
OVERALL PATTERN CHANGES LITTLE ON FRIDAY ALTHOUGH MODELS SHOWING
ONLY MINIMAL SBCAPE AVAILABLE SO SEVERE THREAT MAY NOT BE AS
GREAT. ANOTHER STRONG UPPER LOW WILL KICK OUT OF THE DESERT
SOUTHWEST ON SATURDAY WITH A NEGATIVE TILT AND PROVIDE THE
SYNOPTIC SCALE FORCING FOR THUNDERSTORMS. THE PATTERN SUGGESTS A
SEVERE THREAT WITH MODELS SHOWING DEEP LAYER SHEAR OF OVER 50KTS
AND SUFFICIENT INSTABILITY FOR SUPERCELLS. IF CURRENT TIMING
TRENDS CONTINUE WOULD EXPECT TO SEE A DRY SLOT SATURDAY NIGHT
FOLLOWED BY WRAPAROUND PRECIPITATION CHANCES ON SUNDAY.
THE PATTERN FINALLY CHANGES BY EARLY NEXT WEEK WITH SUBTLE
SHORTWAVE RIDGING IN A ZONAL FLOW WHICH WOULD TRANSLATE TO DRY
CONDITIONS AND SEASONABLE TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 555 PM MDT MON MAY 4 2015
VFR TO LIFR CONDITIONS FOR THE TAFS. CHALLENGING SET OF TAFS DUE
TO TIMING OF THE DIFFERENT WAVES OF RAINFALL...THE CEILING
HEIGHTS AND VISIBILITY. IN GENERAL LOOKS LIKE KGLD WILL HAVE A
BETTER CHANCE FOR RECEIVING RAINFALL THAN KMCK...ESPECIALLY
PROLONGED RAINFALL. BASED TIMING OF THE STORMS FOR BOTH SITES BY
TRACKING THE SPEED OF THE CURRENT STORMS. IF STORM MOVEMENT
CHANGES THAT WILL AFFECT THE TIMING IN THE TAFS. BASED ON
OBSERVATIONS AND MODEL SOUNDINGS...LOOKS LIKE THE SECOND WAVE OF
STORMS WILL CAUSE CEILINGS TO FALL. OVERNIGHT VISIBILITIES WILL
DECLINE SOME BUT THEN IMPROVE BY MID MORNING. HAVE VC FOR KMCK DUE
TO UNCERTAINTY THERE WILL STILL BE RAINFALL AT THE SITE DURING THE
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1149 PM CDT MON MAY 4 2015
.AVIATION...A FEW SHOWERS WILL AFFECT KLCH AND KBPT THROUGH THE
NEXT FEW HOURS AND THESE SHOWERS MAY LINGER THROUGH THE NIGHT. A
FEW TSRA MAY BE IN VICINITY OF THESE TERMINAL TOMORROW, HOWEVER
COVERAGE WILL DECREASE AS SUNSET APPROACHES. WITH ANY SHOWER MVFR
CEILINGS AND VIS MAY OCCUR. LIGHT SE WINDS WILL PREVAIL TONIGHT
WITH WINDS BECOMING GUSTY BY MID MORNING TUE.
&&
.PREV DISCUSSION... /ISSUED 1036 PM CDT MON MAY 4 2015/
UPDATE...
WEAK INVERTED TROF/ELY WAVE CONTINUES ITS TREK WEST...CURRENTLY
LOCATED ROUGHLY SOUTH OF THE CAMERON/VERMILION PARISH LINE. LATEST
KLCH RADAR SHOWS ISLTD SHOWERS OVER THE COASTAL WATERS EAST OF
CAMERON ALONG WITH A NARROW BAND MOVING WEST ACRS THE SABINE
RIVER. SHOWER CHCS SHOULD DIMINISH ACRS ERN PORTIONS OF THE AREA
TONIGHT...WITH A SLT TO LOW END CHC EXPECTED MAINLY ALONG AND WEST
OF A LINE FROM LEESVILLE TO LAKE CHARLES. ADJUSTED POP/WX GRIDS
SLIGHTLY TO INCORPORATE RECENT HRRR GUIDANCE. ALSO TWEAKED HOURLY
WINDS AS WELL AS TEMP AND DEWPOINT GRIDS...ACCOUNTING FOR RECENT
OBSERVATIONS. REMAINDER OF FCST IS IN OTHERWISE DECENT SHAPE AND
UPDATES HAVE BEEN SENT. 24
PREV DISCUSSION... /ISSUED 706 PM CDT MON MAY 4 2015/
DISCUSSION...
05/00Z TAF ISSUANCE.
AVIATION...
ISLTD SHRA/TSRA AND BKN VFR CIGS ACCOMPANY A WEAK INVERTED TROF
CROSSING SRN LA AND THE NRN GULF OF MEXICO. THIS TROF WILL CROSS
THE REGION TONIGHT INTO TUESDAY MORNING...WITH THE MAIN AXIS OF
CLOUDS/SHRA SHIFTING WEST. ACTIVITY EXPECTED TO DIMINISH THIS
EVENING THEN INCREASE LATE TONIGHT...MAINLY NEAR LCH/BPT...AS
SHOWERS OR STORMS MOVE INLAND OFF THE GULF. OTHERWISE...EXPECT VFR
CONDITIONS TO PREVAIL THROUGH THE PERIOD AT LFT/ARA/AEX WITH MVFR
CIGS DEVELOPING AT LCH/BPT AFTER MIDNIGHT. SELY WINDS 5-10 KT
TONIGHT WILL STRENGTHEN 10-15 KT TUESDAY MORNING WITH GUSTS TO 25
KT AT TIMES DURING THE DAY. 24
PREV DISCUSSION... /ISSUED 350 PM CDT MON MAY 4 2015/
DISCUSSION...
NORTH-SOUTH ORIENTED INVERTED SFC TROF...OR EASTERLY
WAVE...STRETCHES ROUGHLY ALONG THE ATCHAFALAYA RIVER AND ON OUT
INTO THE CENTRAL GULF OF MEXICO AS OF 20Z. THIS FEATURE HAS
ASSISTED WITH THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER PARTS OF SOUTH AND EAST CENTRAL LOUISIANA THIS
AFTERNOON. THE WAVE IS PROGGED TO CONTINUE WWD TONIGHT...WITH A
GENERAL DECREASE IN BOTH COVERAGE AND INTENSITY OF CONVECTION EXPECTED
THIS EVENING WITH THE LOSS OF DIURNAL INSTABILITY. AN UPTICK IS
LIKELY OVER THE GULF WATERS AFTER MIDNIGHT AND TWD THE EARLY
MORNING HRS WITH THE MARINE DMAX...WITH THE NWD CELL MOTION
LEADING TO AT LEAST SOME ACTIVITY SPREADING INLAND.
POPS WERE RAISED OVER EAST TX TOMORROW AS THE WAVE ENTERS A
REGION OF INCREASED UPPER DIVERGENCE AND DEEPER MSTR...WITH
COVERAGE EXPECTED TO EXCEED THAT OBSERVED TODAY.
PATTERN THEREAFTER MARKED BY A SW TO NE RIDGE AXIS OVERHEAD...WITH
A MOIST SOUTHERLY LOW LEVEL FLOW AND SUBTLE IMPULSES EJECTING
AHEAD OF A DIGGING WRN CONUS TROF. LOW END POPS...WITH A GRADIENT
THAT GENERALLY DECREASES FROM WEST TO EAST...ALONG WITH SEASONAL
HIGHS AND ABOVE NORMAL LOWS WILL RESULT.
THE TROF IS PROGGED TO EDGE EASTWARD OVER THE WEEKEND...SLOWLY
ERODING THE RIDGE ALOFT...THEN FINALLY LIFTING OUT INTO THE
CENTRAL CONUS AND FLATTENING IT OUT EARLY NEXT WEEK. GLOBAL MODELS
ALSO PROG A FRONTAL BOUNDARY INTO THE REGION ON SUN NIGHT INTO
MON.
13
MARINE...
WINDS AND SEAS WILL INCREASE TONIGHT INTO TUESDAY AS THE PRESSURE
GRADIENT TIGHTENS WHILE AN EASTERLY WAVE MOVES WEST ACROSS THE
NORTHERN GULF. ELEVATED WINDS AND SEAS WILL CONTINUE INTO
TUESDAY NIGHT...SUBSIDING ON WEDNESDAY AS THE PRESSURE GRADIENT
RELAXES. THE CHANCE OF SHOWERS WILL INCREASE AS THE EASTERLY WAVE
MOVES ACROSS THE REGION TODAY AND TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 63 81 62 83 / 10 10 10 10
LCH 67 80 66 82 / 30 30 10 20
LFT 65 81 64 83 / 10 10 10 20
BPT 68 80 69 82 / 40 50 10 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR GMZ452-455-470-
472-475.
SMALL CRAFT EXERCISE CAUTION THROUGH LATE TUESDAY NIGHT FOR
GMZ450.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
504 AM EDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT TUE MAY 5 2015
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT WRLY MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND A
RIDGE FROM THE SE CONUS INTO THE CNTRL PLAINS. WITH A SFC RIDGE
EXTENDING FROM NW ONTARIO THROUGH THE NRN LAKES...LIGHT WINDS AND
CLEAR SKIES OVER UPPER MI HAS ALLOWED TEMPS TO DROP OFF INTO THE MID
AND UPPER 30S WITH SEVERAL INLAND COLD SPOTS IN THE UPPER 20S TO
AROUND 30. CLOUDS AND
TODAY...EXPECT THAT HIGH PRES WILL CONTINUE TO DOMINATE AS THE
CLOUDS AND PCPN ASSOCIATED WITH A FRONTAL BOUNDARY FROM SRN IA INTO
NRN IL REMAIN WELL TO THE SOUTH. MIXING TO 5K FT WITH 850 MB TEMPS
FCST IN THE 6C TO 8C RANGE WILL SUPPORT HIGHS IN THE UPPER 60S TO
AROUND 70...EXCEPT ALONG THE GREAT LAKES WHERE READING WILL REMAIN
IN THE UPPER 50S AND LOWER 60S. SIMILAR TO MONDAY...AFTERNOON
DEWPOINTS WILL DROP INTO THE LOWER 20S WITH RH VALUES FROM 15 TO 20
PCT. HOWEVER...WINDS WILL REMAIN LIGHT...AOB 10 MPH.
TONIGHT...AS THE HIGH SHIFTS OFF TO THE EAST AND AND 850 MB WARM
FRONT APPROACHES FROM THE SOUTH...EXPECT INCREASING CLOUDS OVERNIGHT.
THIS WILL KEEP TEMPS FROM FALLING OFF AS MUCH WITH MIN READINGS IN
THE UPPER 30S TO AROUND 40. WITH THE VERY DRY AIRMASS IN PLACE...THE
SLOWER END OF GUIDANCE WAS FAVORED WITH THE PCPN ADVANCING FROM THE
SOUTH. SO...NO PCPN MENTION WAS INCLUDED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE MAY 5 2015
ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEK AMIDST SMALL
CHANCES OF PRECIP WEDNESDAY...AND A CHANCE OF SHOWERS AND STORMS
LATE THURSDAY INTO FRIDAY. MUCH COOLER WEATHER WILL THEN RETURN FOR
THE WEEKEND.
WEDNESDAY AND WEDNESDAY NIGHT...A STOUT MID-LEVEL RIDGE WILL BE
ENTERING THE WESTERN CWA AT 12Z WED AS AN ASSOCIATED SFC HIGH OVER
GEORGIAN BAY SHIFTS SOUTHEASTWARD. MEANWHILE...A SHORTWAVE TROUGH
DRIFTING NE FROM THE SOUTHERN ROCKIES WILL BEGIN TO CONSOLIDATE A
BROAD SFC TROUGH ALONG THE ENTIRE U.S. ROCKIES. MODELS CONTINUE
THEIR TWO-DAY TREND IN LOWERING QPF ALONG AN 850 HPA WARM FRONT
ACROSS THE SW CWA WED MORNING. IN FACT...MOST OF THE HIGHER-RES
GUIDANCE SUITE SHOWS VERY LITTLE PRECIP DURING THE DAY WEDNESDAY.
THE STEEP MID-LEVEL RIDGE IS PROVING TO BE TOO MUCH TO MAINTAIN MOST
OF THE INCOMING RAIN SHOWERS FROM WI. ADDITIONALLY...THE BULK OF THE
BETTER LOW-LEVEL MOISTURE WILL REMAIN ACROSS MN. HAVE THUS OPTED TO
CUT NEARLY ALL CHANCES OF PRECIP EXCEPT FOR A SLIGHT CHANCE FOR
SHOWERS ALONG THE WI BORDER IN THE MORNING.
THURSDAY THROUGH FRIDAY...AFTER THE H8 WARM FRONT CROSSES THE
CWA...THERE IS LITTLE SUPPORT FOR PRECIP UNTIL AT LEAST THURSDAY
AFTERNOON. ADDITIONALLY...CAPPING AROUND 750 HPA SHOULD KEEP PRECIP
CHANCES LIMITED THROUGH THURSDAY MORNING. THE SFC COLD FRONT UNDER
INCREASING MOISTURE FROM AN H8 50KT JET AND A DEVELOPING LEFT-EXIT
OF A WEAK UPPER JET STREAK SHOULD BE ENOUGH TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS LATE THU AFTERNOON THROUGH MUCH OF THU
NIGHT. HOWEVER...KEPT POPS AT JUST A CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE BEST MID-LEVEL FORCING PEELS OFF TO THE NORTH.
TEMPS COULD GET QUITE WARM THU IF ENOUGH AFTERNOON CLEARING OCCURS.
GIVEN THE CAP...THINK THERE WILL BE ENOUGH INSOLATION TO BOOST TEMPS
INTO THE LOW 80S ACROSS THE WEST UNDER H8 TEMPS UP TO 14C. IN
ADDITION TO THE WARMER WX...MIXING INTO 35 TO 45KT WINDS SHOULD
RESULT IN QUITE A GUSTY DAY...ESPECIALLY WEST. EVEN THOUGH MUCH OF
WEST DID NOT BENEFIT FROM SATURDAYS PRECIP...FIRE WX CONCERNS SHOULD
BE PARTIALLY MITIGATED BY INCREASING LOW-LEVEL MOISTURE...RESULTING
IN MIN RH VALUES ONLY INTO THE UPPER 30S. HOWEVER...FIRE INDICES
ARE BEGINNING TO INDICATE INCREASING FIRE POTENTIAL ACROSS THE
WEST...SO THURSDAY WILL NEED TO BE MONITORED IF LOW-LEVEL MOISTURE
IS SLOW TO ARRIVE.
FRIDAY...THE COLD FRONT LOOKS TO CLEAR THE CWA BY FRIDAY
AFTERNOON...ENDING PRECIP CHANCES AND USHERING IN COOLER AIR. TEMPS
WILL DROP ALONG PORTIONS OF LAKE SUPERIOR DURING THE AFTERNOON HOURS
AS WINDS BECOME NW.
SATURDAY...THE ECMWF AND CANADIAN GEM STRUGGLE TO PUSH THE COLD
FRONT FAR AWAY FROM THE CWA...LEAVING LINGERING CHANCES OF SHOWERS
ACROSS THE SE HALF. THE GFS KEEPS THE AREA DRY...AND GIVEN ITS
BETTER RUN TO RUN CONSISTENCY WITH THIS SYSTEM...HAVE OPTED TO KEEP
NEARLY ALL POPS OUT OF THE CWA. HOWEVER...SOME SPRINKLES/DRIZZLE
CANNOT BE RULED OUT ALONG LAKE SUPERIOR...WHERE N WINDS AND
LINGERING LOW-LEVEL MOISTURE SHOULD RESULT IN DECENT LOW-LEVEL
CLOUDS. ADDITIONALLY...TEMPS WILL LIKELY STRUGGLE TO REACH 50F NEAR
THE SHORE.
SUNDAY AND MONDAY...MODEL DIFFERENCE QUICKLY DEVELOP WITH THE
HANDLING OF A DEEP TROUGH EXITING THE WESTERN CONUS. FOLLOWING THE
GFS SOLUTION...A SFC LOW IN THE LEE OF THE ROCKIES WILL TRACK ENE
ALONG THE STALLED W TO E SFC BOUNDARY BIFURCATING THE CENTRAL CONUS.
THE ECMWF AND CANADIAN GEM TRACK THE LOW FARTHER NORTH. ABUNDANT
CONVECTION ACROSS THE PLAINS ONLY LEADS TO MORE UNCERTAINTY WITH THE
SYNOPTIC EVOLUTION OF THIS SYSTEM...SO HAD TO RESORT TO USING
CONSENSUS CHANCE POPS SUNDAY AFTERNOON THROUGH MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 135 AM EDT TUE MAY 5 2015
WITH DRY HI PRES DOMINATING...EXPECT VFR CONDITIONS AND LIGHT WINDS
AT ALL 3 TAF SITES THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT TUE MAY 5 2015
AS A TROUGH MOVES FROM THE PLAINS TO THE UPPER MS VALLEY...SRLY
WINDS WILL INCREASE TO AROUND 25 KNOTS OVER THE EAST BY LATE THU INTO
THU NIGHT. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW 20
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
354 AM MDT TUE MAY 5 2015
.SHORT TERM...VALID FOR TDY AND WED...
UNSETTLED WEATHER BEGINS TODAY AND WILL CONTINUE RIGHT THROUGH
THE REMAINDER OF THE WEEK. AN UPPER LOW AND TROUGH WILL MOVE ONTO
THE PACIFIC NORTHWEST COAST TODAY AND REMAIN STATIONARY OR SLOWLY
SHIFT SOUTHEAST TOWARD THE GREAT BASIN AREA DURING THE DAY
WEDNESDAY. THIS WILL ALLOW A SOUTHWEST FLOW ALOFT TO BEGIN TO
DEVELOP OVER OUR AREA TODAY AND ESPECIALLY BE IN PLACE FOR
WEDNESDAY. SEVERAL SURFACE LOWS WILL DEVELOP ACROSS THE NORTHERN
AND CENTRAL ROCKIES BRINGING A PREDOMINATELY SOUTHEAST SURFACE
FLOW ALLOWING FOR INCREASING LOW-LEVEL MOISTURE ACROSS THE AREA
THROUGH WEDNESDAY. MODELS INCLUDING THE HRRR BRING A VORT MAX OVER
OUR AREA TODAY RESULTING IN SHOWERS AND ISOLATED THUNDERSTORMS.
SHEAR IS A BIT BETTER TODAY BUT STILL NOT IMPRESSIVE. CAPES ARE
ALSO SLIGHTLY BETTER TODAY AND MORE WIDESPREAD SO THUNDERSTORM
CHANCES WILL BE BETTER TODAY THAN TUESDAY. PRE-FRONTAL WARMING
TODAY WILL ALLOW TEMPERATURES TO WARM WELL INTO THE 70S TO AROUND
80 DEGREES.
A COLD FRONT WILL MOVE ACROSS THE FORECAST AREA WEDNESDAY MORNING
USHERING IN GUSTY NORTHWEST WINDS BY AFTERNOON ALONG WITH A CHANCE
FOR SHOWERS AND ISOLATED THUNDERSTORMS. TEMPERATURES WILL BE MUCH
COOLER WITH READINGS ONLY IN THE LOWER TO MIDDLE 60S SO
INSTABILITY FOR THUNDERSTORMS WILL NOT BE AS GOOD AS TODAY. A
STRONGER DISTURBANCE AND UPPER LOW WILL MOVE NORTHEAST OUT OF
WYOMING WEDNESDAY INTO WEDNESDAY NIGHT. MODELS SHOW GOOD WRAP-
AROUND MOISTURE WITH THIS ALONG WITH DECENT QPF AMOUNTS. AS A
RESULT...HAVE INCREASED POPS INTO THE LIKELY AND CATEGORICAL RANGE
DURING THIS TIME FROM CUSTER AND POWDER RIVER COUNTIES EASTWARD.
ELSEWHERE...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS. HOOLEY
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
LATEST MODEL RUNS HAVE CONTINUED TO KEEP THE BULK OF THE ENERGY
AND MOISTURE OUT OF THE THE AREA. MODELS HAVE CONTINUED TO TRACK
WELL WITH EACH OTHER...WITH THE 00Z DATA HAVING MORE OF A CLOSED
LOW EJECTING FROM THE GREAT BASIN THIS WEEKEND...BUT IT TRACKS
MORE INTO THE CENTRAL PLAINS. THIS HAS THE EFFECT OF KEEPING THE
BULK OF THE MOISTURE AND ENERGY SOUTH OF MONTANA. CONTINUE TO SEE
DIFFLUENT FLOW ALOFT ACROSS THE AREA THIS WEEKEND...ALONG WITH
SOME MID-LEVEL MOISTURE. THIS WILL KEEP AT LEAST A CHANCE OF LIGHT
SCATTERED PRECIP ACROSS THE AREA. HAVE TRENDED POPS DOWN SOME
GIVEN THE TREND AWAY FROM A MORE FAVORABLE SOLUTION. THE COLUMN
IS NOT OVERLY SATURATED...WITH PRECIPITABLE WATER VALUES ONLY
AROUND A HALF INCH. THE POTENTIAL FOR MUCH ACCUMULATION REMAINS
LOW. WITH THE MID LEVEL MOISTURE...MUCH OF THE EXTENDED PERIOD
WILL BE CLOUDY...THUS COOLER. TEMPERATURES CONTINUE BE IN THE 50S
FOR HIGHS. REIMER
&&
.AVIATION...
VFR CONDITIONS EXPECT THROUGH MUCH OF THE NEXT 24. SOME SHOWERS
AND THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS AND WILL MOVE
EAST IN THE ADJACENT PLAINS. LATEST HIRES MODELS SHOW ACTIVITY
STAYING WEST OF BILLINGS...LIMITING MOST THUNDERSTORM ACTIVITY TO
LIVINGSTON AND SHERIDAN. LOW LEVEL WIND SHEER WILL CONTINUE
AROUND MILES CITY UNTIL AROUND MID MORNING BEFORE SURFACE WIND
BEGIN TO INCREASE. REIMER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 079 049/059 040/053 040/053 039/051 038/059 040/060
2/T 43/W 22/W 24/W 55/W 43/W 32/W
LVM 076 043/061 036/050 034/048 034/050 034/059 035/060
3/T 64/W 35/W 35/W 55/W 43/W 33/W
HDN 082 050/061 042/056 038/057 039/053 037/059 035/062
1/B 34/W 22/W 23/W 55/W 43/W 32/W
MLS 079 051/060 041/055 037/056 038/054 037/057 038/061
1/U 38/W 42/W 12/W 44/W 43/W 32/W
4BQ 075 051/061 043/055 035/055 039/052 035/053 034/059
1/B 48/T 42/W 12/W 55/W 44/W 32/W
BHK 073 050/060 042/054 034/054 035/052 034/054 031/057
1/N 39/T 72/W 12/W 44/W 33/W 22/W
SHR 075 048/054 037/053 035/054 038/050 035/051 032/058
2/T 45/W 43/W 34/W 55/W 54/W 33/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
327 AM MDT TUE MAY 5 2015
.SYNOPSIS...
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS
AN UPPER LEVEL DISTURBANCE PASSES OVERHEAD. THE STRONGEST STORMS
WILL BE FOUND ACROSS THE FAR EASTERN PLAINS WHERE LARGE
HAIL...DAMAGING WINDS AND HEAVY RAIN WILL BE A CONCERN. AFTER
TODAY...MAINLY DRY AND WINDY CONDITIONS ARE IN STORE THROUGH FRIDAY.
HOWEVER...A FEW THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON
ACROSS THE FAR EASTERN PLAINS ALONG THE DRYLINE. THE NEXT STORM
SYSTEM LOOKS TO CROSS THE STATE ON SATURDAY...WHICH MAY INCREASE
PRECIPITATION CHANCES ACROSS THE WEST. OTHERWISE... TEMPERATURES
WILL REMAIN NEAR TO BELOW NORMAL FOR THE NEXT SEVEN DAYS.
&&
.DISCUSSION...
SHOWERS AND A FEW THUNDERSTORMS CONTINUE THIS MORNING ACROSS EASTERN
NM AHEAD OF UPPER LEVEL LOW WHICH IS NOW CENTERED IN THE VICINITY OF
FLAGSTAFF. THIS CURRENT ACTIVITY SHOULD LARGELY PUSH EAST OF THE
TEXAS BORDER BY 12-14Z AND ALLOW FOR A SHORT BREAK BEFORE THE NEXT
ROUND BEGINS. WITH STRONG FORCING AND LITTLE TO NO INHIBITION...
STORMS SHOULD DEVELOP EARLY...PERHAPS BY 17Z...ALONG OR JUST EAST OF
HIGHER TERRAIN AND/OR ALONG REMNANT BOUNDARIES. BEST INSTABILITY
REMAINS ACROSS THE FAR EASTERN PLAINS WHERE CAPE VALUES MAY APPROACH
2000 J/KG. THUS STORMS MAY INITIATE NEAR THE CENTRAL MTN CHAIN...BUT
INCREASE IN STRENGTH AS THEY MOVE INTO BETTER MOISTURE AND
INSTABILITY. LOW LEVEL WINDS LOOK TO VEER TO AROUND TO THE SW BY
EARLY AFTERNOON AS THE TROUGH AXIS MOVES EASTWARD AND DRIER WESTERLY
FLOW MOVES INTO THE AREA. PRIOR TO THE DRY AIR MOVING IN...PWATS
WILL REMAIN NEAR 1 INCH...OR BETTER THAN 200 PERCENT OF NORMAL FOR
THIS TIME OF YEAR. THUS...A HEAVY RAIN THREAT WILL CONTINUE TO EXIST
WITH THESE STORMS. AREAS THAT HAVE ALREADY RECEIVED SIGNFICANT
AMOUNTS OF RAIN WILL BE THE MOST SUSCEPTIBLE TO ADDITIONAL FLOODING.
THIS INCLUDES THE CLOVIS AREA WHERE UP TO 5 INCHES OF RAIN FELL
YESTERDAY. THE FLASH FLOOD WATCH REMAINS INTACT THROUGH 00Z AND ANY
SEVERE WEATHER IS MOST LIKELY TO OCCUR BETWEEN NOON AND 6PM.
MEANWHILE ACROSS WESTERN AND CENTRAL NM...ANOTHER ROUND OF SCATTERED
TO NUMEROUS THUNDERSTORMS WILL DEVELOP. THIS AREA WILL BE UNDER THE
COLD CORE OF THE LOW...THUS A FEW STORMS MAY CONTAIN SOME SMALL HAIL
AND HEAVY RAIN. A COLD CORE FUNNEL IS ALSO NOT OUT OF THE QUESTION.
BRIEF SHORTWAVE RIDGING WILL OCCUR ON WEDNESDAY BEFORE SOUTHWESTERLY
FLOW INCREASES AHEAD OF THE NEXT STORM SYSTEM. A 996 MB SURFACE LOW
ACROSS SE CO WILL ALLOW FOR WINDS TO INCREASE ACROSS THE PLAINS.
OTHERWISE MUCH DRIER CONDITIONS AS THE DRY SLOT MOVES OVERHEAD AND
SOME DRY AIR MIXES DOWN TO THE SURFACE. BEST CHANCE FOR A FEW STORMS
WILL BE ACROSS THE NW OR NC NM.
THE DRYLINE WILL SLOSH BACK WESTWARD WEDNESDAY NIGHT AND THIS WILL
BE A THEME FOR THE REST OF THE WEEK. THE NEXT LOW PRESSURE SYSTEM
LOOKS TO DIVE MUCH FURTHER SOUTH THAN PREVIOUSLY INDICATED. IT
APPEARS IT MAY ACTUALLY REMAIN A CLOSED LOW AS IT CROSSES NORTHERN NM
ON SATURDAY. IF THE LOW DOES INDEED DIVE THAT FAR SOUTH...EXPECT THE
DRYLINE TO RETREAT WESTWARD INTO EASTERN NM EACH NIGHT AND THEN MIX
BACK EASTWARD EACH DAY. WITH THAT...WILL COME A CHANCE FOR A FEW
STORMS NEAR THE TEXAS BORDER EACH AFTERNOON. ELSEWHERE...IT WILL BE
MAINLY DRY AND BREEZY UNTIL SATURDAY WHEN BETTER CHANCES OF PRECIP
WILL EXIST AS LOW SHIFTS OVERHEAD.
34
&&
.FIRE WEATHER...
NO WIDESPREAD FIRE WEATHER CONCERNS THROUGH THE FORECAST PERIOD.
SMALL AREAS OF MARGINAL CRITICAL FIRE WEATHER CONDITIONS ARE
POSSIBLE FRIDAY AND SATURDAY.
IT WAS A WET MONDAY ACROSS THE FORECAST AREA...ESPECIALLY IN THE
EAST. AROUND FIVE INCHES OF RAIN FELL AT THE CANNON AIR FORCE BASE.
THE UPPER LOW CAUSING ALL THIS RAIN IS NOW OVER AZ. IT WILL TRACK
NORTHEAST ACROSS THE FOUR CORNERS AREA TODAY. A DRY SLOT IS EVIDENT
ON SATELLITE IMAGES ACROSS SOUTHWEST NM AND IT WILL CONTINUE ACROSS
SOUTHERN NM TODAY. SHOWER AND THUNDERSTORM COVERAGE WILL BE LESS
TODAY COMPARED TO MONDAY. BUT PLENTY OF LOW LEVEL MOISTURE IS STILL
AROUND ALONG WITH A VERY UNSTABLE AIRMASS...ESPECIALLY IN THE EAST.
SO ANOTHER ACTIVE DAY ON TAP WITH THE POTENTIAL FOR SEVERE STORMS
NEAR THE TX BORDER. SOME OF THE RAIN WILL BE HEAVY AS WELL WITH
FLASH FLOODING A CONCERN...ESPECIALLY FOR PLACES HIT HARD MONDAY.
SOME OF THE STORMS WILL PRODUCE SMALL HAIL AS TEMPERATURES ALOFT
WILL BE QUITE COLD FOR EARLY MAY. MIN RH VALUES WILL ONLY DROP TO
BETWEEN 40 AND 60 PERCENT TODAY WHILE VENT RATES WILL BE MOSTLY
EXCELLENT.
A DRYING TREND REMAINS ON TRACK FOR THE REST OF THE WEEK. HIGH
TEMPERATURES WILL WARM TO WITHIN SIX OR SEVEN DEGREES EITHER SIDE
OF NORMAL WEDNESDAY THROUGH FRIDAY. THERE WILL STILL BE SHOWERS AND
A FEW STORMS OVER THE NORTHWEST THIRD OF THE STATE WEDNESDAY AND
NEAR THE TX BORDER ON THURSDAY ALONG A POTENTIAL DRYLINE.
MODELS CONTINUE TO TREND FARTHER SOUTH WITH A UNSEASONABLY DEEP
CLOSED LOW DROPPING SOUTH THROUGH CALIFORNIA THURSDAY INTO FRIDAY.
INCREASING SOUTHWEST WINDS AHEAD OF THE STORM MAY RESULT IN A FEW
HOURS OF CRITICAL CONDITIONS FOR THE LOWER RIO GRANDE VALLEY FRIDAY
AFTERNOON...AND BORDERLINE CRITICAL CONDITIONS OVER A SMALL AREA OF
THE EASTERN PLAINS SATURDAY. VENTILATION RATES WILL GENERALLY REMAIN
IN THE GOOD TO EXCELLENT RANGE DURING THIS TIME.
THE ABOVE MENTIONED STORM WILL BRING COOLER AND WETTER CONDITIONS
BACK TO NM FOR FRIDAY NIGHT INTO THE WEEKEND. THE STORM SHOULD LIFT
NORTHEAST INTO CO SUNDAY...BRINGING SOME DRYING AND WARMING TO THE
AREA. THIS TREND WILL CONTINUE ON MONDAY. AN ACTIVE DRY LINE MIGHT
SET UP TUESDAY ACROSS THE EAST.
CHJ
&&
.AVIATION...
06Z TAF CYCLE
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO
STEER BANDS OF SHOWERS AND THUNDERSTORMS NORTH AND NORTHEASTWARD
ACROSS N AND E PARTS OF THE FORECAST AREA THROUGH THE OVERNIGHT
HOURS. THE TRUSTED HRRR MODELS DEPICTION OF DECREASING ACTIVITY
ACROSS SW AND CENTRAL AREAS APPEARS TO BE COMING TRUE. AREAS OF
LOW CLOUDS AND POSSIBLY SOME FOG ARE EXPECTED TO BECOME GRADUALLY
MORE WIDESPREAD THROUGH THE NIGHT ACROSS MUCH OF THE PLAINS.
THOUGH ITS FORMATION COULD BE A BIT PATCHY DUE TO SOME MID LEVEL
CLOUD COVER. MODELS AGREE ON A DOWNTICK IN CONVECTIVE ACTIVITY
TUESDAY MORNING AS LOW CLOUDS GRADUALLY BREAK UP IN THE EAST. THEN
ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
IS EXPECTED IN THE AFTERNOON AND EVENING WITH HIGHEST
PROBABILITIES ACROSS NORTHERN AREAS.
44
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 66 46 71 41 / 60 50 20 10
DULCE........................... 59 39 65 35 / 70 60 40 30
CUBA............................ 60 41 66 38 / 60 50 20 20
GALLUP.......................... 61 39 67 34 / 50 40 10 10
EL MORRO........................ 58 38 64 35 / 60 30 10 10
GRANTS.......................... 62 38 68 33 / 50 30 5 5
QUEMADO......................... 60 37 67 34 / 50 20 5 5
GLENWOOD........................ 69 44 74 42 / 30 10 0 5
CHAMA........................... 58 36 59 31 / 70 60 40 20
LOS ALAMOS...................... 60 44 67 44 / 70 40 20 10
PECOS........................... 58 43 65 42 / 70 30 10 10
CERRO/QUESTA.................... 60 38 64 34 / 70 40 20 20
RED RIVER....................... 50 35 52 31 / 70 50 30 20
ANGEL FIRE...................... 54 35 58 28 / 70 40 20 10
TAOS............................ 61 38 65 34 / 60 40 20 10
MORA............................ 57 42 64 39 / 70 30 10 10
ESPANOLA........................ 63 45 71 43 / 60 30 10 10
SANTA FE........................ 60 44 66 42 / 60 30 10 5
SANTA FE AIRPORT................ 65 43 70 40 / 60 30 10 5
ALBUQUERQUE FOOTHILLS........... 67 48 73 47 / 40 30 5 5
ALBUQUERQUE HEIGHTS............. 69 49 74 50 / 40 20 0 5
ALBUQUERQUE VALLEY.............. 70 47 76 46 / 40 20 0 5
ALBUQUERQUE WEST MESA........... 69 48 75 47 / 40 30 0 5
LOS LUNAS....................... 71 47 78 45 / 30 20 0 5
RIO RANCHO...................... 67 49 74 48 / 50 30 5 5
SOCORRO......................... 71 49 79 48 / 30 20 0 5
SANDIA PARK/CEDAR CREST......... 64 44 71 44 / 50 40 10 5
TIJERAS......................... 66 44 73 44 / 40 30 5 5
MORIARTY/ESTANCIA............... 64 40 69 37 / 40 20 0 5
CLINES CORNERS.................. 63 41 68 40 / 50 20 0 5
GRAN QUIVIRA.................... 65 44 70 44 / 40 20 0 5
CARRIZOZO....................... 69 48 74 48 / 20 10 0 5
RUIDOSO......................... 65 45 71 45 / 30 10 0 5
CAPULIN......................... 61 44 69 43 / 70 30 10 10
RATON........................... 64 42 72 40 / 70 20 5 10
SPRINGER........................ 65 44 74 41 / 60 20 5 5
LAS VEGAS....................... 61 44 69 39 / 60 20 5 5
CLAYTON......................... 64 47 79 48 / 80 30 5 5
ROY............................. 64 46 73 44 / 60 20 5 5
CONCHAS......................... 70 52 79 50 / 60 20 0 5
SANTA ROSA...................... 70 50 78 48 / 60 20 0 5
TUCUMCARI....................... 72 53 81 51 / 70 20 0 5
CLOVIS.......................... 71 49 78 51 / 70 20 0 10
PORTALES........................ 72 51 79 52 / 70 20 0 10
FORT SUMNER..................... 72 51 80 51 / 60 20 0 5
ROSWELL......................... 79 51 84 50 / 30 10 0 5
PICACHO......................... 73 49 79 49 / 30 10 0 5
ELK............................. 68 47 74 47 / 30 10 0 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES...
NMZ535>538.
&&
$$
34
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1154 PM MDT MON MAY 4 2015
.AVIATION...
06Z TAF CYCLE
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO
STEER BANDS OF SHOWERS AND THUNDERSTORMS NORTH AND NORTHEASTWARD
ACROSS N AND E PARTS OF THE FORECAST AREA THROUGH THE OVERNIGHT
HOURS. THE TRUSTED HRRR MODELS DEPICTION OF DECREASING ACTIVITY
ACROSS SW AND CENTRAL AREAS APPEARS TO BE COMING TRUE. AREAS OF
LOW CLOUDS AND POSSIBLY SOME FOG ARE EXPECTED TO BECOME GRADUALLY
MORE WIDESPREAD THROUGH THE NIGHT ACROSS MUCH OF THE PLAINS.
THOUGH ITS FORMATION COULD BE A BIT PATCHY DUE TO SOME MID LEVEL
CLOUD COVER. MODELS AGREE ON A DOWNTICK IN CONVECTIVE ACTIVITY
TUESDAY MORNING AS LOW CLOUDS GRADUALLY BREAK UP IN THE EAST. THEN
ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
IS EXPECTED IN THE AFTERNOON AND EVENING WITH HIGHEST
PROBABILITIES ACROSS NORTHERN AREAS.
44
&&
.PREV DISCUSSION...1027 PM MDT MON MAY 4 2015...
.UPDATE...
RATHER MODEST UPDATE TO LOWER POPS SOME ACROSS PARTS OF THE WEST
AND FAR NE FOR REST OF PRE MIDNIGHT PERIOD...BUT NOT MANY CHANGES
AFTER MIDNIGHT. LOWERED QPF SHARPLY FOR REST OF PRE MIDNIGHT
PERIOD DUE MOST TO THERE BEING UNDER TWO HOURS LEFT TIL THEN...BUT
ALLOWED FOR RADAR TRENDS AS WELL. DROPPED LOW TEMPS A DEGREE OR
TWO PORTIONS OF CENTRAL NM AND IMMEDIATELY ADJACENT LOCALES...ALSO
FAR NW. FAR E CENTRAL NM...WHERE MOST OF REPORTED SIGNIFICANT
FLOODING HAS OCCURRED WILL BE SEEING MUCH LESS INTENSE OFF AND ON
RAIN REST OF THE NIGHT.
43
&&
.PREV DISCUSSION...330 PM MDT MON MAY 4 2015...
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT THE STATE
THROUGH TUESDAY AS AN UPPER LEVEL LOW PRESSURE SYSTEM...CURRENTLY
OVER ARIZONA...MOVES SLOWLY EAST ACROSS THE REGION. MOST AREAS WILL
SEE GOOD CHANCES FOR WETTING RAINS...BUT LOCALES BETWEEN THE
CENTRAL MOUNTAIN CHAIN AND THE TEXAS BORDER WILL HAVE THE BEST
CHANCES WITH THE POTENTIAL FOR FLASH FLOODING AND SOME HAIL. LOOK
FOR MOSTLY DRY...WARM AND BREEZY TO LOCALLY WINDY CONDITIONS TO
PREVAIL FROM WEDNESDAY THROUGH SATURDAY AS ANOTHER UPPER LEVEL LOW
PRESSURE SYSTEM GRADUALLY APPROACHES FROM THE WEST. TEMPERATURES
WILL TREND DOWN OVER THE WEEKEND AS THE UPPER LEVEL LOW PRESSURE
SYSTEM PUSHES A PACIFIC COLD FRONT THROUGH.
&&
.DISCUSSION...
MOISTURE ADVECTION AND DESTABILIZATION OF THE ATMOSPHERE WITH THE
APPROACH OF THE UPPER LOW...CURRENTLY OVER ARIZONA...IS RESULTING
IN THUNDERSTORMS BREAKING-OUT ACROSS MUCH OF THE AREA. THROUGH 3
PM MDT...THE MOST ROBUST THUNDERSTORMS HAVE BEEN ACROSS THE
EASTERN PLAINS WHERE SEVERAL REPORTS OF HAIL UP TO QUARTER SIZE
AND RAIN AMOUNTS IN EXCESS OF ONE INCH IN 30 MINUTES HAVE BEEN
REPORTED. MOISTURE ADVECTION IS FORECAST TO CONTINUE INTO THE
EVENING HOURS...WITH PWATS EXCEEDING ONE INCH ACROSS SOUTHEAST
PORTIONS OF OUR AREA WHICH WOULD BE NEAR THE 99TH PERCENTILE IN
TERMS OF MAY PWAT CLIMATOLOGY. AT THIS POINT...THE FLASH FLOOD
THREAT WOULD APPEAR LIMITED...BUT SOME MERGING/ORGANIZATION OF
STORMS IS FORECAST TO OCCUR OVERNIGHT AND WILL INCREASE THE FLASH
FLOOD THREAT OVER THE WATCH AREA. ELSEWHERE...THE FLASH FLOOD
THREAT SHOULD BE LOCALIZED...THOUGH SOAKING RAINS ARE LIKELY ACROSS
CENTRAL AND NORTHERN PORTIONS OF NEW MEXICO.
ANOTHER HEALTHY ROUND OF STORMS FORECAST TUESDAY AS THE UPPER LOW
MOVES OVERHEAD...WITH THE BEST CHANCES FOR DEEP...PERHAPS
SEVERE..CONVECTION NEAR THE TEXAS BORDER WHERE THE SPC SHOWS A
SLIGHT RISK FOR SEVERE STORMS IN THE DAY 2 CONVECTIVE OUTLOOK.
THAT SAID...CONVECTION IS FORECAST TO SHIFT RAPIDLY INTO THE TEXAS
PANHANDLE TUESDAY AFTERNOON...SO THE SEVERE THREAT MAY BE LIMITED
TO A FEW HOURS DURING THE AFTERNOON. ELSEWHERE...HAIL-PRODUCING
STORMS ARE FORECAST BY AFTERNOON...ESPECIALLY IN THE MOUNTAINS...
WITH THE POTENTIAL FOR SEVERAL INCHES OF HAIL ACCUMULATION THOUGH
ACTUAL HAIL SIZE SHOULD BE LESS THAN ONE INCH. TUESDAY WILL BE A
"COOL" DAY WITH HIGHS BELOW NORMAL AREAWIDE.
A DRYING/WARMING TREND TO KICK-OFF WEDNESDAY AND CONTINUE THROUGH
THE END OF THE WORK WEEK WITH BREEZY TO LOCALLY WINDY CONDITIONS.
A FEW SHOWERS AND THUNDERSTORMS ARE FORECAST EACH DAY...MAINLY
ACROSS THE WESTERN AND NORTHERN HIGH TERRAIN...BUT GIVEN A
SIGNIFICANT DOWNTREND IN PWATS WETTING RAINS WILL BE HARD TO COME-
BY. SOME POTENTIAL EXISTS FOR A DRYLINE THUNDERSTORM OR TWO
BETWEEN WEDNESDAY NIGHT AND FRIDAY ACROSS THE FAR SOUTHEAST...
DEPENDENT ON THE EXTENT OF THE DRYLINE SLOSHING WESTWARD.
A COOLING TREND FORECAST OVER THE WEEKEND AS THE EASTWARD
ADVANCING UPPER LOW PUSHES A PACIFIC COLD FRONT THROUGH. THE 12Z
MODEL SUITE TRENDED FURTHER SOUTH WITH THE BOTTOMING OF THE UPPER LOW
LATER THIS WEEK AND PUSHES IT FURTHER EAST BEFORE PULLING IT OUT
TO THE NORTHEAST COMPARED TO PREVIOUS RUNS. IF THIS TREND
CONTINUES THEN THIS FEATURE MAY BE MORE OF A WEATHER-MAKER FOR US
THAN WHAT IS CURRENTLY IN OUR FORECAST.
11
&&
.FIRE WEATHER...
ATMOSPHERIC LIFT ASSOCIATED WITH UPPER LOW/TROUGH OVER WESTERN
ARIZONA DRAWING UP PLENTIFUL MID LEVEL SUBTROPICAL MOISTURE TO
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS OVER MUCH OF THE AREA.
LOW LEVEL GULF MOISTURE SURGED NORTHWARD LAST NIGHT AND THIS MORNING
ON A LOW LEVEL JET CENTERED OVER FAR WEST TX AND SE NM. SHOWERS AND
STORMS WILL CONTINUE WELL INTO THE EVENING HOURS AS LIFT AHEAD OF
THE UPPER LOW REMAINS OVER NEW MEXICO. STRONG TO SEVERE STORMS OVER
THE EASTERN PLAINS WILL CONTINUE OVERNIGHT. HEAVY RAINFALL AMOUNTS
ARE LIKELY OVER THE EAST-CENTRAL AND SOUTHEAST PLAINS.
ABOVE MENTIONED UPPER LOW/TROUGH SLIDES NORTHEASTWARD TO NEAR THE
FOUR CORNERS BY TUESDAY MORNING. COLD POOL OF AIR ALOFT WILL COMBINE
WITH DAYTIME HEATING AND RESIDUAL MOISTURE TO GENERATE ANOTHER ROUND
OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAY OF THE
STORMS WILL LIKELY PRODUCE SMALL HAIL AS TEMPERATURES ALOFT WILL BE
QUITE COLD FOR EARLY MAY. WIDESPREAD WETTING RAINS REMAIN ON TRACK
BETWEEN THIS AFTERNOON AND TUESDAY EVENING OVER MUCH OF CENTRAL AND
NORTHERN NEW MEXICO.
DRIER BUT COOLER THAN AVERAGE TEMPERATURES REMAIN ON TRACK FOR
WEDNESDAY. WEATHER PREDICTION MODELS ARE IN GOOD AGREEMENT THAT LOW
LEVEL SOUTHERLY WINDS WILL INCREASE THURSDAY...RESULTING IN SLIGHT
WARMING. MODELS ARE TRENDING FARTHER SOUTH WITH A UNSEASONABLY DEEP
CLOSED LOW DROPPING SOUTH THROUGH CALIFORNIA WEDNESDAY NIGHT AND
THURSDAY. ANY FARTHER SOUTH AND THE FLOW ALOFT COULD BACK ENOUGH TO
DRAW UP SUBTROPICAL MOISTURE ONCE AGAIN...RESULTING IN MORE
PRECIPITATION THAN WIND. AT THIS TIME...HOWEVER...CURRENT MODEL
SOLUTIONS WOULD RESULT IN INCREASING SOUTHWEST WINDS AND A FEW HOURS
OF CRITICAL CONDITIONS FOR THE LOWER RIO GRANDE VALLEY FRIDAY
AFTERNOON. VENTILATION RATES WILL GENERALLY BE IN GOOD TO EXCELLENT
RANGE DURING THE NEXT SEVEN DAYS.
33
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ535>538.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
340 AM CDT TUE MAY 5 2015
.DISCUSSION...
PRIMARY FORECAST CONCERN THIS MORNING IS FOCUSED ON TODAY THROUGH
WEDNESDAY THUNDERSTORM CHANCES. HOWEVER... THUNDERSTORM CHANCES WILL
CONTINUE NEAR DAILY THROUGH THE WEEKEND.
CURRENTLY... CONVECTION ACROSS WEST TEXAS... ALONG AND EAST OF THE
LLANO ESTACADO... CONTINUES... WITH THE SFC LOW SLOWLY EVOLVING
ACROSS THE BIG BEND OF TEXAS. THROUGH MIDNIGHT... NEARLY 4 TO 5
INCHES OF RAIN HAD FALLEN ACROSS PORTIONS OF WEST TEXAS. EXPECT THE
SFC LOW TO SLOWLY LIFT N/NE ACROSS FAR WEST TEXAS... WITH SHOWERS
AND THUNDERSTORMS CONTINUING TO MOVE NWRD ACROSS THE W TX AND THE
PANHANDLES INTO WRN N TX AND FAR WRN OK THROUGH SUNRISE. MESOSCALE
GUIDANCE IS IN GOOD AGREEMENT... ALTHOUGH THE HRRR MIGHT BE A TAD
BULLISH WITH THE EWRD EXTENT OF PRECIP INTO OK THROUGH MID MORNING.
SHOWERS AND THUNDERSTORMS CHANCES WILL SLOWLY INCREASE ACROSS WRN OK
AND WRN N TX THROUGH THE AFTN. LOCALLY HEAVY RAINFALL MAY BE AN
ISSUE LATER THIS MORNING/THIS AFTN AS BANDING MAY DEVELOP ALONG THE
ERN PANHANDLES/WRN OK... WHERE THE BETTER ISENTROPIC RESPONSE MAY
SET UP ON THE ERN PERIPHERY OF THE H500 LOW. WITH GOOD MID-LEVEL
ASCENT AND A NARROW BAND OF MUCAPE VALUES OF 600 TO 900 J/KG...
WOULD NOT BE SURPRISED TO SEE SOME LOCALLY HIGHER RAINFALL GREATER
THAN 1 INCH THROUGH THE DAY. THE NAM IS THE MOST AGGRESSIVE WITH
QPF... SO IT WILL BE INTERESTING TO SEE HOW TODAY UNFOLDS.
AS FOR STRONG TO SEVERE STORMS TODAY... THE BEST CHANCE WILL BE LATE
THIS AFTN/EVENING ACROSS FAR W/SWRN OK AND WRN N TX. OF COURSE...
ANY STORM DEVELOPMENT WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS THIS
MORNING AND AFTN. THERE IS SOME CONCERN CLOUD COVER WILL PERSIST
THROUGH THE AFTN HOURS... LIMITING HEATING/INSTABILITY DEVELOPMENT.
FORCING WILL BE AVAILABLE FROM A WEAK DRYLINE AND BROAD SCALE
ASCENT... AS WELL AS ANY LEFT OVER BOUNDARIES FROM EARLIER
CONVECTION. ALTHOUGH INSTABILITY WILL BE PRIMARY QUESTION THIS
AFTN... THERE WILL BE QUITE A BIT OF SHEAR AVAILABLE... 40 TO 55KTS
0-6KM AND IF WE CAN RECOVER... A WINDOW AROUND 21-03Z FOR SOME 1000-
1400 J/KG SKINNY CAPE PROFILES. MUCH OF THE INSTABILITY WILL BE
ELEVATED... AND GIVEN BUFR PROFILES... LARGE HAIL... UP TO GOLF
BALLS... AND SEVERE WINDS WOULD BE THE PRIMARY HAZARDS... WITH THE
TORNADO HAZARD LOW.
FOR WEDNESDAY... CLUSTERS OR A COMPLEX OF THUNDERSTORMS WILL LIKELY
BE ONGOING AND LIFTING EWRD ACROSS CENTRAL OK THROUGH SUNRISE. THIS
ACTIVITY WILL SLOWLY DIMINISH AND EXIT EWRD THROUGH THE DAY AS THE
H500 SHORT WAVE FINALLY EJECTS NWRD INTO THE NRN HIGH PLAINS. ONCE
AGAIN... HOW THIS ACTIVITY EVOLVES THROUGH THE MORNING WILL PLAY THE
LEAD ROLE IN OUR SEVERE WEATHER CHANCES WED AFTN/EVENING. AT THE
MOMENT... IF WE CAN GET CLEARING ACROSS WRN OK IN THE VICINITY OF
THE DRYLINE... MODEST MLCAPE VALUES CAN BE ANTICIPATED... 1000-1500
J/KG. THIS PAIRED WITH GOOD SHEAR ONCE AGAIN... STORMS ON THE
DRYLINE WILL LIKELY DEVELOP RAPIDLY AND BE GOOD HAIL PRODUCERS... UP
TO TENNIS BALL SIZED... AS WELL AS PRODUCING POTENTIALLY DAMAGING
WIND GUSTS. AS FOR TORNADOES... CHANCES LOOK BETTER IN KS... WHERE
SHEAR/LL WINDS WILL BE ENHANCED BY THE MORE FAVORABLE POSITION OF
THE SFC LOW OVER ERN CO/WRN KS. GUIDANCE SUGGESTS OK AND NRN TX
STORMS WILL MOVE OFF THE DRYLINE... BECOMING ELEVATED QUICKLY AFTER
SUNSET. THE CHANCE FOR SEVERE STORMS WILL DIMINISH OVERNIGHT... WITH
SCATTERED THUNDERSTORMS PERSISTING THROUGH THU MORNING.
FOR THURSDAY INTO FRIDAY... PRECIPITATION CHANCES WILL CONTINUE...
ESPECIALLY THU NIGHT INTO FRI... AS A DIFFUSE FRONTAL BOUNDARY
STALLS/LINGERS NEAR THE OK/KS BORDER... EXTENDING FROM THE PANHANDLE
INTO ERN KS. H500 FLOW REMAINS FAIRLY STATIC AS THE SRN PLAINS
REMAINS SANDWICHED BETWEEN A DEEPENING TROUGH IN THE WEST AND A
SHARP POSITIVE RIDGE INTO THE MID-ATLANTIC COAST. WITH THIS FLOW
REGIME AND THE LINGERING WEAK FRONTAL BOUNDARY... COUPLED WITH
CONTINUOUS MOISTURE ADVECTION FROM THE GULF... PERSISTENT AND
POSSIBLY EXCESSIVE RAINFALL LIKELY... ESPECIALLY FRI INTO SAT AM.
THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE WEEKEND AS THE H500
TROUGH FINALLY LIFTS E/NE ACROSS THE CENTRAL ROCKIES. WITH THIS...
THE DRY LINE WILL MAKE ANOTHER PUSH ON SATURDAY... WITH STRONG TO
SEVERE STORMS POSSIBLE ONCE AGAIN. DETAILS REMAIN HAZY GIVEN WHATS
POSSIBLE TO TRANSPIRE BETWEEN NOW AN THEN. AS WITH TODAY AND WED...
THUNDERSTORMS SAT WILL BE DEPENDENT ON HOW THE ATMOSPHERE RECOVERS
FROM THE MORNING CONVECTION.
PRECIP CHANCES WILL DIMINISH MON INTO TUES.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 63 78 65 / 40 70 40 50
HOBART OK 72 63 80 63 / 70 80 40 50
WICHITA FALLS TX 76 65 82 66 / 60 70 30 50
GAGE OK 69 60 82 62 / 70 80 20 20
PONCA CITY OK 79 65 78 66 / 10 80 50 40
DURANT OK 78 65 78 66 / 60 70 50 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
416 AM CDT TUE MAY 5 2015
.SHORT TERM /NOW THROUGH WEDNESDAY/...UPPER TROF ACROSS THE FOUR
CORNERS REGION WILL OPEN UP AND WEAKEN AS IT HEADS NORTHEASTWARD
INTO COLORADO THEN BECOME ABSORBED IN THE DEEPENING LARGER SCALE
TROUGH ACROSS THE WESTERN CONUS. DIFFLUENCE REMAINS ACROSS THE
AREA BUT BETTER DYNAMICS ASSOCIATED WITH THE UPPER TROF WILL
REMAIN WELL REMOVED FROM THE AREA. 700MB FLOW STRENGTHENS AND
REINFORCES MID LEVEL CAPPING WITH DRY AIR ADVECTING FROM THE
MEXICAN PLATEAU AND OVER SPREADING THE AREA. LEFT SLIGHT CHANCE
POPS THIS MORNING FOR FAR WESTERN SECTIONS BUT BELIEVE CAP WILL
KEEP THE LID ON MOST IF NOT ALL PRECIPITATION TODAY. HRRR AND
NAM12 SUPPORT THIS IDEA. BREEZY CONDITIONS CONTINUE TODAY WITH
DEEPENING LOW PRESSURE ACROSS WEST TEXAS WITH GUSTS APPROACHING 30
MPH. THERE ARE INDICATIONS IN THE MODELS OF THUNDERSTORMS
DEVELOPING ON THE HIGHER TERRAIN THIS EVENING AND MOVE EASTWARD
TOWARDS OUR AREA BUT DRY AIR SHOULD WEAKEN THEM BEFORE MAKING
ACROSS THE RIVER. THEREFORE WILL KEEP FORECAST DRY TONIGHT. BREEZY
CONDITIONS CONTINUE WEDNESDAY WITH ANOTHER ROUND OF 700MB DRY AIR
ADVECTING FROM THE WEST. CONDITIONS WILL BE FAIRLY SIMILIAR TO THE
PAST SEVERAL DAYS. HIGHS IN THE 80S THE NEXT SEVERAL DAYS AND
PERHAPS REACHING 90 DEGREES IN THE FAR NORTHWESTERN SECTIONS OF
ZAPATA COUNTY. LOWS WILL BE IN THE 70S.
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...AS LOW PRESSURE
TROUGHS DEEPEN ACROSS SW U.S. AND JUST OFF THE SE U.S. COAST MID
TO UPPER LEVEL RIDGE BUILDS OVER SOUTH TEXAS AND THE WESTERN
GULF. THIS SHOULD IN A MOSTLY DRY RAINFREE WED NIGHT THROUGH
SUNDAY PERIOD. NOT UNTIL THE WESTERN TROUGH BEGINS TO MOVE
NORTHEAST LATE NEXT WEEKEND INTO EARLY NEXT WEEK WILL THERE BE
SOME INCREASE IN THE CHANCE OF RAIN. MODELS REMAIN RATHER
PERSISTENT IN THIS PATTERN AND HAVE BEEN IN GOOD CONSISTENCY
MAKING FOR A BETTER THAN AVERAGE CONFIDENCE IN THE OUTGOING
FORECAST.
OVERALL, THE EARLY DOG DAYS OF SUMMER WILL BE SETTING UP AS THE
BUILDING UPPER RIDGE AND STRONG CAPPING INVERSION BETWEEN
850-700MB TO DOMINATE. THE BUILDING RIDGE PROMOTES A DIVERGENT Q
VECTOR FIELD OR A CONFLUENT FLOW ALOFT AND THE 850-700MB CAPPING
INVERSION STRENGTHENS WITH A THE PERSISTENT SOUTHWEST FLOW.
WITHOUT ANY LIFTING MECHANISM AND DISTURBANCES/VORT MAXES LIKELY
TO BE DIVERTED NORTHEAST OF THE AREA DO NOT SEE ANY SIGNIFICANT
CHANCE OF RAIN. WITH THAT SAID HAVE KEPT THE LOW CHANCE POPS
ACROSS THE NW ZONES JUST IN CASE A ROUGE THUNDERSTORM MOVES IN
FROM THE SIERRA MADRE.
WARM/HOT, HUMID AND BREEZY WILL BE THE WORD THROUGH AT LEAST
SUNDAY WITH WINDIEST DAYS NEXT WEEKEND AS THE UPPER TROUGH OVER
THE DESERT SW LIFTS INTO THE CENTRAL PLAINS STRENGTHENING THE
PRESSURE GRADIENT. AS WE MOVE INTO NEXT WEEK MODELS SUGGEST AN
INCREASE IN RAIN CHANCES. THE WEAKENING OF THE RIDGE AND A
TRAILING COLD FRONT MOVING INTO CENTRAL TEXAS ALONG WITH POOLING
MOISTURE SOUTH OF THE BOUNDARY LOOKS TO THE INGREDIENTS NEEDED TO
GET A FEW STORMS IN OUR REGION. HAVE BROAD BRUSHED THE CWA WITH
LOW GRADE POPS NEXT MONDAY AND TUESDAY TO ACCOMMODATE THE MODEL
CONSENSUS.
&&
.MARINE...NOW THROUGH WEDNESDAY...MODERATE SOUTHEAST WINDS
AND MODERATE SEAS WILL CONTINUE AS HIGH PRES REMAINS DOMINANT
OVER THE SOUTHEAST U.S. AND THE NORTH GULF...COUNTERBALANCED BY
SOMEWHAT LOWER PRESSURE OVER THE SOUTHERN HIGH PLAINS. WINDS AND
SEAS MAY INCREASE SLIGHTLY AT TIMES...WITH SMALL CRAFT EXERCISE
CAUTION TO LOW END SMALL CRAFT ADVISORY CONDITIONS POSSIBLE.
WEDNESDAY NIGHT THROUGH SUNDAY...A MODERATE TO STRONG PRESSURE
GRADIENT TO PERSIST THIS PERIOD. BROAD HIGH PRESSURE OVER THE
GULF TO INTERACT WITH LOWER PRESSURE OVER NW TEXAS TO PRODUCE
MARGINAL SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY NIGHT THROUGH
FRIDAY. LOW PRESSURE STRENGTHEN OVER THE WEEKEND WITH A POSSIBLE
UPTICK IN WINDS AND SEAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 85 75 83 75 / 10 10 10 10
BROWNSVILLE 86 74 85 75 / 10 10 10 10
HARLINGEN 87 74 87 74 / 10 10 10 10
MCALLEN 89 75 88 75 / 20 10 10 10
RIO GRANDE CITY 87 74 90 74 / 20 10 20 20
SOUTH PADRE ISLAND 81 75 83 75 / 10 10 10 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55/59
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1141 PM CDT Mon May 4 2015
.AVIATION...
/06Z TAFS/
Widespread convection continues across West Central TX and may be
a factor at KABI during the overnight hours. At KABI, VCSH was
included after 08z, with the remaining terminals dry. Low clouds
are expected to develop once again areawide, and may encroach on
IFR range (<1000 ft) during the early morning hours. The most
likely area for IFR ceilings will be along the I-10 corridor.
However, the abundant mid/high cloud cover and strong low-level
jet may preclude ceilings below 1000 ft.
MVFR ceilings will persist most of the day and scattered
convection is anticipated by late morning across much of West
Central TX. Thunderstorms are forecast for the afternoon and
evening hours, but scattered coverage limits the probability at
any given forecast terminal. Thus, -SHRA and VCSH were included as
the prevailing weather group for now.
Johnson
&&
.PREV DISCUSSION... /ISSUED 836 PM CDT Mon May 4 2015/
UPDATE...
Convection continues to the west of the CWA. One batch of storms
is lifting slowly northeast across the South Plains from Lamesa to
near Snyder. A few showers and thunderstorms extend to the south
and southeast from this complex, generally along and north of the
Colorado River. Farther south, a persistent, right-moving
supercell continues to parallel I-10 near Ft. Stockton, with
additional development to its west. Given the proximity of this
storm to Crockett County, a Tornado Watch was issued through 2 AM.
Surface based instability is a bit more limited east of the Pecos
River, so the thinking is that this storm should weaken as it
moves into Crockett County. However, the HRRR has shown a tendency
for additional development in the Big Bend area overnight. There
is also the potential for additional thunderstorms to move into
the Big Country and Concho Valley late tonight and early Tuesday.
If this occurs, it may limit the severe weather potential for
tomorrow afternoon/evening. Will have to wait and see how this
plays out.
PREV DISCUSSION... /ISSUED 629 PM CDT MON MAY 4 2015/
AVIATION...
/00Z TAFS/
Flight conditions will deteriorate at all terminals through the
next 24 hours. Ceilings will drop into the 1500 to 2500 feet
range after 04z at all TAF sites, with southern terminals dropping
to around 800 feet after 08z. Southeast winds gusting over 20
knots are likely area- wide tonight, with these gusts increasing
to near 30 knots tomorrow afternoon across the northern terminals,
and near/over 20 knots farther south. Showers and thunderstorms
may develop at any time during the TAF cycle. For now, have
inserted VCTS at KABI and KSJT for the next couple of hours based
on radar trends..
PREV DISCUSSION... /ISSUED 353 PM CDT Mon May 4 2015/
SHORT TERM...
(Tonight-Tuesday Night)
The main weather concerns for the short term will be the isolated
threat of severe thunderstorms this afternoon and a little more
widespread threat for severe weather Tuesday.
Thunderstorms have already developed this afternoon across much of
west central Texas. So far, storms have been of the single cell
pulse variety and staying below severe levels. We may see an
isolated storm or two produce severe hail this afternoon/evening.
However, the bigger threat for severe weather today will be
farther west over the Permian Basin. We may see a few storms cross
into our western counties this evening...so have kept
precipitation chances going overnight. For tomorrow...an upper
trough over eastern New Mexico will head northeast across west
Texas as the dryline heads east toward our area. Increased cloud
cover may limit instability slightly. However, with decent shear
across the area, expect more organized convection to develop
tomorrow afternoon with a slightly higher threat for severe
weather. Think the best chance for severe storms will be across
the northern and western parts of the area. Storms should continue
into the evening hours.
LONG TERM...
(Wednesday-Monday)
Unsettled weather will continue through the majority of the
extended period, with showers and thunderstorms possible through
next weekend.
The short-wave trough will lift northeast of the area on
Wednesday, while another significant upper trough develops across
the western states. We`ll remain in southwest flow aloft ahead of
this system through Friday, with periodic disturbances moving
across the area. The dryline will remain west of the area on
Wednesday but will mix east into far western counties Thursday
and Friday. Showers and thunderstorms are expected to develop
just about anywhere on Wednesday due to a weaker CAP, with a few
strong to severe storms possible during the late afternoon and
evening hours.
Scattered strong to severe thunderstorms will remain a possibility
Thursday and Friday ahead of the upper trough to our west, with a
continued chance for severe storms next weekend as the upper
trough moves across the Plains.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 62 74 64 80 66 / 30 50 60 40 40
San Angelo 63 76 65 82 66 / 30 30 40 30 30
Junction 64 77 66 80 67 / 20 40 40 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
348 AM MDT TUE MAY 5 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
WEBCAMS ALONG INTERSTATE 80 HAVE CONSISTENTLY SHOWN DENSE FOG FROM
THE SUMMIT TO CHEYENNE OVER THE PAST FEW HOURS. DECIDED TO ADD
CENTRAL LARAMIE COUNTY (CHEYENNE) TO THE DENSE FOG ADVISORY
THRU 16Z WITH THE CYS OBS DROPPING TO ONE QUARTER MILE. THE LOW
CLOUDS AND FOG WILL REMAIN QUITE PERSISTENT THROUGH THE MORNING
WITH THE HRRR MODEL INDICATING LIFR/IFR CONDITIONS THROUGH 18Z
FROM THE INTERSTATE 80 SUMMIT EASTWARD TO CHEYENNE COUNTY. THIS
MAKES SENSE AS THE OVERALL SFC PATTERN OF VERY MOIST SOUTH TO
SOUTHEAST WINDS WILL CONTINUE THROUGH THE MORNING. WATER VAPOR
IMAGERY SHOWS THE SUBTROPICAL UPPER LOW SPINNING OVER NORTHEAST
ARIZONA. THE MODELS MOVE THIS FEATURE TO THE NORTHEAST OVER THE
COURSE OF THE DAY TO NEAR NORTHERN COLORADO BY THIS EVENING.
ONLY AN ISOLATED TO SCATTERED COVERAGE OF SHOWERS IS
EXPECTED THROUGH THE EARLY AFTN ALONG THE COLORADO BORDER.
HOWEVER...MIDLVL HEIGHT FALLS WILL COMBINE WITH INCREASING
DEEP LAYER MOISTURE TO PROMOTE A MORE WIDESPREAD COVERAGE BY THE
LATE AFTN AND EARLY EVENING. MOISTURE IS PLENTIFUL WITH THIS
SYSTEM...IN FACT PW VALUES OF 0.75-1.0 INCHES OVER THE PLAINS ARE 2
STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY MAY. THUS...WITH
RELATIVELY SLOW STORM MOTIONS...LOCALLY HEAVY RAIN WILL BE A
CONCERN ESPECIALLY OVER THE NEBRASKA PANHANDLE. WHILE ISOLATED
TSTMS WILL BE POSSIBLE THIS AFTN...THE VERY WEAK INSTABILITY AND
SHEAR WILL MAKE STRONG STORMS UNLIKELY. SPC HAS DROPPED THE
MARGINAL THREAT OVER THE SOUTHERN PANHANDLE. WITH THE MIDLVL
DISTURBANCE OVERHEAD TONIGHT...WILL KEEP A CHANCE OF SHOWERS
GOING. SOUTHEAST SFC WINDS ARE IN PLACE THRU 12Z WED...SO FOG
WILL AGAIN BE A THREAT OVER PORTIONS OF THE AREA.
THE SHORTWAVE WILL PUSH INTO WESTERN SOUTH DAKOTA/NEBRASKA BY WED
AFTN. THE MODELS SHOW THE HIGHEST QPF OVER THE PLAINS OF SOUTHEAST
WY AS A SFC COLD FRONT INTERACTS WITH GOOD MOISTURE. WILL HAVE
ISOLATED TSTMS DURING THE AFTN WITH SOME LIMITED CAPE. PRECIP
CHANCES DROP OFF WED EVENING BEHIND THE FRONT AS A DRIER AIRMASS
MOVES IN. THERE COULD ACTUALLY BE A 18-24 HR PERIOD FROM WED
EVENING THRU THURS AFTN WHEN MUCH OF THE CWA WILL BE PRECIP FREE.
SCATTERED STORMS WILL ONCE AGAIN DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE BY THURS AFTN...WITH LIMITED COVERAGE OVER THE
PLAINS IN A MORE STABLE AIRMASS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
UNSETTLED WEATHER CONTINUES IN THE LONG TERM. MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE THE POSSIBILITY OF WINTER WEATHER
RETURNING TO THE AREA LATE IN THE WEEKEND.
STARTING OFF THURSDAY NIGHT...WE STILL HAVE THE STALLED SURFACE
BOUNDARY LAYING ALONG THE LARAMIE RANGE...OR SLIGHTLY WEST. BOTH
THE GFS AND ECMWF VERY SIMILAR BRINGING ANOTHER PIECE OF ENERGY
NORTHEAST FROM THE DESERT SOUTHWEST TO INTERACT WITH THIS
BOUNDARY...SO WILL KEEP CHANCE POPS GOING FOR THE THURSDAY NIGHT
TIME FRAME. PROBABLY PRETTY LIGHT SHOWERS THOUGH AS HAS BEEN THE
CASE THE PAST FEW NIGHTS. CONVECTION PICKS UP THROUGH FRIDAY AFTERNOON
WITH BOTH MODELS CONCENTRATING ON THE SOUTHERN PANHANDLE AND
NORTHEASTERN COLORADO. SOUTHEAST UPSLOPING WINDS TO CONTINUE.
GFS AND ECMWF CONTINUE TO AGREE ON A CLOSED LOW ROUNDING THE BASE
OF THE LONGWAVE TROUGH SATURDAY MORNING AND BEGINNING TO LIFT
NORTHEAST INTO SOUTHWESTERN COLORADO SATURDAY AFTERNOON. OUR
FORECAST AREA IS SQUARE IN THE WRAP AROUND MOISTURE TO THE NORTH
OF THIS LOW. ECMWF A LITTLE FASTER ON MOVEMENT OVER THE
GFS...MOVING THE LOW INTO CENTRAL NEBRASKA ROUGHLY 12 HOURS FASTER
THAN THE GFS. BOTH ARE COLD THOUGH ON 700MB TEMPERATURES AND COLD
ENOUGH FOR WIDESPREAD SNOW. BOTH ARE SHOWING 850MB WINDS OF 40 TO
45KTS ACROSS THE PANHANDLE AND EASTERN WYOMING. WINTER IS NOT DONE
WITH SOUTHEAST WYOMING AND WE NEED TO BE WATCHING THE EVOLUTION OF
THIS EVENT AS HEAVY SNOW AND WINTER HEADLINES ARE DEFINITELY A
POSSIBILITY FOR PORTIONS OF THE FORECAST AREA...POSSIBLY EVEN THE
PANHANDLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1055 PM MDT MON MAY 4 2015
WIDESPREAD IFR/LIFR FOR THE OVERNIGHT HOURS FOR MOST SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE AIRPORTS WITH SOUTHEAST TO EAST
UPSLOPING WINDS. EXPECT THIS TO LAST THROUGH THE MID TO LATE
MORNING HOURS BEFORE CONDITIONS IMPROVE SOME...BUT THEN WE WILL BE
DEALING WITH SHOWERS AND THUNDERSTORMS. LOW STRATUS RETURNING
TUESDAY EVENING...BECOMING WIDESPREAD ONCE AGAIN.
&&
.FIRE WEATHER...
ISSUED AT 345 AM MDT TUE MAY 5 2015
A COOL AND WET WEATHER PATTERN WILL KEEP FIRE WEATHER CONCERNS VERY
LOW THROUGH THE WEEKEND. AFTERNOON AND EVENING SHOWERS WILL BE
POSSIBLE TODAY THROUGH THURSDAY...WITH GOOD CHANCES FOR MEASURABLE
RAIN. MORE SUBSTANTIAL PRECIPITATION AMOUNTS ARE LOOKING POSSIBLE
BY LATE FRIDAY INTO SUNDAY ASSOCIATED WITH A STRONG STORM SYSTEM.
MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE PERIOD.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR WYZ116>118.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS TUCSON AZ
853 AM MST TUE MAY 5 2015
.SYNOPSIS...THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY
NORTHEAST OF TUCSON INTO THIS EVENING. DRY CONDITIONS WILL THEN
PREVAIL WEDNESDAY INTO EARLY NEXT WEEK. THE EXCEPTION WILL BE A FEW
SHOWERS AND THUNDERSTORMS ACROSS THE WHITE MOUNTAINS SATURDAY.
EXPECT BREEZY TO WINDY CONDITIONS DURING THE LATTER PART OF THE
WEEK. BELOW NORMAL DAYTIME TEMPERATURES WILL OCCUR INTO SATURDAY
FOLLOWED BY A SIGNIFICANT WARMING TREND EARLY NEXT WEEK.
&&
.DISCUSSION...THE UPPER LOW THAT BROUGHT SHOWERS AND THUNDERSTORMS
TO THE AREA YESTERDAY AND LAST NIGHT WILL CONTINUE TO INFLUENCE THE
WEATHER TODAY. RESIDUAL MOISTURE COMBINED WITH DAYTIME HEATING AND
SOME SUPPORT FROM THE UPPER LOW WILL RESULT IN MORE SHOWERS AND
THUNDERSTORMS TODAY. LATEST HRRR MODEL SOLUTION KEEPS MOST OF THIS
ACTIVITY JUST EAST AND NORTHEAST OF THE TUCSON METRO THIS AFTERNOON
AND EVENING. THEREAFTER...MODELS EJECT THIS UPPER LOW NORTHEAST INTO
THE CENTRAL PLAINS BY TOMORROW MORNING RESULTING IN A BREAK IN RAIN
CHANCES. HOWEVER...ANOTHER SYSTEM WAS PROGGED TO DROP SOUTH ALONG
THE INTERIOR WEST COAST INTO CENTRAL CALIFORNIA ON THURSDAY. THIS
NEXT SYSTEM WILL BRING STRONG AND GUSTY WINDS TO THE AREA AS EARLY
AS TOMORROW BUT MORE SO THURSDAY. CURRENT FORECAST LOOKED ON
TRACK...SO NO UPDATES NECESSARY THIS MORNING. PLEASE REFER TO THE
ADDITIONAL SECTIONS FOR MORE DETAILS.
&&
.AVIATION...VALID THRU 06/18Z.
SCATTERED -TSRA/-SHRA WILL PREVAIL TODAY MAINLY ACROSS THE WHITE
MOUNTAINS NE OF KSAD. EXPECT ISOLATED -TSRA/-SHRA FURTHER SWWD TO
NEAR THE CATALINA/RINCON MOUNTAINS NEAR KTUS. DRY CONDITIONS WILL
THEN PREVAIL LATE TONIGHT AND EARLY WEDNESDAY MORNING. OTHERWISE...
IMPROVING CONDITIONS THIS PERIOD AS A LOW PRESSURE TROUGH OVER
ARIZONA THIS MORNING MOVES INTO NEW MEXICO THIS EVENING. CLOUDS WILL
DECREASE FROM WEST TO EAST THIS AFTERNOON WITH CLEAR SKIES OR MOSTLY
CLEAR SKIES EARLY WEDNESDAY MORNING. SURFACE WIND THIS AFTERNOON
WILL BE WLY/NWLY 12-18 KTS WITH GUSTS OF 20-25 KTS. SURFACE WIND
WILL BE MAINLY LESS THAN 10 KTS AT OTHER TIMES. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUES
MAINLY EAST OF TUCSON TODAY...AND A FEW SHOWERS MAY LINGER ACROSS
THE WHITE MOUNTAINS THIS EVENING. DRY CONDITIONS WILL THEN PREVAIL
LATE TONIGHT.
A LOW PRESSURE SYSTEM WILL STRENGTHEN NORTHWEST OF THE AREA
WEDNESDAY INTO FRIDAY. THIS SYSTEM WILL PRODUCE BREEZY CONDITIONS
WEDNESDAY AFTERNOON FOLLOWED BY BREEZY TO WINDY CONDITIONS THURSDAY
AND FRIDAY. HOWEVER...DAYTIME MINIMUM RELATIVE HUMIDITIES AND
FUEL MOISTURE WILL BE MARGINAL AT BEST TO PRODUCE CRITICAL FIRE
CONDITIONS. A FEW SHOWERS AND THUNDERSTORMS MAY THEN OCCUR ACROSS
THE WHITE MOUNTAINS SATURDAY AS THE LOW PRESSURE SYSTEM MOVES NORTH
OF THE AREA. EXPECT LESS WIND THIS WEEKEND ALTHOUGH SOME AFTERNOON
GUSTINESS WILL OCCUR DUE TO DAYTIME HEATING.
&&
.PREV DISCUSSION...UPPER LEVEL TROUGH WAS OVER THE WRN CONUS THIS
MORNING WITH A WEAK LOW PRESSURE SYSTEM CENTERED OVER NERN ARIZONA.
THIS LOW PRESSURE SYSTEM WILL FILL AND MOVE EWD INTO THE CENTRAL
ROCKIES THIS AFTERNOON. THE NEXT UPSTREAM COLD UPPER LOW WILL DIG
OVER SRN BRITISH COLUMBIA AND THE PACIFIC NW.
MEANWHILE...ADEQUATE MOISTURE WILL PROVIDE A CHANCE OF SHOWERS/TSTMS
THIS MORNING ACROSS THE WHITE MOUNTAINS...AND A SLIGHT CHANCE OF
SHOWERS/TSTMS WILL OCCUR FURTHER SWWD TO NEAR THE TUCSON METRO AREA.
DRIER AIR WILL THEN SPREAD EWD ACROSS THE AREA THIS AFTERNOON INTO
TONIGHT. A CHANCE OF SHOWERS/TSTMS CONTINUES THIS AFTERNOON ACROSS
THE WHITE MOUNTAINS WITH ISOLATED SHOWERS/TSTMS ACROSS GRAHAM
COUNTY. ANY SHOWERS/TSTMS THIS EVENING SHOULD BE CONFINED TO THE
WHITE MOUNTAINS. DRY CONDITIONS WILL THEN PREVAIL LATE TONIGHT.
THE FLOW ALOFT WILL BECOME INCREASINGLY SWLY WED AS THE COLD UPPER
LOW PRESENTLY OVER SRN BRITISH COLUMBIA AND THE PACIFIC NW DIGS INTO
THE GREAT BASIN. A TIGHTENING MID-LEVEL GRADIENT AHEAD OF THIS
SYSTEM WILL PRODUCE SOME BREEZINESS WED AFTERNOON. EXPECT BREEZY TO
WINDY CONDITIONS THUR-FRI AS THE LOW PRESSURE SYSTEM CONTINUES TO
DEEPEN NW OF THE AREA. HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS/
TSTMS ACROSS THE WHITE MOUNTAINS SAT AS THE UPPER LOW FILLS AND
MOVES NORTH OF THE AREA. OTHERWISE...DRY CONDITIONS WILL PREVAIL SAT-
MON. EXPECT LESS WIND THIS WEEKEND...ALTHOUGH SOME AFTERNOON GUSTS
WILL OCCUR DUE TO DAYTIME HEATING.
BELOW NORMAL DAYTIME TEMPS WILL OCCUR THRU SATURDAY FOLLOWED BY A
WARMING TREND SUN-MON.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1042 AM EDT TUE MAY 5 2015
.SYNOPSIS...
A WEAK COLD FRONT MAY BRING A FEW BRIEF SHOWERS TODAY...BUT DRY
WEATHER AND MILD TEMPERATURES WILL DOMINATE. LITTLE CHANGE IS
EXPECTED THROUGH THE WEEKEND...WITH MILD TO WARM AFTERNOON/S AND
MAINLY DRY WEATHER PERSIST. A SLOW MOVING FRONT MAY BRING A FEW
SHOWERS LATE THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1041 AM UPDATE...
WEAK COLD FRONT STILL CROSSING THE REGION. THIS FRONT EXTENDED
FROM JUST EAST OF KLWM...TO NEAR KORH...TO JUST SOUTH OF KBDL.
05/12Z CHH SOUNDING SHOWED AN IMPRESSIVE SURFACE-BASED INVERSION.
KBOX 88D SHOWING THE MAJORITY OF THE SHOWERS MOVING OVER THE
COASTAL WATERS EAST OF MA MID-MORNING. LATEST RUNS OF THE HRRR AND
RAP PREDICTING MORE SHOWERS DEVELOPING FARTHER WEST LATE THIS
MORNING...THEN MOVING ACROSS PORTIONS OF RI AND SOUTHEAST MA. THIS
IS ALSO STARTING TO SHOW IN THE RADAR DATA...SO RELIED HEAVILY ON
A HRRR/RAP COMBINATION TO UPDATE RAINFALL CHANCES THROUGH THE REST
OF TODAY.
TEMPERATURES WILL BE TRICKY. LOTS OF CLOUD COVER THIS MORNING.
VISIBLE SATELLITE DATA SHOWING PLENTY OF CLEARING THOUGH BEHIND
THE COLD FRONT...AT LEAST FOR NOW. OPEN-CELLULAR STRATOCUMULUS
CLOUDS STARTING TO POP ACROSS SOUTHERN VT AND SOUTHERN NH. FULLY
EXPECT THIS TREND TO CONTINUE ACROSS SOUTHERN NEW ENGLAND LATER
TODAY...ONCE THIS COLD FRONT MOVES COMPLETELY OFFSHORE. KEPT
TEMPERATURES WELL ABOVE NORMAL...BUT NOT QUITE AS HIGH AS
YESTERDAY.
PREVIOUS DISCUSSION...
PLENTY OF MID LEVEL CLOUDINESS WILL BE AROUND DURING THE MORNING...
BUT STILL EXPECT PEEKS OF SUN. AS THE AFTERNOON WEARS ON...EXPECT
SUNSHINE TO BECOME MORE PREVALENT AS DRIER AIR WORKS IN BEHIND THE
COLD FRONT.
GIVEN VERY MILD START...HIGH TEMPS IN MOST LOCALES SHOULD CLIMB WELL
UP INTO THE 70S. IT/S NOT OUT OF THE QUESTION THAT A SPOT
LOCATION OR TWO HITS 80. HOWEVER...ACROSS THE IMMEDIATE COAST
WEAKENING PRESSURE GRADIENT BEHIND THE COLD FRONT WILL ALLOW
COOLING SEA BREEZES TO DEVELOP. IN THESE LOCATIONS...MILD LATE
MORNING TEMPS WILL PROBABLY FALL BACK INTO THE UPPER 50S AND LOWER
60S...INCLUDING BOSTON. JUST INLAND FROM THE COAST THOUGH IT WILL
REMAIN QUITE MILD EVEN BEHIND THE FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT AND WEDNESDAY...
DRY AND PLEASANT WEATHER EXPECTED FOR MOST OF TONIGHT AS HIGH
PRESSURE BUILDS IN BEHIND THE COLD FRONT. LOW TEMPS WILL MAINLY BE
IN THE 40S...TO LOWER 50S.
A MOISTURE STARVED SHORTWAVE WILL DROP DOWN IN WEST TO NORTHWEST
FLOW ALOFT WED MORNING. NOT SURE IF IT WILL TRACK FAR ENOUGH
NORTHWEST TO RESULT IN A BRIEF PERIOD OF SCATTERED SHOWERS ACROSS
ANY PORTION OF OUR REGION. BEST SHOT IS NORTHERN CT...AND PERHAPS
EVEN INTO PART OF RHODE ISLAND AND SOUTHEAST MA FOR A SHORT TIME.
REGARDLESS...EVEN IF A FEW SHOWERS OCCUR THEY WILL BE SHORT-LIVED
AND NOT AMOUNT TO MUCH. MORE IN THE WAY OF SUNSHINE SHOULD DEVELOP
FROM NORTH TO SOUTH THROUGH WED AFTERNOON. HIGHS SHOULD GENERALLY
REACH WELL INTO THE 70S IN MOST LOCATIONS...WITH THE WARMEST
READINGS NORTH OF THE PIKE WHERE THE MOST SUNSHINE IS EXPECTED. ITS
ALSO POSSIBLE THAT AREAS NEAR THE SOUTH COAST DO NOT REACH 70 ON
WEDNESDAY...IF CLOUDS HANG ON LONGER THEN EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* SPRING TO SUMMER-LIKE TEMPERATURES THROUGH EARLY NEXT WEEK
* HIGH PRESSURE WILL KEEP MAINLY DRY CONDITIONS INTO THIS WEEKEND
* A SLOW MOVING FRONT MAY BRING SCATTERED SHOWERS SUN INTO MON
OVERVIEW AND MODEL PREFERENCES...
00Z GEFS/12Z ECENS REMAIN IN GOOD AGREEMENT WITH OVERALL UPPER
LEVEL STEERING FLOW IN KEEPING AMPLIFIED PATTERN ACROSS THE LOWER
48 THROUGH MOST OF THIS FORECAST PERIOD. NOTING LONG WAVE
TROUGHING WITH A FEW CUTOFF SHORT WAVES DIVE S INTO THE BASE OF
THE TROUGH INTO THIS WEEKEND WHILE LONG WAVE RIDGE SLOWLY BUILDS E
AS IT NOSES N THROUGH EASTERN QUEBEC TO LABRADOR. ALSO NOTING
NEARLY STATIONARY CUTOFF LOW OFF THE SE U.S. COAST WITH SURFACE
LOW/POSSIBLE SUBTROPICAL SYSTEM LATE IN THE WEEK OR THIS WEEKEND.
WHILE THIS SYSTEM WILL NOT DIRECTLY AFFECT THE REGION... IT COULD
CAUSE THE RIDGE TO HOLD IN PLACE AND SLOW AN APPROACHING COLD
FRONT FOR LATE THIS WEEKEND INTO NEXT MONDAY.
00Z MODEL SUITE ALSO IN FAIRLY GOOD AGREEMENT INTO THIS WEEKEND...
THEN THE GFS LOOKS TO BREAK DOWN RIDGING FASTER THAN GGEM/ECMWF...
MAINLY DUE TO SHORT WAVE TRYING TO WORK OUT OF CENTRAL CANADA
WHICH FLATTENS OUT THE RIDGE. WITH OVERALL BLOCKING PATTERN IN
PLACE ACROSS NORTH AMERICA AND FURTHER E ACROSS THE ATLC...FEEL
THIS WILL BE SLOW TO BREAK DOWN SO THINK THE SLOWER GUIDANCE IS
THE WAY TO GO FOR SUN-MON. HOWEVER...WITH THE WIDE MODEL
SOLUTIONS...HAVE LOW CONFIDENCE FROM SATURDAY INTO EARLY NEXT
WEEK.
LEANED TOWARD A BLEND OF MODEL GUIDANCE INTO THIS WEEKEND...THEN
BLENDED TOWARD THE ENSEMBLES FOR SUN-MON WHICH WAS CLOSE TO THE
HPC GUIDANCE. THIS YIELDED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.
DETAILS...
WEDNESDAY NIGHT...EXPECT STALLED FRONT NEAR THE S COAST TO TEND TO
WASH OUT AS IT SHIFTS A BIT FURTHER S AS HIGH PRES AT THE SURFACE
AND ALOFT SLOWLY PUSHES ACROSS THE REGION. WILL SEE GENERALLY DRY
CONDITIONS WITH LIGHT/VRBL WINDS.
THURSDAY-FRIDAY...RIDGING BUILDS E ACROSS NEW ENGLAND INTO EASTERN
CANADA DURING THIS TIMEFRAME. EXPECT LIGHT/VRBL WINDS EARLY THU TO
BECOME S-SW. THIS WILL KEEP MILD TEMPS IN PLACE EXCEPT ALONG THE S
COAST WHERE THEY WILL BE TEMPERED WITH THE GENERAL ONSHORE WIND
FLOW. MAY ALSO SEE BRIEF SEA BREEZES ALONG THE E COAST MAINLY ON
FRIDAY. ALSO...DUE TO SEA SURFACE TEMPS RUNNING IN THE MID-UPPER
40S AND MILD TEMPS DURING THE NIGHTTIME HOURS...MAY SEE OVERNIGHT
PATCHY FOG DEVELOP MAINLY ALONG THE COAST WHILE INCREASING DEWPTS
MAY ALSO MEAN BRIEF PATCHY FOG ACROSS THE NORMALLY SUSCEPTIBLE
INLAND LOCATIONS EACH NIGHT.
HIGHS BOTH DAYS AWAY FROM THE S COAST WILL BE IN THE 70S...
POSSIBLY UP TO AROUND 80 ACROSS PORTIONS OF THE CT VALLEY BOTH
DAYS.
SATURDAY THROUGH MONDAY...AS MENTIONED ABOVE...MODEL SOLUTIONS
WIDEN. HAVE MENTIONED ONLY SLIGHT CHANCE POPS MAINLY N OF THE MASS
PIKE SAT AFTERNOON/NIGHT. INCREASED POPS TO ONLY LOW CHANCE FOR
SUN/MON FOR MOST AREAS...BUT WILL DEPEND UPON TIMING OF THE
APPROACHING FRONT. EXPECT MILD TEMPS TO REMAIN IN PLACE THROUGH
THIS WEEKEND WITH HIGHS IN THE 70S /EXCEPT COOLER ALONG IMMEDIATE
S COAST/.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH WEDNESDAY/...
TODAY...HIGH CONFIDENCE. EXPECT VFR CONDITIONS...THOUGH CIGS WILL
LOWER TO 4-5KFT ALONG FRONT INVOF BAND OF SHOWERS AS IT MOVES S
OUT OF CENTRAL MA THROUGH MIDDAY. MAY SEE BRIEF LOCAL MVFR
CONDITIONS IN ANY HEAVIER SHOWERS.
TONIGHT AND WEDNESDAY...HIGH CONFIDENCE. MAINLY VFR CONDITIONS. A
BRIEF PERIOD OF ISOLATED TO SCATTERED SHOWERS MAY AFFECT NORTHERN CT
AND POSSIBLY A PART OF RI/SOUTHEAST MA FOR A TIME WED AM. THIS MAY
RESULT IN VERY BRIEF LOCALIZED MVFR CONDITIONS IF ANY OCCUR.
KBOS TAF...HIGH CONFIDENCE IN TAF. SEA BREEZES EXPECTED TO DEVELOP
THIS AFTERNOON AS A RESULT OF A WEAKENING PRESSURE GRADIENT BEHIND A
COLD FRONT.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
HIGH CONFIDENCE THROUGH THE PERIOD. VFR AND DRY CONDITIONS. LOW
RISK FOR PATCHY FOG EACH NIGHT FROM AROUND MIDNIGHT THROUGH SUNRISE
WITH LOCAL MVFR-IFR CIGS/VSBYS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH WEDNESDAY/...
TODAY THROUGH WEDNESDAY...HIGH CONFIDENCE. MARGINAL SMALL CRAFT
SEAS WILL CONTINUE TO DIMINISH ACROSS THE OUTER COASTAL WATERS
INTO THIS AFTERNOON. WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT
ADVISORY THRESHOLDS THROUGH WEDNESDAY UNDER A WEAK RIDGE OF HIGH
PRESSURE.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE
THROUGH THE PERIOD.
WEDNESDAY NIGHT...LIGHT/VRBL WINDS BECOME S-SW AROUND OR AFTER
MIDNIGHT AT 15 KT OR LESS. SEAS 3 FT OR LESS.
THURSDAY...W-SW WINDS UP TO 15 KT ACROSS THE OPEN WATERS DURING
THE AFTERNOON. SEAS REMAIN BELOW 5 FT.
THURSDAY NIGHT THROUGH SATURDAY...SW WINDS 15 KT OR LESS WITH SEAS
2-4 FT. LOW CHANCE OF 5 FT SEAS ON THE EASTERN OUTER WATERS SAT
AFTERNOON/NIGHT.
&&
.FIRE WEATHER...
MAINLY DRY WEATHER WITH LITTLE APPRECIABLE RAINFALL WILL CONTINUE
THROUGH AT LEAST SATURDAY IF NOT INTO SUNDAY/MONDAY. WHILE WINDS
FOR THE REST OF THE WORK WEEK WILL PROBABLY NOT BE STRONG ENOUGH
FOR FIRE WEATHER HEADLINES...WE MAY HAVE TO BE MORE CONCERNED BY
SATURDAY. THERE WILL BE AT LEAST A BIT MORE POTENTIAL FOR SOME
MARGINAL FIRE WEATHER HEADLINE WIND GUSTS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...BELK/FRANK/EVT
SHORT TERM...FRANK
LONG TERM...EVT
AVIATION...BELK/FRANK/EVT
MARINE...BELK/FRANK/EVT
FIRE WEATHER...STAFF
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT TUE MAY 5 2015
.UPDATE...
ISSUED AT 1045 AM CDT TUE MAY 5 2015
15Z/10AM SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY EXTENDING FROM
NORTH-CENTRAL ILLINOIS INTO CENTRAL IOWA...GENERALLY ALONG A
KANKAKEE...TO PEORIA...TO DES MOINES LINE. WIDESPREAD RAIN
CONTINUES TO FALL NORTH OF THE FRONT: HOWEVER, MOSTLY SUNNY AND
DRY CONDITIONS PREVAIL TO THE SOUTH ACROSS CENTRAL ILLINOIS.
TEMPERATURES HAVE ALREADY RISEN WELL INTO THE 70S ACROSS ALL BUT
THE FAR NORTHERN KILX CWA. BASED ON THE 12Z UPPER AIR SOUNDING AND
ASSUMING MIXING UP TO ABOUT 750MB SIMILAR TO YESTERDAY
AFTERNOON...HIGHS TODAY SHOULD REACH THE LOWER TO MIDDLE 80S. HAVE
ADJUSTED TEMPS UP BY A FEW DEGREES ACCORDINGLY.
&&
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
A FRONTAL BOUNDARY IS ORIENTED WEST-EAST ACROSS CENTRAL IL THIS
MORNING WITH PRECIPITATION IN ISENTROPIC ASCENT REGION LARGELY TO
THE NORTH OF THE BOUNDARY. MODELS INDICATE THE BOUNDARY AND
PRECIPITATION WILL SHIFT SLOWLY NORTHWARD TODAY. WEAK DISTURBANCES
MOVING ALONG THE BOUNDARY WILL PRODUCE SOME ENHANCEMENTS IN
CONVECTIVE SHOWER COVERAGE IN THE VICINITY...EARLY THIS MORNING FROM
AROUND THE ILLINOIS RIVER NORTHWESTWARD...AND LATE IN THE AFTERNOON
NORTH OF THE I-74 CORRIDOR. FOR THE MOST PART...CONVECTION SHOULD BE
WEAK AT THIS POINT WITH ONLY WEAK MID-LEVEL INSTABILITY REMAINING
THROUGH THE NIGHT...AND 0-6KM BULK SHEAR UP TO 25-30 KTS THIS
MORNING DIMINISHING SUBSTANTIALLY FOR THE AFTERNOON. 1000-1500
JOULES OF SURFACE-BASED CAPE SHOULD BE ABLE TO DEVELOP WITH
AFTERNOON HEATING ALONG/NORTH OF I-72 AND CAN`T RULE OUT ISOLATED
THUNDERSTORMS SOUTHWARD TO I-72 AS A RESULT.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
ONGOING CONVECTION ALONG THE BOUNDARY OVER NORTHERN ILLINOIS THIS
MORNING NOT ONLY DRIVING THE WEATHER THROUGHOUT THE DAY, BUT INTO
THE OVERNIGHT AS WELL. GFS AND NAM CONTINUE TO KEEP A BIT OF PRECIP
PRETTY FAR SOUTH, AS FAR SOUTH AS A LINE FROM HAVANA TO BLOOMINGTON.
HOWEVER, THE RAP/RUC AND THE HRRR ARE PUSHING THE AREA OF CONVECTION
WELL TO THE NORTH THROUGH THE MORNING WITH THE BOUNDARY. WHEN THE
SECONDARY WAVE RIPPLES THROUGH THE REGION AFTER 00Z, IT WOULD BE
DISPLACED NORTH OF THE FA. THE 4KM WRF HAS JUST THAT SOLUTION,
STARTING MORE IN LINE WITH THE RAP/RUC AND HRRR...AND KEEPING THE FA
DRY AFTER 00Z, BUT A LITTLE MORE GENEROUS WITH SOME ISOLATED
INSTABILITY SHOWERS. HAVE KEPT ISO TS IN THE NORTH, MAINLY ALONG
AND NORTH OF I-74 FOR THE EARLY EVENING.
HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION LATER TONIGHT,
SOUTHERLY WINDS PUSHING THE FRONT BACK TO THE NORTH AND OUT OF THE
FORECAST AREA THROUGH WED NIGHT. FORECAST REMAINS ROUGHLY THE SAME
BEYOND DAY 3... PRECIP CHANCES SLOWLY EDGING BACK INTO WEST CENTRAL
ILLINOIS FOR THURSDAY AS AN UPPER LEVEL WAVE PUSHES OUT OF THE SW.
THE ENERGY IS PART OF A GENERAL PATTERN SHIFT TO MORE SOUTHWESTERLY
FLOW WITH THE UPPER LEVEL TROF DIGGING BACK IN OVER THE SWRN CONUS.
THE SFC LOW MOVES OUT INTO THE UPPER MIDWEST AND INTO CANADA BY THE
END OF THE WEEK, BUT IN SHIFTING TO MORE SOUTHWESTERLY FLOW ALOFT,
OPENS THE DOOR TO A SERIES OF SHORTWAVES THAT KEEP THE FORECAST WET
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND. TEMPS RATHER
WARM THROUGH THE FORECAST WITH OVERCAST AND RAINY SKIES KEEPING THE
OVERNIGHT LOWS UP A BIT, BUT LIKELY NOT NEARLY AS WARM AS THE TREND
IN THE GUIDANCE. HAVE KNOCKED THEM DOWN A COUPLE DEGREES. SOUTHERLY
FLOW AND A RELATIVELY WARM AIRMASS KEEPING THE HIGHS A BIT ABOVE
NORMS, EVEN WITH THE PASSAGE OF THE FIRST LOW SKIRTING TO THE
NW...THE MID LEVELS REMAIN WARM UNTIL THE MAIN TROF OVER THE SW
LIFTS INTO AND OUT OF THE GREAT LAKES. COOLER AIR IN THE MIDLEVELS
IS ONLY AROUND FOR 36 HOURS DAY 7/8 BEFORE THE WARM AIRMASS
REESTABLISHES ITSELF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 647 AM CDT TUE MAY 5 2015
SHOWERS HAVE MOVED OUT OF CENTRAL IL TAF SITES THIS MORNING WITH
VFR CONDITIONS AT MOST SITES...AREAS BKN060-080 CIGS...AND IFR-
LIFR CONDITIONS IN FOG AT SITES FROM KPIA-KC75 NORTHWESTWARD. FOG
WILL DISSIPATE WITH DAYTIME HEATING IN A FEW HOURS. ALSO WITH
DAYTIME HEATING...EXPECTING ISOLD TSRA DEVELOPING FROM AROUND
18Z-24Z. SCT-BKN CLOUD COVER SHOULD DEVELOP AS WELL GENERALLY
ABOVE MVFR THRESHOLDS. PROBABILITY OF DEVELOPMENT AND TIMING
UNCERTAINTY PREVENT EXPLICIT MENTION OF TSRA IN CENTRAL IL
TAFS...HOWEVER MVFR OR WORSE CIGS/VSBYS POSSIBLE IN ISOLATED
STORMS. INSTABILITY DECREASING OVERNIGHT SHOULD BRING AN END TO
ANY STORMS SHORTLY AFTER SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1040 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* EAST-NORTHEAST WINDS INCREASING BACK TO 10 KT THIS AFTERNOON.
* IFR CIGS POSSIBLY LIFTING TO MVFR THIS AFTERNOON...RETURNING TO
LIFR TONIGHT.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN...MAINLY
ALONG AND MORE LIKELY SOUTH OF MDW.
KMD
//DISCUSSION...UPDATED 12Z...
THE RAIN IS SLOWLY SHIFTING NORTHEAST AND WILL CLEAR THE REGION
THIS MORNING. NO ADDITIONAL LIGHTNING STRIKES ARE ANTICIPATED WITH
THESE SHOWERS. THERE ARE SCATTERED REPORTS OF MVFR CIGS AND THE
CIGS SHOULD LIFT TO VFR BEHIND THE SHOWERS. A STATIONARY FRONT
WILL REMAIN SOUTH OF THE TERMINALS TODAY AND COULD SEE SHOWERS AND
PERHAPS A THUNDERSTORM FIRE ALONG THE FRONT THIS AFTERNOON. THE
SHOWERS AND STORMS COULD IMPACT THE EASTERN TERMINALS...BUT DUE
TO LOW CONFIDENCE ONLY HAVE A VCSH. THINKING RFD WILL NOT BE
IMPACTED.
EAST WINDS AT 10 KT DIMINISH TO BELOW 10 KT THIS EVENING AND THEN
BEGIN TO BACK TO SOUTHEAST TOMORROW AS THE FRONT LIFTS NORTH.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH THAT EAST-NORTHEAST WINDS PICK BACK UP TO AROUND 10
KT THIS AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN ORD REMAINING DRY THE REST OF THE
DAY. MEDIUM THAT AFTERNOON SHOWERS/ISOLATED T-STORMS REMAIN
SOUTH OF MDW.
* MEDIUM CONFIDENCE IN IFR CIGS LIFTING TO MVFR BUT LOW ON TIMING
AND DURATION. HIGH THAT IFR/LIFR CIGS AND VSBYS RETURN TONIGHT
BUT LOW ON TIMING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.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:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
903 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SCATTERED RAIN SHOWERS SHIFT EAST OF THE TERMINALS OVER THE NEXT
COUPLE OF HOURS. ISOLATED THUNDER GENERALLY SOUTH OF MDW BUT
POSSIBLY IN THE 5-10 MILE RANGE.
* EAST WINDS 10-11 KT.
* IFR CIGS LIFTING TO MVFR
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN.
KMD/JEE
//DISCUSSION...UPDATED 12Z...
THE RAIN IS SLOWLY SHIFTING NORTHEAST AND WILL CLEAR THE REGION
THIS MORNING. NO ADDITIONAL LIGHTNING STRIKES ARE ANTICIPATED WITH
THESE SHOWERS. THERE ARE SCATTERED REPORTS OF MVFR CIGS AND THE
CIGS SHOULD LIFT TO VFR BEHIND THE SHOWERS. A STATIONARY FRONT
WILL REMAIN SOUTH OF THE TERMINALS TODAY AND COULD SEE SHOWERS AND
PERHAPS A THUNDERSTORM FIRE ALONG THE FRONT THIS AFTERNOON. THE
SHOWERS AND STORMS COULD IMPACT THE EASTERN TERMINALS...BUT DUE
TO LOW CONFIDENCE ONLY HAVE A VCSH. THINKING RFD WILL NOT BE
IMPACTED.
EAST WINDS AT 10 KT DIMINISH TO BELOW 10 KT THIS EVENING AND THEN
BEGIN TO BACK TO SOUTHEAST TOMORROW AS THE FRONT LIFTS NORTH.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN SHOWERS...MEDIUM ON NO ADDITIONAL LIGHTNING
THIS MORNING EXCEPT ALONG AND SOUTH OF MDW.
* MEDIUM-LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF -SHRA THIS
AFTN. LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF TSRA.
* MEDIUM CONFIDENCE IN IFR CIGS LIFTING TO MVFR BUT LOW ON TIMING
AND DURATION.
KMD/JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.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:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
648 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* RAIN SHIFTS EAST OF THE TERMINALS OVER THE NEXT COUPLE OF
HOURS.
* EAST WINDS 10-11 KT.
* MVFR CIGS LIFT TO VFR AFTER SHOWERS MOVE OUT THIS MORNING.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN.
JEE
//DISCUSSION...UPDATED 12Z...
THE RAIN IS SLOWLY SHIFTING NORTHEAST AND WILL CLEAR THE REGION
THIS MORNING. NO ADDITIONAL LIGHTNING STRIKES ARE ANTICIPATED WITH
THESE SHOWERS. THERE ARE SCATTERED REPORTS OF MVFR CIGS AND THE
CIGS SHOULD LIFT TO VFR BEHIND THE SHOWERS. A STATIONARY FRONT
WILL REMAIN SOUTH OF THE TERMINALS TODAY AND COULD SEE SHOWERS AND
PERHAPS A THUNDERSTORM FIRE ALONG THE FRONT THIS AFTERNOON. THE
SHOWERS AND STORMS COULD IMPACT THE EASTERN TERMINALS...BUT DUE
TO LOW CONFIDENCE ONLY HAVE A VCSH. THINKING RFD WILL NOT BE
IMPACTED.
EAST WINDS AT 10 KT DIMINISH TO BELOW 10 KT THIS EVENING AND THEN
BEGIN TO BACK TO SOUTHEAST TOMORROW AS THE FRONT LIFTS NORTH.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN SHOWERS AND NO ADDITIONAL LIGHTNING THIS
MORNING.
* MEDIUM-LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF -SHRA THIS
AFTN. LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF TSRA.
* MEDIUM-HIGH CONFIDENCE IN CIGS IMPROVING TO VFR THIS MORNING.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.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:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
647 AM CDT TUE MAY 5 2015
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
A FRONTAL BOUNDARY IS ORIENTED WEST-EAST ACROSS CENTRAL IL THIS
MORNING WITH PRECIPITATION IN ISENTROPIC ASCENT REGION LARGELY TO
THE NORTH OF THE BOUNDARY. MODELS INDICATE THE BOUNDARY AND
PRECIPITATION WILL SHIFT SLOWLY NORTHWARD TODAY. WEAK DISTURBANCES
MOVING ALONG THE BOUNDARY WILL PRODUCE SOME ENHANCEMENTS IN
CONVECTIVE SHOWER COVERAGE IN THE VICINITY...EARLY THIS MORNING FROM
AROUND THE ILLINOIS RIVER NORTHWESTWARD...AND LATE IN THE AFTERNOON
NORTH OF THE I-74 CORRIDOR. FOR THE MOST PART...CONVECTION SHOULD BE
WEAK AT THIS POINT WITH ONLY WEAK MID-LEVEL INSTABILITY REMAINING
THROUGH THE NIGHT...AND 0-6KM BULK SHEAR UP TO 25-30 KTS THIS
MORNING DIMINISHING SUBSTANTIALLY FOR THE AFTERNOON. 1000-1500
JOULES OF SURFACE-BASED CAPE SHOULD BE ABLE TO DEVELOP WITH
AFTERNOON HEATING ALONG/NORTH OF I-72 AND CAN`T RULE OUT ISOLATED
THUNDERSTORMS SOUTHWARD TO I-72 AS A RESULT.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
ONGOING CONVECTION ALONG THE BOUNDARY OVER NORTHERN ILLINOIS THIS
MORNING NOT ONLY DRIVING THE WEATHER THROUGHOUT THE DAY, BUT INTO
THE OVERNIGHT AS WELL. GFS AND NAM CONTINUE TO KEEP A BIT OF PRECIP
PRETTY FAR SOUTH, AS FAR SOUTH AS A LINE FROM HAVANA TO BLOOMINGTON.
HOWEVER, THE RAP/RUC AND THE HRRR ARE PUSHING THE AREA OF CONVECTION
WELL TO THE NORTH THROUGH THE MORNING WITH THE BOUNDARY. WHEN THE
SECONDARY WAVE RIPPLES THROUGH THE REGION AFTER 00Z, IT WOULD BE
DISPLACED NORTH OF THE FA. THE 4KM WRF HAS JUST THAT SOLUTION,
STARTING MORE IN LINE WITH THE RAP/RUC AND HRRR...AND KEEPING THE FA
DRY AFTER 00Z, BUT A LITTLE MORE GENEROUS WITH SOME ISOLATED
INSTABILITY SHOWERS. HAVE KEPT ISO TS IN THE NORTH, MAINLY ALONG
AND NORTH OF I-74 FOR THE EARLY EVENING.
HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION LATER TONIGHT,
SOUTHERLY WINDS PUSHING THE FRONT BACK TO THE NORTH AND OUT OF THE
FORECAST AREA THROUGH WED NIGHT. FORECAST REMAINS ROUGHLY THE SAME
BEYOND DAY 3... PRECIP CHANCES SLOWLY EDGING BACK INTO WEST CENTRAL
ILLINOIS FOR THURSDAY AS AN UPPER LEVEL WAVE PUSHES OUT OF THE SW.
THE ENERGY IS PART OF A GENERAL PATTERN SHIFT TO MORE SOUTHWESTERLY
FLOW WITH THE UPPER LEVEL TROF DIGGING BACK IN OVER THE SWRN CONUS.
THE SFC LOW MOVES OUT INTO THE UPPER MIDWEST AND INTO CANADA BY THE
END OF THE WEEK, BUT IN SHIFTING TO MORE SOUTHWESTERLY FLOW ALOFT,
OPENS THE DOOR TO A SERIES OF SHORTWAVES THAT KEEP THE FORECAST WET
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND. TEMPS RATHER
WARM THROUGH THE FORECAST WITH OVERCAST AND RAINY SKIES KEEPING THE
OVERNIGHT LOWS UP A BIT, BUT LIKELY NOT NEARLY AS WARM AS THE TREND
IN THE GUIDANCE. HAVE KNOCKED THEM DOWN A COUPLE DEGREES. SOUTHERLY
FLOW AND A RELATIVELY WARM AIRMASS KEEPING THE HIGHS A BIT ABOVE
NORMS, EVEN WITH THE PASSAGE OF THE FIRST LOW SKIRTING TO THE
NW...THE MID LEVELS REMAIN WARM UNTIL THE MAIN TROF OVER THE SW
LIFTS INTO AND OUT OF THE GREAT LAKES. COOLER AIR IN THE MIDLEVELS
IS ONLY AROUND FOR 36 HOURS DAY 7/8 BEFORE THE WARM AIRMASS
REESTABLISHES ITSELF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 647 AM CDT TUE MAY 5 2015
SHOWERS HAVE MOVED OUT OF CENTRAL IL TAF SITES THIS MORNING WITH
VFR CONDITIONS AT MOST SITES...AREAS BKN060-080 CIGS...AND IFR-
LIFR CONDITIONS IN FOG AT SITES FROM KPIA-KC75 NORTHWESTWARD. FOG
WILL DISSIPATE WITH DAYTIME HEATING IN A FEW HOURS. ALSO WITH
DAYTIME HEATING...EXPECTING ISOLD TSRA DEVELOPING FROM AROUND
18Z-24Z. SCT-BKN CLOUD COVER SHOULD DEVELOP AS WELL GENERALLY
ABOVE MVFR THRESHOLDS. PROBABILITY OF DEVELOPMENT AND TIMING
UNCERTAINTY PREVENT EXPLICIT MENTION OF TSRA IN CENTRAL IL
TAFS...HOWEVER MVFR OR WORSE CIGS/VSBYS POSSIBLE IN ISOLATED
STORMS. INSTABILITY DECREASING OVERNIGHT SHOULD BRING AN END TO
ANY STORMS SHORTLY AFTER SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
627 AM EDT TUE MAY 5 2015
.SYNOPSIS...
A SLOW MOVING FRONTAL BOUNDARY WILL KEEP RAIN CHANCES IN THE
FORECAST THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR IMAGERY SHOWS A MASS OF SHOWERS CONGEALING OVER
EASTERN OHIO...PUSHING SLOWLY TO THE EAST. THIS ACTIVITY IS
LOCATED ALONG AND JUST SOUTH OF THE CURRENT WEAK SURFACE
FRONT...ORIENTED WITH HIGHER MOISTURE CONTENT. EXPECTING THESE
SHOWERS TO REACH THE PITTSBURGH METRO WITHIN THE NEXT TWO HOURS
BRINGING LIGHT RAIN FOR THE MORNING COMMUTE. HRRR HAS HAD A GOOD
HANDLE ON THIS REMNANT SHOWER ACTIVITY OVER THE LAST SEVERAL
HOURS...AND THUS WAS FOLLOWED THROUGH MID-MORNING.
BROAD FRONTAL ZONE AND DEEPER MOISTURE WILL SHIFT NORTH SOME
THROUGH MIDDAY AS A WAVE CURRENTLY NEARING LAKE MICHIGAN TRACKS
THROUGH THE SOUTHERN GREAT LAKES. THIS WILL SHIFT THE FOCUS OF
ANY AFTERNOON SHOWER OR THUNDERSTORM ACTIVITY NORTH AS WELL. HI-
RES MODELS THAT ARE HANDLING THE CURRENT TRENDS WITH SOME
SUCCESS...HAVE BEEN LESS THAN EXCITED ABOUT CONVECTIVE
DEVELOPMENT THIS AFTERNOON...TO THE POINT OF VERY LITTLE
PRECIPITATION ACROSS THE FORECAST AREA. STILL THINKING MODELS ARE
UNDERPRODUCING...GIVEN THE AVAILABILITY OF MOISTURE AND THE AT
LEAST MARGINAL INSTABILITY NOTED IN THE AFTERNOON SOUNDINGS. WILL
MAINTAIN CHANCE TO LIKELY POPS NORTH OF PITTSBURGH.
MODEL GUIDANCE HAS TRENDED FURTHER NORTH WITH THE TRACK OF THE
UPPER-LEVEL WAVE TONIGHT...AS THE RIDGE OF HIGH PRESSURE RE-BUILDS
IN THE MID-WEST. MODIFICATIONS WERE MADE TO PUSH TONIGHTS RAIN
CHANCES WELL NORTH OF PREVIOUS FORECAST. SOME OF OUR SOUTHERN AND
WESTERN ZONES SHOULD EVEN GET SOME CLEARING HEADING INTO TONIGHT
WITH THE FOCUS OF DEEPER MOISTURE SHIFTING NORTH.
TAX
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
RIDGING STARTS TO BUILD OVER THE OHIO VALLEY DURING THE DAY ON
WEDNESDAY. THIS WILL DROP H500 HEIGHTS ACROSS THE CWA IN RESPONSE
AND HELP TO SAG THE FRONTAL BOUNDARY A BIT FURTHER SOUTH DURING
THE DAY. FOCUSED HIGHER POPS IN SOUTHERN PORTIONS OF CWA DURING
THE AFTERNOON. ENOUGH INSTABILITY IS PRESENT FOR THE CONTINUED
CHANCE OF THUNDER AS WELL. KEPT POPS IN CHANCE CATEGORY WITH
CONTINUED UNCERTAINTY AS TO FRONTAL EVOLUTION. AS RIDGE STARTS TO
BUILD EASTWARD...FRONTAL BOUNDARY WILL BECOME MORE DIFFUSE WITH
TIME. ALLOW POPS TO FALL OFF DURING THE EVENING HOURS WITH LOSS OF
HEATING.
H500 RIDGE IS IN CONTROL FOR THE REMAINDER OF THIS PERIOD...WITH
THE RIDGE AXIS PASSING BY AROUND 00Z FRIDAY. GFS/ECMWF BOTH PAINT
SOME DIURNAL QPF ACROSS THE AREA THURSDAY AND FRIDAY AFTERNOONS.
THINK THAT THIS IS OVERDONE FOR THE MOST PART AS AT LEAST MODEST
CAPPING SHOULD BE PRESENT UNDER THE RIDGE. EXCEPTION COULD BE
ALONG THE EASTERN RIDGES WITH MODEST UPSLOPE FLOW...AND KEPT AN
AFTERNOON/EVENING SLIGHT CHANCE BOTH AFTERNOONS IN THIS AREA.
OTHERWISE...DRY AND WARM CONDITIONS WILL PERSIST. A SLOW WARMING
TREND WILL SEE TEMPERATURES RISE BACK INTO THE LOWER AND MID 80S
FOR MOST AREAS BY FRIDAY.
CL
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
UPPER RIDGE GETS SLOWLY DISLODGED WITH TIME AS ENERGY EJECTS FROM
WESTERN U.S. TROUGH AND TOWARDS THE UPPER MISSISSIPPI VALLEY BY
00Z MONDAY. RESULTING SURFACE LOW AND FRONTAL SYSTEM WILL ADVANCE
EASTWARD WITH TIME...PERHAPS ARRIVING MONDAY NIGHT OR TUESDAY.
AHEAD OF THIS...MAINLY DIURNAL POPS GET A BIT HIGHER EACH DAY
WITH THE DEPARTURE OF THE RIDGE. RIPPLES ALONG THE BACK SIDE OF
THE RIDGE MAY PROVIDE LOCALIZED ENHANCEMENT...WHICH OF COURSE ARE
TOUGH TO TIME AT THIS DISTANCE. THE FRONT BRINGS MORE GENERALIZED
PRECIPITATION CHANCES MONDAY INTO TUESDAY.
FAIRLY STATIC ABOVE NORMAL TEMPERATURES ARE FORECAST FRIDAY NIGHT
THROUGH MONDAY NIGHT...WITH HIGHS IN THE 80S AND LOWS ON EITHER
SIDE OF 60. COOLER TEMPERATURES MAY ARRIVE TUESDAY WITH THE FRONT.
CL
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
VISIBILITY RESTRICTIONS THIS MORNING HAVE BEEN CONFINED TO A
SELECT FEW TERMINALS WHERE AT LEAST SOME CLEARING HAD TAKEN
PLACE...AND FOG WAS ABLE TO FORM. ANY REMAINING RESTRICTIONS
DUE TO FOG SHOULD END QUICKLY AFTER SUNRISE WITH MIXING AND AS A
BROADER CLOUD SHIELD MOVES IN.
ADDITIONALLY...AN AREA OF SHOWERS IS MOVING ALONG THE BROAD
FRONTAL ZONE...AND ARE CURRENTLY THROUGH EASTERN OHIO. NOT
EXPECTING MUCH FURTHER EXPANSION OR STRENGTHENING OF THESE
SHOWERS THROUGH MID-MORNING...BUT THEY COULD BRING TEMPORARY
VISIBILITY RESTRICTIONS AS THEY SLOWLY MOVE EAST ACROSS
HLG/BVI/PIT/AGC.
LATER TODAY...HAVE THIS LINE OF SHOWERS LIFTING NORTH WITH THE
BROAD FRONTAL ZONE WHERE INSTABILITY THIS AFTERNOON COULD DRIVE
ADDITIONAL SHOWERS/THUNDERSTORMS. HAVE INCLUDED VCTS FOR NORTHERN
AND EASTERN TAF SITES...BUT SPATIAL EXTENT OF THUNDERSTORM
ACTIVITY SHOULD BE FAIRLY LIMITED.
TAX
.OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
SCATTERED RESTRICTIONS IS A POSSIBILITY EARLY WEDNESDAY AS
FRONTAL BOUNDARY SLOWLY DECAYS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1034 AM EDT TUE MAY 5 2015
.UPDATE...
THE DETAILED FORECAST REASONING PROVIDED IN THE EARLY MORNING
DISCUSSION WAS WELL DONE AND REMAINS VALID.
A MATURE MCS AND COMPLEX OF SHORTWAVE ENERGY SUPPORTED BY RIGHT
ENTRANCE REGION DYNAMICS ALOFT IS CURRENTLY LIFTING INTO
SOUTHEASTERN MICHIGAN THIS MORNING. SURFACE PRECIPITATION REPORTS
SUPPORT LIGHT TO MODERATE RAIN OCCURRING WITHIN THE
FORWARD...WARM AIR ADVECTION QUADRANTS OF THE MCS. WITH THE RAIN
MOVING IN...SOUTHEASTERN MICHIGAN CAN EXPECT CATEGORICAL/PERIODS
OF RAIN THROUGHOUT THE AFTERNOON HOURS. FORECAST UNCERTAINTY FOR
THE SHORT TERM PERIOD CENTERS ON WHEN EXACTLY SYNOPTIC
SUPPORT/RAIN WILL END OVER THE AREA. LATEST NAM AND RAP ARE REALLY
PAINTING DIFFERENT PICTURES. NAM SUGGESTS SUBSIDENCE IN THE WAKE
OF THIS MCS...MAY BRING A QUIET PERIOD EARLY THIS EVENING...WHILE
THE RAP DRAGS OUT THE DURATION OF THIS CATEGORICAL RAIN INTO THE
EVENING. THERE REMAINS A WINDOW OF OPPORTUNITY FOR SOME THUNDER
CHANCES LATE THIS AFTERNOON...POST 20Z. THOSE CHANCES APPEAR TO
HINGE ON THE LIKELIHOOD OF THE NAM SOLUTION VERIFYING. NEGLIGIBLE
CONVECTIVE INSTABILITY YIELDS NO SUPPORT FOR SEVERE THUNDERSTORM
POTENTIAL.
&&
.AVIATION...ISSUED 707 AM EDT TUE MAY 5 2015
A NOTABLE DECREASE IN LIGHTNING WITHIN ONGOING ACTIVITY MOVING IN
FROM THE WEST FOR THE MORNING. A FEW STRAY LIGHTNING STRIKES WILL BE
POSSIBLE BUT MORE LIKELY AN MVFR RESTRICTION DUE TO A HEAVIER
DOWNPOUR OF RAIN. EXPECT MVFR RESTRICTION DUE TO LOW VISIBILITY IN
SHOWERS INITIALLY...ESPECIALLY PTK TO FNT WHERE THE MOST PERSISTENT
RAIN WILL SET UP...AND THEN MVFR DUE TO LOW CEILING LATER TODAY AND
THIS EVENING. IFR CEILING IS THEN LIKELY OVERNIGHT INTO WEDNESDAY
MORNING AS THE SURFACE FRONT DRIFTS NORTHWARD FROM INDIANA AND OHIO.
FOR DTW... SHOWERS WILL MOVE INTO THE TERMINAL AREA SHORTLY AFTER
ISSUANCE TIME AND THEN PERSIST THROUGH THE MORNING. THE HEAVIEST AND
MOST FREQUENT ACTIVITY WILL THEN SHIFT NORTH DURING THE AFTERNOON.
THERE IS A LATE AFTERNOON OR EARLY EVENING WINDOW FOR THUNDERSTORMS
BUT THIS WILL DEPEND ON THE EXTENT OF DEVELOPMENT ALONG THE SURFACE
FRONT DURING PEAK DAYTIME HEATING. OTHERWISE...CEILING WILL LOWER
STEADILY INTO MVFR THROUGH THE EVENING AND THEN IFR OVERNIGHT
THROUGH WEDNESDAY MORNING AS THE SURFACE FRONT DRIFTS CLOSER FROM
INDIANA AND OHIO.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING BELOW 5000 FT TODAY AND TONIGHT.
* LOW FOR THUNDERSTORMS TODAY AND TONIGHT.
&&
.PREV DISCUSSION...ISSUED 355 AM EDT TUE MAY 5 2015
SHORT TERM... TODAY AND TONIGHT
A WET 24 HOUR PERIOD IS SETTING UP OVER SOUTHERN LOWER MICHIGAN
TODAY THROUGH TONIGHT. THE TRI CITIES AND NORTHERN THUMB MAY ESCAPE
THE BULK OF THE RAINFALL TODAY BUT THE REST OF SE MICHIGAN STANDS TO
PICK UP A PROLONGED PERIOD OF SHOWERS AND THUNDERSTORMS. THE SURFACE
FRONT WILL REMAIN SOUTH OF THE OHIO BORDER THROUGH THE PERIOD SO
THUNDERSTORMS WILL BE THE ELEVATED VARIETY AND MAINLY CONTRIBUTE TO
LOCALLY HEAVY DOWNPOURS. RAINFALL TOTALS LOCALLY AROUND 1 INCH WILL
BE POSSIBLE BY SUNRISE WEDNESDAY.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ALREADY UNDERWAY OVER THE
MIDWEST AND WILL SPREAD TO THE NORTH AND EAST DURING THE REST OF THE
MORNING. THIS AREA OF CONVECTION ORIGINATED ALONG THE FRONT OVER THE
CENTRAL PLAINS DURING PEAK HEATING YESTERDAY AND HAS SINCE GROWN
LARGE ENOUGH AND PERSISTENT ENOUGH TO SUPPORT MCV DEVELOPMENT ALOFT
AND AN AREA OF SURFACE PRESSURE FALLS OVER IOWA AND MISSOURI. THE
WAVE IS JUST STRONG ENOUGH TO SUPPORT A WEAK LOW LEVEL JET FUELING
ACTIVITY OVER NORTHERN ILLINOIS WHICH WILL CONTINUE TO DEVELOP INTO
SOUTHERN LOWER MICHIGAN AS THE LOW TO MID LEVELS OF THE FRONT
STRENGTHEN WITH TIME. CONVECTIVE DEBRIS IN SATELLITE IMAGERY SHOWS
THE ENTRANCE REGION OF A 120 KNOT UPPER JET ANALYZED IN MODEL DATA
AT 250 MB. THIS FEATURE IS POSITIONED FAVORABLY OVER THE GREAT LAKES
TO GENERATE STRONG FRONTOGENESIS THROUGH TODAY WHILE THE LARGE SCALE
FRONTAL POSITION REMAINS STATIONARY AND THEN DRIFTS SLOWLY NORTHWARD
TONIGHT. CROSS SECTIONS OF MODEL DATA FROM THE POSITION OF THE
SURFACE FRONT EXTENDING NORTHWARD TO THE UPPER JET AXIS SHOW THE
STEEPEST PORTION OF THE AGEOSTROPHIC CIRCULATION SETTING UP THROUGH
CENTRAL SECTIONS OF OUR AREA BY AFTERNOON THROUGH THIS EVENING. DEEP
CONVECTIVE INSTABILITY ABOVE THE FRONTAL SURFACE COMBINED WITH
PRECIPITABLE WATER RISING TO ABOUT 1.25 INCHES WILL ENSURE
WIDESPREAD COVERAGE OF SHOWERS WITH EMBEDDED THUNDERSTORMS. LOCALLY
HEAVY RAINFALL WILL ALSO BE POSSIBLE DUE TO THE PERSISTENCE OF THIS
TEXTBOOK UPPER JET ENHANCED FRONTAL CIRCULATION AND THE CONVECTIVE
NATURE OF THE PRECIPITATION PATTERN. SO THEN WHAT COULD GO WRONG IN
THIS FORECAST? THE POTENTIAL FOR SURFACE BASED CONVECTION OVER
INDIANA AND OHIO...COMBINED WITH THE TENDENCY FOR ELEVATED
INSTABILITY TO BECOME LESS EFFECTIVE DURING THE DAY...COULD LEAD TO
A WEAKENING TREND IN THE PATTERN OVER SE MICHIGAN DURING THE
AFTERNOON INTO THIS EVENING. SHOULD THIS OCCUR...IT WOULD DO MORE TO
REDUCE THE POTENTIAL FOR HEAVY RAINFALL IN OUR AREA AND POSSIBLY
ALTER THE LOCATION OF THE MOST PERSISTENT SHOWERS AND OVERALL QPF...
BUT MOST AREAS WILL SEE A LENGTHY PERIOD OF RAIN AS THE MORNING RAMP
UP WOULD CARRY OVER INTO THE AFTERNOON JUST BASED ON INERTIA.
PROGRESSION OF THE UPPER LEVEL RIDGE AND THE ENTRANCE REGION OF THE
UPPER JET WILL NUDGE THE MID LEVEL FRONTAL ZONE TO THE NORTH AND
EAST OVERNIGHT. THIS WILL BRING THE TRI CITIES AND NORTHERN THUMB
MORE INTO THE PATTERN OF REMAINING SHOWERS AND WILL BE THE FAVORED
LOCATION FOR ANY NOCTURNAL REDEVELOPMENT. THE AXIS OF LIKELY POPS
OVER SE MICHIGAN IS PLACED ALONG THE 850 MB THETA-E GRADIENT WHICH
IS WELL AGREED UPON BY THE 00Z MODEL CYCLE AND IS THE MOST FAVORED
LOCATION FOR RENEWED DEVELOPMENT OF NOCTURNAL ELEVATED INSTABILITY
AND SUPPORT FOR SHOWERS THROUGH SUNRISE WEDNESDAY.
LONG TERM...WEDNESDAY THROUGH MONDAY
SE MICHIGAN WILL RESIDE ALONG THE IMMEDIATE DOWNSTREAM SIDE OF AN
ELONGATING UPPER RIDGE ON WEDNESDAY. THE RESULTING WEAKLY SHEARED
WEST-NORTHWEST FLOW WILL SUSTAIN A PERTURBED 850-925 MB FRONTAL ZONE
ACROSS THE REGION. MODELS TRENDING SLIGHTLY STRONGER WITH THE
ASCENT/CONVERGENCE THROUGH THIS LAYER...SUGGESTING THE EXISTING
FRONTAL SLOPE WILL POTENTIALLY BE MORE ACTIVE. THIS WILL SUPPORT
THE INCLUSION OF A LOWER END POP. GREATER POTENTIAL FOR SHOWER
PRODUCTION DURING THE MORNING PERIOD...BEFORE BOTH THE MOISTURE
QUALITY AND AVAILABLE FORCING DIMINISHES AS THE INBOUND UPPER RIDGE
MAKES BETTER INROADS. SUBSTANTIAL CLOUD COVER WITHIN PERSISTENT LOW
LEVEL EASTERLY FLOW WILL CAP THE DIURNAL TEMPERATURE RESPONSE TO
SOME DEGREE...REGARDLESS OF SHOWER COVERAGE. ABSENT OF A LARGER AND
PERSISTENT COVERAGE OF SHOWERS TO DISRUPT THE HEATING CYCLE...
EXISTING THERMAL PROFILE WILL SUPPORT HIGHS GENERALLY WITHIN THE MID
AND UPPER 60S RANGE.
UPPER RIDGE STEADILY BUILDS INTO LOWER MICHIGAN WEDNESDAY NIGHT...
580 DM AT 500 MB MARKING THE RIDGE AXIS CENTERING OVERHEAD BY EARLY
THURSDAY MORNING. THIS PROGRESSION WILL SEND SE MICHIGAN INTO THE
WARM SECTOR BY THURSDAY...SOLID DEPTH TO THE EMERGING SOUTHWEST FLOW
CONTINUING TO POINT TOWARD HIGHS MAKING A RUN INTO THE LOWER 80S.
DRY/STABLE PROFILE STILL INFLUENCED BY EXITING UPPER RIDGING WILL
RESULT IN LITTLE MORE THAN A STANDARD DIURNAL CU FIELD.
CLOSED LOW CURRENTLY PARKED OVER THE DESERT SOUTHWEST WILL LIFT
NORTHEAST THROUGH THE LATTER HALF OF THE WEEK...EVENTUALLY SHEARING
OVER THE TOP OF THE UPPER RIDGE STAGNATING ALONG THE EAST COAST.
THIS LOWERING HEIGHT FIELD WILL BEGIN TO EASE AN ATTENDANT FRONTAL
BOUNDARY EASTWARD WITHIN THE FRIDAY AND SATURDAY WINDOW. GENERAL
TIMING ACROSS THE MODEL SPECTRUM SUGGESTS FRIDAY WILL REMAIN
CHARACTERED BY THE PRE-FRONTAL WARM SECTOR...WITH ANY POSSIBLE LATE
DAY/EVENING CONVECTIVE CHANCES ARRIVING TOO LATE TO DISRUPT ANOTHER
DAY WITH HIGHS IN THE 80S. POTENTIAL IS THERE FOR AN ACTIVE PERIOD
HEADING INTO THE UPCOMING WEEKEND...FRONTAL BOUNDARY EVENTUALLY
ALIGNING OVER OR NEAR THE REGION FOR AN EXTENDED TIME AS THE AXIS
BECOMES PARALLEL TO THE MEAN FLOW. THIS PATTERN WOULD SHAVE A FEW
DEGREE OFF PROSPECTIVE HIGHS THIS WEEKEND RELATIVE TO THE
THU/FRI WARMTH...STILL NEAR TO ABOVE NORMAL THROUGH THIS TIME.
MARINE...
SHOWERY CONDITIONS WITH THE CHANCE OF THUNDERSTORMS WILL EXIST UNDER
PERSIST EAST TO NORTHEAST FLOW OVER THE SOUTHERN LAKE HURON BASIN
AND POINTS SOUTHWARD THROUGH TONIGHT. FAVORABLE MARINE CONDITIONS
ACROSS NORTHERN LAKE HURON DURING THIS TIME AS HIGH PRESSURE BUILDS
INTO THE REGION. MODEST WAVE AND WIND CONDITIONS THROUGH THE
MIDWEEK PERIOD AS HIGH PRESSURE SUSTAINS A WEAK GRADIENT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......CB
AVIATION.....BT
SHORT TERM...BT
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT TUE MAY 5 2015
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT WRLY MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND A
RIDGE FROM THE SE CONUS INTO THE CNTRL PLAINS. WITH A SFC RIDGE
EXTENDING FROM NW ONTARIO THROUGH THE NRN LAKES...LIGHT WINDS AND
CLEAR SKIES OVER UPPER MI HAS ALLOWED TEMPS TO DROP OFF INTO THE MID
AND UPPER 30S WITH SEVERAL INLAND COLD SPOTS IN THE UPPER 20S TO
AROUND 30. CLOUDS AND
TODAY...EXPECT THAT HIGH PRES WILL CONTINUE TO DOMINATE AS THE
CLOUDS AND PCPN ASSOCIATED WITH A FRONTAL BOUNDARY FROM SRN IA INTO
NRN IL REMAIN WELL TO THE SOUTH. MIXING TO 5K FT WITH 850 MB TEMPS
FCST IN THE 6C TO 8C RANGE WILL SUPPORT HIGHS IN THE UPPER 60S TO
AROUND 70...EXCEPT ALONG THE GREAT LAKES WHERE READING WILL REMAIN
IN THE UPPER 50S AND LOWER 60S. SIMILAR TO MONDAY...AFTERNOON
DEWPOINTS WILL DROP INTO THE LOWER 20S WITH RH VALUES FROM 15 TO 20
PCT. HOWEVER...WINDS WILL REMAIN LIGHT...AOB 10 MPH.
TONIGHT...AS THE HIGH SHIFTS OFF TO THE EAST AND AND 850 MB WARM
FRONT APPROACHES FROM THE SOUTH...EXPECT INCREASING CLOUDS OVERNIGHT.
THIS WILL KEEP TEMPS FROM FALLING OFF AS MUCH WITH MIN READINGS IN
THE UPPER 30S TO AROUND 40. WITH THE VERY DRY AIRMASS IN PLACE...THE
SLOWER END OF GUIDANCE WAS FAVORED WITH THE PCPN ADVANCING FROM THE
SOUTH. SO...NO PCPN MENTION WAS INCLUDED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE MAY 5 2015
ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEK AMIDST SMALL
CHANCES OF PRECIP WEDNESDAY...AND A CHANCE OF SHOWERS AND STORMS
LATE THURSDAY INTO FRIDAY. MUCH COOLER WEATHER WILL THEN RETURN FOR
THE WEEKEND.
WEDNESDAY AND WEDNESDAY NIGHT...A STOUT MID-LEVEL RIDGE WILL BE
ENTERING THE WESTERN CWA AT 12Z WED AS AN ASSOCIATED SFC HIGH OVER
GEORGIAN BAY SHIFTS SOUTHEASTWARD. MEANWHILE...A SHORTWAVE TROUGH
DRIFTING NE FROM THE SOUTHERN ROCKIES WILL BEGIN TO CONSOLIDATE A
BROAD SFC TROUGH ALONG THE ENTIRE U.S. ROCKIES. MODELS CONTINUE
THEIR TWO-DAY TREND IN LOWERING QPF ALONG AN 850 HPA WARM FRONT
ACROSS THE SW CWA WED MORNING. IN FACT...MOST OF THE HIGHER-RES
GUIDANCE SUITE SHOWS VERY LITTLE PRECIP DURING THE DAY WEDNESDAY.
THE STEEP MID-LEVEL RIDGE IS PROVING TO BE TOO MUCH TO MAINTAIN MOST
OF THE INCOMING RAIN SHOWERS FROM WI. ADDITIONALLY...THE BULK OF THE
BETTER LOW-LEVEL MOISTURE WILL REMAIN ACROSS MN. HAVE THUS OPTED TO
CUT NEARLY ALL CHANCES OF PRECIP EXCEPT FOR A SLIGHT CHANCE FOR
SHOWERS ALONG THE WI BORDER IN THE MORNING.
THURSDAY THROUGH FRIDAY...AFTER THE H8 WARM FRONT CROSSES THE
CWA...THERE IS LITTLE SUPPORT FOR PRECIP UNTIL AT LEAST THURSDAY
AFTERNOON. ADDITIONALLY...CAPPING AROUND 750 HPA SHOULD KEEP PRECIP
CHANCES LIMITED THROUGH THURSDAY MORNING. THE SFC COLD FRONT UNDER
INCREASING MOISTURE FROM AN H8 50KT JET AND A DEVELOPING LEFT-EXIT
OF A WEAK UPPER JET STREAK SHOULD BE ENOUGH TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS LATE THU AFTERNOON THROUGH MUCH OF THU
NIGHT. HOWEVER...KEPT POPS AT JUST A CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE BEST MID-LEVEL FORCING PEELS OFF TO THE NORTH.
TEMPS COULD GET QUITE WARM THU IF ENOUGH AFTERNOON CLEARING OCCURS.
GIVEN THE CAP...THINK THERE WILL BE ENOUGH INSOLATION TO BOOST TEMPS
INTO THE LOW 80S ACROSS THE WEST UNDER H8 TEMPS UP TO 14C. IN
ADDITION TO THE WARMER WX...MIXING INTO 35 TO 45KT WINDS SHOULD
RESULT IN QUITE A GUSTY DAY...ESPECIALLY WEST. EVEN THOUGH MUCH OF
WEST DID NOT BENEFIT FROM SATURDAYS PRECIP...FIRE WX CONCERNS SHOULD
BE PARTIALLY MITIGATED BY INCREASING LOW-LEVEL MOISTURE...RESULTING
IN MIN RH VALUES ONLY INTO THE UPPER 30S. HOWEVER...FIRE INDICES
ARE BEGINNING TO INDICATE INCREASING FIRE POTENTIAL ACROSS THE
WEST...SO THURSDAY WILL NEED TO BE MONITORED IF LOW-LEVEL MOISTURE
IS SLOW TO ARRIVE.
FRIDAY...THE COLD FRONT LOOKS TO CLEAR THE CWA BY FRIDAY
AFTERNOON...ENDING PRECIP CHANCES AND USHERING IN COOLER AIR. TEMPS
WILL DROP ALONG PORTIONS OF LAKE SUPERIOR DURING THE AFTERNOON HOURS
AS WINDS BECOME NW.
SATURDAY...THE ECMWF AND CANADIAN GEM STRUGGLE TO PUSH THE COLD
FRONT FAR AWAY FROM THE CWA...LEAVING LINGERING CHANCES OF SHOWERS
ACROSS THE SE HALF. THE GFS KEEPS THE AREA DRY...AND GIVEN ITS
BETTER RUN TO RUN CONSISTENCY WITH THIS SYSTEM...HAVE OPTED TO KEEP
NEARLY ALL POPS OUT OF THE CWA. HOWEVER...SOME SPRINKLES/DRIZZLE
CANNOT BE RULED OUT ALONG LAKE SUPERIOR...WHERE N WINDS AND
LINGERING LOW-LEVEL MOISTURE SHOULD RESULT IN DECENT LOW-LEVEL
CLOUDS. ADDITIONALLY...TEMPS WILL LIKELY STRUGGLE TO REACH 50F NEAR
THE SHORE.
SUNDAY AND MONDAY...MODEL DIFFERENCE QUICKLY DEVELOP WITH THE
HANDLING OF A DEEP TROUGH EXITING THE WESTERN CONUS. FOLLOWING THE
GFS SOLUTION...A SFC LOW IN THE LEE OF THE ROCKIES WILL TRACK ENE
ALONG THE STALLED W TO E SFC BOUNDARY BIFURCATING THE CENTRAL CONUS.
THE ECMWF AND CANADIAN GEM TRACK THE LOW FARTHER NORTH. ABUNDANT
CONVECTION ACROSS THE PLAINS ONLY LEADS TO MORE UNCERTAINTY WITH THE
SYNOPTIC EVOLUTION OF THIS SYSTEM...SO HAD TO RESORT TO USING
CONSENSUS CHANCE POPS SUNDAY AFTERNOON THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 732 AM EDT TUE MAY 5 2015
WITH DRY HIGH PRESSURE DOMINATING...EXPECT VFR CONDITIONS AND LIGHT
WINDS AT ALL 3 TAF SITES THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT TUE MAY 5 2015
AS A TROUGH MOVES FROM THE PLAINS TO THE UPPER MS VALLEY...SRLY
WINDS WILL INCREASE TO AROUND 25 KNOTS OVER THE EAST BY LATE THU INTO
THU NIGHT. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW 20
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
954 AM MDT TUE MAY 5 2015
.UPDATE...
MINOR ADJUSTMENTS TO THE GOING FORECAST TODAY. AREA WILL BE UNDER
A SOUTHERLY FLOW REGIME TODAY AHEAD OF TONIGHTS COLD FRONT. A
COUPLE OF DISTURBANCES CROSSING SOUTH TO NORTH OVER WESTERN ZONES
THIS AFTERNOON WILL TRIGGER ISOLATED TO SCATTERED THUNDERSTORMS.
SHEAR PROFILES AND INSTABILITY LOOK WEAK SO NOT EXPECTING ANY
SEVERE STORMS BUT COULD SEE AN ISOLATED STRONG WIND GUST WITH THIS
ACTIVITY. LOOKS LIKE THIS MORNING WILL BE MAINLY DRY SO DROPPED
MOST POPS BEFORE NOON. ALSO REMOVED MENTION OF AFTERNOON POPS FOR
SOUTHEAST MONTANA AS IT LOOKS CONVECTION WILL HOLD OFF UNTIL LATER
IN THE EVENING THERE. LOWERED RH/TD VALUES A BIT AS WELL AHEAD OF
THE FRONT. REST OF THE FORECAST IN PRETTY GOOD SHAPE. CHAMBERS
&&
.SHORT TERM...VALID FOR TDY AND WED...
UNSETTLED WEATHER BEGINS TODAY AND WILL CONTINUE RIGHT THROUGH
THE REMAINDER OF THE WEEK. AN UPPER LOW AND TROUGH WILL MOVE ONTO
THE PACIFIC NORTHWEST COAST TODAY AND REMAIN STATIONARY OR SLOWLY
SHIFT SOUTHEAST TOWARD THE GREAT BASIN AREA DURING THE DAY
WEDNESDAY. THIS WILL ALLOW A SOUTHWEST FLOW ALOFT TO BEGIN TO
DEVELOP OVER OUR AREA TODAY AND ESPECIALLY BE IN PLACE FOR
WEDNESDAY. SEVERAL SURFACE LOWS WILL DEVELOP ACROSS THE NORTHERN
AND CENTRAL ROCKIES BRINGING A PREDOMINATELY SOUTHEAST SURFACE
FLOW ALLOWING FOR INCREASING LOW-LEVEL MOISTURE ACROSS THE AREA
THROUGH WEDNESDAY. MODELS INCLUDING THE HRRR BRING A VORT MAX OVER
OUR AREA TODAY RESULTING IN SHOWERS AND ISOLATED THUNDERSTORMS.
SHEAR IS A BIT BETTER TODAY BUT STILL NOT IMPRESSIVE. CAPES ARE
ALSO SLIGHTLY BETTER TODAY AND MORE WIDESPREAD SO THUNDERSTORM
CHANCES WILL BE BETTER TODAY THAN TUESDAY. PRE-FRONTAL WARMING
TODAY WILL ALLOW TEMPERATURES TO WARM WELL INTO THE 70S TO AROUND
80 DEGREES
A COLD FRONT WILL MOVE ACROSS THE FORECAST AREA WEDNESDAY MORNING
USHERING IN GUSTY NORTHWEST WINDS BY AFTERNOON ALONG WITH A CHANCE
FOR SHOWERS AND ISOLATED THUNDERSTORMS. TEMPERATURES WILL BE MUCH
COOLER WITH READINGS ONLY IN THE LOWER TO MIDDLE 60S SO
INSTABILITY FOR THUNDERSTORMS WILL NOT BE AS GOOD AS TODAY. A
STRONGER DISTURBANCE AND UPPER LOW WILL MOVE NORTHEAST OUT OF
WYOMING WEDNESDAY INTO WEDNESDAY NIGHT. MODELS SHOW GOOD WRAP-
AROUND MOISTURE WITH THIS ALONG WITH DECENT QPF AMOUNTS. AS A
RESULT...HAVE INCREASED POPS INTO THE LIKELY AND CATEGORICAL RANGE
DURING THIS TIME FROM CUSTER AND POWDER RIVER COUNTIES EASTWARD.
ELSEWHERE...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS. HOOLEY
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
LATEST MODEL RUNS HAVE CONTINUED TO KEEP THE BULK OF THE ENERGY
AND MOISTURE OUT OF THE THE AREA. MODELS HAVE CONTINUED TO TRACK
WELL WITH EACH OTHER...WITH THE 00Z DATA HAVING MORE OF A CLOSED
LOW EJECTING FROM THE GREAT BASIN THIS WEEKEND...BUT IT TRACKS
MORE INTO THE CENTRAL PLAINS. THIS HAS THE EFFECT OF KEEPING THE
BULK OF THE MOISTURE AND ENERGY SOUTH OF MONTANA. CONTINUE TO SEE
DIFFLUENT FLOW ALOFT ACROSS THE AREA THIS WEEKEND...ALONG WITH
SOME MID-LEVEL MOISTURE. THIS WILL KEEP AT LEAST A CHANCE OF LIGHT
SCATTERED PRECIP ACROSS THE AREA. HAVE TRENDED POPS DOWN SOME
GIVEN THE TREND AWAY FROM A MORE FAVORABLE SOLUTION. THE COLUMN
IS NOT OVERLY SATURATED...WITH PRECIPITABLE WATER VALUES ONLY
AROUND A HALF INCH. THE POTENTIAL FOR MUCH ACCUMULATION REMAINS
LOW. WITH THE MID LEVEL MOISTURE...MUCH OF THE EXTENDED PERIOD
WILL BE CLOUDY...THUS COOLER. TEMPERATURES CONTINUE BE IN THE 50S
FOR HIGHS. REIMER
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THIS MORNING. ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP FROM ROUNDUP TO KBIL TO
KSHR W THIS AFTERNOON...AND CONTINUE INTO EARLY EVENING. THE
PRECIPITATION WILL PRODUCE MVFR/IFR CONDITIONS. AREAS OF MOUNTAIN
OBSCURATION WILL DEVELOP THIS AFTERNOON. PRECIPITATION WILL BECOME
MORE WIDESPREAD THIS EVENING AS A COLD FRONT PUSHES INTO THE AREA
BRINGING A WIND SHIFT TO THE NW AT KLVM BY 06Z. THE THREAT FOR
THUNDER WILL DECREASE LATE THIS EVENING. SCATTERED SHOWERS ARE
EXPECTED LATE TONIGHT. MVFR TO IFR CONDITIONS WILL CONTINUE WITH
THE PRECIPITATION TONIGHT...WITH AREAS OF MOUNTAIN OBSCURATION.
THE COLD FRONT WILL REACH KMLS BY 12Z WED. ARTHUR
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 079 049/059 040/053 040/053 039/051 038/059 040/060
2/T 43/W 22/W 24/W 55/W 43/W 32/W
LVM 076 043/061 036/050 034/048 034/050 034/059 035/060
3/T 64/W 35/W 35/W 55/W 43/W 33/W
HDN 082 050/061 042/056 038/057 039/053 037/059 035/062
1/B 34/W 22/W 23/W 55/W 43/W 32/W
MLS 079 051/060 041/055 037/056 038/054 037/057 038/061
1/B 38/W 42/W 12/W 44/W 43/W 32/W
4BQ 075 051/061 043/055 035/055 039/052 035/053 034/059
1/B 48/T 42/W 12/W 55/W 44/W 32/W
BHK 073 050/060 042/054 034/054 035/052 034/054 031/057
1/N 39/T 72/W 12/W 44/W 33/W 22/W
SHR 075 048/054 037/053 035/054 038/050 035/051 032/058
2/T 45/W 43/W 34/W 55/W 54/W 33/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1046 AM CDT TUE MAY 5 2015
.UPDATE...
SHOWERS/STORMS CONTINUE TO MOVE ACROSS WESTERN PORTIONS OF THE FA.
THIS ACTIVITY WILL SLOWLY SHIFT E AND NE IN THE AREA... MAYBE
REACHING PARTS OF THE I-35 CORRIDOR BY LATE AFTN. HAVE ADJUSTED
POPS/WX TO SHOW CURRENT TRENDS AND STRETCH HIGHER CHANCE AND
LIKELY POPS JUST A LITTLE FURTHER EAST. CLOUDS ARE EXPECTED TO
STAY PUT/INCREASE ACROSS THE AREA. THIS CLOUD COVER ALONG WITH THE
RAIN WILL SLOW THE WARM UP ACROSS AT LEAST THE WESTERN HALF OF
THE AREA... ESPECIALLY IN WESTERN OK AND WESTERN NORTH TEXAS.
UPDATES OUT SOON.
&&
.PREV DISCUSSION... /ISSUED 624 AM CDT TUE MAY 5 2015/
AVIATION...05/12Z TAF ISSUANCE...
ACTIVE AVIATION FORECAST PERIOD. RA WILL CONTINUE TO SLOWLY SPREAD
INTO WRN OK THROUGH THE MORNING HOURS. RA AND TSRA WILL INCREASE
THROUGH THE AFTN AND SPREAD EASTWARD INTO CENTRAL OKLAHOMA INTO
THE EVENING. TRIED TO KEEP TAFS SIMPLE... WITH PREVAILING RA OR
TSRA WHEN NECESSARY. HEAVY SHOWERS AND THUNDERSTORMS MAY RESULT IN
BRIEF PERIODS OF MVFR TO POTENTIALLY IFR VIS THROUGH THE DAY. AS
CLOUD COVER INCREASES THROUGH THE AFTN AND EVENING... MVFR
CEILINGS WILL SLOWLY DROP TO IFR AT SOME SITES OVERNIGHT. WINDS
WILL REMAIN OUT OF THE S/SE THROUGH THE PERIOD... GUSTY THROUGH
THE MORNING AND AFTERNOON... BETWEEN 20 TO 25KTS.
JTK
PREV DISCUSSION... /ISSUED 340 AM CDT TUE MAY 5 2015/
DISCUSSION...
PRIMARY FORECAST CONCERN THIS MORNING IS FOCUSED ON TODAY THROUGH
WEDNESDAY THUNDERSTORM CHANCES. HOWEVER... THUNDERSTORM CHANCES WILL
CONTINUE NEAR DAILY THROUGH THE WEEKEND.
CURRENTLY... CONVECTION ACROSS WEST TEXAS... ALONG AND EAST OF THE
LLANO ESTACADO... CONTINUES... WITH THE SFC LOW SLOWLY EVOLVING
ACROSS THE BIG BEND OF TEXAS. THROUGH MIDNIGHT... NEARLY 4 TO 5
INCHES OF RAIN HAD FALLEN ACROSS PORTIONS OF WEST TEXAS. EXPECT THE
SFC LOW TO SLOWLY LIFT N/NE ACROSS FAR WEST TEXAS... WITH SHOWERS
AND THUNDERSTORMS CONTINUING TO MOVE NWRD ACROSS THE W TX AND THE
PANHANDLES INTO WRN N TX AND FAR WRN OK THROUGH SUNRISE. MESOSCALE
GUIDANCE IS IN GOOD AGREEMENT... ALTHOUGH THE HRRR MIGHT BE A TAD
BULLISH WITH THE EWRD EXTENT OF PRECIP INTO OK THROUGH MID MORNING.
SHOWERS AND THUNDERSTORMS CHANCES WILL SLOWLY INCREASE ACROSS WRN OK
AND WRN N TX THROUGH THE AFTN. LOCALLY HEAVY RAINFALL MAY BE AN
ISSUE LATER THIS MORNING/THIS AFTN AS BANDING MAY DEVELOP ALONG THE
ERN PANHANDLES/WRN OK... WHERE THE BETTER ISENTROPIC RESPONSE MAY
SET UP ON THE ERN PERIPHERY OF THE H500 LOW. WITH GOOD MID-LEVEL
ASCENT AND A NARROW BAND OF MUCAPE VALUES OF 600 TO 900 J/KG...
WOULD NOT BE SURPRISED TO SEE SOME LOCALLY HIGHER RAINFALL GREATER
THAN 1 INCH THROUGH THE DAY. THE NAM IS THE MOST AGGRESSIVE WITH
QPF... SO IT WILL BE INTERESTING TO SEE HOW TODAY UNFOLDS.
AS FOR STRONG TO SEVERE STORMS TODAY... THE BEST CHANCE WILL BE LATE
THIS AFTN/EVENING ACROSS FAR W/SWRN OK AND WRN N TX. OF COURSE...
ANY STORM DEVELOPMENT WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS THIS
MORNING AND AFTN. THERE IS SOME CONCERN CLOUD COVER WILL PERSIST
THROUGH THE AFTN HOURS... LIMITING HEATING/INSTABILITY DEVELOPMENT.
FORCING WILL BE AVAILABLE FROM A WEAK DRYLINE AND BROAD SCALE
ASCENT... AS WELL AS ANY LEFT OVER BOUNDARIES FROM EARLIER
CONVECTION. ALTHOUGH INSTABILITY WILL BE PRIMARY QUESTION THIS
AFTN... THERE WILL BE QUITE A BIT OF SHEAR AVAILABLE... 40 TO 55KTS
0-6KM AND IF WE CAN RECOVER... A WINDOW AROUND 21-03Z FOR SOME 1000-
1400 J/KG SKINNY CAPE PROFILES. MUCH OF THE INSTABILITY WILL BE
ELEVATED... AND GIVEN BUFR PROFILES... LARGE HAIL... UP TO GOLF
BALLS... AND SEVERE WINDS WOULD BE THE PRIMARY HAZARDS... WITH THE
TORNADO HAZARD LOW.
FOR WEDNESDAY... CLUSTERS OR A COMPLEX OF THUNDERSTORMS WILL LIKELY
BE ONGOING AND LIFTING EWRD ACROSS CENTRAL OK THROUGH SUNRISE. THIS
ACTIVITY WILL SLOWLY DIMINISH AND EXIT EWRD THROUGH THE DAY AS THE
H500 SHORT WAVE FINALLY EJECTS NWRD INTO THE NRN HIGH PLAINS. ONCE
AGAIN... HOW THIS ACTIVITY EVOLVES THROUGH THE MORNING WILL PLAY THE
LEAD ROLE IN OUR SEVERE WEATHER CHANCES WED AFTN/EVENING. AT THE
MOMENT... IF WE CAN GET CLEARING ACROSS WRN OK IN THE VICINITY OF
THE DRYLINE... MODEST MLCAPE VALUES CAN BE ANTICIPATED... 1000-1500
J/KG. THIS PAIRED WITH GOOD SHEAR ONCE AGAIN... STORMS ON THE
DRYLINE WILL LIKELY DEVELOP RAPIDLY AND BE GOOD HAIL PRODUCERS... UP
TO TENNIS BALL SIZED... AS WELL AS PRODUCING POTENTIALLY DAMAGING
WIND GUSTS. AS FOR TORNADOES... CHANCES LOOK BETTER IN KS... WHERE
SHEAR/LL WINDS WILL BE ENHANCED BY THE MORE FAVORABLE POSITION OF
THE SFC LOW OVER ERN CO/WRN KS. GUIDANCE SUGGESTS OK AND NRN TX
STORMS WILL MOVE OFF THE DRYLINE... BECOMING ELEVATED QUICKLY AFTER
SUNSET. THE CHANCE FOR SEVERE STORMS WILL DIMINISH OVERNIGHT... WITH
SCATTERED THUNDERSTORMS PERSISTING THROUGH THU MORNING.
FOR THURSDAY INTO FRIDAY... PRECIPITATION CHANCES WILL CONTINUE...
ESPECIALLY THU NIGHT INTO FRI... AS A DIFFUSE FRONTAL BOUNDARY
STALLS/LINGERS NEAR THE OK/KS BORDER... EXTENDING FROM THE PANHANDLE
INTO ERN KS. H500 FLOW REMAINS FAIRLY STATIC AS THE SRN PLAINS
REMAINS SANDWICHED BETWEEN A DEEPENING TROUGH IN THE WEST AND A
SHARP POSITIVE RIDGE INTO THE MID-ATLANTIC COAST. WITH THIS FLOW
REGIME AND THE LINGERING WEAK FRONTAL BOUNDARY... COUPLED WITH
CONTINUOUS MOISTURE ADVECTION FROM THE GULF... PERSISTENT AND
POSSIBLY EXCESSIVE RAINFALL LIKELY... ESPECIALLY FRI INTO SAT AM.
THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE WEEKEND AS THE H500
TROUGH FINALLY LIFTS E/NE ACROSS THE CENTRAL ROCKIES. WITH THIS...
THE DRY LINE WILL MAKE ANOTHER PUSH ON SATURDAY... WITH STRONG TO
SEVERE STORMS POSSIBLE ONCE AGAIN. DETAILS REMAIN HAZY GIVEN WHATS
POSSIBLE TO TRANSPIRE BETWEEN NOW AN THEN. AS WITH TODAY AND WED...
THUNDERSTORMS SAT WILL BE DEPENDENT ON HOW THE ATMOSPHERE RECOVERS
FROM THE MORNING CONVECTION.
PRECIP CHANCES WILL DIMINISH MON INTO TUES.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 75 63 78 65 / 60 70 40 50
HOBART OK 67 63 80 63 / 80 80 40 50
WICHITA FALLS TX 68 65 82 66 / 90 70 30 50
GAGE OK 67 60 82 62 / 70 80 20 20
PONCA CITY OK 78 65 78 66 / 30 80 50 40
DURANT OK 78 65 78 66 / 50 70 50 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/03
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
624 AM CDT TUE MAY 5 2015
.AVIATION...05/12Z TAF ISSUANCE...
ACTIVE AVIATION FORECAST PERIOD. RA WILL CONTINUE TO SLOWLY SPREAD
INTO WRN OK THROUGH THE MORNING HOURS. RA AND TSRA WILL INCREASE
THROUGH THE AFTN AND SPREAD EASTWARD INTO CENTRAL OKLAHOMA INTO
THE EVENING. TRIED TO KEEP TAFS SIMPLE... WITH PREVAILING RA OR
TSRA WHEN NECESSARY. HEAVY SHOWERS AND THUNDERSTORMS MAY RESULT IN
BRIEF PERIODS OF MVFR TO POTENTIALLY IFR VIS THROUGH THE DAY. AS
CLOUD COVER INCREASES THROUGH THE AFTN AND EVENING... MVFR
CEILINGS WILL SLOWLY DROP TO IFR AT SOME SITES OVERNIGHT. WINDS
WILL REMAIN OUT OF THE S/SE THROUGH THE PERIOD... GUSTY THROUGH
THE MORNING AND AFTERNOON... BETWEEN 20 TO 25KTS.
JTK
&&
.PREV DISCUSSION... /ISSUED 340 AM CDT TUE MAY 5 2015/
DISCUSSION...
PRIMARY FORECAST CONCERN THIS MORNING IS FOCUSED ON TODAY THROUGH
WEDNESDAY THUNDERSTORM CHANCES. HOWEVER... THUNDERSTORM CHANCES WILL
CONTINUE NEAR DAILY THROUGH THE WEEKEND.
CURRENTLY... CONVECTION ACROSS WEST TEXAS... ALONG AND EAST OF THE
LLANO ESTACADO... CONTINUES... WITH THE SFC LOW SLOWLY EVOLVING
ACROSS THE BIG BEND OF TEXAS. THROUGH MIDNIGHT... NEARLY 4 TO 5
INCHES OF RAIN HAD FALLEN ACROSS PORTIONS OF WEST TEXAS. EXPECT THE
SFC LOW TO SLOWLY LIFT N/NE ACROSS FAR WEST TEXAS... WITH SHOWERS
AND THUNDERSTORMS CONTINUING TO MOVE NWRD ACROSS THE W TX AND THE
PANHANDLES INTO WRN N TX AND FAR WRN OK THROUGH SUNRISE. MESOSCALE
GUIDANCE IS IN GOOD AGREEMENT... ALTHOUGH THE HRRR MIGHT BE A TAD
BULLISH WITH THE EWRD EXTENT OF PRECIP INTO OK THROUGH MID MORNING.
SHOWERS AND THUNDERSTORMS CHANCES WILL SLOWLY INCREASE ACROSS WRN OK
AND WRN N TX THROUGH THE AFTN. LOCALLY HEAVY RAINFALL MAY BE AN
ISSUE LATER THIS MORNING/THIS AFTN AS BANDING MAY DEVELOP ALONG THE
ERN PANHANDLES/WRN OK... WHERE THE BETTER ISENTROPIC RESPONSE MAY
SET UP ON THE ERN PERIPHERY OF THE H500 LOW. WITH GOOD MID-LEVEL
ASCENT AND A NARROW BAND OF MUCAPE VALUES OF 600 TO 900 J/KG...
WOULD NOT BE SURPRISED TO SEE SOME LOCALLY HIGHER RAINFALL GREATER
THAN 1 INCH THROUGH THE DAY. THE NAM IS THE MOST AGGRESSIVE WITH
QPF... SO IT WILL BE INTERESTING TO SEE HOW TODAY UNFOLDS.
AS FOR STRONG TO SEVERE STORMS TODAY... THE BEST CHANCE WILL BE LATE
THIS AFTN/EVENING ACROSS FAR W/SWRN OK AND WRN N TX. OF COURSE...
ANY STORM DEVELOPMENT WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS THIS
MORNING AND AFTN. THERE IS SOME CONCERN CLOUD COVER WILL PERSIST
THROUGH THE AFTN HOURS... LIMITING HEATING/INSTABILITY DEVELOPMENT.
FORCING WILL BE AVAILABLE FROM A WEAK DRYLINE AND BROAD SCALE
ASCENT... AS WELL AS ANY LEFT OVER BOUNDARIES FROM EARLIER
CONVECTION. ALTHOUGH INSTABILITY WILL BE PRIMARY QUESTION THIS
AFTN... THERE WILL BE QUITE A BIT OF SHEAR AVAILABLE... 40 TO 55KTS
0-6KM AND IF WE CAN RECOVER... A WINDOW AROUND 21-03Z FOR SOME 1000-
1400 J/KG SKINNY CAPE PROFILES. MUCH OF THE INSTABILITY WILL BE
ELEVATED... AND GIVEN BUFR PROFILES... LARGE HAIL... UP TO GOLF
BALLS... AND SEVERE WINDS WOULD BE THE PRIMARY HAZARDS... WITH THE
TORNADO HAZARD LOW.
FOR WEDNESDAY... CLUSTERS OR A COMPLEX OF THUNDERSTORMS WILL LIKELY
BE ONGOING AND LIFTING EWRD ACROSS CENTRAL OK THROUGH SUNRISE. THIS
ACTIVITY WILL SLOWLY DIMINISH AND EXIT EWRD THROUGH THE DAY AS THE
H500 SHORT WAVE FINALLY EJECTS NWRD INTO THE NRN HIGH PLAINS. ONCE
AGAIN... HOW THIS ACTIVITY EVOLVES THROUGH THE MORNING WILL PLAY THE
LEAD ROLE IN OUR SEVERE WEATHER CHANCES WED AFTN/EVENING. AT THE
MOMENT... IF WE CAN GET CLEARING ACROSS WRN OK IN THE VICINITY OF
THE DRYLINE... MODEST MLCAPE VALUES CAN BE ANTICIPATED... 1000-1500
J/KG. THIS PAIRED WITH GOOD SHEAR ONCE AGAIN... STORMS ON THE
DRYLINE WILL LIKELY DEVELOP RAPIDLY AND BE GOOD HAIL PRODUCERS... UP
TO TENNIS BALL SIZED... AS WELL AS PRODUCING POTENTIALLY DAMAGING
WIND GUSTS. AS FOR TORNADOES... CHANCES LOOK BETTER IN KS... WHERE
SHEAR/LL WINDS WILL BE ENHANCED BY THE MORE FAVORABLE POSITION OF
THE SFC LOW OVER ERN CO/WRN KS. GUIDANCE SUGGESTS OK AND NRN TX
STORMS WILL MOVE OFF THE DRYLINE... BECOMING ELEVATED QUICKLY AFTER
SUNSET. THE CHANCE FOR SEVERE STORMS WILL DIMINISH OVERNIGHT... WITH
SCATTERED THUNDERSTORMS PERSISTING THROUGH THU MORNING.
FOR THURSDAY INTO FRIDAY... PRECIPITATION CHANCES WILL CONTINUE...
ESPECIALLY THU NIGHT INTO FRI... AS A DIFFUSE FRONTAL BOUNDARY
STALLS/LINGERS NEAR THE OK/KS BORDER... EXTENDING FROM THE PANHANDLE
INTO ERN KS. H500 FLOW REMAINS FAIRLY STATIC AS THE SRN PLAINS
REMAINS SANDWICHED BETWEEN A DEEPENING TROUGH IN THE WEST AND A
SHARP POSITIVE RIDGE INTO THE MID-ATLANTIC COAST. WITH THIS FLOW
REGIME AND THE LINGERING WEAK FRONTAL BOUNDARY... COUPLED WITH
CONTINUOUS MOISTURE ADVECTION FROM THE GULF... PERSISTENT AND
POSSIBLY EXCESSIVE RAINFALL LIKELY... ESPECIALLY FRI INTO SAT AM.
THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE WEEKEND AS THE H500
TROUGH FINALLY LIFTS E/NE ACROSS THE CENTRAL ROCKIES. WITH THIS...
THE DRY LINE WILL MAKE ANOTHER PUSH ON SATURDAY... WITH STRONG TO
SEVERE STORMS POSSIBLE ONCE AGAIN. DETAILS REMAIN HAZY GIVEN WHATS
POSSIBLE TO TRANSPIRE BETWEEN NOW AN THEN. AS WITH TODAY AND WED...
THUNDERSTORMS SAT WILL BE DEPENDENT ON HOW THE ATMOSPHERE RECOVERS
FROM THE MORNING CONVECTION.
PRECIP CHANCES WILL DIMINISH MON INTO TUES.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 63 78 65 / 40 70 40 50
HOBART OK 72 63 80 63 / 70 80 40 50
WICHITA FALLS TX 76 65 82 66 / 60 70 30 50
GAGE OK 69 60 82 62 / 70 80 20 20
PONCA CITY OK 79 65 78 66 / 10 80 50 40
DURANT OK 78 65 78 66 / 60 70 50 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
629 AM CDT TUE MAY 5 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...MVFR CIGS DID NOT MATERIALIZE AT BRO AND HRL WITH
THOSE CIGS AFFECTING MFE ATTM. GUSTY WINDS TO BEGIN AROUND 14Z AT
WHICH TIME THOSE CIGS SHOULD BEGIN TO SCATTER TO VFR BY LATE
MORNING. GUSTS TO 30 KNOTS APPEAR POSSIBLE ESPECIALLY AT MFE WHERE
STRONGER LOW LEVEL WINDS RESIDE. WINDS WILL DECREASE AFTER SUNSET
BUT GUSTS WILL CONTINUE TILL AROUND MIDNIGHT. MVFR CIGS WILL BUILD
BACK IN AFTER SUNSET WHICH WILL CONTINUE THROUGH THE REST OF THE
TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 416 AM CDT TUE MAY 5 2015/
SHORT TERM /NOW THROUGH WEDNESDAY/...UPPER TROF ACROSS THE FOUR
CORNERS REGION WILL OPEN UP AND WEAKEN AS IT HEADS NORTHEASTWARD
INTO COLORADO THEN BECOME ABSORBED IN THE DEEPENING LARGER SCALE
TROUGH ACROSS THE WESTERN CONUS. DIFFLUENCE REMAINS ACROSS THE
AREA BUT BETTER DYNAMICS ASSOCIATED WITH THE UPPER TROF WILL
REMAIN WELL REMOVED FROM THE AREA. 700MB FLOW STRENGTHENS AND
REINFORCES MID LEVEL CAPPING WITH DRY AIR ADVECTING FROM THE
MEXICAN PLATEAU AND OVER SPREADING THE AREA. LEFT SLIGHT CHANCE
POPS THIS MORNING FOR FAR WESTERN SECTIONS BUT BELIEVE CAP WILL
KEEP THE LID ON MOST IF NOT ALL PRECIPITATION TODAY. HRRR AND
NAM12 SUPPORT THIS IDEA. BREEZY CONDITIONS CONTINUE TODAY WITH
DEEPENING LOW PRESSURE ACROSS WEST TEXAS WITH GUSTS APPROACHING 30
MPH. THERE ARE INDICATIONS IN THE MODELS OF THUNDERSTORMS
DEVELOPING ON THE HIGHER TERRAIN THIS EVENING AND MOVE EASTWARD
TOWARDS OUR AREA BUT DRY AIR SHOULD WEAKEN THEM BEFORE MAKING
ACROSS THE RIVER. THEREFORE WILL KEEP FORECAST DRY TONIGHT. BREEZY
CONDITIONS CONTINUE WEDNESDAY WITH ANOTHER ROUND OF 700MB DRY AIR
ADVECTING FROM THE WEST. CONDITIONS WILL BE FAIRLY SIMILIAR TO THE
PAST SEVERAL DAYS. HIGHS IN THE 80S THE NEXT SEVERAL DAYS AND
PERHAPS REACHING 90 DEGREES IN THE FAR NORTHWESTERN SECTIONS OF
ZAPATA COUNTY. LOWS WILL BE IN THE 70S.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...AS LOW PRESSURE
TROUGHS DEEPEN ACROSS SW U.S. AND JUST OFF THE SE U.S. COAST MID
TO UPPER LEVEL RIDGE BUILDS OVER SOUTH TEXAS AND THE WESTERN
GULF. THIS SHOULD IN A MOSTLY DRY RAINFREE WED NIGHT THROUGH
SUNDAY PERIOD. NOT UNTIL THE WESTERN TROUGH BEGINS TO MOVE
NORTHEAST LATE NEXT WEEKEND INTO EARLY NEXT WEEK WILL THERE BE
SOME INCREASE IN THE CHANCE OF RAIN. MODELS REMAIN RATHER
PERSISTENT IN THIS PATTERN AND HAVE BEEN IN GOOD CONSISTENCY
MAKING FOR A BETTER THAN AVERAGE CONFIDENCE IN THE OUTGOING
FORECAST.
OVERALL, THE EARLY DOG DAYS OF SUMMER WILL BE SETTING UP AS THE
BUILDING UPPER RIDGE AND STRONG CAPPING INVERSION BETWEEN
850-700MB TO DOMINATE. THE BUILDING RIDGE PROMOTES A DIVERGENT Q
VECTOR FIELD OR A CONFLUENT FLOW ALOFT AND THE 850-700MB CAPPING
INVERSION STRENGTHENS WITH A THE PERSISTENT SOUTHWEST FLOW.
WITHOUT ANY LIFTING MECHANISM AND DISTURBANCES/VORT MAXES LIKELY
TO BE DIVERTED NORTHEAST OF THE AREA DO NOT SEE ANY SIGNIFICANT
CHANCE OF RAIN. WITH THAT SAID HAVE KEPT THE LOW CHANCE POPS
ACROSS THE NW ZONES JUST IN CASE A ROUGE THUNDERSTORM MOVES IN
FROM THE SIERRA MADRE.
WARM/HOT, HUMID AND BREEZY WILL BE THE WORD THROUGH AT LEAST
SUNDAY WITH WINDIEST DAYS NEXT WEEKEND AS THE UPPER TROUGH OVER
THE DESERT SW LIFTS INTO THE CENTRAL PLAINS STRENGTHENING THE
PRESSURE GRADIENT. AS WE MOVE INTO NEXT WEEK MODELS SUGGEST AN
INCREASE IN RAIN CHANCES. THE WEAKENING OF THE RIDGE AND A
TRAILING COLD FRONT MOVING INTO CENTRAL TEXAS ALONG WITH POOLING
MOISTURE SOUTH OF THE BOUNDARY LOOKS TO THE INGREDIENTS NEEDED TO
GET A FEW STORMS IN OUR REGION. HAVE BROAD BRUSHED THE CWA WITH
LOW GRADE POPS NEXT MONDAY AND TUESDAY TO ACCOMMODATE THE MODEL
CONSENSUS.
MARINE...NOW THROUGH WEDNESDAY...MODERATE SOUTHEAST WINDS
AND MODERATE SEAS WILL CONTINUE AS HIGH PRES REMAINS DOMINANT
OVER THE SOUTHEAST U.S. AND THE NORTH GULF...COUNTERBALANCED BY
SOMEWHAT LOWER PRESSURE OVER THE SOUTHERN HIGH PLAINS. WINDS AND
SEAS MAY INCREASE SLIGHTLY AT TIMES...WITH SMALL CRAFT EXERCISE
CAUTION TO LOW END SMALL CRAFT ADVISORY CONDITIONS POSSIBLE.
WEDNESDAY NIGHT THROUGH SUNDAY...A MODERATE TO STRONG PRESSURE
GRADIENT TO PERSIST THIS PERIOD. BROAD HIGH PRESSURE OVER THE
GULF TO INTERACT WITH LOWER PRESSURE OVER NW TEXAS TO PRODUCE
MARGINAL SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY NIGHT THROUGH
FRIDAY. LOW PRESSURE STRENGTHEN OVER THE WEEKEND WITH A POSSIBLE
UPTICK IN WINDS AND SEAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
604 AM CDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 232 AM CDT TUE MAY 5 2015
MAIN FOCUS IS ON RAIN CHANCES AND RESULTANT TEMPERATURES. WEAK
SHORT WAVE TROUGH ENHANCED BY WHAT APPEARS TO BE AN EMBEDDED
MESOSCALE CONVECTIVE VORTICITY WAS SPINNING THROUGH IA OVERNIGHT
RESULTING IN WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. THUS
FAR THE RAIN HAS BEEN CONFINED TO IA/IL AND EXTREME SOUTHERN WI.
VARIOUS SHORT TERM MODELS SUGGEST SOME OF THE FRONTOGENETIC
FORCING WILL TRY AND SET UP FURTHER NORTH NEAR THE I-90 CORRIDOR
BUT THUS FAR NOTHING HAS BEEN DEVELOPING. NORTHWARD DEVELOPMENT
MAY BE HAMPERED BY ENTRAINMENT OF DRY AIR ON EAST/NORTHEAST WINDS
WHERE LOW LEVEL DEWPOINTS ARE IN THE 30S.
OTHERWISE ANTICIPATE THAT THE RAIN AREA WILL SHIFT EAST AND ANY
LINGERING RAIN CHANCE WILL REALLY DIMINISH AS THE DAY WEARS ON.
WILL MAINTAIN A SLIGHT CHANCE OVER THE SOUTH WHERE BETTER MOISTURE
AND RESIDUAL BOUNDARIES MAY WORK WITH DAYTIME HEATING TO GENERATE
SOME SHOWERS LATER TODAY. ATTENTION THEN SHIFTS TO CONVECTIVE
POTENTIAL TONIGHT AS THE FRONTAL BOUNDARY ACROSS IA MOVES BACK
NORTH. TREND HAS BEEN FOR LESS AND LESS ACTION ALONG THE NORTHWARD
MOVING AND WEAKENING WARM FRONT. STILL...MAINTAINED RAIN RISK LATE
TONIGHT INTO EARLY WEDNESDAY AS MOISTURE CONVERGENCE AND WEAK
FRONTOGENETIC SIGNAL TRANSLATE THROUGH.
CLOUDS AND RAIN SHOULD KEEP TEMPERATURES SOMEWHAT IN CHECK. THIS
ALREADY ACCOUNTED FOR IN PREVIOUS FORECAST SO MINIMAL CHANGES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 232 AM CDT TUE MAY 5 2015
ACTIVE WEATHER PATTERN ON TAP WITH SEVERAL DISTURBANCES MOVING
THROUGH THE REGION OUT OF THE MEAN LONG WAVE TROUGH OVER THE
WESTERN CONUS. CHALLENGE FOR THE LONGER TERM IS TRYING TO IDENTIFY
THE BEST CHANCE FOR NO RAIN AND HOW TO DEPICT THAT IN THE
FORECAST. SIGNIFICANT SHORT WAVE TROUGH EJECTS NORTHEAST ACROSS
THE PLAINS AND INTO THE DAKOTAS BY THURSDAY...INDUCING A SURFACE
LOW AND TRACKING IT INTO WESTERN ONTARIO BY THURSDAY NIGHT. BEST
RAIN CHANCES WILL REMAIN WEST OF THE GENERAL FORECAST AREA...BUT
THERE IS A SUGGESTION BY SEVERAL OF THE MEDIUM RANGE MODELS THAT
SOME ACTIVITY COULD DEVELOP IN THE WARM/MOIST ADVECTION REGIME OUT
AHEAD OF THE SYSTEM. SO AM FORCED TO KEEP SOME CHANCES IN THE
FORECAST. COLD FRONT TRAILING THIS SYSTEM WILL EDGE THROUGH THE
FORECAST AREA ON FRIDAY AND MAY LINGER AROUND THE AREA INTO
SATURDAY. MODELS SOMEWHAT AT ODDS AS TO HOW FAR SOUTH IT WILL
PUSH...WITH THE GFS MOST AGGRESSIVE WITH THE COOLER AND DRIER AIR.
IF THIS SCENARIO PANS OUT...SATURDAY COULD BE QUITE PLEASANT AND
DRY. ECMWF LESS OPTIMISTIC WITH THE BOUNDARY NEARBY. MESSY
PATTERN THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK AS THE CLOSED
CIRCULATION IN THE BASE OF THE LONG WAVE TROUGH FINALLY EJECTS
NORTHEAST THROUGH THE UPPER MIDWEST. MODELS DIFFER IN THE
DETAILS...AND THERE ARE NOW INDICATIONS THAT THIS GENERAL
CIRCULATION WILL LINGER AROUND THE REGION THROUGH NEARLY ALL OF
NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 604 AM CDT TUE MAY 5 2015
BAND OF SHOWERS NORTH OF THE STATIONARY FRONT CONTINUE TO WORK
SLOWLY NORTH THIS MORNING...BUT THE 05.09Z HRRR SUGGESTS THEY
SHOULD NOT GET MUCH FARTHER NORTH. AS A RESULT...WILL STAY WITH
VCSH AT BOTH TAF SITES FOR NOW BUT WILL MONITOR KLSE CLOSELY FOR
AN UPDATE TO INCLUDE A SHORT PERIOD OF SOME RAIN. MVFR CEILINGS
AHEAD OF THESE SHOWERS ARE ALREADY IMPACTING BOTH TAF SITES AND
WILL INCLUDE THESE INTO THE EARLY AFTERNOON. AFTER THAT...THE
05.06Z NAM WOULD SUGGEST BOTH TAF SITES WOULD BE STUCK IN THE MVFR
CEILINGS ALL DAY WHILE THE 05.09Z RAP FOR THE MOST PART KEEPS VFR.
LOOKING DOWNSTREAM INTO IOWA...THERE IS A BACK EDGE TO THE MVFR
CLOUDS SO WILL GO WITH THE RAP FOR THE REMAINDER OF THE DAY WITH
VFR CONDITIONS. THE FRONT SHOULD THEN START TO LIFT NORTH TOWARD
THE AREA LATE TONIGHT. THE FORCING WITH THE FRONT LOOKS TO BE
RATHER WEAK AND WHILE THERE COULD BE SOME SHOWERS AROUND AFTER
06.06Z...NOT CONFIDENT ENOUGH IN THESE OCCURRING TO EVEN INCLUDE A
VCSH AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
934 AM MDT TUE MAY 5 2015
.UPDATE...VISIBLE SATELLITE IMAGERY AND WYDOT WEBCAMS CONTINUE TO
SHOW AREAS OF DENSE FOG AROUND CHEYENNE TO THE SUMMIT EAST OF
LARAMIE...AND BETWEEN SINCLAIR AND RAWLINS WY. WE UPDATED TO
INCLUDE THE RAWLINS AREA ALONG I-80 IN THE DENSE FOG ADVISORY AND
TO EXTEND THE ADVISORY UNTIL NOON MDT. EXPECT THE FOG WILL START
TO LIFT BY EARLY AFTERNOON. OTHERWISE...NO FURTHER CHANGES NEEDED
IN THE NEAR TERM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
WEBCAMS ALONG INTERSTATE 80 HAVE CONSISTENTLY SHOWN DENSE FOG FROM
THE SUMMIT TO CHEYENNE OVER THE PAST FEW HOURS. DECIDED TO ADD
CENTRAL LARAMIE COUNTY (CHEYENNE) TO THE DENSE FOG ADVISORY
THRU 16Z WITH THE CYS OBS DROPPING TO ONE QUARTER MILE. THE LOW
CLOUDS AND FOG WILL REMAIN QUITE PERSISTENT THROUGH THE MORNING
WITH THE HRRR MODEL INDICATING LIFR/IFR CONDITIONS THROUGH 18Z
FROM THE INTERSTATE 80 SUMMIT EASTWARD TO CHEYENNE COUNTY. THIS
MAKES SENSE AS THE OVERALL SFC PATTERN OF VERY MOIST SOUTH TO
SOUTHEAST WINDS WILL CONTINUE THROUGH THE MORNING. WATER VAPOR
IMAGERY SHOWS THE SUBTROPICAL UPPER LOW SPINNING OVER NORTHEAST
ARIZONA. THE MODELS MOVE THIS FEATURE TO THE NORTHEAST OVER THE
COURSE OF THE DAY TO NEAR NORTHERN COLORADO BY THIS EVENING.
ONLY AN ISOLATED TO SCATTERED COVERAGE OF SHOWERS IS
EXPECTED THROUGH THE EARLY AFTN ALONG THE COLORADO BORDER.
HOWEVER...MIDLVL HEIGHT FALLS WILL COMBINE WITH INCREASING
DEEP LAYER MOISTURE TO PROMOTE A MORE WIDESPREAD COVERAGE BY THE
LATE AFTN AND EARLY EVENING. MOISTURE IS PLENTIFUL WITH THIS
SYSTEM...IN FACT PW VALUES OF 0.75-1.0 INCHES OVER THE PLAINS ARE 2
STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY MAY. THUS...WITH
RELATIVELY SLOW STORM MOTIONS...LOCALLY HEAVY RAIN WILL BE A
CONCERN ESPECIALLY OVER THE NEBRASKA PANHANDLE. WHILE ISOLATED
TSTMS WILL BE POSSIBLE THIS AFTN...THE VERY WEAK INSTABILITY AND
SHEAR WILL MAKE STRONG STORMS UNLIKELY. SPC HAS DROPPED THE
MARGINAL THREAT OVER THE SOUTHERN PANHANDLE. WITH THE MIDLVL
DISTURBANCE OVERHEAD TONIGHT...WILL KEEP A CHANCE OF SHOWERS
GOING. SOUTHEAST SFC WINDS ARE IN PLACE THRU 12Z WED...SO FOG
WILL AGAIN BE A THREAT OVER PORTIONS OF THE AREA.
THE SHORTWAVE WILL PUSH INTO WESTERN SOUTH DAKOTA/NEBRASKA BY WED
AFTN. THE MODELS SHOW THE HIGHEST QPF OVER THE PLAINS OF SOUTHEAST
WY AS A SFC COLD FRONT INTERACTS WITH GOOD MOISTURE. WILL HAVE
ISOLATED TSTMS DURING THE AFTN WITH SOME LIMITED CAPE. PRECIP
CHANCES DROP OFF WED EVENING BEHIND THE FRONT AS A DRIER AIRMASS
MOVES IN. THERE COULD ACTUALLY BE A 18-24 HR PERIOD FROM WED
EVENING THRU THURS AFTN WHEN MUCH OF THE CWA WILL BE PRECIP FREE.
SCATTERED STORMS WILL ONCE AGAIN DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE BY THURS AFTN...WITH LIMITED COVERAGE OVER THE
PLAINS IN A MORE STABLE AIRMASS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
UNSETTLED WEATHER CONTINUES IN THE LONG TERM. MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE THE POSSIBILITY OF WINTER WEATHER
RETURNING TO THE AREA LATE IN THE WEEKEND.
STARTING OFF THURSDAY NIGHT...WE STILL HAVE THE STALLED SURFACE
BOUNDARY LAYING ALONG THE LARAMIE RANGE...OR SLIGHTLY WEST. BOTH
THE GFS AND ECMWF VERY SIMILAR BRINGING ANOTHER PIECE OF ENERGY
NORTHEAST FROM THE DESERT SOUTHWEST TO INTERACT WITH THIS
BOUNDARY...SO WILL KEEP CHANCE POPS GOING FOR THE THURSDAY NIGHT
TIME FRAME. PROBABLY PRETTY LIGHT SHOWERS THOUGH AS HAS BEEN THE
CASE THE PAST FEW NIGHTS. CONVECTION PICKS UP THROUGH FRIDAY AFTERNOON
WITH BOTH MODELS CONCENTRATING ON THE SOUTHERN PANHANDLE AND
NORTHEASTERN COLORADO. SOUTHEAST UPSLOPING WINDS TO CONTINUE.
GFS AND ECMWF CONTINUE TO AGREE ON A CLOSED LOW ROUNDING THE BASE
OF THE LONGWAVE TROUGH SATURDAY MORNING AND BEGINNING TO LIFT
NORTHEAST INTO SOUTHWESTERN COLORADO SATURDAY AFTERNOON. OUR
FORECAST AREA IS SQUARE IN THE WRAP AROUND MOISTURE TO THE NORTH
OF THIS LOW. ECMWF A LITTLE FASTER ON MOVEMENT OVER THE
GFS...MOVING THE LOW INTO CENTRAL NEBRASKA ROUGHLY 12 HOURS FASTER
THAN THE GFS. BOTH ARE COLD THOUGH ON 700MB TEMPERATURES AND COLD
ENOUGH FOR WIDESPREAD SNOW. BOTH ARE SHOWING 850MB WINDS OF 40 TO
45KTS ACROSS THE PANHANDLE AND EASTERN WYOMING. WINTER IS NOT DONE
WITH SOUTHEAST WYOMING AND WE NEED TO BE WATCHING THE EVOLUTION OF
THIS EVENT AS HEAVY SNOW AND WINTER HEADLINES ARE DEFINITELY A
POSSIBILITY FOR PORTIONS OF THE FORECAST AREA...POSSIBLY EVEN THE
PANHANDLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 536 AM MDT TUE MAY 5 2015
WIDESPREAD IFR/LIFR CEILINGS AND VISIBILITIES TO PERSIST ACROSS
MUCH OF THE AREA THROUGH THE MORNING HOURS. SHOWERS BECOME
WIDESPREAD ACROSS THE SOUTHERN PANHANDLE AND I-80 CORRIDOR LATE
AFTERNOON INTO THE EVENING WITH IFR/LIFR CONDITIONS RETURNING.
&&
.FIRE WEATHER...
ISSUED AT 345 AM MDT TUE MAY 5 2015
A COOL AND WET WEATHER PATTERN WILL KEEP FIRE WEATHER CONCERNS VERY
LOW THROUGH THE WEEKEND. AFTERNOON AND EVENING SHOWERS WILL BE
POSSIBLE TODAY THROUGH THURSDAY...WITH GOOD CHANCES FOR MEASURABLE
RAIN. MORE SUBSTANTIAL PRECIPITATION AMOUNTS ARE LOOKING POSSIBLE
BY LATE FRIDAY INTO SUNDAY ASSOCIATED WITH A STRONG STORM SYSTEM.
MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE PERIOD.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL NOON MDT TODAY FOR WYZ104-105-109-110-
116>118.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
538 AM MDT TUE MAY 5 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
WEBCAMS ALONG INTERSTATE 80 HAVE CONSISTENTLY SHOWN DENSE FOG FROM
THE SUMMIT TO CHEYENNE OVER THE PAST FEW HOURS. DECIDED TO ADD
CENTRAL LARAMIE COUNTY (CHEYENNE) TO THE DENSE FOG ADVISORY
THRU 16Z WITH THE CYS OBS DROPPING TO ONE QUARTER MILE. THE LOW
CLOUDS AND FOG WILL REMAIN QUITE PERSISTENT THROUGH THE MORNING
WITH THE HRRR MODEL INDICATING LIFR/IFR CONDITIONS THROUGH 18Z
FROM THE INTERSTATE 80 SUMMIT EASTWARD TO CHEYENNE COUNTY. THIS
MAKES SENSE AS THE OVERALL SFC PATTERN OF VERY MOIST SOUTH TO
SOUTHEAST WINDS WILL CONTINUE THROUGH THE MORNING. WATER VAPOR
IMAGERY SHOWS THE SUBTROPICAL UPPER LOW SPINNING OVER NORTHEAST
ARIZONA. THE MODELS MOVE THIS FEATURE TO THE NORTHEAST OVER THE
COURSE OF THE DAY TO NEAR NORTHERN COLORADO BY THIS EVENING.
ONLY AN ISOLATED TO SCATTERED COVERAGE OF SHOWERS IS
EXPECTED THROUGH THE EARLY AFTN ALONG THE COLORADO BORDER.
HOWEVER...MIDLVL HEIGHT FALLS WILL COMBINE WITH INCREASING
DEEP LAYER MOISTURE TO PROMOTE A MORE WIDESPREAD COVERAGE BY THE
LATE AFTN AND EARLY EVENING. MOISTURE IS PLENTIFUL WITH THIS
SYSTEM...IN FACT PW VALUES OF 0.75-1.0 INCHES OVER THE PLAINS ARE 2
STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY MAY. THUS...WITH
RELATIVELY SLOW STORM MOTIONS...LOCALLY HEAVY RAIN WILL BE A
CONCERN ESPECIALLY OVER THE NEBRASKA PANHANDLE. WHILE ISOLATED
TSTMS WILL BE POSSIBLE THIS AFTN...THE VERY WEAK INSTABILITY AND
SHEAR WILL MAKE STRONG STORMS UNLIKELY. SPC HAS DROPPED THE
MARGINAL THREAT OVER THE SOUTHERN PANHANDLE. WITH THE MIDLVL
DISTURBANCE OVERHEAD TONIGHT...WILL KEEP A CHANCE OF SHOWERS
GOING. SOUTHEAST SFC WINDS ARE IN PLACE THRU 12Z WED...SO FOG
WILL AGAIN BE A THREAT OVER PORTIONS OF THE AREA.
THE SHORTWAVE WILL PUSH INTO WESTERN SOUTH DAKOTA/NEBRASKA BY WED
AFTN. THE MODELS SHOW THE HIGHEST QPF OVER THE PLAINS OF SOUTHEAST
WY AS A SFC COLD FRONT INTERACTS WITH GOOD MOISTURE. WILL HAVE
ISOLATED TSTMS DURING THE AFTN WITH SOME LIMITED CAPE. PRECIP
CHANCES DROP OFF WED EVENING BEHIND THE FRONT AS A DRIER AIRMASS
MOVES IN. THERE COULD ACTUALLY BE A 18-24 HR PERIOD FROM WED
EVENING THRU THURS AFTN WHEN MUCH OF THE CWA WILL BE PRECIP FREE.
SCATTERED STORMS WILL ONCE AGAIN DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE BY THURS AFTN...WITH LIMITED COVERAGE OVER THE
PLAINS IN A MORE STABLE AIRMASS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
UNSETTLED WEATHER CONTINUES IN THE LONG TERM. MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE THE POSSIBILITY OF WINTER WEATHER
RETURNING TO THE AREA LATE IN THE WEEKEND.
STARTING OFF THURSDAY NIGHT...WE STILL HAVE THE STALLED SURFACE
BOUNDARY LAYING ALONG THE LARAMIE RANGE...OR SLIGHTLY WEST. BOTH
THE GFS AND ECMWF VERY SIMILAR BRINGING ANOTHER PIECE OF ENERGY
NORTHEAST FROM THE DESERT SOUTHWEST TO INTERACT WITH THIS
BOUNDARY...SO WILL KEEP CHANCE POPS GOING FOR THE THURSDAY NIGHT
TIME FRAME. PROBABLY PRETTY LIGHT SHOWERS THOUGH AS HAS BEEN THE
CASE THE PAST FEW NIGHTS. CONVECTION PICKS UP THROUGH FRIDAY AFTERNOON
WITH BOTH MODELS CONCENTRATING ON THE SOUTHERN PANHANDLE AND
NORTHEASTERN COLORADO. SOUTHEAST UPSLOPING WINDS TO CONTINUE.
GFS AND ECMWF CONTINUE TO AGREE ON A CLOSED LOW ROUNDING THE BASE
OF THE LONGWAVE TROUGH SATURDAY MORNING AND BEGINNING TO LIFT
NORTHEAST INTO SOUTHWESTERN COLORADO SATURDAY AFTERNOON. OUR
FORECAST AREA IS SQUARE IN THE WRAP AROUND MOISTURE TO THE NORTH
OF THIS LOW. ECMWF A LITTLE FASTER ON MOVEMENT OVER THE
GFS...MOVING THE LOW INTO CENTRAL NEBRASKA ROUGHLY 12 HOURS FASTER
THAN THE GFS. BOTH ARE COLD THOUGH ON 700MB TEMPERATURES AND COLD
ENOUGH FOR WIDESPREAD SNOW. BOTH ARE SHOWING 850MB WINDS OF 40 TO
45KTS ACROSS THE PANHANDLE AND EASTERN WYOMING. WINTER IS NOT DONE
WITH SOUTHEAST WYOMING AND WE NEED TO BE WATCHING THE EVOLUTION OF
THIS EVENT AS HEAVY SNOW AND WINTER HEADLINES ARE DEFINITELY A
POSSIBILITY FOR PORTIONS OF THE FORECAST AREA...POSSIBLY EVEN THE
PANHANDLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 536 AM MDT TUE MAY 5 2015
WIDESPREAD IFR/LIFR CEILINGS AND VISIBILITIES TO PERSIST ACROSS
MUCH OF THE AREA THROUGH THE MORNING HOURS. SHOWERS BECOME
WIDESPREAD ACROSS THE SOUTHERN PANHANDLE AND I-80 CORRIDOR LATE
AFTERNOON INTO THE EVENING WITH IFR/LIFR CONDITIONS RETURNING.
&&
.FIRE WEATHER...
ISSUED AT 345 AM MDT TUE MAY 5 2015
A COOL AND WET WEATHER PATTERN WILL KEEP FIRE WEATHER CONCERNS VERY
LOW THROUGH THE WEEKEND. AFTERNOON AND EVENING SHOWERS WILL BE
POSSIBLE TODAY THROUGH THURSDAY...WITH GOOD CHANCES FOR MEASURABLE
RAIN. MORE SUBSTANTIAL PRECIPITATION AMOUNTS ARE LOOKING POSSIBLE
BY LATE FRIDAY INTO SUNDAY ASSOCIATED WITH A STRONG STORM SYSTEM.
MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE PERIOD.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR WYZ116>118.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS TUCSON AZ
235 PM MST TUE MAY 5 2015
.SYNOPSIS...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
MAINLY NORTHEAST OF TUCSON INTO THIS EVENING. DRY CONDITIONS WILL
THEN PREVAIL WEDNESDAY INTO EARLY NEXT WEEK. THE EXCEPTION WILL BE A
FEW SHOWERS AND THUNDERSTORMS ACROSS THE WHITE MOUNTAINS SATURDAY.
EXPECT BREEZY TO WINDY CONDITIONS DURING THE LATTER PART OF THE
WEEK. BELOW NORMAL DAYTIME TEMPERATURES WILL OCCUR INTO SATURDAY
FOLLOWED BY A SIGNIFICANT WARMING TREND EARLY NEXT WEEK.
&&
.DISCUSSION...THE SYSTEM THAT BROUGHT SHOWERS AND THUNDERSTORMS TO
THE AREA YESTERDAY AND LAST NIGHT WILL CONTINUE TO INFLUENCE THE
WEATHER TODAY. RESIDUAL MOISTURE COMBINED WITH DAYTIME HEATING AND
SOME SUPPORT FROM THE UPPER LOW WILL RESULT IN A FEW SHOWERS AND
THUNDERSTORMS YET THIS EVENING. LATEST HRRR MODEL SOLUTION KEPT MOST
OF THIS ACTIVITY NORTHEAST OF THE TUCSON METRO THIS EVENING.
ALTHOUGH THE MODEL DEPICTED VERY SPOTTY ACTIVITY...SO WILL JUST KEEP
LOW POP VALUES IN THE FORECAST FOR NOW. OTHERWISE...MODELS EJECT THE
SYSTEM NORTHEAST INTO THE CENTRAL PLAINS BY TOMORROW MORNING
RESULTING IN A BREAK IN THE RAIN CHANCES. HOWEVER...ANOTHER SYSTEM
WAS PROGGED TO DROP SOUTH ALONG THE INTERIOR WEST COAST INTO CENTRAL
CALIFORNIA ON THURSDAY. THIS NEXT SYSTEM WILL BRING STRONG AND GUSTY
WINDS TO THE AREA AS EARLY AS TOMORROW AFTERNOON BUT MORE SO ON
THURSDAY. MODELS TRACK THIS SYSTEM THROUGH NORTHERN ARIZONA FRIDAY
INTO SATURDAY. FOR NOW...THE BEST CHANCE OF RAIN WILL BE ACROSS
NORTHERN ARIZONA INTO THE WHITE MOUNTAINS MAINLY ON SATURDAY.
THEREAFTER...A RIDGE OF HIGH PRESSURE WAS PROGGED TO BUILD OVER THE
AREA BEFORE ANOTHER SYSTEM APPROACHES THE SOUTHERN CALIFORNIA COAST
EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL REMAIN BELOW NORMAL THIS
WEEK.
&&
.AVIATION...VALID THRU 07/00Z. SCATTERED SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE OVER THE WHITE MOUNTAINS NE OF KSAD INTO THIS
EVENING. GUSTY AFTERNOON WINDS WILL DIMINISH TO NORMAL DIURNAL
TRENDS AFTER SUNSET...GENERALLY LESS THAN 10 KTS THROUGH THE
MORNING. LOW AND MID LEVEL CLOUDS DIMINISHING TONIGHT...WITH SCT
HIGH CLOUDS MOVING IN LATE TONIGHT INTO WEDNESDAY MORNING. EXPECT
STRONGER WINDS WEDNESDAY...15 TO 20 KTS GUSTING TO AROUND 30 KTS. AN
EARLIER START TO WINDS WEDNESDAY...PICKING UP AROUND 16Z AT KSAD AND
KDUG...17Z AT KTUS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...A CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUES
MAINLY EAST OF TUCSON TODAY AND ACROSS THE WHITE MOUNTAINS INTO THIS
EVENING. DRY CONDITIONS WILL THEN PREVAIL LATE TONIGHT.
A LOW PRESSURE SYSTEM WILL STRENGTHEN NORTHWEST OF THE AREA
WEDNESDAY INTO FRIDAY. THIS SYSTEM WILL PRODUCE BREEZY CONDITIONS
WEDNESDAY AFTERNOON FOLLOWED BY BREEZY TO WINDY CONDITIONS THURSDAY
AND FRIDAY. HOWEVER...DAYTIME MINIMUM RELATIVE HUMIDITIES AND FUEL
MOISTURE WILL BE MARGINAL AT BEST TO PRODUCE CRITICAL FIRE
CONDITIONS. A FEW SHOWERS AND THUNDERSTORMS MAY THEN OCCUR ACROSS
THE WHITE MOUNTAINS SATURDAY AS THE LOW PRESSURE SYSTEM MOVES NORTH
OF THE AREA. EXPECT LESS WIND THIS WEEKEND ALTHOUGH SOME AFTERNOON
GUSTINESS WILL OCCUR DUE TO DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
334 PM MDT TUE MAY 5 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 328 PM MDT TUE MAY 5 2015
CURRENTLY...UPPER LOW LIFTING SLOWLY E-NE ALONG THE CO/NM
BORDER...WITH DEEP E-SE FLOW DRIVING WIDESPREAD SHOWER ACTIVITY
ACROSS THE AREA. LACK OF INSTABILITY HAS KEPT THUNDERSTORMS TO A
MINIMUM...THOUGH A FEW LIGHTNING STRIKES HAVE BEGIN TO APPEAR ACROSS
THE SAN LUIS VALLEY AS STRONGER CONVECTION ROTATES NORTHWARD OUT OF
NEW MEXICO. RAINFALL RATES SO FAR TODAY HAVE BEEN FAIRLY
MODEST...WITH 0.25-0.50 INCH PER HOUR UNDER THE HEAVIEST
SHOWERS...MAINLY A TENTH OF INCH PER HOUR OR LESS UNDER THE LIGHTER
ACTIVITY.
TONIGHT...LATEST HRRR SUGGESTS BAND OF MODERATE TO HEAVY SHOWERS
ALONG THE ARKANSAS RIVER AT 21Z WILL LIKELY BE THE LAST AREA OF
ORGANIZED HEAVIER PRECIP THIS EVENING...WITH ACTIVITY LIFTING SLOWLY
NORTHWARD AND WEAKENING AFTER 00Z. STILL A LOW THREAT OF AN ISOLATED
TSRA THIS EVENING...ESPECIALLY SOUTHERN SECTIONS NEAR THE NM BORDER
WHERE INSTABILITY (CAPES 200-400 J/KG) IS SLIGHTLY DEEPER...BUT
OVERALL...CHANCE OF STRONGER CONVECTION AND EXTREME RAINFALL RATES
APPEARS TO BE FAIRLY LOW...SO WILL LET FLASH FLOOD WATCH END
SLIGHTLY EARLY WITH AFTERNOON FORECAST UPDATE. AS LOW LIFTS
NORTHEAST ACROSS THE AREA OVERNIGHT...SCATTERED SHOWERS WILL
CONTINUE OVER THE MOUNTAINS...WHILE DEVELOPING WESTERLY LOW/MID
LEVEL FLOW GRADUALLY BRINGS AN END TO PRECIP OVER THE I-25
CORRIDOR AND EASTERN PLAINS AFTER 06Z. WON`T MENTION FOG IN THE
FORECAST AS CLOUDS AND WEAK WESTERLY FLOW SHOULD KEEP VISIBILITY
FROM DROPPING TOO MUCH...THOUGH WITH PLENTIFUL RAIN/BL MOISTURE
AREAS OF GROUND FOG LOOK POSSIBLE...ESPECIALLY EL PASO COUNTY
WHERE LOW LEVEL FLOW TAKES MUCH OF THE NIGHT TO TURN W-NW.
WEDNESDAY...UPPER LOW LIFTS SLOWLY NORTHEAST INTO THE CENTRAL PLAINS
BY LATE AFTERNOON WITH LOW AND MID LEVEL FLOW BECOMING MORE SWLY
THROUGH THE DAY. MOISTURE DECREASES SOMEWHAT AS WELL...THOUGH WITH
RATHER STEEP LAPSE RATES DEVELOPING DURING THE AFTERNOON AND WEAK
UPPER WAVE LIFTING OUT OF THE SOUTHWEST...AT LEAST SCATTERED
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS WILL DEVELOP MANY AREAS.
BEST CHANCES WILL BE ALONG THE CONTINENTAL DIVIDE AND NORTHERN
AREAS...LESSER POPS FARTHER SOUTH AND SOUTHEAST WHERE DRIER AIR
PUNCHES NORTHWARD FROM NM. MAX TEMPS WILL RECOVER ALL AREAS WITH
MORE SUN AND LACK OF WIDESPREAD RAINFALL...AND A FEW SPOTS ON THE
PLAINS WILL APPROACH 80F...WITH 60S AND 70S ACROSS MOST LOWER
ELEVATIONS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM MDT TUE MAY 5 2015
...WEATHER PATTERN TO REMAIN ACTIVE FOR NEXT SEVERAL DAYS...
AFTER A BRIEF LULL WEDNESDAY...WEDNESDAY NIGHT THROUGH
THURSDAY...LOW LEVEL UPSLOPE FLOW WILL REDEVELOP OVER THE
EASTERN PLAINS...LEADING TO MORE SHOWER AND THUNDERSTORM
CHANCES THURSDAY AFTERNOON AND EVENING...MAINLY FOR AREAS
ALONG AND NEAR THE EASTERN MOUNTAINS ACROSS THE PIKES
PEAK REGION...BUT ALSO FOR SPOTS OUT ON THE PLAINS. LOW LEVEL
EASTERLY FLOW COMBINED WITH UPPER LEVEL SOUTHWEST FLOW WILL INCREASE
SHEAR VALUES SUCH THAT A FEW SEVERE STORMS WILL BE POSSIBLE THURSDAY.
THURSDAY NIGHT THROUGH FRIDAY...LOW LEVEL UPSLOPE BECOMES MORE
FIRMLY ENTRENCHED ACROSS THE PLAINS. THE UPSLOPE LOOKS LIKE
IT GETS DEEP ENOUGH TO BRING IN WIDESPREAD LOW CLOUDS AND AREAS
OF LIGHT PRECIP...BUT POTENTIALLY REDUCES THE CONVECTIVE POTENTIAL
THIS DAY...BY LIMITING THE AMOUNT OF HEATING. SEVERE STORMS
PRESENTLY LOOK LESS LIKELY THIS DAY...BUT THIS IS CONTINGENT ON
HOW DEEP THE UPSLOPE FLOW REALLY TURNS OUT TO BE. COULD STILL HAVE
SOME PROBLEMS ALONG AND NEAR THE EAST SLOPES OF THE MOUNTAINS ACROSS
THE PIKES PEAK REGION...ESPECIALLY LATE FRIDAY AFTERNOON AND EVENING.
THEN...ON SATURDAY...WE BRING THE NEXT MAJOR NEGATIVE TILT TROUGH
NORTHEAST INTO SOUTHERN COLORADO. THIS TROUGH LOOKS VIGOROUS...WITH
THE POTENTIAL TO CREATE A LOT OF LIFT...AND GENERATE A LOT OF INTENSE
CONVECTION...IN A STRONGLY SHEARED ATMOSPHERE. PROBLEM IS...NOT
EXACTLY SURE WHAT TRAJECTORY THIS THING IS GOING TO TAKE AS IT
EJECTS NORTHEAST ON SATURDAY. THE 12Z GFS AND THE OLD 00Z ECMWF
TRACK IT FARTHER NORTH THAN SOME OF THE 06Z RUNS...GENERALLY
YIELDING LESS SEVERE POTENTIAL. BUT...IF THE 06Z RUNS TURN OUT
TO BE MORE TRUE TO FORM...WATCH OUT. COULD BE BIG SEVERE WEATHER
DAY OVER THE EAST...WITH TORNADO POTENTIAL AS WELL AS HAIL/WIND
POTENTIAL.
THEN...AS WE MOVE INTO SUNDAY...THINGS SHIFT OVER MORE TOWARD WINTER
WEATHER AS WE GET ON THE BACK SIDE OF THE SATURDAY SYSTEM. COLD AIR
ON THE BACK SIDE OF THE SYSTEM COULD BRING SNOW TO THE MOUNTAINS...
AND POSSIBLY DOWN TO THE LEVEL OF EL PASO COUNTY. FARTHER EAST...
AWAY FROM THE MOUNTAINS...IT WOULD LIKELY BE JUST SPOTTY LIGHTER
AMOUNTS OF RAIN.
NORTHWEST FLOW COULD BRING MORE RAIN AND SNOW SHOWERS TO THE
MOUNTAINS ON MONDAY. AND THEN...BY TUESDAY...IT`S LOOKING LIKE
ANOTHER ROUND OF MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS OVER
THE MOUNTAINS.
A LOT OF WEATHER TO TAKE PLACE OVER THE NEXT 7 DAYS. DETAILS
PRESENTED NOW WILL INEVITABLY CHANGE. PLEASE KEEP CHECKING BACK FOR
LATER UPDATES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 328 PM MDT TUE MAY 5 2015
AT KALS...PERIODS OF SHOWERS EXPECTED INTO EARLY EARLY
EVENING...WITH AN ISOLATED TSRA ALSO POSSIBLE. IN BETWEEN
SHOWERS...PREVAILING CONDITIONS WILL BE MAINLY VFR...WHILE UNDER THE
HEAVIER PRECIP MVFR CIGS/VIS ARE LIKELY. PRECIP DIMINISHES LATE THIS
EVENING AND OVERNIGHT...THOUGH MID-LEVEL CLOUD DECK WILL BE SLOW TO
CLEAR. ON WED...VFR WITH SCT -SHRA AND ISOLD -TSRA AFTER 18Z.
AT KCOS...RAIN SHOWERS WILL CONTINUE INTO THE EVENING WITH MAINLY
MVFR CONDITIONS...THOUGH SOME BRIEF IFR IS POSSIBLE UNDER THE HEAVIER
SHOWERS. LATE THIS EVENING AND OVERNIGHT SHOWERS WILL GRADUALLY
DIMINISH...THOUGH CIGS WILL BE SLOW TO LIFT WITH MVFR AND AREAS OF
IFR LIKELY TO PERSIST THROUGH THE NIGHT. MAY ALSO HAVE TO DEAL WITH
AT LEAST PATCHY AREAS OF FOG AS WELL WITH VERY WET GROUND AND MOIST
BOUNDARY LAYER. ON WED...ANY LOW CLOUDS SHOULD BREAK BY MID MORNING
WITH VFR CONDITIONS THROUGH THE DAY...THOUGH THERE WILL BE A CHANCE
OF TSRA AFTER 20Z.
AT KPUB...EXPECT PERIODS OF SHOWERS TO PERSIST INTO THE EVENING WITH
MVFR CONDITIONS UNDER THE HEAVIER PRECIP AND BRIEF VFR IN BETWEEN
SHOWERS. LATE THIS EVENING AND OVERNIGHT PRECIP WILL
DIMINISH...THOUGH AREAS OF MVFR CIGS WILL PERSIST ALONG WITH PATCHY
GROUND FOG AS WELL. ON WED...VFR FROM MID MORNING ONWARD WITH SCT -
SHRA AND ISOLD -TSRA AFTER 20Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...LW
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
245 PM CDT TUE MAY 5 2015
.UPDATE...
UPDATED TEMPERATURES AND WEATHER FOR THE REST OF TODAY. IT APPEARS
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORM REDEVELOPMENT THIS
AFTERNOON WILL BE PRIMARILY ALONG AND SOUTH OF INTERSTATE 80 IN
CLOSER PROXIMATE TO THE NORTHWARD ADVANCING SURFACE BOUNDARY.
TEMPERATURES ACROSS CENTRAL ILLINOIS..SOUTH OF THIS BOUNDARY ARE
ALREADY WELL INTO THE 70S TO NEAR 80 IN MANY LOCATIONS...WITH DEW
POINTS POOLING INTO THE LOWER TO MID 60S RIGHT ALONG THE BOUNDARY.
MODIFYING THE 12 UTC ILX SOUNDING WITH THESE SURFACE CONDITIONS
YIELDS SCAPE AROUND 1300 J/KG WITH VERY LITTLE CAP. WITH THIS IN
MIND...IN SPITE OF THE FACT THAT THERE IS NO SIGNIFICANT MID LEVEL
DISTURBANCE EXPECTED TO MOVE OVER THE AREA THIS AFTERNOON...IT
SEEMS PROBABLE THAT SCT CONVECTION WILL STILL CONTINUE TO BUBBLE
UP THIS AFTERNOON WITHIN THE VICINTY OF THIS SURFACE
BOUNDARY...WHERE INSTABILITY AND SURFACE CONVERGENCE WILL BE
MAXIMIZED. FARTHER NORTH...VERY COOL AND STABLE CONDITIONS SHOULD
LIMIT SHOWER AND THUNDERSTORM POTENTIAL. THEREFORE...I HAVE
POINTED THE FORECAST IN THIS DIRECTION.
TEMPERATURES ACROSS MUCH OF THE CHICAGO AREA NEAR LAKE MICHGAN
WILL LIKELY REMAIN IN THE LOW TO MID 50S TODAY. HOWEVER...FARTHER
INLAND AND SOUTH...EXPECT TEMPERATURES WELL INTO THE
70S...ESPECIALLY SOUTH OF INTERSTATE 80.
KJB
&&
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST-NORTHEAST WINDS AROUND 10 KT THROUGH THIS AFTERNOON.
* IFR/LIFR CIGS THROUGH THE BEGINNING OF THE MORNING RUSH
WEDNESDAY.
* IFR/LIFR VSBYS AT ORD THROUGH EARLY TOMORROW. RETURNING TO MDW
TONIGHT.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN...MAINLY SOUTH
OF MDW.
KMD
//DISCUSSION...UPDATED 18Z...
THE BATTLE OF THE COLD LAKE AND LOW LEVEL ONSHORE FLOW VERSUS THE
WARM MAY SUN IS UNDERWAY...MAKING FOR A CHALLENGING AFTERNOON
FORECAST ACROSS THE TERMINALS. MONITORING WEBCAMS DOWNTOWN SHOW
CLOUDS BRIEFLY ATTEMPTING TO LIFT BEFORE FILLING RIGHT BACK IN. WE
ALSO CONTINUE TO ADVECT WARMER AND MOIST AIR JUST OFF THE DECK
WHICH IS AIDING IN KEEPING THE LOW LEVEL INVERSION IN PLACE. FEEL
THAT THESE LATTER FACTORS WILL WIN OUT AND KEEP MOST OF THE TAF
SITES LOCKED IN LIFR TO IFR CONDITIONS...WHILE POINTS SOUTH WILL
LIFT TO VFR BEFORE MVFR CUMULUS FILL IN AS WELL.
THE LOW LEVEL FRONT IS NOT EXPECTED TO LIFT MUCH FARTHER
NORTH...AND THUS EXPECT THE NNE WINDS TO REMAIN IN PLACE. WITH THE
FRONT HOLDING SOUTH...EXPECT ANY CONVECTION THAT STIRS THIS
AFTERNOON TO BE FOCUSED IN THESE AREAS...SOUTH OF INTERSTATE 80.
TONIGHT WINDS SHOULD WEAKEN SOME AND EXPECT CIGS/VSBYS TO REMAIN
LOCKED IN DOWN LOW MOST OF THE NIGHT. FOG COULD BE DENSE
TONIGHT...ESPECIALLY CLOSER TO THE LAKE. LOW LEVEL FRONT GETS
SOME NORTHWARD MOVEMENT EARLY WEDS WHICH SHOULD ALLOW FOR SOME
LIFTING WEDNESDAY MORNING. PRECIP CHANCES DO EXIST TONIGHT/EARLY
WEDS BUT TOO LOW FOR A MENTION IN THE TAFS JUST YET. AT BEST SOME
ISOLATED SHOWERS AHEAD OF THE FRONT 8Z-12Z TIME FRAME FOR THE TAF
SITES.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH THAT EAST-NORTHEAST WINDS HOLD AROUND 10 KT THIS AFTERNOON.
* HIGH IN LIFR CIGS HOLDING AT ORD... AND IFR/LIFR CIGS RETURNING
TO MDW. MEDIUM ON CIG HEIGHTS OVERNIGHT THOUGH LOW-MEDIUM ON
CLEARING TIME WEDS.
* MEDIUM-LOW ON VSBYS THIS AFTERNOON AND TONIGHT. COULD BE WORSE
VSBY OVERNIGHT.
* HIGH IN ORD REMAINING DRY THE REST OF THE DAY. MEDIUM THAT
AFTERNOON SHOWERS/ISOLATED T-STORMS REMAIN SOUTH OF MDW. MEDIUM
THAT TAF SITES REMAIN DRY OVERNIGHT AS WELL.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 11 AM WEDNESDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 4 PM WEDNESDAY.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
111 PM CDT TUE MAY 5 2015
.UPDATE...1135 AM CDT
UPDATED TEMPERATURES AND WEATHER FOR THE REST OF TODAY. IT APPEARS
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORM REDEVELOPMENT THIS
AFTERNOON WILL BE PRIMARILY ALONG AND SOUTH OF INTERSTATE 80 IN
CLOSER PROXIMATE TO THE NORTHWARD ADVANCING SURFACE BOUNDARY.
TEMPERATURES ACROSS CENTRAL ILLINOIS..SOUTH OF THIS BOUNDARY ARE
ALREADY WELL INTO THE 70S TO NEAR 80 IN MANY LOCATIONS...WITH DEW
POINTS POOLING INTO THE LOWER TO MID 60S RIGHT ALONG THE BOUNDARY.
MODIFYING THE 12 UTC ILX SOUNDING WITH THESE SURFACE CONDITIONS
YIELDS SCAPE AROUND 1300 J/KG WITH VERY LITTLE CAP. WITH THIS IN
MIND...IN SPITE OF THE FACT THAT THERE IS NO SIGNIFICANT MID LEVEL
DISTURBANCE EXPECTED TO MOVE OVER THE AREA THIS AFTERNOON...IT
SEEMS PROBABLE THAT SCT CONVECTION WILL STILL CONTINUE TO BUBBLE
UP THIS AFTERNOON WITHIN THE VICINTY OF THIS SURFACE
BOUNDARY...WHERE INSTABILITY AND SURFACE CONVERGENCE WILL BE
MAXIMIZED. FARTHER NORTH...VERY COOL AND STABLE CONDITIONS SHOULD
LIMIT SHOWER AND THUNDERSTORM POTENTIAL. THEREFORE...I HAVE
POINTED THE FORECAST IN THIS DIRECTION.
TEMPERATURES ACROSS MUCH OF THE CHICAGO AREA NEAR LAKE MICHGAN
WILL LIKELY REMAIN IN THE LOW TO MID 50S TODAY. HOWEVER...FARTHER
INLAND AND SOUTH...EXPECT TEMPERATURES WELL INTO THE
70S...ESPECIALLY SOUTH OF INTERSTATE 80.
KJB
&&
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST-NORTHEAST WINDS AROUND 10 KT THROUGH THIS AFTERNOON.
* IFR/LIFR CIGS THROUGH THE BEGINNING OF THE MORNING RUSH
WEDNESDAY.
* IFR/LIFR VSBYS RETURNING TONIGHT.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN...MAINLY SOUTH
OF MDW.
KMD
//DISCUSSION...UPDATED 18Z...
THE BATTLE OF THE COLD LAKE AND LOW LEVEL ONSHORE FLOW VERSUS THE
WARM MAY SUN IS UNDERWAY...MAKING FOR A CHALLENGING AFTERNOON
FORECAST ACROSS THE TERMINALS. MONITORING WEBCAMS DOWNTOWN SHOW
CLOUDS BRIEFLY ATTEMPTING TO LIFT BEFORE FILLING RIGHT BACK IN. WE
ALSO CONTINUE TO ADVECT WARMER AND MOIST AIR JUST OFF THE DECK
WHICH IS AIDING IN KEEPING THE LOW LEVEL INVERSION IN PLACE. FEEL
THAT THESE LATTER FACTORS WILL WIN OUT AND KEEP MOST OF THE TAF
SITES LOCKED IN LIFR TO IFR CONDITIONS...WHILE POINTS SOUTH WILL
LIFT TO VFR BEFORE MVFR CUMULUS FILL IN AS WELL.
THE LOW LEVEL FRONT IS NOT EXPECTED TO LIFT MUCH FARTHER
NORTH...AND THUS EXPECT THE NNE WINDS TO REMAIN IN PLACE. WITH THE
FRONT HOLDING SOUTH...EXPECT ANY CONVECTION THAT STIRS THIS
AFTERNOON TO BE FOCUSED IN THESE AREAS...SOUTH OF INTERSTATE 80.
TONIGHT WINDS SHOULD WEAKEN SOME AND EXPECT CIGS/VSBYS TO REMAIN
LOCKED IN DOWN LOW MOST OF THE NIGHT. FOG COULD BE DENSE
TONIGHT...ESPECIALLY CLOSER TO THE LAKE. LOW LEVEL FRONT GETS
SOME NORTHWARD MOVEMENT EARLY WEDS WHICH SHOULD ALLOW FOR SOME
LIFTING WEDNESDAY MORNING. PRECIP CHANCES DO EXIST TONIGHT/EARLY
WEDS BUT TOO LOW FOR A MENTION IN THE TAFS JUST YET. AT BEST SOME
ISOLATED SHOWERS AHEAD OF THE FRONT 8Z-12Z TIME FRAME FOR THE TAF
SITES.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH THAT EAST-NORTHEAST WINDS HOLD AROUND 10 KT THIS AFTERNOON.
* HIGH IN LIFR CIGS HOLDING OR LIFTING SLIGHTLY AT ORD... AND
IFR/LIFR CIGS RETURNING TO MDW. MEDIUM ON CIG HEIGHTS OVERNIGHT
THOUGH LOW-MEDIUM ON CLEARING TIME WEDS.
* MEDIUM-LOW ON VSBYS THIS AFTERNOON AND TONIGHT. COULD BE WORSE
VSBY OVERNIGHT.
* HIGH IN ORD REMAINING DRY THE REST OF THE DAY. MEDIUM-HIGH THAT
AFTERNOON SHOWERS/ISOLATED T-STORMS REMAIN SOUTH OF MDW. MEDIUM
THAT TAF SITES REMAIN DRY OVERNIGHT AS WELL.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1249 PM CDT TUE MAY 5 2015
.UPDATE...
ISSUED AT 1045 AM CDT TUE MAY 5 2015
15Z/10AM SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY EXTENDING FROM
NORTH-CENTRAL ILLINOIS INTO CENTRAL IOWA...GENERALLY ALONG A
KANKAKEE...TO PEORIA...TO DES MOINES LINE. WIDESPREAD RAIN
CONTINUES TO FALL NORTH OF THE FRONT: HOWEVER, MOSTLY SUNNY AND
DRY CONDITIONS PREVAIL TO THE SOUTH ACROSS CENTRAL ILLINOIS.
TEMPERATURES HAVE ALREADY RISEN WELL INTO THE 70S ACROSS ALL BUT
THE FAR NORTHERN KILX CWA. BASED ON THE 12Z UPPER AIR SOUNDING AND
ASSUMING MIXING UP TO ABOUT 750MB SIMILAR TO YESTERDAY
AFTERNOON...HIGHS TODAY SHOULD REACH THE LOWER TO MIDDLE 80S. HAVE
ADJUSTED TEMPS UP BY A FEW DEGREES ACCORDINGLY.
&&
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
A FRONTAL BOUNDARY IS ORIENTED WEST-EAST ACROSS CENTRAL IL THIS
MORNING WITH PRECIPITATION IN ISENTROPIC ASCENT REGION LARGELY TO
THE NORTH OF THE BOUNDARY. MODELS INDICATE THE BOUNDARY AND
PRECIPITATION WILL SHIFT SLOWLY NORTHWARD TODAY. WEAK DISTURBANCES
MOVING ALONG THE BOUNDARY WILL PRODUCE SOME ENHANCEMENTS IN
CONVECTIVE SHOWER COVERAGE IN THE VICINITY...EARLY THIS MORNING FROM
AROUND THE ILLINOIS RIVER NORTHWESTWARD...AND LATE IN THE AFTERNOON
NORTH OF THE I-74 CORRIDOR. FOR THE MOST PART...CONVECTION SHOULD BE
WEAK AT THIS POINT WITH ONLY WEAK MID-LEVEL INSTABILITY REMAINING
THROUGH THE NIGHT...AND 0-6KM BULK SHEAR UP TO 25-30 KTS THIS
MORNING DIMINISHING SUBSTANTIALLY FOR THE AFTERNOON. 1000-1500
JOULES OF SURFACE-BASED CAPE SHOULD BE ABLE TO DEVELOP WITH
AFTERNOON HEATING ALONG/NORTH OF I-72 AND CAN`T RULE OUT ISOLATED
THUNDERSTORMS SOUTHWARD TO I-72 AS A RESULT.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
ONGOING CONVECTION ALONG THE BOUNDARY OVER NORTHERN ILLINOIS THIS
MORNING NOT ONLY DRIVING THE WEATHER THROUGHOUT THE DAY, BUT INTO
THE OVERNIGHT AS WELL. GFS AND NAM CONTINUE TO KEEP A BIT OF PRECIP
PRETTY FAR SOUTH, AS FAR SOUTH AS A LINE FROM HAVANA TO BLOOMINGTON.
HOWEVER, THE RAP/RUC AND THE HRRR ARE PUSHING THE AREA OF CONVECTION
WELL TO THE NORTH THROUGH THE MORNING WITH THE BOUNDARY. WHEN THE
SECONDARY WAVE RIPPLES THROUGH THE REGION AFTER 00Z, IT WOULD BE
DISPLACED NORTH OF THE FA. THE 4KM WRF HAS JUST THAT SOLUTION,
STARTING MORE IN LINE WITH THE RAP/RUC AND HRRR...AND KEEPING THE FA
DRY AFTER 00Z, BUT A LITTLE MORE GENEROUS WITH SOME ISOLATED
INSTABILITY SHOWERS. HAVE KEPT ISO TS IN THE NORTH, MAINLY ALONG
AND NORTH OF I-74 FOR THE EARLY EVENING.
HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION LATER TONIGHT,
SOUTHERLY WINDS PUSHING THE FRONT BACK TO THE NORTH AND OUT OF THE
FORECAST AREA THROUGH WED NIGHT. FORECAST REMAINS ROUGHLY THE SAME
BEYOND DAY 3... PRECIP CHANCES SLOWLY EDGING BACK INTO WEST CENTRAL
ILLINOIS FOR THURSDAY AS AN UPPER LEVEL WAVE PUSHES OUT OF THE SW.
THE ENERGY IS PART OF A GENERAL PATTERN SHIFT TO MORE SOUTHWESTERLY
FLOW WITH THE UPPER LEVEL TROF DIGGING BACK IN OVER THE SWRN CONUS.
THE SFC LOW MOVES OUT INTO THE UPPER MIDWEST AND INTO CANADA BY THE
END OF THE WEEK, BUT IN SHIFTING TO MORE SOUTHWESTERLY FLOW ALOFT,
OPENS THE DOOR TO A SERIES OF SHORTWAVES THAT KEEP THE FORECAST WET
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND. TEMPS RATHER
WARM THROUGH THE FORECAST WITH OVERCAST AND RAINY SKIES KEEPING THE
OVERNIGHT LOWS UP A BIT, BUT LIKELY NOT NEARLY AS WARM AS THE TREND
IN THE GUIDANCE. HAVE KNOCKED THEM DOWN A COUPLE DEGREES. SOUTHERLY
FLOW AND A RELATIVELY WARM AIRMASS KEEPING THE HIGHS A BIT ABOVE
NORMS, EVEN WITH THE PASSAGE OF THE FIRST LOW SKIRTING TO THE
NW...THE MID LEVELS REMAIN WARM UNTIL THE MAIN TROF OVER THE SW
LIFTS INTO AND OUT OF THE GREAT LAKES. COOLER AIR IN THE MIDLEVELS
IS ONLY AROUND FOR 36 HOURS DAY 7/8 BEFORE THE WARM AIRMASS
REESTABLISHES ITSELF.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM CDT TUE MAY 5 2015
LATEST SURFACE ANALYSIS CONTINUES TO SHOW NEARLY STATIONARY
FRONTAL BOUNDARY DRAPED ACROSS NORTH-CENTRAL ILLINOIS FROM JUST
NORTH OF KGBG TO SOUTH OF KPNT. WINDS IN THE VICINITY OF THE
BOUNDARY ARE LIGHT/VARIABLE AT KPIA...BUT ARE SOUTHWESTERLY AT 10
TO 15KT FURTHER SOUTH AT THE REMAINING TERMINALS. HIGH-RES MODELS
SUGGEST THE FRONT WILL SINK SLIGHTLY SOUTHWARD LATER THIS
AFTERNOON AND EVENING...RESULTING IN A WIND SHIFT TO THE E/NE AT
BOTH KPIA AND KBMI. MODELS DIFFER ON THE EXACT TIMING...WITH THE
HRRR SHOWING THE SHIFT AT ABOUT 22Z. AFTER THAT...THE FRONT WILL
REMAIN IN PLACE ALONG/JUST SOUTH OF I-74 THROUGHOUT THE NIGHT.
HAVE CONTINUED WITH A LIGHT E/NE WIND AT KPIA AND KBMI
ACCORDINGLY...WITH SOUTHERLY WINDS AT KSPI AND KDEC. THE FRONT
WILL FINALLY GET A SOLID PUSH NORTHWARD BY WEDNESDAY
MORNING...ALLOWING WINDS TO BECOME SOUTHERLY AT ALL TAF SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1150 AM CDT TUE MAY 5 2015
.UPDATE...
1135 AM CDT
UPDATED TEMPERATURES AND WEATHER FOR THE REST OF TODAY. IT APPEARS
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORM REDEVELOPMENT THIS
AFTERNOON WILL BE PRIMARILY ALONG AND SOUTH OF INTERSTATE 80 IN
CLOSER PROXIMATE TO THE NORTHWARD ADVANCING SURFACE BOUNDARY.
TEMPERATURES ACROSS CENTRAL ILLINOIS..SOUTH OF THIS BOUNDARY ARE
ALREADY WELL INTO THE 70S TO NEAR 80 IN MANY LOCATIONS...WITH DEW
POINTS POOLING INTO THE LOWER TO MID 60S RIGHT ALONG THE BOUNDARY.
MODIFYING THE 12 UTC ILX SOUNDING WITH THESE SURFACE CONDITIONS
YIELDS SCAPE AROUND 1300 J/KG WITH VERY LITTLE CAP. WITH THIS IN
MIND...IN SPITE OF THE FACT THAT THERE IS NO SIGNIFICANT MID LEVEL
DISTURBANCE EXPECTED TO MOVE OVER THE AREA THIS AFTERNOON...IT
SEEMS PROBABLE THAT SCT CONVECTION WILL STILL CONTINUE TO BUBBLE
UP THIS AFTERNOON WITHIN THE VICINTY OF THIS SURFACE
BOUNDARY...WHERE INSTABILITY AND SURFACE CONVERGENCE WILL BE
MAXIMIZED. FARTHER NORTH...VERY COOL AND STABLE CONDITIONS SHOULD
LIMIT SHOWER AND THUNDERSTORM POTENTIAL. THEREFORE...I HAVE
POINTED THE FORECAST IN THIS DIRECTION.
TEMPERATURES ACROSS MUCH OF THE CHICAGO AREA NEAR LAKE MICHGAN
WILL LIKELY REMAIN IN THE LOW TO MID 50S TODAY. HOWEVER...FARTHER
INLAND AND SOUTH...EXPECT TEMPERATURES WELL INTO THE
70S...ESPECIALLY SOUTH OF INTERSTATE 80.
KJB
&&
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* EAST-NORTHEAST WINDS INCREASING BACK TO 10 KT THIS AFTERNOON.
* IFR CIGS POSSIBLY LIFTING TO MVFR THIS AFTERNOON...RETURNING TO
LIFR TONIGHT.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN...MAINLY
ALONG AND MORE LIKELY SOUTH OF MDW.
KMD
//DISCUSSION...UPDATED 12Z...
THE RAIN IS SLOWLY SHIFTING NORTHEAST AND WILL CLEAR THE REGION
THIS MORNING. NO ADDITIONAL LIGHTNING STRIKES ARE ANTICIPATED WITH
THESE SHOWERS. THERE ARE SCATTERED REPORTS OF MVFR CIGS AND THE
CIGS SHOULD LIFT TO VFR BEHIND THE SHOWERS. A STATIONARY FRONT
WILL REMAIN SOUTH OF THE TERMINALS TODAY AND COULD SEE SHOWERS AND
PERHAPS A THUNDERSTORM FIRE ALONG THE FRONT THIS AFTERNOON. THE
SHOWERS AND STORMS COULD IMPACT THE EASTERN TERMINALS...BUT DUE
TO LOW CONFIDENCE ONLY HAVE A VCSH. THINKING RFD WILL NOT BE
IMPACTED.
EAST WINDS AT 10 KT DIMINISH TO BELOW 10 KT THIS EVENING AND THEN
BEGIN TO BACK TO SOUTHEAST TOMORROW AS THE FRONT LIFTS NORTH.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH THAT EAST-NORTHEAST WINDS PICK BACK UP TO AROUND 10
KT THIS AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN ORD REMAINING DRY THE REST OF THE
DAY. MEDIUM THAT AFTERNOON SHOWERS/ISOLATED T-STORMS REMAIN
SOUTH OF MDW.
* MEDIUM CONFIDENCE IN IFR CIGS LIFTING TO MVFR BUT LOW ON TIMING
AND DURATION. HIGH THAT IFR/LIFR CIGS AND VSBYS RETURN TONIGHT
BUT LOW ON TIMING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
330 PM CDT TUE MAY 5 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 330 PM CDT TUE MAY 5 2015
THE FRONTAL BOUNDARY REMAINS DRAPED ACROSS CENTRAL IOWA AND HAS NOT
MOVED MUCH AT ALL TODAY. IT MADE A VERY SLOW PROGRESSION NORTHWARD
AND CURRENTLY SITS JUST SOUTH OF HIGHWAY 20...VERSUS INTERSTATE 80
THIS MORNING. PRECIPITATION FROM EARLIER THIS MORNING FADED AS IT
TREKKED NORTHWARD AND AWAY FROM WHAT LITTLE LIFT...MAINLY WAA
OVER THE BOUNDARY...REMAINED. CLOUD COVER THAT LINGERED WELL INTO
THIS AFTERNOON ACROSS SOUTHERN IOWA PREVENTED SBCAPE VALUES FROM
SOARING...BUT HAVE REBOUNDED TO 1500-2000 J/KG WITH NIL CIN ACROSS
CENTRAL AND SOUTHERN IOWA. AREAS THAT SAW SUNSHINE WILL LIKELY
REACH THEIR CONVECTIVE TEMPS...GENERALLY IN THE UPPER 70S...AND IS
BEING REALIZED NOW AS SOME WEAK CONVECTION IS CURRENTLY FIRING UP
IN SOUTH CENTRAL IOWA AND WEST OF FORT DODGE. WEAK
SHEAR...GENERALLY 20KTS OR LESS...AND NO CAP WILL RESULT IN
NUMEROUS PULSE STORMS THAT WILL LIMIT SEVERE POTENTIAL AS THEY
FIGHT FOR ENERGY. THE HRRR APPEARS TO HAVE THE BEST HANDLE ON THE
SITUATION ON CURRENT CONVECTION AND HAS ALL OF IT GONE BY 03Z WITH
THE LACK OF ANY SIGNIFICANT LIFTING MECHANISM OVER NIGHT.
TEMPERATURES STRUGGLED TO REACH DAYTIME HIGHS WITH THICK...AND
GENERALLY LOW...CLOUDS OVER MUCH OF NORTHERN IOWA. AS A RESULT MANY
LOCATIONS STILL SIT IN THE UPPER 50S. WITH THAT IN MIND...HAVE
DROPPED LOWS ONLY A COUPLE OF DEGREES SINCE DEWPOINTS WILL REMAIN
FAIRLY HIGH AND STOP ANY CRASHING TEMPS. FOG MAY BE OF CONCERN
ACROSS THE NORTH AS WELL...BUT MAY BE LIMITED WITH WINDS AROUND
10KTS. SITES THAT SEE WINDS DROP A BIT MAY SEE PERIODS OF FOG.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 330 PM CDT TUE MAY 5 2015
GENERALLY SOUTHWESTERLY 500 MB FLOW ACROSS IOWA AND THE MIDWEST
WILL RESULT IN AN ACTIVE AND FAIRLY WET WEATHER PATTERN THROUGH
THE WEEKEND. THIS PATTERN WILL BE PUNCTUATED BY TWO FAIRLY ROBUST
LOW PRESSURE SYSTEMS AND AN INTERMEDIARY PERIOD OF SUBTLE
SHORTWAVES MOVING THROUGH THE AFOREMENTIONED SOUTHWESTERLY FLOW.
THE FIRST BIG SYSTEM IS CURRENTLY TRACKING ACROSS THE SOUTHERN
ROCKIES IN THE FORM OF A DEEP OPEN WAVE...AND WILL MOVE UP OVER
OUR REGION ON WEDNESDAY AND WEDNESDAY NIGHT. MEANWHILE A LARGE
CLOSED 500 MB LOW CURRENTLY MOVING ASHORE OVER WASHINGTON/BRITISH
COLUMBIA WILL DIVE SOUTHWARD ALONG THE PACIFIC U.S.
COAST...REACHING NORTHERN CALIFORNIA BY LATE WEDNESDAY NIGHT.
THEREAFTER...AS THE FIRST SYSTEM DEPARTS QUICKLY TO OUR NORTHEAST
AND THE SECOND SYSTEM DIGS IN AND DEEPENS OVER THE SOUTHWEST U.S.
IT WILL MAINTAIN SOUTHWESTERLY FLOW OVER IOWA...THROUGH WHICH
SUBTLE SHORTWAVES WILL MOVE AT THE END OF THIS WEEK. FINALLY...THE
LARGE SOUTHWEST U.S. LOW WILL EJECT UP ACROSS THE MIDWEST SOMETIME
AROUND SUNDAY.
AS THE LEADING LOW PRESSURE TROUGH MOVES UP INTO THE REGION ON
WEDNESDAY IT WILL PUSH A LARGE REGION OF WARM AIR AND THETA E
ADVECTION UP ACROSS IOWA. WITHIN THIS REGION WIDESPREAD
THUNDERSTORMS SHOULD DEVELOP OVER NEBRASKA AND KANSAS
TONIGHT...THEN SLOWLY FADE AS THEY TRANSLATE ACROSS OUR FORECAST
AREA DURING THE DAY WEDNESDAY. WILL MAINTAIN LIKELY POPS FOR MOST
OF THE DAY...HOWEVER...CONFIDENCE BY WEDNESDAY AFTERNOON IS NOT
HIGH AS IT APPEARS THAT IN WAKE OF THE INITIAL BAND OF WARM AIR
ADVECTION THERE MAY BE LITTLE TO FORCE TRAILING CONVECTION AND WE
COULD SEE A LULL SIMILAR TO TODAY. IN ANY EVENT...WHILE THERE IS
SOME MARGINAL INSTABILITY AND DECENT DEEP LAYER SHEAR...NEARLY
UNIFORM LOW LEVEL WINDS AND A LACK OF ANY KIND OF FOCUS MECHANISM
LEAD TO A LOW RISK OF SEVERE WEATHER WHICH IS WELL OUTLINED BY
SPC. ON WEDNESDAY NIGHT ANOTHER EXPANSION OF THUNDERSTORM COVERAGE
WILL LIKELY OCCUR WITH THE NOCTURNAL LOW LEVEL JET ON THE EASTERN
FLANK OF THE UPPER LOW PRESSURE SYSTEM...BUT THIS ACTIVITY WILL
MOSTLY BE TO OUR WEST ACROSS NEBRASKA...SOUTH DAKOTA AND
NORTHWESTERN IOWA AND ONCE AGAIN WITH A LOW SEVERE WEATHER THREAT
IN OUR AREA. FORECAST POPS HAVE BEEN TRENDED TOWARD THIS DIRECTION
AND TIMING.
POTENTIALLY THE MOST ACTIVE PERIOD FOR OUR AREA WILL COME ON
THURSDAY. IT APPEARS THAT ONE OR TWO SHORTWAVES MOVING OVERHEAD
WILL PUSH A SYNOPTIC SURFACE TROUGH SLOWLY ACROSS OUR AREA ON
THURSDAY NIGHT. AHEAD OF THIS TROUGH...AT PEAK HEATING TIME LATE
THURSDAY AFTERNOON AND EVENING PROGNOSTIC MODELS UNANIMOUSLY
DEPICT A SWATH OF STRONG INSTABILITY DEVELOPING AHEAD OF THE
BOUNDARY...THOUGH THIS COULD BE TEMPERED BY DEBRIS FROM EARLY
MORNING CONVECTION. WHILE UPPER LEVEL FORCING IS SOMEWHAT LESS
IMPRESSIVE DURING THIS TIME...DEEP SHEAR IN THE 25 TO 35 KT RANGE
COUPLED WITH SURFACE CAPE APPROACHING 3000 J/KG WOULD CERTAINLY
INDICATE A SEVERE WEATHER THREAT. THIS WILL BEAR WATCHING AS WE
PROGRESS THROUGH THE WORK WEEK.
THE FORECAST FROM LATE THURSDAY NIGHT THROUGH SATURDAY IS
DEPENDENT ON HOW FAR SOUTHEAST THE ABOVE DISCUSSED SURFACE TROUGH
CAN PROGRESS. IT WILL LIKELY STALL SOMEWHERE OVER SOUTHEASTERN
IOWA OR MISSOURI/ILLINOIS...WITH SUBSEQUENT SHORTWAVES MOVING
OVERHEAD AND KICKING OFF ONE OR MORE ROUNDS OF THUNDERSTORMS ALONG
AND NORTHWEST OF THE FRONTAL ZONE. HOWEVER...IT IS UNCLEAR HOW FAR
SOUTHEAST OF OUR AREA THE BOUNDARY WILL LIE AND THUS HOW FAR INTO
OUR AREA THESE STORMS MAY PENETRATE. THERE IS LITTLE TO NO MODEL
CONSISTENCY IN THIS AREA...AND FOR NOW HAVE STUCK TO CHANCE POPS
ACROSS OUR SOUTHEASTERN AREAS DEPICTING A ROUGH CONSENSUS
APPROACH. IN ANY EVENT...THE SEVERE WEATHER THREAT DURING THIS
TIME WILL BE LOW ALTHOUGH THERE IS SOME POTENTIAL FOR HEAVY RAIN
AS STORMS MAY TRAIN ALONG THE FRONTAL ZONE.
FINALLY...THE SECOND AND STRONGER LOW PRESSURE SYSTEM DISCUSSED
EARLIER WILL MAKE FOR AN ACTIVE PERIOD WITH SEVERAL ROUNDS OF
THUNDERSTORMS BETWEEN SATURDAY NIGHT AND SUNDAY NIGHT. GIVEN THE
ENERGETIC NATURE OF THE SYSTEM THERE WILL AGAIN BE A POTENTIAL FOR
SEVERE WEATHER...HOWEVER AT THIS RANGE THE CRITICAL DETAILS OF
TRACK AND TIMING AND THUS THE REGION OF MAXIMUM SEVERE WEATHER
POTENTIAL REMAIN VERY UNCLEAR. IN ANY EVENT...IN WAKE OF THIS
WEEKEND SYSTEM IT APPEARS THAT A BRIEF RESPITE OF COOL AND QUIET
WEATHER MAY BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION...05/18Z
ISSUED AT 1238 PM CDT TUE MAY 5 2015
FRONTAL BOUNDARY IS DRAPED ACROSS THE THE STATE...LOCATED JUST
SOUTH OF FOD AND ALO SITES. WITH ALO AND FOD JUST NORTH OF THE
BOUNDARY...CIGS AND VSBY HAVE BEEN IN IFR AND MVFR MOST OF THE
DAY FROM. IMPROVEMENT AT THOSE SITES WILL BE SLOW AS CIGS
GRADUALLY MOVE TOWARDS VFR THIS EVENING AND OVERNIGHT AS THE FRONT
SLOWLY SHIFTS NORTH. DSM AND OTM SHOULD REMAIN VFR THROUGH MUCH OF
THE TAF PERIOD...WITH CHANCES OF FOG OVERNIGHT. THE NORTHERN SITES
MAY SEE PRECIPITATION THIS EVENING...INCLUDING OCCASIONAL
THUNDER...BUT NONE OF THE MODELS ARE IN GREAT AGREEMENT ON TIMING
AND INTENSITY...SO MENTIONED ONLY VCSH FOR NOW AT ALO AND MCW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...CURTIS
LONG TERM...LEE
AVIATION...CURTIS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
447 PM EDT TUE MAY 5 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WELL OFF THE SOUTHEAST AND MID ATLANTIC
COAST THROUGH TONIGHT...BRINGING VERY WARM AND MAINLY DRY
CONDITIONS TO THE LOCAL AREA. A BACKDOOR COLD FRONT APPROACHES
FROM THE NORTH TONIGHT...THEN DROPS INTO VIRGINIA LATE WEDNESDAY
INTO EARLY THURSDAY...BEFORE DISSIPATING. LOW PRESSURE WILL SPIN
OFF OR NEAR THE SOUTHEAST COAST THURSDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST ANALYSIS REVEALS SFC HIGH PRESSURE CENTERED WELL OFFSHORE
OF THE VA/NC COAST, EXTENDING BACK ACROSS EASTERN NC. ~1006 MB
LOW PRESSURE WAS ANALYZED ACROSS NEWFOUNDLAND, WITH SFC COLD FRONT
SNAKING BACK ACROSS NEW ENGLAND INTO NE PA/NW NJ AND THE EASTERN
GRT LAKES. A PRE-FRONTAL SFC TROUGH EXTENDS SW FROM SE PA INTO SRN
MD AND NORTHERN VA.
HAVE NOTED SOME INCREASING CU OVER THE PAST FEW HOURS ALONG THE
BLUE RIDGE AND EXPECT TO SEE A BIT MORE TO DEVELOP ACROSS WESTERN
SECTIONS OF THE LOCAL AREA ALONG THE TROUGH BY OVER THE NEXT FEW
HOURS. DO HAVE SOME LOW CHANCES FOR SHOWERS/TSTMS ACRS THE FAR
N/NW LATE THIS AFTN/EVENING. EXPECT ANY SHOWERS TO BE SHORT LIVED
OWING TO FLAT/QUASI-ZONAL FLOW ALOFT AND SHOULD THEREFORE ALLOW
LIMITED CONVECTIVE DEVELOPMENT AND WILL YIELD A VERY SLOW
SOUTHWARD PROGRESSION OF THE FRONT THROUGH TONIGHT AND INTO
TOMORROW.
BY TONIGHT, SHORTWAVE ENERGY NOTED ON IR SAT ACRS THE LWR GRT
LAKES WILL DAMPEN AS IT DIVES SOUTHEAST ACROSS THE NORTHERN MID-
ATLANTIC. RESULTANT UPPER FLOW SHIFTS TO THE WNW, AND WOULD ALLOW
ANY LIGNERING SHOWERS AND STORMS TO CROSS A BIT FARTHER TO THE
SOUTH. GIVEN THE LIMITED ACTIVITY THUS FAR, AND W/ HRRR NOT OVERLY
EXCITED ABOUT ACTIVITY TONIGHT, WILL HANG ON TO A 30-40% RAIN
CHANCE FOR SOME SCT SHRAS THIS EVENING ACROSS THE WEST, AND LATE
TONIGHT/OVERNIGHT FOR THE EASTERN SHORE. FARTHER S-SE, EXPECT DRY
CONDS TO CONTINUE UNDER A PARTLY CLOUDY SKY. LOWS TONIGHT IN THE
UPPER 50S TO LWR 60S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
HAVE LINGERED A SLIGHT CHC FOR LINGERING SHOWERS JUST AFTER SUNSET
TOMORROW MORNING...W/AREA OF WEAK LIFT SLIDING ESE ALONG AND AHEAD
OF THE BACKDOOR FRONT COINCIDENT WITH PLENTY OF LINGERING LLVL
MOISTURE. ANY SHOWERS WOULD BE BRIEF AND WIDELY SCT AT MOST.
OTHERWISE...DRY IN THE MORNING FOR MOST. EARLY SUN WILL GIVE WAY TO
INCREASING AFTN CLOUDS ACROSS CENTRAL/SOUTHERN ZONES. STRONG HEATING
AND THE ARRIVAL OF THE FRONT WILL LIKELY PROVIDE THE TRIGGER FOR
SOME SCT AFTN SHRAS/THUNDERSTORMS...MAINLY OVR WRN AND NRN COUNTIES
LATE IN THE AFTN INTO WED NIGHT. FOR TEMPS, STILL ON THE WARM SIDE
OF THE GUIDANCE ENVELOPE IN EXPECTATION OF A SLOWER FRONTAL
PROGRESSION...RESULTING IN A PARTLY TO MOSTLY SUNNY SKY EARLY AND
HIGHS FM 80-85 WEST OF THE BAY...TO THE 70S ON THE ERN SHORE. FRONT
BECOMES VERY DIFFUSE TOMORROW NIGHT AND WASHES OUT BY THE TIME IT
REACHES THE VA/NC BORDER. MEANWHILE, SFC LOW PRES WILL BEGIN TO TAKE
SHAPE AND CLOSE OFF ALONG THE EAST COAST OF FLORIDA/SE GA WED
AFTN/NIGHT. WEAK SFC RIDGING WILL RE-ESTABLISH ITSELF OVERHEAD AND
ALLOW FOR A DRY OVERNIGHT WED NIGHT INTO THU MORNING. HOWEVER,
EXPECT A GOOD AMOUNT OF LOW TO MID LEVEL CLOUD TO LINGER OVERNIGHT
INTO THU MORNING ALONG AND BEHIND THE FRONT ACROSS NORTHERN HALF OF
THE AREA. GENERALLY PARTLY SUNNY FARTHER SOUTH A 20-30% CHC FOR A
SHOWER OR TSTM, AGAIN MAINLY IN THE AFTN/EARLY EVENING. E-NE WINDS
WILL RESULT IN HI TEMPS RANGING THRU THE 70S TO NEAR 80 SW TO THE
UPPER 60S/LWR 70S ERN SHORE.
STILL MONITORING THE PROGRESS OF AFOREMENTIONED LOW ALONG THE SE
COAST. MODELS STILL HAVING TROUBLE RESOLVING THIS SYSTEM...WHICH IS
CASTING A BIT OF LOWER CONFIDENCE ON THE HANDLING OF THIS SYSTEM.
THE 12Z/5 GFS CONTINUES TO BRING THE SFC LOW INLAND OF THE SC/NC
COAST...WITH THE 12Z/NAM NOW IN CLOSE ENOUGH TO COVER THU NIGHT AND
FRIDAY. ITS SOLUTION IS SLIGHTLY FASTER THAN THE GFS AND TAKES THE
SURFACE LOW INLAND ACROSS EXTREME NE GA/COASTAL SC BY EARLY FRIDAY
MORNING. FOR ITS PART, THE OPERATIONAL ECMWF REMAINS OFFSHORE, BUT
HAS TRENDED TOWARD THE GFS IN MOVING A BIT CLOSER TO THE COAST WITH
THE SFC LOW...AND EVEN KEEPS THE LOW NEARLY STATIONARY ALONG THE
CAROLINA COAST FOR FRIDAY AND THROUGH THE WEEKEND. HAVE GONE WITH A
GFS WEIGHTED GFS/ECMWF BLEND FOR FRIDAY UNTIL MODELS COME INTO A BIT
CLOSER AGREEMENT. EITEHR WAY, EXPECT FRIDAY TO BE PREDOMINATELY
DRY ACROSS THE LOCAL AREA, BUT SHOULD SEE SOME (MAINLY) DIURNALLY
DRIVEN SCT SHOWERS/TSTMS POSSIBLE OVER THE SOUTHERN HALF OF THE
AREA (BEST CHC SOUTH OF THE BORDER INTO NC). HIGHS 80-85 INLAND,
COOLER U60S TO M70S ALONG THE COAST IN CONTINUED ONSHORE FLOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE EXTENDED PERIOD WILL BEGIN WITH LO PRES SPINNING JUST OFF OR
ALNG THE SE OR NC CST FRI NGT INTO MON MORNG. THEN...MODELS SHOW
THE LO WEAKENING AND GETTING PUSHED NNE ALNG OR JUST OFF THE VA
CST MON NGT INTO TUE MORNG...AS A COLD FRONT APPROACHES FM THE W.
THAT FRONT WILL THEN MOVE ACRS THE AREA TUE INTO TUE NGT. WILL
HAVE 20%-30% POPS FOR SHOWERS OR TSTMS OVR MUCH OF THE REGION FRI
NGT THRU MON NGT...DUE TO MOISTURE/LIFT FM THE LO PRES AREA.
THEN...HAVE 30%-40% POPS FOR TUE/TUE NGT ASSOCIATED WITH THE COLD
FRONT. TEMPS WILL BE ABV NORMAL THRU THE PERIOD...WITH HIGHS
RANGING FM THE MID 70S TO MID 80S. LOWS WILL RANGE FM THE UPR 50S
TO MID 60S.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE GENERALLY IN CONTROL OVER THE MID-ATLANTIC THIS
AFTERNOON WITH A WEAK SURFACE TROUGH TO THE NORTH OF THE AKQ CWA.
A COLD FRONT REMAINS OVER SOUTHERN NY STRETCHING WEST INTO PA AND
OH. SWLY WINDS 10-15 KT CONTINUE WITH A FEW AFTERNOON GUSTS AROUND
20 KT. SHOWERS/THUNDERSTORMS DEVELOP ALONG THE FRONT LATE
TODAY...DROPPING SWD TOWARD THE NRN LOCAL AREA TONIGHT. WILL
LIKELY SEE AN INCREASE IN MID-HIGH CLOUDS EARLY TONIGHT AT KSBY
AND KRIC...WITH SHOWERS (POSSIBLY A THUNDERSTORM) POSSIBLE LATE
TONIGHT AT KSBY.
OUTLOOK: THERE WILL BE A DAILY CHANCE FOR MAINLY AFTN AND EARLY
EVENING SHOWERS AND THUNDERSTORMS WEDNESDAY THROUGH
SATURDAY. THEY ARE NOT EXPECTED TO BE WIDESPREAD. OTHERWISE
MAINLY VFR CONDITIONS ARE EXPECTED DURING THE PERIOD. LATE IN THE
WEEK...PATCHY FOG WILL BE PSBL AROUND SUNRISE.
&&
.MARINE...
NO HEADLINES IN THE SHORT TERM TNGT THRU THU. HI PRES WILL SLIDE
FARTHER OUT TO SEA TNGT THRU WED. MODELS STILL SHOW LO PRES
SPINNING JUST OFF OR NEAR THE SE CST THU INTO SUN. EXPECT SSW
WINDS 15 KT OR LESS TNGT INTO WED NGT...THEN E OR SE WINDS 5 TO 15
KT THU INTO SUN. WAVES WILL BE 1 TO 2 FT...AND SEAS WILL BE 2 TO 4
FT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...LKB/MAM
LONG TERM...TMG
AVIATION...DAP
MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
335 PM EDT TUE MAY 5 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WELL OFF THE SOUTHEAST AND MID ATLANTIC
COAST THROUGH TONIGHT...BRINGING VERY WARM AND MAINLY DRY
CONDITIONS TO THE LOCAL AREA. A BACKDOOR COLD FRONT APPROACHES
FROM THE NORTH TONIGHT...THEN DROPS INTO VIRGINIA LATE WEDNESDAY
INTO EARLY THURSDAY...BEFORE DISSIPATING. LOW PRESSURE WILL SPIN
OFF OR NEAR THE SOUTHEAST COAST THURSDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST ANALYSIS REVEALS SFC HIGH PRESSURE CENTERED WELL OFFSHORE
OF THE VA/NC COAST, EXTENDING BACK ACROSS EASTERN NC. ~1006 MB
LOW PRESSURE WAS ANALYZED ACROSS NEWFOUNDLAND, WITH SFC COLD FRONT
SNAKING BACK ACROSS NEW ENGLAND INTO NE PA/NW NJ AND THE EASTERN
GRT LAKES. A PRE-FRONTAL SFC TROUGH EXTENDS SW FROM SE PA INTO SRN
MD AND NORTHERN VA.
HAVE NOTED SOME INCREASING CU OVER THE PAST FEW HOURS ALONG THE
BLUE RIDGE AND EXPECT TO SEE A BIT MORE TO DEVELOP ACROSS WESTERN
SECTIONS OF THE LOCAL AREA ALONG THE TROUGH BY OVER THE NEXT FEW
HOURS. DO HAVE SOME LOW CHANCES FOR SHOWERS/TSTMS ACRS THE FAR
N/NW LATE THIS AFTN/EVENING. EXPECT ANY SHOWERS TO BE SHORT LIVED
OWING TO FLAT/QUASI-ZONAL FLOW ALOFT AND SHOULD THEREFORE ALLOW
LIMITED CONVECTIVE DEVELOPMENT AND WILL YIELD A VERY SLOW
SOUTHWARD PROGRESSION OF THE FRONT THROUGH TONIGHT AND INTO
TOMORROW.
BY TONIGHT, SHORTWAVE ENERGY NOTED ON IR SAT ACRS THE LWR GRT
LAKES WILL DAMPEN AS IT DIVES SOUTHEAST ACROSS THE NORTHERN MID-
ATLANTIC. RESULTANT UPPER FLOW SHIFTS TO THE WNW, AND WOULD ALLOW
ANY LIGNERING SHOWERS AND STORMS TO CROSS A BIT FARTHER TO THE
SOUTH. GIVEN THE LIMITED ACTIVITY THUS FAR, AND W/ HRRR NOT OVERLY
EXCITED ABOUT ACTIVITY TONIGHT, WILL HANG ON TO A 30-40% RAIN
CHANCE FOR SOME SCT SHRAS THIS EVENING ACROSS THE WEST, AND LATE
TONIGHT/OVERNIGHT FOR THE EASTERN SHORE. FARTHER S-SE, EXPECT DRY
CONDS TO CONTINUE UNDER A PARTLY CLOUDY SKY. LOWS TONIGHT IN THE
UPPER 50S TO LWR 60S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
HAVE LINGERED A SLIGHT CHC FOR LINGERING SHOWERS JUST AFTER SUNSET
TOMORROW MORNING...W/AREA OF WEAK LIFT SLIDING ESE ALONG AND AHEAD
OF THE BACKDOOR FRONT COINCIDENT WITH PLENTY OF LINGERING LLVL
MOISTURE. ANY SHOWERS WOULD BE BRIEF AND WIDELY SCT AT MOST.
OTHERWISE...DRY IN THE MORNING FOR MOST. EARLY SUN WILL GIVE WAY TO
INCREASING AFTN CLOUDS ACROSS CENTRAL/SOUTHERN ZONES. STRONG HEATING
AND THE ARRIVAL OF THE FRONT WILL LIKELY PROVIDE THE TRIGGER FOR
SOME SCT AFTN SHRAS/THUNDERSTORMS...MAINLY OVR WRN AND NRN COUNTIES
LATE IN THE AFTN INTO WED NIGHT. FOR TEMPS, STILL ON THE WARM SIDE
OF THE GUIDANCE ENVELOPE IN EXPECTATION OF A SLOWER FRONTAL
PROGRESSION...RESULTING IN A PARTLY TO MOSTLY SUNNY SKY EARLY AND
HIGHS FM 80-85 WEST OF THE BAY...TO THE 70S ON THE ERN SHORE. FRONT
BECOMES VERY DIFFUSE TOMORROW NIGHT AND WASHES OUT BY THE TIME IT
REACHES THE VA/NC BORDER. MEANWHILE, SFC LOW PRES WILL BEGIN TO TAKE
SHAPE AND CLOSE OFF ALONG THE EAST COAST OF FLORIDA/SE GA WED
AFTN/NIGHT. WEAK SFC RIDGING WILL RE-ESTABLISH ITSELF OVERHEAD AND
ALLOW FOR A DRY OVERNIGHT WED NIGHT INTO THU MORNING. HOWEVER,
EXPECT A GOOD AMOUNT OF LOW TO MID LEVEL CLOUD TO LINGER OVERNIGHT
INTO THU MORNING ALONG AND BEHIND THE FRONT ACROSS NORTHERN HALF OF
THE AREA. GENERALLY PARTLY SUNNY FARTHER SOUTH A 20-30% CHC FOR A
SHOWER OR TSTM, AGAIN MAINLY IN THE AFTN/EARLY EVENING. E-NE WINDS
WILL RESULT IN HI TEMPS RANGING THRU THE 70S TO NEAR 80 SW TO THE
UPPER 60S/LWR 70S ERN SHORE.
STILL MONITORING THE PROGRESS OF AFOREMENTIONED LOW ALONG THE SE
COAST. MODELS STILL HAVING TROUBLE RESOLVING THIS SYSTEM...WHICH IS
CASTING A BIT OF LOWER CONFIDENCE ON THE HANDLING OF THIS SYSTEM.
THE 12Z/5 GFS CONTINUES TO BRING THE SFC LOW INLAND OF THE SC/NC
COAST...WITH THE 12Z/NAM NOW IN CLOSE ENOUGH TO COVER THU NIGHT AND
FRIDAY. ITS SOLUTION IS SLIGHTLY FASTER THAN THE GFS AND TAKES THE
SURFACE LOW INLAND ACROSS EXTREME NE GA/COASTAL SC BY EARLY FRIDAY
MORNING. FOR ITS PART, THE OPERATIONAL ECMWF REMAINS OFFSHORE, BUT
HAS TRENDED TOWARD THE GFS IN MOVING A BIT CLOSER TO THE COAST WITH
THE SFC LOW...AND EVEN KEEPS THE LOW NEARLY STATIONARY ALONG THE
CAROLINA COAST FOR FRIDAY AND THROUGH THE WEEKEND. HAVE GONE WITH A
GFS WEIGHTED GFS/ECMWF BLEND FOR FRIDAY UNTIL MODELS COME INTO A BIT
CLOSER AGREEMENT. EITEHR WAY, EXPECT FRIDAY TO BE PREDOMINATELY
DRY ACROSS THE LOCAL AREA, BUT SHOULD SEE SOME (MAINLY) DIURNALLY
DRIVEN SCT SHOWERS/TSTMS POSSIBLE OVER THE SOUTHERN HALF OF THE
AREA (BEST CHC SOUTH OF THE BORDER INTO NC). HIGHS 80-85 INLAND,
COOLER U60S TO M70S ALONG THE COAST IN CONTINUED ONSHORE FLOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE PERIOD HIGHLY DEPENDENT PERSISTENT UPPER RIDGE OVER THE
EAST, AS WELL AS THE DEVELOPMENT AND EVENTUAL PROGRESS OF EXPECTED
DEVELOPMENT OF AN AREA OF LOW PRESSURE OFF THE EAST COAST OF
FLORIDA. MODELS ARE IN GENERAL AGREEMENT OF THE DEVELOPMENT AND
INITIAL SLOW DRIFT NORTHWARD ON WEDNESDAY. THE HURRICANE CENTER IS
CONTINUING TO MONITOR THIS FEATURE FOR POTENTIAL SUBTROPICAL
DEVELOPMENT. SFC RIDGING TO THE NORTH AND W-NW FLOW ALOFT SHOULD
FORCE THE LOW TO MEANDER AROUND A POSITION ALONG/JUST OFF THE
SOUTHEAST COAST THROUGH THE WEEKEND. THE GEFS AND EURO ENSEMBLES
BOTH CONTINUE TO TAKE THE LOW INLAND ALONG THE SC/GA COAST, AS DOES
THE NEW 12Z/04 GFS. THE OPERATIONAL EUROPEAN, MEANWHILE CONTINUES TO
KEEP THE SYSTEM OFFSHORE. A SOLUTION TOWARDS THE GFS REMAINS THE HPC
PREFERENCE, AND HV EDGED THE FORECAST IN THIS DIRECTION. THIS
SCENARIO WOULD YIELD SLIGHT CHC TO LOW CHC POP FOR MAINLY DIURNALLY
DRIVEN SHOWERS/T-STORMS AT MOST ACROSS OUR AREA. LOWEST CHANCES WILL
BE ACROSS THE NORTH WITH SFC RIDGING IN PLACE NORTH OF THE AREA.
OTHER HEADLINE FOR THE PERIOD WILL BE THE WARMER TEMPERATURES.
E-SE FLOW WILL BRING A MODEST INCREASE IN HUMIDITY, AND INCREASING
LOW LEVEL THICKNESSES FAVOR WARM HIGHS IN THE 80S UNDER A PARTLY
TO MOSTLY SUNNY SKY. EARLY MORNING LOWS LOOK TO REMAIN WELL INTO
THE 50S TO MID 60S LATE WEEK INTO EARLY NEXT WEEK.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE GENERALLY IN CONTROL OVER THE MID-ATLANTIC THIS
AFTERNOON WITH A WEAK SURFACE TROUGH TO THE NORTH OF THE AKQ CWA.
A COLD FRONT REMAINS OVER SOUTHERN NY STRETCHING WEST INTO PA AND
OH. SWLY WINDS 10-15 KT CONTINUE WITH A FEW AFTERNOON GUSTS AROUND
20 KT. SHOWERS/THUNDERSTORMS DEVELOP ALONG THE FRONT LATE
TODAY...DROPPING SWD TOWARD THE NRN LOCAL AREA TONIGHT. WILL
LIKELY SEE AN INCREASE IN MID-HIGH CLOUDS EARLY TONIGHT AT KSBY
AND KRIC...WITH SHOWERS (POSSIBLY A THUNDERSTORM) POSSIBLE LATE
TONIGHT AT KSBY.
OUTLOOK: THERE WILL BE A DAILY CHANCE FOR MAINLY AFTN AND EARLY
EVENING SHOWERS AND THUNDERSTORMS WEDNESDAY THROUGH
SATURDAY. THEY ARE NOT EXPECTED TO BE WIDESPREAD. OTHERWISE
MAINLY VFR CONDITIONS ARE EXPECTED DURING THE PERIOD. LATE IN THE
WEEK...PATCHY FOG WILL BE PSBL AROUND SUNRISE.
&&
.MARINE...
LATEST WEATHER ANALYSIS ACROSS THE WATERS DEPICTS HIGH PRESSURE
CENTERED ROUGHLY 500 NM OFF THE MID ATLANTIC COAST AND LOW PRESSURE
OVER NEWFOUNDLAND. AN ATTENDANT COLD FRONT EXTENDS FROM THE SFC LOW
SWWD INTO NEW ENGLAND AND THE OH VALLEY. GRADIENT HAS RESULTED IN A
PERIOD OF MARGINAL SCA CONDITIONS OVER THE BAY AND LOWER JAMES RIVER
EARLY THIS MORNING...WITH OCCASIONAL GUSTS 20-25 KT. HAVE OPTED TO
ISSUE SCA HEADLINES THRU 7 AM AS GRADIENT EXPECTED TO RELAX AND LOW
LEVELS STABILIZE. WAVES GENERALLY 2-3 FT AND SEAS AROUND 3 FT. HIGH
PRESSURE PUSHES FARTHER OFFSHORE TODAY AS THE COLD FRONT SLOWLY
APPROACHES FROM THE NORTH. S-SW WINDS GENERALLY 10-15 KT
TODAY...WITH OCCASIONAL GUSTS TO 20 KT IN THE COASTAL WATERS. SLIGHT
UPTICK IN WINDS POSSIBLE AGAIN TONIGHT...BUT NOT AS STRONG AS EARLY
THIS MORNING AS THE WINDS ALOFT ARE PROGGED TO BE WEAKER. THE COLD
FRONT IS PROGGED TO REACH THE NRN WATERS LATE WEDS...DROPPING ACROSS
THE WATERS WEDS NIGHT INTO THURS. THE FRONT THEN WASHES OUT OVER THE
REGION THURS AS LOW PRESSURE LOCATES OFF THE SE COAST. FLOW BEHIND
THE FRONT BECOMES NELY...REMAINING AOB 15 KT. SEAS ONLY PROGGED TO
BUILD TO 3-4 FT WEDS NIGHT-THURS. UNCERTAINTY STILL EXISTS IN THE
EXACT TRACK AND STRENGTH OF THE COASTAL LOW LATE IN THE WEEK.
ATTM...MODELS KEEP THE LOW OFF THE SE COAST INTO THE WEEKEND. THIS
TRACK STAYS TOO FAR SOUTH TO BRING ANY SIGNIFICANT INCREASE IN SEAS
AND WINDS TO THE LOCAL AREA. OTHERWISE...HIGH PRESSURE REMAINS OVER
THE LOCAL WATERS THRU THE WEEKEND WITH SE WINDS GENERALLY AOB 15 KT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...LKB/MAM
LONG TERM...MAM
AVIATION...SAM/DAP
MARINE...MAM/SAM
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
154 PM EDT TUE MAY 5 2015
.AVIATION...
THE MATURE MCS AND INITIAL SURGE OF DEEP MOISTURE IS CURRENTLY
TRACKING THROUGH SOUTHEASTERN MICHIGAN THIS AFTERNOON. LATEST DATA
SUGGESTS A CONTINUED POTENTIAL FOR SHOWERS AND THUNDERSTORMS OVER
MUCH OF THE AREA THROUGH AT LEAST THE EARLY EVENING HOURS. A
DEVELOPING WARM FRONT IS THEN EXPECTED TO SLOWLY ORGANIZE OVER
SECTIONS OF SEMICH TONIGHT. UNCERTAINTY EXISTS TO EXACTLY WHERE THIS
BOUNDARY WILL STALL OUT FOR A TIME...BUT LATEST INDICATIONS ARE
SUGGESTING THE NORTHERN DETROIT METRO AREA THROUGH THE I 69 CORRDOR.
IT IS ALONG THIS BOUNDARY THAT A POTENTIAL EXISTS FOR
CONTINUED...LONG DURATION RAIN OVERNIGHT. FOCUSED THIS RAIN MENTION
AT THE KPTK/KFNT FOR THIS TAF ISSUANCE...WILL CONTINUE TO MONITOR
THE NEED FOR THE SOUTHERN TAF SITES. THE OTHER IMPORTANT ISSUE FOR
TONIGHT WILL BE THE POTENTIAL FOR IFR/LIFR CIGS ALONG AND TO THE
SOUTH OF THE DEVELOPING FRONTAL BOUNDARY. WENT MORE AGGRESSIVE WITH
IFR/LIFR CIGS SOUTH.
FOR DTW...RAIN POTENTIAL WILL NOW SHIFT TO MORE SHOWER CHARACTER AS
THE INITIAL MATURE MCS SHIFTS NORTHWARD THROUGH THE CWA. WILL NEED
TO MONITOR PORTIONS OF NORTHERN ILLINOIS/INDIANA WHERE ADDITIONAL
SHOWER AND THUNDERSTORM DEVELOPMENT IS FORECASTED TO TAKE PLACE. IT
REMAINS POSSIBLE THIS ACTIVITY WHILE MOVING EASTWARD COULD IMPACT
PORTIONS OF FAR SOUTHERN MICHIGAN...INCLUDING THE METRO TERMINAL.
OTHERWISE TONIGHT...EXPECTATIONS AT THIS TIME ARE FOR THE WARM FRONT
TO SET UP NORTH OF THE TERMINAL...FOCUSING BEST LONG DURATION RAINS
CHANCES NORTH. LIFR CIGS TONIGHT AND TOMORROW MORNING.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING BELOW 5000 FT TONIGHT.
* LOW FOR THUNDERSTORMS THIS EVENING AND TONIGHT
* LOW FOR CIGS TO FALL BELOW 200 FEET.
&&
.PREV DISCUSSION...ISSUED 1034 AM EDT TUE MAY 5 2015
UPDATE...
THE DETAILED FORECAST REASONING PROVIDED IN THE EARLY MORNING
DISCUSSION WAS WELL DONE AND REMAINS VALID.
A MATURE MCS AND COMPLEX OF SHORTWAVE ENERGY SUPPORTED BY RIGHT
ENTRANCE REGION DYNAMICS ALOFT IS CURRENTLY LIFTING INTO
SOUTHEASTERN MICHIGAN THIS MORNING. SURFACE PRECIPITATION REPORTS
SUPPORT LIGHT TO MODERATE RAIN OCCURRING WITHIN THE
FORWARD...WARM AIR ADVECTION QUADRANTS OF THE MCS. WITH THE RAIN
MOVING IN...SOUTHEASTERN MICHIGAN CAN EXPECT CATEGORICAL/PERIODS
OF RAIN THROUGHOUT THE AFTERNOON HOURS. FORECAST UNCERTAINTY FOR
THE SHORT TERM PERIOD CENTERS ON WHEN EXACTLY SYNOPTIC
SUPPORT/RAIN WILL END OVER THE AREA. LATEST NAM AND RAP ARE REALLY
PAINTING DIFFERENT PICTURES. NAM SUGGESTS SUBSIDENCE IN THE WAKE
OF THIS MCS...MAY BRING A QUIET PERIOD EARLY THIS EVENING...WHILE
THE RAP DRAGS OUT THE DURATION OF THIS CATEGORICAL RAIN INTO THE
EVENING. THERE REMAINS A WINDOW OF OPPORTUNITY FOR SOME THUNDER
CHANCES LATE THIS AFTERNOON...POST 20Z. THOSE CHANCES APPEAR TO
HINGE ON THE LIKELIHOOD OF THE NAM SOLUTION VERIFYING. NEGLIGIBLE
CONVECTIVE INSTABILITY YIELDS NO SUPPORT FOR SEVERE THUNDERSTORM
POTENTIAL.
PREV DISCUSSION...ISSUED 355 AM EDT TUE MAY 5 2015
SHORT TERM... TODAY AND TONIGHT
A WET 24 HOUR PERIOD IS SETTING UP OVER SOUTHERN LOWER MICHIGAN
TODAY THROUGH TONIGHT. THE TRI CITIES AND NORTHERN THUMB MAY ESCAPE
THE BULK OF THE RAINFALL TODAY BUT THE REST OF SE MICHIGAN STANDS TO
PICK UP A PROLONGED PERIOD OF SHOWERS AND THUNDERSTORMS. THE SURFACE
FRONT WILL REMAIN SOUTH OF THE OHIO BORDER THROUGH THE PERIOD SO
THUNDERSTORMS WILL BE THE ELEVATED VARIETY AND MAINLY CONTRIBUTE TO
LOCALLY HEAVY DOWNPOURS. RAINFALL TOTALS LOCALLY AROUND 1 INCH WILL
BE POSSIBLE BY SUNRISE WEDNESDAY.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ALREADY UNDERWAY OVER THE
MIDWEST AND WILL SPREAD TO THE NORTH AND EAST DURING THE REST OF THE
MORNING. THIS AREA OF CONVECTION ORIGINATED ALONG THE FRONT OVER THE
CENTRAL PLAINS DURING PEAK HEATING YESTERDAY AND HAS SINCE GROWN
LARGE ENOUGH AND PERSISTENT ENOUGH TO SUPPORT MCV DEVELOPMENT ALOFT
AND AN AREA OF SURFACE PRESSURE FALLS OVER IOWA AND MISSOURI. THE
WAVE IS JUST STRONG ENOUGH TO SUPPORT A WEAK LOW LEVEL JET FUELING
ACTIVITY OVER NORTHERN ILLINOIS WHICH WILL CONTINUE TO DEVELOP INTO
SOUTHERN LOWER MICHIGAN AS THE LOW TO MID LEVELS OF THE FRONT
STRENGTHEN WITH TIME. CONVECTIVE DEBRIS IN SATELLITE IMAGERY SHOWS
THE ENTRANCE REGION OF A 120 KNOT UPPER JET ANALYZED IN MODEL DATA
AT 250 MB. THIS FEATURE IS POSITIONED FAVORABLY OVER THE GREAT LAKES
TO GENERATE STRONG FRONTOGENESIS THROUGH TODAY WHILE THE LARGE SCALE
FRONTAL POSITION REMAINS STATIONARY AND THEN DRIFTS SLOWLY NORTHWARD
TONIGHT. CROSS SECTIONS OF MODEL DATA FROM THE POSITION OF THE
SURFACE FRONT EXTENDING NORTHWARD TO THE UPPER JET AXIS SHOW THE
STEEPEST PORTION OF THE AGEOSTROPHIC CIRCULATION SETTING UP THROUGH
CENTRAL SECTIONS OF OUR AREA BY AFTERNOON THROUGH THIS EVENING. DEEP
CONVECTIVE INSTABILITY ABOVE THE FRONTAL SURFACE COMBINED WITH
PRECIPITABLE WATER RISING TO ABOUT 1.25 INCHES WILL ENSURE
WIDESPREAD COVERAGE OF SHOWERS WITH EMBEDDED THUNDERSTORMS. LOCALLY
HEAVY RAINFALL WILL ALSO BE POSSIBLE DUE TO THE PERSISTENCE OF THIS
TEXTBOOK UPPER JET ENHANCED FRONTAL CIRCULATION AND THE CONVECTIVE
NATURE OF THE PRECIPITATION PATTERN. SO THEN WHAT COULD GO WRONG IN
THIS FORECAST? THE POTENTIAL FOR SURFACE BASED CONVECTION OVER
INDIANA AND OHIO...COMBINED WITH THE TENDENCY FOR ELEVATED
INSTABILITY TO BECOME LESS EFFECTIVE DURING THE DAY...COULD LEAD TO
A WEAKENING TREND IN THE PATTERN OVER SE MICHIGAN DURING THE
AFTERNOON INTO THIS EVENING. SHOULD THIS OCCUR...IT WOULD DO MORE TO
REDUCE THE POTENTIAL FOR HEAVY RAINFALL IN OUR AREA AND POSSIBLY
ALTER THE LOCATION OF THE MOST PERSISTENT SHOWERS AND OVERALL QPF...
BUT MOST AREAS WILL SEE A LENGTHY PERIOD OF RAIN AS THE MORNING RAMP
UP WOULD CARRY OVER INTO THE AFTERNOON JUST BASED ON INERTIA.
PROGRESSION OF THE UPPER LEVEL RIDGE AND THE ENTRANCE REGION OF THE
UPPER JET WILL NUDGE THE MID LEVEL FRONTAL ZONE TO THE NORTH AND
EAST OVERNIGHT. THIS WILL BRING THE TRI CITIES AND NORTHERN THUMB
MORE INTO THE PATTERN OF REMAINING SHOWERS AND WILL BE THE FAVORED
LOCATION FOR ANY NOCTURNAL REDEVELOPMENT. THE AXIS OF LIKELY POPS
OVER SE MICHIGAN IS PLACED ALONG THE 850 MB THETA-E GRADIENT WHICH
IS WELL AGREED UPON BY THE 00Z MODEL CYCLE AND IS THE MOST FAVORED
LOCATION FOR RENEWED DEVELOPMENT OF NOCTURNAL ELEVATED INSTABILITY
AND SUPPORT FOR SHOWERS THROUGH SUNRISE WEDNESDAY.
LONG TERM...WEDNESDAY THROUGH MONDAY
SE MICHIGAN WILL RESIDE ALONG THE IMMEDIATE DOWNSTREAM SIDE OF AN
ELONGATING UPPER RIDGE ON WEDNESDAY. THE RESULTING WEAKLY SHEARED
WEST-NORTHWEST FLOW WILL SUSTAIN A PERTURBED 850-925 MB FRONTAL ZONE
ACROSS THE REGION. MODELS TRENDING SLIGHTLY STRONGER WITH THE
ASCENT/CONVERGENCE THROUGH THIS LAYER...SUGGESTING THE EXISTING
FRONTAL SLOPE WILL POTENTIALLY BE MORE ACTIVE. THIS WILL SUPPORT
THE INCLUSION OF A LOWER END POP. GREATER POTENTIAL FOR SHOWER
PRODUCTION DURING THE MORNING PERIOD...BEFORE BOTH THE MOISTURE
QUALITY AND AVAILABLE FORCING DIMINISHES AS THE INBOUND UPPER RIDGE
MAKES BETTER INROADS. SUBSTANTIAL CLOUD COVER WITHIN PERSISTENT LOW
LEVEL EASTERLY FLOW WILL CAP THE DIURNAL TEMPERATURE RESPONSE TO
SOME DEGREE...REGARDLESS OF SHOWER COVERAGE. ABSENT OF A LARGER AND
PERSISTENT COVERAGE OF SHOWERS TO DISRUPT THE HEATING CYCLE...
EXISTING THERMAL PROFILE WILL SUPPORT HIGHS GENERALLY WITHIN THE MID
AND UPPER 60S RANGE.
UPPER RIDGE STEADILY BUILDS INTO LOWER MICHIGAN WEDNESDAY NIGHT...
580 DM AT 500 MB MARKING THE RIDGE AXIS CENTERING OVERHEAD BY EARLY
THURSDAY MORNING. THIS PROGRESSION WILL SEND SE MICHIGAN INTO THE
WARM SECTOR BY THURSDAY...SOLID DEPTH TO THE EMERGING SOUTHWEST FLOW
CONTINUING TO POINT TOWARD HIGHS MAKING A RUN INTO THE LOWER 80S.
DRY/STABLE PROFILE STILL INFLUENCED BY EXITING UPPER RIDGING WILL
RESULT IN LITTLE MORE THAN A STANDARD DIURNAL CU FIELD.
CLOSED LOW CURRENTLY PARKED OVER THE DESERT SOUTHWEST WILL LIFT
NORTHEAST THROUGH THE LATTER HALF OF THE WEEK...EVENTUALLY SHEARING
OVER THE TOP OF THE UPPER RIDGE STAGNATING ALONG THE EAST COAST.
THIS LOWERING HEIGHT FIELD WILL BEGIN TO EASE AN ATTENDANT FRONTAL
BOUNDARY EASTWARD WITHIN THE FRIDAY AND SATURDAY WINDOW. GENERAL
TIMING ACROSS THE MODEL SPECTRUM SUGGESTS FRIDAY WILL REMAIN
CHARACTERED BY THE PRE-FRONTAL WARM SECTOR...WITH ANY POSSIBLE LATE
DAY/EVENING CONVECTIVE CHANCES ARRIVING TOO LATE TO DISRUPT ANOTHER
DAY WITH HIGHS IN THE 80S. POTENTIAL IS THERE FOR AN ACTIVE PERIOD
HEADING INTO THE UPCOMING WEEKEND...FRONTAL BOUNDARY EVENTUALLY
ALIGNING OVER OR NEAR THE REGION FOR AN EXTENDED TIME AS THE AXIS
BECOMES PARALLEL TO THE MEAN FLOW. THIS PATTERN WOULD SHAVE A FEW
DEGREE OFF PROSPECTIVE HIGHS THIS WEEKEND RELATIVE TO THE
THU/FRI WARMTH...STILL NEAR TO ABOVE NORMAL THROUGH THIS TIME.
MARINE...
SHOWERY CONDITIONS WITH THE CHANCE OF THUNDERSTORMS WILL EXIST UNDER
PERSIST EAST TO NORTHEAST FLOW OVER THE SOUTHERN LAKE HURON BASIN
AND POINTS SOUTHWARD THROUGH TONIGHT. FAVORABLE MARINE CONDITIONS
ACROSS NORTHERN LAKE HURON DURING THIS TIME AS HIGH PRESSURE BUILDS
INTO THE REGION. MODEST WAVE AND WIND CONDITIONS THROUGH THE
MIDWEEK PERIOD AS HIGH PRESSURE SUSTAINS A WEAK GRADIENT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
UPDATE.......CB
SHORT TERM...BT
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 PM EDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT TUE MAY 5 2015
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT WRLY MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND A
RIDGE FROM THE SE CONUS INTO THE CNTRL PLAINS. WITH A SFC RIDGE
EXTENDING FROM NW ONTARIO THROUGH THE NRN LAKES...LIGHT WINDS AND
CLEAR SKIES OVER UPPER MI HAS ALLOWED TEMPS TO DROP OFF INTO THE MID
AND UPPER 30S WITH SEVERAL INLAND COLD SPOTS IN THE UPPER 20S TO
AROUND 30. CLOUDS AND
TODAY...EXPECT THAT HIGH PRES WILL CONTINUE TO DOMINATE AS THE
CLOUDS AND PCPN ASSOCIATED WITH A FRONTAL BOUNDARY FROM SRN IA INTO
NRN IL REMAIN WELL TO THE SOUTH. MIXING TO 5K FT WITH 850 MB TEMPS
FCST IN THE 6C TO 8C RANGE WILL SUPPORT HIGHS IN THE UPPER 60S TO
AROUND 70...EXCEPT ALONG THE GREAT LAKES WHERE READING WILL REMAIN
IN THE UPPER 50S AND LOWER 60S. SIMILAR TO MONDAY...AFTERNOON
DEWPOINTS WILL DROP INTO THE LOWER 20S WITH RH VALUES FROM 15 TO 20
PCT. HOWEVER...WINDS WILL REMAIN LIGHT...AOB 10 MPH.
TONIGHT...AS THE HIGH SHIFTS OFF TO THE EAST AND AND 850 MB WARM
FRONT APPROACHES FROM THE SOUTH...EXPECT INCREASING CLOUDS OVERNIGHT.
THIS WILL KEEP TEMPS FROM FALLING OFF AS MUCH WITH MIN READINGS IN
THE UPPER 30S TO AROUND 40. WITH THE VERY DRY AIRMASS IN PLACE...THE
SLOWER END OF GUIDANCE WAS FAVORED WITH THE PCPN ADVANCING FROM THE
SOUTH. SO...NO PCPN MENTION WAS INCLUDED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1248 PM EDT TUE MAY 5 2015
THE APEX OF THE 500MB RIDGE WILL RESIDE FROM N MANITOBA THROUGH
CENTRAL UPPER AND LOWER MI AT 00Z THURSDAY WITH RAIN APPROACHING
FROM THE W-SW. THIS RAIN IS ASSOCIATED WITH A WAVE IN THE 500MB SW
FLOW OVER THE N PLAINS.
SE FLOW IN THE EVENING AT THE SFC WILL TURN MORE OUT OF THE S
OVERNIGHT...USHERING IN WARMER/MORE MOIST AIR. THIS AND 850MB TEMPS
OF 11-12C SHOULD KEEP DOWNSLOPE AREAS WEDNESDAY NIGHT/THURSDAY
MORNING FROM FALLING BELOW THE MID 50S FAR W. HIGHS ON THURSDAY IN
THE LOW 80S OVER THE INTERIOR AND FAR W DOWNSLOPE AREAS LOOKS
REASONABLE. OTHER LOCATIONS OVER THE E AND ACROSS THE TIP OF THE
KEWEENAW PENINSULA WILL BE MAINLY IN THE 60S AND 70S. THE CONTINUED
DRY CONDITIONS AND WARMER AIR...ALONG WITH INCREASING WINDS. WILL
CONTINUE TO HIGHLIGHT THE BREEZY CONDITIONS AND MODERATE RH VALUES
IN THE FWF.
AFTERNOON CONVECTION IS STILL IN QUESTION FOR THURSDAY...WITH FCST
SOLUTIONS STILL GOING ON THE IDEA THAT PRECIP WILL EITHER END UP
JUST FAR W OF MAINLY OVER LAKE SUPERIOR AND TO OUR S. MUCH OF THAT
WILL DEPEND ON THE EVOLUTION OF CONVECTION TO OUR SW. THE BEST
INSTABILITY REMAINS WELL TO OUR SW...CLOSER TO THE NEARING COLD
FRONT STRETCHING FROM THE SFC LOW OVER NW ONTARIO AND THE NW HALF OF
MN. THERE IS STILL SOME TEMPORAL DISCREPANCIES BETWEEN THE FCST
SOLUTIONS AT THIS POINT. THE 05/00Z ECMWF IS APPROX 6HRS SLOWER NOW
THAN THE GFS. THIS IS A CHANGE FROM 24HRS AGO...WHEN THE ECMWF WAS
ON THE FAST SIDE. AT THIS POINT IT LOOKS LIKE A BLENDED SOLUTION IS
MOST REASONABLE...AS THE ECMWF IS BACKED UP BY THE SLOWER 05/00Z
CANADIAN AND WHILE THE OPERATIONAL GFS IS QUICKEST IT IS RUNNING IN
LINE WITH THE 05/12Z NAM.
LOOK FOR THE LOW OVER CENTRAL ONTARIO AROUND 06Z FRIDAY TO EJECT
NE...DRAGGING THE COLD FRONT OVER E MN/FAR W LAKE SUPERIOR ACROSS
UPPER MI DURING THE DAY FRIDAY. A SECONDARY LOW RIDING UP THE COLD
FRONT FROM THE S PLAINS FRIDAY AFTERNOON WILL ACT TO STALL THE FRONT
ACROSS LOWER MI /AND POSSIBLY EVEN FAR E UPPER MI/ FRIDAY NIGHT INTO
SATURDAY MORNING. STILL EXPECTING ANOTHER BREEZY DAY FRIDAY WITH
WINDS OUT OF A MORE SW DIRECTION. NAM SOUNDINGS INDICATE THE
POTENTIAL FOR OVER 30KT GUSTS. WHILE THE GFS AGREES...IT DOES HAVE A
STRONGER INVERSION SET UP E WITH LIMIT MIXING...AND OVERALL LIGHTER
WINDS OVER THE W.
OVER THE W TWO-THIRDS OF UPPER MI A RIDGE OF HIGH PRESSURE WILL BE
OVERHEAD SATURDAY MORNING...BUILDING IN FROM W CENTRAL CANADA. THE
RIDGE WILL CONTINUE TO STRENGTHEN OVER THE AREA THROUGH SATURDAY
NIGHT AS THE HIGH SHIFTS ACROSS MANITOBA AND ONTARIO.
THE NEXT SYSTEM OF INTEREST WILL BE IN THE FORM OF LOW PRESSURE
ACROSS THE CENTRAL PLAINS AT 12Z SUNDAY. WILL AGAIN FOLLOW A BLENDED
SOLUTION FOR THIS TIME PERIOD AS THERE COULD BE SIGNIFICANT
DIFFERENCES COMPARING THE ECMWF PLACEMENT OF THE LOW OVER S MN/SW WI
AT 12Z AND THE GFS WHICH HAS IT STILL OVER NE/KS. THE LOW WILL
LIKELY DRIFT ACROSS S WI /CLOSER TO THE ECMWF SOLUTION/ ON
MONDAY...AND ACROSS S LOWER MI MONDAY NIGHT BEFORE EXITING E. WITH
EITHER SOLUTION KEEPING THE LOW TO OUR S...WILL CONTINUE THE BEST
CHANCE OF ANY PRECIP OVER THE S HALF OF THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 120 PM EDT TUE MAY 5 2015
EXPECT VFR CONDITIONS AND LIGHT WINDS AT ALL 3 TAF SITES THIS FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT TUE MAY 5 2015
AS A TROUGH MOVES FROM THE PLAINS TO THE UPPER MS VALLEY...SRLY
WINDS WILL INCREASE TO AROUND 25 KNOTS OVER THE EAST BY LATE THU INTO
THU NIGHT. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW 20
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1249 PM EDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT TUE MAY 5 2015
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT WRLY MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND A
RIDGE FROM THE SE CONUS INTO THE CNTRL PLAINS. WITH A SFC RIDGE
EXTENDING FROM NW ONTARIO THROUGH THE NRN LAKES...LIGHT WINDS AND
CLEAR SKIES OVER UPPER MI HAS ALLOWED TEMPS TO DROP OFF INTO THE MID
AND UPPER 30S WITH SEVERAL INLAND COLD SPOTS IN THE UPPER 20S TO
AROUND 30. CLOUDS AND
TODAY...EXPECT THAT HIGH PRES WILL CONTINUE TO DOMINATE AS THE
CLOUDS AND PCPN ASSOCIATED WITH A FRONTAL BOUNDARY FROM SRN IA INTO
NRN IL REMAIN WELL TO THE SOUTH. MIXING TO 5K FT WITH 850 MB TEMPS
FCST IN THE 6C TO 8C RANGE WILL SUPPORT HIGHS IN THE UPPER 60S TO
AROUND 70...EXCEPT ALONG THE GREAT LAKES WHERE READING WILL REMAIN
IN THE UPPER 50S AND LOWER 60S. SIMILAR TO MONDAY...AFTERNOON
DEWPOINTS WILL DROP INTO THE LOWER 20S WITH RH VALUES FROM 15 TO 20
PCT. HOWEVER...WINDS WILL REMAIN LIGHT...AOB 10 MPH.
TONIGHT...AS THE HIGH SHIFTS OFF TO THE EAST AND AND 850 MB WARM
FRONT APPROACHES FROM THE SOUTH...EXPECT INCREASING CLOUDS OVERNIGHT.
THIS WILL KEEP TEMPS FROM FALLING OFF AS MUCH WITH MIN READINGS IN
THE UPPER 30S TO AROUND 40. WITH THE VERY DRY AIRMASS IN PLACE...THE
SLOWER END OF GUIDANCE WAS FAVORED WITH THE PCPN ADVANCING FROM THE
SOUTH. SO...NO PCPN MENTION WAS INCLUDED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1248 PM EDT TUE MAY 5 2015
THE APEX OF THE 500MB RIDGE WILL RESIDE FROM N MANITOBA THROUGH
CENTRAL UPPER AND LOWER MI AT 00Z THURSDAY WITH RAIN APPROACHING
FROM THE W-SW. THIS RAIN IS ASSOCIATED WITH A WAVE IN THE 500MB SW
FLOW OVER THE N PLAINS.
SE FLOW IN THE EVENING AT THE SFC WILL TURN MORE OUT OF THE S
OVERNIGHT...USHERING IN WARMER/MORE MOIST AIR. THIS AND 850MB TEMPS
OF 11-12C SHOULD KEEP DOWNSLOPE AREAS WEDNESDAY NIGHT/THURSDAY
MORNING FROM FALLING BELOW THE MID 50S FAR W. HIGHS ON THURSDAY IN
THE LOW 80S OVER THE INTERIOR AND FAR W DOWNSLOPE AREAS LOOKS
REASONABLE. OTHER LOCATIONS OVER THE E AND ACROSS THE TIP OF THE
KEWEENAW PENINSULA WILL BE MAINLY IN THE 60S AND 70S. THE CONTINUED
DRY CONDITIONS AND WARMER AIR...ALONG WITH INCREASING WINDS. WILL
CONTINUE TO HIGHLIGHT THE BREEZY CONDITIONS AND MODERATE RH VALUES
IN THE FWF.
AFTERNOON CONVECTION IS STILL IN QUESTION FOR THURSDAY...WITH FCST
SOLUTIONS STILL GOING ON THE IDEA THAT PRECIP WILL EITHER END UP
JUST FAR W OF MAINLY OVER LAKE SUPERIOR AND TO OUR S. MUCH OF THAT
WILL DEPEND ON THE EVOLUTION OF CONVECTION TO OUR SW. THE BEST
INSTABILITY REMAINS WELL TO OUR SW...CLOSER TO THE NEARING COLD
FRONT STRETCHING FROM THE SFC LOW OVER NW ONTARIO AND THE NW HALF OF
MN. THERE IS STILL SOME TEMPORAL DISCREPANCIES BETWEEN THE FCST
SOLUTIONS AT THIS POINT. THE 05/00Z ECMWF IS APPROX 6HRS SLOWER NOW
THAN THE GFS. THIS IS A CHANGE FROM 24HRS AGO...WHEN THE ECMWF WAS
ON THE FAST SIDE. AT THIS POINT IT LOOKS LIKE A BLENDED SOLUTION IS
MOST REASONABLE...AS THE ECMWF IS BACKED UP BY THE SLOWER 05/00Z
CANADIAN AND WHILE THE OPERATIONAL GFS IS QUICKEST IT IS RUNNING IN
LINE WITH THE 05/12Z NAM.
LOOK FOR THE LOW OVER CENTRAL ONTARIO AROUND 06Z FRIDAY TO EJECT
NE...DRAGGING THE COLD FRONT OVER E MN/FAR W LAKE SUPERIOR ACROSS
UPPER MI DURING THE DAY FRIDAY. A SECONDARY LOW RIDING UP THE COLD
FRONT FROM THE S PLAINS FRIDAY AFTERNOON WILL ACT TO STALL THE FRONT
ACROSS LOWER MI /AND POSSIBLY EVEN FAR E UPPER MI/ FRIDAY NIGHT INTO
SATURDAY MORNING. STILL EXPECTING ANOTHER BREEZY DAY FRIDAY WITH
WINDS OUT OF A MORE SW DIRECTION. NAM SOUNDINGS INDICATE THE
POTENTIAL FOR OVER 30KT GUSTS. WHILE THE GFS AGREES...IT DOES HAVE A
STRONGER INVERSION SET UP E WITH LIMIT MIXING...AND OVERALL LIGHTER
WINDS OVER THE W.
OVER THE W TWO-THIRDS OF UPPER MI A RIDGE OF HIGH PRESSURE WILL BE
OVERHEAD SATURDAY MORNING...BUILDING IN FROM W CENTRAL CANADA. THE
RIDGE WILL CONTINUE TO STRENGTHEN OVER THE AREA THROUGH SATURDAY
NIGHT AS THE HIGH SHIFTS ACROSS MANITOBA AND ONTARIO.
THE NEXT SYSTEM OF INTEREST WILL BE IN THE FORM OF LOW PRESSURE
ACROSS THE CENTRAL PLAINS AT 12Z SUNDAY. WILL AGAIN FOLLOW A BLENDED
SOLUTION FOR THIS TIME PERIOD AS THERE COULD BE SIGNIFICANT
DIFFERENCES COMPARING THE ECMWF PLACEMENT OF THE LOW OVER S MN/SW WI
AT 12Z AND THE GFS WHICH HAS IT STILL OVER NE/KS. THE LOW WILL
LIKELY DRIFT ACROSS S WI /CLOSER TO THE ECMWF SOLUTION/ ON
MONDAY...AND ACROSS S LOWER MI MONDAY NIGHT BEFORE EXITING E. WITH
EITHER SOLUTION KEEPING THE LOW TO OUR S...WILL CONTINUE THE BEST
CHANCE OF ANY PRECIP OVER THE S HALF OF THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 732 AM EDT TUE MAY 5 2015
WITH DRY HIGH PRESSURE DOMINATING...EXPECT VFR CONDITIONS AND LIGHT
WINDS AT ALL 3 TAF SITES THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT TUE MAY 5 2015
AS A TROUGH MOVES FROM THE PLAINS TO THE UPPER MS VALLEY...SRLY
WINDS WILL INCREASE TO AROUND 25 KNOTS OVER THE EAST BY LATE THU INTO
THU NIGHT. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW 20
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
411 PM CDT Tue May 5 2015
.DISCUSSION...
Issued at 409 PM CDT TUE MAY 5 2015
Active pattern will continue through the rest of the week, and into
the weekend. Perhaps the quietest of the next several days will be
this afternoon. Warm and muggy conditions persist across the area
today, with temperatures in the middle 70s to lower 80s, with
dewpoints in the upper 50s to lower 60s. RAP soundings indicate that
the atmosphere is uncapped, which has allowed for the CU field to
form across the area. However the lack of any appreciable forcing
has prevented much in the way of thunderstorm development. That
being said, with the uncapped environment there is enough weak
forcing to get a few storms to form across central Missouri. These
storms will generally be pretty scattered in nature across the area,
but coverage will not be very great. Any shower will likely be
rather brief in nature. No strong or severe weather is anticipated
with any of these storms outside of a wind gust or two near the
storm. These diurnally driven showers will likely fall apart and
diminish around sunset.
Over the next several days several shortwave troughs will be rolling
through the area, bringing several chances of rain. The first
appreciable chance for rain will be during the morning to early
afternoon hours on Wednesday as a vorticity lobe will swing through
the area, bringing some scattered convection. While there will be
some instability in the area, on the order of 500 to 1000 J/kg the
amount of instability will be somewhat meager. Deep layer shear will
also be on the low side, with 20 to 30 kts of 0-6 km shear. So given
those particular CAPE/shear parameters it doesn`t look like severe
weather will be the main story for Wednesday, but some of those
morning and afternoon storms could be strong, to perhaps isolated
severe. With the instability axis generally lined up to the west,
the farther east any storms form will have a lessor chance to be
severe.
For Thursday another area of low pressure will eject through the
area, and perhaps be accompanied by convection rolling eastward off
the High Plains. This should kick off another round of convection
across the area. Thursday will likely bring quite a bit more
instability with ML CAPE values approaching 1000 to 2000 J/kg, but
shear will still be on the low end, with 0-6 km layer shear in the
20 to 30 kt range. Even though the CAPE/shear values are not
incredibly high they will be ample to possibly produced some
organized rotating cells, and perhaps an isolated supercell or two
across the area. Once again, the main threats will be hail and wind
for
Friday brings a slightly different story, as a surface boundary will
sag southward, and basically bisect the forecast area E-W. Friday
looks to be a little more capped than the previous couple of days,
and that convective inhibition is a bit more influenced by some
moderate height rises across the Plains for that time period. With
good turning in the atmosphere, characterized by veering-with-height
wind profile deep shear will be a bit higher, and instability will
be in the 1000 to 2000 J/kg range any storm that is able to go up on
Friday has a chance to be severe. If a storm does latch itself to
the boundary, which will be somewhere near I-70 it could get a
little extra low level turning, which would make any storm in that
area even stronger. Synoptically speaking Friday doesn`t seem to
bring much in the way of severe weather potential, but the mesoscale
forecast closer to the event might reveal some potential for some
isolated to scattered severe storms.
By Saturday, the chances for severe weather start to synoptically
increase. A very large trough, off to the west, will eventually take
on a negative tilt and move through the Central Plains this weekend.
Saturday still looks to be a little too far west to bring much in
the way of widespread severe weather to the area. But during the
overnight hours on Saturday night into Sunday morning the convection
that occurs over the western and central plains will likely roll
through the area. Convection during this overnight period would
likely not be as organized, but it could roll through as an
organized MCS, bringing a low end hail threat, but a larger wind
threat Saturday night into Sunday morning.
While this time period is still quite a way out, and much will
depend on how things pan out closer to the event, Sunday is looking
to be the day to watch as far as widespread severe weather across
eastern Kansas and western Missouri is concerned. Recent runs of the
GFS and ECMWF indicate a very potent mid level trough moving through
the area Saturday night and Sunday. At the surface there will likely
be a dry line somewhere between KDDC and KEMP. Where exactly the dry
line sets up will dictate whether heightened concern for significant
severe weather is warranted on Sunday. Should the dry line set up
farther west, as is indicated by the GFS, then the area might be
spared the brunt of the severe weather. But if it sets up near KEMP
or even a little farther east, then this area could see a rather
significant severe weather day on Sunday. But again, despite the
synoptic signal, and with the timing so far out, and with mesoscale
features playing a big roll in how convection plays out it`s much
too early to get super concerned about severe weather this weekend.
Also, despite the uncertainty regarding the timing, location, and
severity of the thunderstorm activity through the rest of the week
and into the weekend, there is also a very strong signal to support a
prolonged period of multiple rounds of heavy rain. Some areas could
see higher amounts, and some locations could see lower amounts, but
generally speaking there appears to be a good signal for several
inches of rain (perhaps up to 5 inches in some areas) through the
next 5 to 7 days.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1228 PM CDT TUE MAY 5 2015
Made some wholesale changes to this forecast. Most notably added a
VCTS group for this afternoon. Cumulus field on satellite, as well as
HRRR model guidance suggests a few scattered cells will be possible
across the area this afternoon. Tough call whether or not the
terminals will be directly affected, but there could be some
vicinity issues. Also, overnight added some wind gusts, per model guidance.
RAP sounding for the overnight period is a bit enigmatic with respect
to gusts reaching to surface due to diurnal decoupling, but would
suggest that if gusts don`t occur that a LLWS concern will develop
overnight, with winds around 40 kts about 800 feet off the surface.
Also added -SHRA group with VCTS for 15z Wed for rain showers
encroaching from the west.
J. Leighton
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Leighton
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
346 PM EDT TUE MAY 5 2015
.SYNOPSIS...
A FRONTAL ZONE WILL REMAIN NEARLY STATIONARY OVER THE MID-ATLANTIC
STATES TONIGHT THROUGH WEDNESDAY. SOME SHOWERS WILL MOVE ALONG AND
NORTH OF THE FRONT BRINGING A CHANCE FOR SOME RAIN TO SOUTHERN NEW
YORK AND NORTHERN PENNSYLVANIA. THE BEST CHANCE FOR RAIN WILL BE
TONIGHT AND EARLY WEDNESDAY. HIGH PRESSURE WILL RETURN ON THURSDAY
BRINGING WARM DRY WEATHER. AN APPROACHING COLD FRONT MAY TRIGGER A
FEW SCATTERED SHOWERS OR THUNDERSTORMS LATER FRIDAY AFTERNOON.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY/...
MAIN FORECAST QUESTION FOR TONIGHT WILL BE THE IMPACT OF A SHORT
WAVE AND ASSOCIATED AREA OF RAIN MOVING EAST FROM THE SOUTHERN
GREAT LAKES TOWARD NORTHERN PENNSYLVANIA AND SOUTHERN NY. THE
NAM/GFS/ECMWF AND SREF ARE ALL IN REASONABLY GOOD AGREEMENT THAT
THE BEST CHANCE OF RAIN WILL BE ACROSS NORTHERN PA THIS EVENING
WITH LOWER CHANCES FARTHER NORTH AND EAST OVERNIGHT. THE IDEA THAT
RAIN MAY STRUGGLE TO REACH VERY FAR EAST OF I-81 IN NY STATE
APPEARS REASONABLE GIVEN THAT SURFACE HIGH PRESSURE WILL BE
BUILDING SOUTHEAST TOWARD THAT AREA OVERNIGHT. LATEST RADAR
ANIMATIONS ARE ALREADY INDICATING A SLUG OF MODERATE TO HEAVY RAIN
MOVING FROM SOUTHERN ONTARIO ACROSS SW NY AND NORTHWEST PA. THE
LAST FEW RUNS OF THE HRRR INDICATE THAT SOME OF THIS RAIN WILL
MOVE ACROSS SOUTHERN NY THROUGH MID- EVENING REACHING THE
CATSKILLS BEFORE MIDNIGHT. THIS SCENARIO IS A BIT FARTHER NORTH
AND EAST THAN SOME OF THE LOWER-RESOLUTION OPERATIONAL MODELS.
BASED ON ALL OF THIS HAVE GONE WITH LIKELY POPS THIS EVENING INTO
THE OVERNIGHT FOR NORTHERN PA AND THE SOUTHERN TIER OF NY WITH
JUST CHC POPS FARTHER NORTH. THUNDER CHANCES LOOK LOW WITH NO
INSTABILITY SHOWING UP ON ANY MODEL FORECAST SOUNDINGS.
&&
.SHORT TERM /6 AM WEDNESDAY THROUGH FRIDAY/...
SHOWERS WILL BE WEAKENING AND PUSHING SOUTH AND SOUTHEAST EARLY
WEDNESDAY. CLOUDS WILL LINGER THROUGH MUCH OF THE DAY ACROSS
NORTHERN PA AND SOUTHERN NEW YORK RESULTING IN A SLIGHTLY COOLER
DAY ACROSS THOSE AREAS. HIGH PRESSURE WILL BUILD ACROSS THE AREA
AT THE SURFACE AND ALOFT LATER WEDNESDAY THROUGH THURSDAY NIGHT
BRINGING DRY WEATHER ALONG WITH A RETURN TO WELL ABOVE NORMAL
TEMPERATURES BY THURSDAY AFTERNOON. WARM AND SLIGHTLY MORE HUMID
WEATHER CAN BE EXPECTED FOR FRIDAY WITH JUST A SMALL CHANCE FOR AN
AFTERNOON THUNDERSTORM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE WHICH LOOKED GOOD. WARM AND DRY MUCH OF THE
WEEKEND THEN BEST CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY.
VERY WARM WITH HUMIDITY THIS WEEKEND UNDER A LARGE UPPER LEVEL
RIDGE. A SURFACE BOUNDARY WILL BE JUST OF THE CWA IN SE CANADA
WHICH STAYS THERE ALL OF THE LONG TERM. THE BIGGEST QUESTION IS
WHERE THIS SETS UP AND STAYS. MODELS DIFFER ON THIS. WPC LEANS ON
EURO WHICH KEEPS THE BOUNDARY IN CANADA WHILE THE GFS DROPS IT
INTO PA SUN AND MON. HAVE FOLLOWED WPC AND HAVE CHC POPS FAR NORTH
SAT NGT THEN EVERYONE SUNDAY. A COLD FRONT MOVES THROUGH TUESDAY
WITH THE BEST CHANCE OF THE WEEK.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
130 PM UPDATE...
VFR NOW WITH HIGH CLOUDS. RAIN MOVING EAST FROM THE WRN SRN TIER
WILL MAKE IT TO ELM BGM AND MAYBE ITH THIS EVE. VSBYS AND CIGS
SHOULD DROP TO MVFR LATE TONIGHT BGM/ELM. SYR AND RME WILL STAY
DRY AND VFR. AS THE LARGE WEST TO EAST AREA OF RAIN SINKS SOUTH
AVP WILL HAVE RAIN SHORTLY AFTER MIDNIGHT WHICH WILL CONTINUE TO
MIDDAY. AGAIN AVP SHOULD FALL TO MVFR AROUND 9Z. AS THE RAIN MOVES
SOUTH OUT OF ELM BGM CONDITIONS WILL IMPROVE TO VFR AT ELM AROUND
14Z AND AT BGM AFTER 16Z. AVP SHOULD IMPROVE CLOSE TO 18Z AS RAIN
ENDS.
NW TO N WIND AT 5 KTS SHIFTING TO NE TONIGHT AND EAST WED. TONIGHT
MANY LOCATIONS WILL BE LIGHT AND VARIABLE OR CALM.
.OUTLOOK...
WED AFTN-SAT...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
307 PM CDT TUE MAY 5 2015
.DISCUSSION...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO DEVELOP
ACROSS SE TX IN A NARROW CORRIDOR OF DEEPER MOISTURE. AIR MASS IS
NOT QUITE AS WORKED OVER THE W-SW ZONES AND FEEL ACTIVITY WILL
DRIFT TOWARD THE UNMODIFIED AIR FOR THE REST OF THE AFTN AND
EVENING. PRECIP SHOULD END EARLY THIS EVENING AS THE DISTURBANCE
THAT MOVED INTO THE AREA FROM THE EAST MERGES WITH THE UPPER
TROUGH. A RIBBON OF DEEPER MOISTURE WILL PERSIST OVER THE W-SW
ZONES THROUGH WEDNESDAY. CAN`T REALLY FIND A SFC TRIGGER AND UPPER
LEVEL WINDS ARE LESS DIVERGENT TOMORROW BUT WILL MAINTAIN CHANCE
POPS OUT WEST DUE TO THE HIGHER MOISTURE CONTENT. THE HRRR AND THE
RAP ARE AGGRESSIVE IN DEVELOPING A BAND OF SHOWERS OVER THE SW
ZONES LATE TONIGHT IN THE AXIS OF DEEPER MSTR. THE NAM SOUNDINGS
ON WEDNESDAY LOOK FAIRLY POTENT OVER THE WESTERN HALF OF THE CWA
WITH CAPE VALUES ABOVE 3000...LI VALUES ARE -8 AND A WEAK INVERTED
V SIGNATURE. UPPER LEVEL RIDGING OVER THE GULF AMPLIFIES INTO SE
TX THU-SAT WITH A SERIES OF UPPER LEVEL DISTURBANCES PASSING WELL
TO THE WEST OF THE CWA. WESTERN AREAS COULD GET CLIPPED BY A
DISTURBANCE OR TWO BUT FOR THE MOST PART...FEEL SE TX WILL REMAIN
WARM AND HUMID BUT GENERALLY RAIN FREE.
A STRONGER UPPER LEVEL TROUGH WILL PIVOT ACROSS THE SOUTHERN
ROCKIES INTO THE SOUTHERN PLAINS ON MONDAY. THE UPPER RIDGE OVER
THE GULF IS FLATTENED A BIT AND NUDGED TO THE EAST. THIS SHOULD
BRING SOME OF THE ACTIVE WEATHER A BIT FURTHER EAST SUN-TUE. A
WEAK COLD FRONT WILL ALSO APPROACH SE TX ON TUESDAY AND PROBABLY
STALL SOMEWHERE OVER THE AREA BEFORE RETREATING NORTH. LOOKS LIKE
MON/TUE COULD BECOME ACTIVE WITH PERIODS OF SHRA/TSRA. 43
&&
.MARINE...
PRESSURE GRADIENT REMAINS FAIRLY TIGHT WITH SMALL CRAFT
ADVISORY CONDITIONS BEING OBSERVED IN THE BAYS AND SLIGHTLY UNDER
CRITERIA OFFSHORE. HOWEVER...GUIDANCE SUGGESTS SPEEDS WILL
EVENTUALLY BUMP UP TO 20KTS OFFSHORE LATER THIS EVENING SO AM GOING
TO HOIST THE SCA FLAGS FOR ALL COASTAL WATERS OVERNIGHT. MODERATE
ONSHORE FLOW SHOULD PREVAIL THRU THE WEEKEND WITH INTERMITTENT
PERIODS WHEREAS CAUTION FLAGS MIGHT BE REQUIRED.
TIDES ARE CURRENTLY RUNNING 1-1.5 FEET ABOVE NORMAL. THIS ALONG WITH
ELEVATED SEAS AND SURF WILL PRODUCE STRONGER THAN NORMAL RIP
CURRENTS (AS WAS OBSERVED BY GALVESTON BEACH PATROL TODAY) THRU
MIDWEEK. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 69 84 71 84 71 / 30 30 20 30 20
HOUSTON (IAH) 71 84 72 86 72 / 20 20 10 20 10
GALVESTON (GLS) 73 81 74 81 75 / 20 20 10 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 3 AM CDT WEDNESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
HIGH ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
106 PM CDT TUE MAY 5 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE
MOSTLY MID LEVEL CLOUDS WITH A FEW LOW AND HIGH CLOUDS ACROSS THE
CWA EARLY THIS AFTERNOON. CEILINGS WERE NEAR 2200FT AT KAPY AND
KPIL TO NEAR 6000FT AT KEBG. EXPECT VFR CONDITIONS TO PREVAIL THE
REST OF THE AFTERNOON INTO THE EVENING BEFORE MVFR CEILINGS
DEVELOP TONIGHT AS LOW TO MID LEVEL MOISTURE INCREASES ACROSS THE
RIO GRANDE VALLEY TONIGHT INTO WED MORNING.
&&
.PREV DISCUSSION... /ISSUED 629 AM CDT TUE MAY 5 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...MVFR CIGS DID NOT MATERIALIZE AT BRO AND HRL WITH
THOSE CIGS AFFECTING MFE ATTM. GUSTY WINDS TO BEGIN AROUND 14Z AT
WHICH TIME THOSE CIGS SHOULD BEGIN TO SCATTER TO VFR BY LATE
MORNING. GUSTS TO 30 KNOTS APPEAR POSSIBLE ESPECIALLY AT MFE WHERE
STRONGER LOW LEVEL WINDS RESIDE. WINDS WILL DECREASE AFTER SUNSET
BUT GUSTS WILL CONTINUE TILL AROUND MIDNIGHT. MVFR CIGS WILL BUILD
BACK IN AFTER SUNSET WHICH WILL CONTINUE THROUGH THE REST OF THE
TAF PERIOD.
PREV DISCUSSION... /ISSUED 416 AM CDT TUE MAY 5 2015/
SHORT TERM /NOW THROUGH WEDNESDAY/...UPPER TROF ACROSS THE FOUR
CORNERS REGION WILL OPEN UP AND WEAKEN AS IT HEADS NORTHEASTWARD
INTO COLORADO THEN BECOME ABSORBED IN THE DEEPENING LARGER SCALE
TROUGH ACROSS THE WESTERN CONUS. DIFFLUENCE REMAINS ACROSS THE
AREA BUT BETTER DYNAMICS ASSOCIATED WITH THE UPPER TROF WILL
REMAIN WELL REMOVED FROM THE AREA. 700MB FLOW STRENGTHENS AND
REINFORCES MID LEVEL CAPPING WITH DRY AIR ADVECTING FROM THE
MEXICAN PLATEAU AND OVER SPREADING THE AREA. LEFT SLIGHT CHANCE
POPS THIS MORNING FOR FAR WESTERN SECTIONS BUT BELIEVE CAP WILL
KEEP THE LID ON MOST IF NOT ALL PRECIPITATION TODAY. HRRR AND
NAM12 SUPPORT THIS IDEA. BREEZY CONDITIONS CONTINUE TODAY WITH
DEEPENING LOW PRESSURE ACROSS WEST TEXAS WITH GUSTS APPROACHING 30
MPH. THERE ARE INDICATIONS IN THE MODELS OF THUNDERSTORMS
DEVELOPING ON THE HIGHER TERRAIN THIS EVENING AND MOVE EASTWARD
TOWARDS OUR AREA BUT DRY AIR SHOULD WEAKEN THEM BEFORE MAKING
ACROSS THE RIVER. THEREFORE WILL KEEP FORECAST DRY TONIGHT. BREEZY
CONDITIONS CONTINUE WEDNESDAY WITH ANOTHER ROUND OF 700MB DRY AIR
ADVECTING FROM THE WEST. CONDITIONS WILL BE FAIRLY SIMILAR TO THE
PAST SEVERAL DAYS. HIGHS IN THE 80S THE NEXT SEVERAL DAYS AND
PERHAPS REACHING 90 DEGREES IN THE FAR NORTHWESTERN SECTIONS OF
ZAPATA COUNTY. LOWS WILL BE IN THE 70S.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...AS LOW PRESSURE
TROUGHS DEEPEN ACROSS SW U.S. AND JUST OFF THE SE U.S. COAST MID
TO UPPER LEVEL RIDGE BUILDS OVER SOUTH TEXAS AND THE WESTERN
GULF. THIS SHOULD IN A MOSTLY DRY RAINFREE WED NIGHT THROUGH
SUNDAY PERIOD. NOT UNTIL THE WESTERN TROUGH BEGINS TO MOVE
NORTHEAST LATE NEXT WEEKEND INTO EARLY NEXT WEEK WILL THERE BE
SOME INCREASE IN THE CHANCE OF RAIN. MODELS REMAIN RATHER
PERSISTENT IN THIS PATTERN AND HAVE BEEN IN GOOD CONSISTENCY
MAKING FOR A BETTER THAN AVERAGE CONFIDENCE IN THE OUTGOING
FORECAST.
OVERALL, THE EARLY DOG DAYS OF SUMMER WILL BE SETTING UP AS THE
BUILDING UPPER RIDGE AND STRONG CAPPING INVERSION BETWEEN
850-700MB TO DOMINATE. THE BUILDING RIDGE PROMOTES A DIVERGENT Q
VECTOR FIELD OR A CONFLUENT FLOW ALOFT AND THE 850-700MB CAPPING
INVERSION STRENGTHENS WITH A THE PERSISTENT SOUTHWEST FLOW.
WITHOUT ANY LIFTING MECHANISM AND DISTURBANCES/VORT MAXES LIKELY
TO BE DIVERTED NORTHEAST OF THE AREA DO NOT SEE ANY SIGNIFICANT
CHANCE OF RAIN. WITH THAT SAID HAVE KEPT THE LOW CHANCE POPS
ACROSS THE NW ZONES JUST IN CASE A ROUGE THUNDERSTORM MOVES IN
FROM THE SIERRA MADRE.
WARM/HOT, HUMID AND BREEZY WILL BE THE WORD THROUGH AT LEAST
SUNDAY WITH WINDIEST DAYS NEXT WEEKEND AS THE UPPER TROUGH OVER
THE DESERT SW LIFTS INTO THE CENTRAL PLAINS STRENGTHENING THE
PRESSURE GRADIENT. AS WE MOVE INTO NEXT WEEK MODELS SUGGEST AN
INCREASE IN RAIN CHANCES. THE WEAKENING OF THE RIDGE AND A
TRAILING COLD FRONT MOVING INTO CENTRAL TEXAS ALONG WITH POOLING
MOISTURE SOUTH OF THE BOUNDARY LOOKS TO THE INGREDIENTS NEEDED TO
GET A FEW STORMS IN OUR REGION. HAVE BROAD BRUSHED THE CWA WITH
LOW GRADE POPS NEXT MONDAY AND TUESDAY TO ACCOMMODATE THE MODEL
CONSENSUS.
MARINE...NOW THROUGH WEDNESDAY...MODERATE SOUTHEAST WINDS
AND MODERATE SEAS WILL CONTINUE AS HIGH PRES REMAINS DOMINANT
OVER THE SOUTHEAST U.S. AND THE NORTH GULF...COUNTERBALANCED BY
SOMEWHAT LOWER PRESSURE OVER THE SOUTHERN HIGH PLAINS. WINDS AND
SEAS MAY INCREASE SLIGHTLY AT TIMES...WITH SMALL CRAFT EXERCISE
CAUTION TO LOW END SMALL CRAFT ADVISORY CONDITIONS POSSIBLE.
WEDNESDAY NIGHT THROUGH SUNDAY...A MODERATE TO STRONG PRESSURE
GRADIENT TO PERSIST THIS PERIOD. BROAD HIGH PRESSURE OVER THE
GULF TO INTERACT WITH LOWER PRESSURE OVER NW TEXAS TO PRODUCE
MARGINAL SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY NIGHT THROUGH
FRIDAY. LOW PRESSURE STRENGTHEN OVER THE WEEKEND WITH A POSSIBLE
UPTICK IN WINDS AND SEAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
61/67/BIRCHFIELD
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1126 AM MDT TUE MAY 5 2015
.UPDATE...VISIBLE SATELLITE IMAGERY AND WYDOT WEBCAMS CONTINUE TO
SHOW AREAS OF DENSE FOG AROUND CHEYENNE TO THE SUMMIT EAST OF
LARAMIE...AND BETWEEN SINCLAIR AND RAWLINS WY. WE UPDATED TO
INCLUDE THE RAWLINS AREA ALONG I-80 IN THE DENSE FOG ADVISORY AND
TO EXTEND THE ADVISORY UNTIL NOON MDT. EXPECT THE FOG WILL START
TO LIFT BY EARLY AFTERNOON. OTHERWISE...NO FURTHER CHANGES NEEDED
IN THE NEAR TERM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
WEBCAMS ALONG INTERSTATE 80 HAVE CONSISTENTLY SHOWN DENSE FOG FROM
THE SUMMIT TO CHEYENNE OVER THE PAST FEW HOURS. DECIDED TO ADD
CENTRAL LARAMIE COUNTY (CHEYENNE) TO THE DENSE FOG ADVISORY
THRU 16Z WITH THE CYS OBS DROPPING TO ONE QUARTER MILE. THE LOW
CLOUDS AND FOG WILL REMAIN QUITE PERSISTENT THROUGH THE MORNING
WITH THE HRRR MODEL INDICATING LIFR/IFR CONDITIONS THROUGH 18Z
FROM THE INTERSTATE 80 SUMMIT EASTWARD TO CHEYENNE COUNTY. THIS
MAKES SENSE AS THE OVERALL SFC PATTERN OF VERY MOIST SOUTH TO
SOUTHEAST WINDS WILL CONTINUE THROUGH THE MORNING. WATER VAPOR
IMAGERY SHOWS THE SUBTROPICAL UPPER LOW SPINNING OVER NORTHEAST
ARIZONA. THE MODELS MOVE THIS FEATURE TO THE NORTHEAST OVER THE
COURSE OF THE DAY TO NEAR NORTHERN COLORADO BY THIS EVENING.
ONLY AN ISOLATED TO SCATTERED COVERAGE OF SHOWERS IS
EXPECTED THROUGH THE EARLY AFTN ALONG THE COLORADO BORDER.
HOWEVER...MIDLVL HEIGHT FALLS WILL COMBINE WITH INCREASING
DEEP LAYER MOISTURE TO PROMOTE A MORE WIDESPREAD COVERAGE BY THE
LATE AFTN AND EARLY EVENING. MOISTURE IS PLENTIFUL WITH THIS
SYSTEM...IN FACT PW VALUES OF 0.75-1.0 INCHES OVER THE PLAINS ARE 2
STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY MAY. THUS...WITH
RELATIVELY SLOW STORM MOTIONS...LOCALLY HEAVY RAIN WILL BE A
CONCERN ESPECIALLY OVER THE NEBRASKA PANHANDLE. WHILE ISOLATED
TSTMS WILL BE POSSIBLE THIS AFTN...THE VERY WEAK INSTABILITY AND
SHEAR WILL MAKE STRONG STORMS UNLIKELY. SPC HAS DROPPED THE
MARGINAL THREAT OVER THE SOUTHERN PANHANDLE. WITH THE MIDLVL
DISTURBANCE OVERHEAD TONIGHT...WILL KEEP A CHANCE OF SHOWERS
GOING. SOUTHEAST SFC WINDS ARE IN PLACE THRU 12Z WED...SO FOG
WILL AGAIN BE A THREAT OVER PORTIONS OF THE AREA.
THE SHORTWAVE WILL PUSH INTO WESTERN SOUTH DAKOTA/NEBRASKA BY WED
AFTN. THE MODELS SHOW THE HIGHEST QPF OVER THE PLAINS OF SOUTHEAST
WY AS A SFC COLD FRONT INTERACTS WITH GOOD MOISTURE. WILL HAVE
ISOLATED TSTMS DURING THE AFTN WITH SOME LIMITED CAPE. PRECIP
CHANCES DROP OFF WED EVENING BEHIND THE FRONT AS A DRIER AIRMASS
MOVES IN. THERE COULD ACTUALLY BE A 18-24 HR PERIOD FROM WED
EVENING THRU THURS AFTN WHEN MUCH OF THE CWA WILL BE PRECIP FREE.
SCATTERED STORMS WILL ONCE AGAIN DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE BY THURS AFTN...WITH LIMITED COVERAGE OVER THE
PLAINS IN A MORE STABLE AIRMASS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
UNSETTLED WEATHER CONTINUES IN THE LONG TERM. MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE THE POSSIBILITY OF WINTER WEATHER
RETURNING TO THE AREA LATE IN THE WEEKEND.
STARTING OFF THURSDAY NIGHT...WE STILL HAVE THE STALLED SURFACE
BOUNDARY LAYING ALONG THE LARAMIE RANGE...OR SLIGHTLY WEST. BOTH
THE GFS AND ECMWF VERY SIMILAR BRINGING ANOTHER PIECE OF ENERGY
NORTHEAST FROM THE DESERT SOUTHWEST TO INTERACT WITH THIS
BOUNDARY...SO WILL KEEP CHANCE POPS GOING FOR THE THURSDAY NIGHT
TIME FRAME. PROBABLY PRETTY LIGHT SHOWERS THOUGH AS HAS BEEN THE
CASE THE PAST FEW NIGHTS. CONVECTION PICKS UP THROUGH FRIDAY AFTERNOON
WITH BOTH MODELS CONCENTRATING ON THE SOUTHERN PANHANDLE AND
NORTHEASTERN COLORADO. SOUTHEAST UPSLOPING WINDS TO CONTINUE.
GFS AND ECMWF CONTINUE TO AGREE ON A CLOSED LOW ROUNDING THE BASE
OF THE LONGWAVE TROUGH SATURDAY MORNING AND BEGINNING TO LIFT
NORTHEAST INTO SOUTHWESTERN COLORADO SATURDAY AFTERNOON. OUR
FORECAST AREA IS SQUARE IN THE WRAP AROUND MOISTURE TO THE NORTH
OF THIS LOW. ECMWF A LITTLE FASTER ON MOVEMENT OVER THE
GFS...MOVING THE LOW INTO CENTRAL NEBRASKA ROUGHLY 12 HOURS FASTER
THAN THE GFS. BOTH ARE COLD THOUGH ON 700MB TEMPERATURES AND COLD
ENOUGH FOR WIDESPREAD SNOW. BOTH ARE SHOWING 850MB WINDS OF 40 TO
45KTS ACROSS THE PANHANDLE AND EASTERN WYOMING. WINTER IS NOT DONE
WITH SOUTHEAST WYOMING AND WE NEED TO BE WATCHING THE EVOLUTION OF
THIS EVENT AS HEAVY SNOW AND WINTER HEADLINES ARE DEFINITELY A
POSSIBILITY FOR PORTIONS OF THE FORECAST AREA...POSSIBLY EVEN THE
PANHANDLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1126 AM MDT TUE MAY 5 2015
WIDESPREAD IFR/LIFR CEILINGS AND VISIBILITIES TO PERSIST ALONG A
KCYS TO KSNY LINE THROUGH TONIGHT WITH VFR AND SCTD MVFR CIGS
ELSEWHERE TODAY...BECOMING MORE WIDESPREAD MVFR/IFR THIS EVENING.
SCTD SHOWERS SHOULD SPREAD NORTH ACROSS THE AREA TONIGHT.
&&
.FIRE WEATHER...
ISSUED AT 345 AM MDT TUE MAY 5 2015
A COOL AND WET WEATHER PATTERN WILL KEEP FIRE WEATHER CONCERNS VERY
LOW THROUGH THE WEEKEND. AFTERNOON AND EVENING SHOWERS WILL BE
POSSIBLE TODAY THROUGH THURSDAY...WITH GOOD CHANCES FOR MEASURABLE
RAIN. MORE SUBSTANTIAL PRECIPITATION AMOUNTS ARE LOOKING POSSIBLE
BY LATE FRIDAY INTO SUNDAY ASSOCIATED WITH A STRONG STORM SYSTEM.
MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE PERIOD.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL NOON MDT TODAY FOR WYZ116>118.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...RE
FIRE WEATHER...ZF