Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/26/15
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1245 PM CDT SUN MAY 24 2015
.AVIATION...
SOUTHERLY FLOW HAS BROUGHT MOISTURE BACK TO ARKANSAS. ATMOSPHERE
WILL CONTINUE TO DESTABILIZE THIS AFTERNOON. THUNDERSTORMS WILL
BECOME MORE NUMEROUS ACROSS THE AREA. SOUTH WINDS WILL BE GUSTY
AND GUST TO 25 KTS OR MORE. EXPECT WIND SHEAR AT LIT. RAIN WILL
CONTINUE TONIGHT AND END TOWARD DAYBREAK. VFR AND MVFR CONDITIONS
ARE EXPECTED THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 651 AM CDT SUN MAY 24 2015/
AVIATION...24/12Z TAF CYCLE
SCTD SHRA/TSRA WL BE NOTED ACRS THE AREA THIS MRNG...ALONG WITH
OCNL STRATUS. THIS WL RESULT IN MAINLY VFR/MVFR CONDS. CONVECTION
WL BCM MORE WIDESPREAD ACRS AR THIS AFTN AND TNGT...WITH CONDS
DETERIORATING. PRIMARILY EXPECT MVFR CONDS BY THAT TIME...WITH IFR
CIGS/VSBYS WHERE STRONGER STORMS OCCUR. BREEZY S/SELY SFC WINDS WL
ALSO BE COMMON THRU MUCH OF THE PD. /44/
PREV DISCUSSION... /ISSUED 443 AM CDT SUN MAY 24 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
SHOWERS AND THUNDERSTORMS THAT BROUGHT WIDESPREAD
RAIN...FLOODING...AND A FEW TORNADOES LAST NIGHT TO OKLAHOMA HAS
CONTINUED ITS SLOW MARCH EASTWARD THROUGH THE OVERNIGHT HOURS. HAVE
BEGUN TO SEE SHOWERS AND THUNDERSTORMS DEVELOP ACROSS THE WESTERN
THIRD OF THE STATE. WRF AND HRRR DISAGREE WITH HOW THIS SYSTEM WILL
EVOLVE OVER THE NEXT EIGHT HOURS OR SO. THE WRF SHOWS THE LINE OF
SHOWERS AND THUNDERSTORMS WEAKENING AROUND MID DAY...BEFORE
REDEVELOPING AFTER THIS EVENING. HOWEVER...AM LEANING TOWARDS THE
HRRR WHICH SHOWS SHOWERS AND THUNDERSTORMS CONTINUING TO FALL
THROUGH THE DAY...AS PRECIPITATION SLOWLY PUSHES TO THE EAST. WITH
HIGH PRECIPTABLE WATER VALUES AROUND THE STATE...THESE TRAINING
STORMS WILL BE EFFICIENT RAIN MAKERS WITH RAIN RATES TOPPING OUT AT
1.5 INCHES PER HOUR.
ON TOP OF EVERYTHING...A BREEZY DAY CAN BE EXPECTED TODAY...WITH
SUSTAINED SE WINDS OF 15 TO 25 MPH AND GUSTS UP TO 35 MPH POSSIBLE.
DID GO AHEAD AND ISSUE A LAKE WIND ADVISORY THROUGH THIS EVENING.
SEVERE WEATHER REMAINS A POSSIBILITY TODAY AS WELL. MIDLEVEL LAPSE
RATES ARE NOT FANTASTIC...HOWEVER CAPE VALUES WILL BE IN EXCESS OF
1000 J PER KG. WITH WINDS OUT OF THE SE AT THE SURFACE...HELICITY
VALUES WILL BE HIGH ENOUGH TO SUPPORT A FEW TORNADOES.
BUT BY FAR THE GREATEST THREAT WILL BE THE POTENTIAL FOR FLOODING.
OVER THE PAST TWO WEEKS...PORTIONS OF WESTERN ARKANSAS HAVE SEEN
BETWEEN 10 TO 14 INCHES OF RAIN...WHICH IS ROUGHLY 4 TO 6 TIMES
NORMAL. COMBINE THIS WITH DEEP SOUTHERLY FLOW AND PRECIPITABLE WATER
VALUES BETWEEN 1.5 TO OVER 2 INCHES...WHICH IS 1 TO 2 STANDARD
DEVIATIONS ABOVE NORMAL...AND HEAVY RAIN AND LIFE THREATENING FLASH
FLOODING WILL BE LIKELY.
CONTINUES TO LOOK LIKE TWO ROUNDS OF HEAVY RAIN...WITH THE FIRST
ROUND SUNDAY WITH TWO TO FOUR INCHES POSSIBLE WITH THE HEAVIEST RAIN
ACROSS WESTERN ARKANSAS. DO EXPECT THERE WILL BE A LULL IN THE
PRECIPITATION DURING THE DAY ON MONDAY BEFORE THE SECOND ROUND OF
HEAVY RAIN DEVELOPS MONDAY NIGHT THROUGH MID DAY TUESDAY. MODELS
HAVE BEEN CONSISTENT IN SHOWING A PERIOD OF VERY HEAVY RAIN MONDAY
NIGHT. AGAIN...DO EXPECT THAT ANOTHER ROUND OF TWO TO FOUR INCHES
WILL BE POSSIBLE MONDAY NIGHT. AS A RESULT DID GO AND ISSUE AND
EXTEND THE FLASH FLOOD WATCH TO THE ENTIRE AREA AND GO THROUGH 18Z
TUESDAY.
LONG TERM...THURSDAY THROUGH SATURDAY
MODELS INDC A WEAK UPR RDG WL SET UP ALONG THE MS RVR VALLEY LATE IN
THE WEEK. WITH PLENTY OF LOW LVL MOISTURE RMNG IN PLACE ACRS THE MID
SOUTH...SCTD MAINLY DIURNAL CONVECTION CAN BE EXPECTED EACH DAY. A
STRONGER UPR LVL STORM SYS IS PROGGED TO AFFECT THE LATE IN THE PD.
KEPT POPS IN CHC CAT THIS FAR IN ADVANCE AS CHGS IN TIMING/STRENGTH
ARE LIKELY WITH THIS SYS WITH LATER MODEL RUNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 67 78 65 79 / 80 50 80 60
CAMDEN AR 68 82 69 84 / 80 90 90 60
HARRISON AR 65 79 62 79 / 80 40 80 60
HOT SPRINGS AR 67 81 68 82 / 80 80 90 60
LITTLE ROCK AR 68 82 67 82 / 80 60 90 60
MONTICELLO AR 70 83 69 82 / 80 90 90 80
MOUNT IDA AR 68 78 67 79 / 80 80 80 60
MOUNTAIN HOME AR 65 80 64 79 / 80 30 80 60
NEWPORT AR 69 80 67 80 / 80 60 80 70
PINE BLUFF AR 68 81 69 81 / 80 80 90 70
RUSSELLVILLE AR 65 82 66 80 / 80 60 80 60
SEARCY AR 66 80 68 78 / 80 50 80 70
STUTTGART AR 69 82 69 81 / 80 60 80 70
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR ARKANSAS-
BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-
DALLAS-DESHA-DREW-FAULKNER-FULTON-GARLAND-GRANT-HOT SPRING-
INDEPENDENCE-IZARD-JACKSON-JEFFERSON-JOHNSON-LINCOLN-LOGAN-
LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-OUACHITA-PERRY-PIKE-POLK-
POPE-PRAIRIE-PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN BUREN-
WHITE-WOODRUFF-YELL.
FLASH FLOOD WATCH THROUGH TUESDAY AFTERNOON FOR ARKANSAS-BAXTER-
BOONE-BRADLEY-CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-
DESHA-DREW-FAULKNER-FULTON-GARLAND-GRANT-HOT SPRING-INDEPENDENCE-
IZARD-JACKSON-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-MARION-
MONROE-MONTGOMERY-NEWTON-OUACHITA-PERRY-PIKE-POLK-POPE-PRAIRIE-
PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN BUREN-WHITE-WOODRUFF-
YELL.
&&
$$
AVIATION...51
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
651 AM CDT SUN MAY 24 2015
.AVIATION...24/12Z TAF CYCLE
SCTD SHRA/TSRA WL BE NOTED ACRS THE AREA THIS MRNG...ALONG WITH
OCNL STRATUS. THIS WL RESULT IN MAINLY VFR/MVFR CONDS. CONVECTION
WL BCM MORE WIDESPREAD ACRS AR THIS AFTN AND TNGT...WITH CONDS
DETERIORATING. PRIMARILY EXPECT MVFR CONDS BY THAT TIME...WITH IFR
CIGS/VSBYS WHERE STRONGER STORMS OCCUR. BREEZY S/SELY SFC WINDS WL
ALSO BE COMMON THRU MUCH OF THE PD. /44/
&&
.PREV DISCUSSION... /ISSUED 443 AM CDT SUN MAY 24 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
SHOWERS AND THUNDERSTORMS THAT BROUGHT WIDESPREAD
RAIN...FLOODING...AND A FEW TORNADOES LAST NIGHT TO OKLAHOMA HAS
CONTINUED ITS SLOW MARCH EASTWARD THROUGH THE OVERNIGHT HOURS. HAVE
BEGUN TO SEE SHOWERS AND THUNDERSTORMS DEVELOP ACROSS THE WESTERN
THIRD OF THE STATE. WRF AND HRRR DISAGREE WITH HOW THIS SYSTEM WILL
EVOLVE OVER THE NEXT EIGHT HOURS OR SO. THE WRF SHOWS THE LINE OF
SHOWERS AND THUNDERSTORMS WEAKENING AROUND MID DAY...BEFORE
REDEVELOPING AFTER THIS EVENING. HOWEVER...AM LEANING TOWARDS THE
HRRR WHICH SHOWS SHOWERS AND THUNDERSTORMS CONTINUING TO FALL
THROUGH THE DAY...AS PRECIPITATION SLOWLY PUSHES TO THE EAST. WITH
HIGH PRECIPTABLE WATER VALUES AROUND THE STATE...THESE TRAINING
STORMS WILL BE EFFICIENT RAIN MAKERS WITH RAIN RATES TOPPING OUT AT
1.5 INCHES PER HOUR.
ON TOP OF EVERYTHING...A BREEZY DAY CAN BE EXPECTED TODAY...WITH
SUSTAINED SE WINDS OF 15 TO 25 MPH AND GUSTS UP TO 35 MPH POSSIBLE.
DID GO AHEAD AND ISSUE A LAKE WIND ADVISORY THROUGH THIS EVENING.
SEVERE WEATHER REMAINS A POSSIBILITY TODAY AS WELL. MIDLEVEL LAPSE
RATES ARE NOT FANTASTIC...HOWEVER CAPE VALUES WILL BE IN EXCESS OF
1000 J PER KG. WITH WINDS OUT OF THE SE AT THE SURFACE...HELICITY
VALUES WILL BE HIGH ENOUGH TO SUPPORT A FEW TORNADOES.
BUT BY FAR THE GREATEST THREAT WILL BE THE POTENTIAL FOR FLOODING.
OVER THE PAST TWO WEEKS...PORTIONS OF WESTERN ARKANSAS HAVE SEEN
BETWEEN 10 TO 14 INCHES OF RAIN...WHICH IS ROUGHLY 4 TO 6 TIMES
NORMAL. COMBINE THIS WITH DEEP SOUTHERLY FLOW AND PRECIPITABLE WATER
VALUES BETWEEN 1.5 TO OVER 2 INCHES...WHICH IS 1 TO 2 STANDARD
DEVIATIONS ABOVE NORMAL...AND HEAVY RAIN AND LIFE THREATENING FLASH
FLOODING WILL BE LIKELY.
CONTINUES TO LOOK LIKE TWO ROUNDS OF HEAVY RAIN...WITH THE FIRST
ROUND SUNDAY WITH TWO TO FOUR INCHES POSSIBLE WITH THE HEAVIEST RAIN
ACROSS WESTERN ARKANSAS. DO EXPECT THERE WILL BE A LULL IN THE
PRECIPITATION DURING THE DAY ON MONDAY BEFORE THE SECOND ROUND OF
HEAVY RAIN DEVELOPS MONDAY NIGHT THROUGH MID DAY TUESDAY. MODELS
HAVE BEEN CONSISTENT IN SHOWING A PERIOD OF VERY HEAVY RAIN MONDAY
NIGHT. AGAIN...DO EXPECT THAT ANOTHER ROUND OF TWO TO FOUR INCHES
WILL BE POSSIBLE MONDAY NIGHT. AS A RESULT DID GO AND ISSUE AND
EXTEND THE FLASH FLOOD WATCH TO THE ENTIRE AREA AND GO THROUGH 18Z
TUESDAY.
LONG TERM...THURSDAY THROUGH SATURDAY
MODELS INDC A WEAK UPR RDG WL SET UP ALONG THE MS RVR VALLEY LATE IN
THE WEEK. WITH PLENTY OF LOW LVL MOISTURE RMNG IN PLACE ACRS THE MID
SOUTH...SCTD MAINLY DIURNAL CONVECTION CAN BE EXPECTED EACH DAY. A
STRONGER UPR LVL STORM SYS IS PROGGED TO AFFECT THE LATE IN THE PD.
KEPT POPS IN CHC CAT THIS FAR IN ADVANCE AS CHGS IN TIMING/STRENGTH
ARE LIKELY WITH THIS SYS WITH LATER MODEL RUNS.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM THIS MORNING TO 9 PM CDT THIS
EVENING FOR ARKANSAS-BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-CLEBURNE-
CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-FULTON-GARLAND-GRANT-
HOT SPRING-INDEPENDENCE-IZARD-JACKSON-JEFFERSON-JOHNSON-LINCOLN-
LOGAN-LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-OUACHITA-PERRY-PIKE-
POLK-POPE-PRAIRIE-PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN
BUREN-WHITE-WOODRUFF-YELL.
FLASH FLOOD WATCH FROM 1 PM CDT THIS AFTERNOON THROUGH TUESDAY
AFTERNOON FOR ARKANSAS-BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-
CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-FULTON-
GARLAND-GRANT-HOT SPRING-INDEPENDENCE-IZARD-JACKSON-JEFFERSON-
JOHNSON-LINCOLN-LOGAN-LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-
OUACHITA-PERRY-PIKE-POLK-POPE-PRAIRIE-PULASKI-SALINE-SCOTT-
SEARCY-SHARP-STONE-VAN BUREN-WHITE-WOODRUFF-YELL.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
443 AM CDT SUN MAY 24 2015
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
SHOWERS AND THUNDERSTORMS THAT BROUGHT WIDESPREAD
RAIN...FLOODING...AND A FEW TORNADOES LAST NIGHT TO OKLAHOMA HAS
CONTINUED ITS SLOW MARCH EASTWARD THROUGH THE OVERNIGHT HOURS. HAVE
BEGUN TO SEE SHOWERS AND THUNDERSTORMS DEVELOP ACROSS THE WESTERN
THIRD OF THE STATE. WRF AND HRRR DISAGREE WITH HOW THIS SYSTEM WILL
EVOLVE OVER THE NEXT EIGHT HOURS OR SO. THE WRF SHOWS THE LINE OF
SHOWERS AND THUNDERSTORMS WEAKENING AROUND MID DAY...BEFORE
REDEVELOPING AFTER THIS EVENING. HOWEVER...AM LEANING TOWARDS THE
HRRR WHICH SHOWS SHOWERS AND THUNDERSTORMS CONTINUING TO FALL
THROUGH THE DAY...AS PRECIPITATION SLOWLY PUSHES TO THE EAST. WITH
HIGH PRECIPTABLE WATER VALUES AROUND THE STATE...THESE TRAINING
STORMS WILL BE EFFICIENT RAIN MAKERS WITH RAIN RATES TOPPING OUT AT
1.5 INCHES PER HOUR.
ON TOP OF EVERYTHING...A BREEZY DAY CAN BE EXPECTED TODAY...WITH
SUSTAINED SE WINDS OF 15 TO 25 MPH AND GUSTS UP TO 35 MPH POSSIBLE.
DID GO AHEAD AND ISSUE A LAKE WIND ADVISORY THROUGH THIS EVENING.
SEVERE WEATHER REMAINS A POSSIBILITY TODAY AS WELL. MIDLEVEL LAPSE
RATES ARE NOT FANTASTIC...HOWEVER CAPE VALUES WILL BE IN EXCESS OF
1000 J PER KG. WITH WINDS OUT OF THE SE AT THE SURFACE...HELICITY
VALUES WILL BE HIGH ENOUGH TO SUPPORT A FEW TORNADOES.
BUT BY FAR THE GREATEST THREAT WILL BE THE POTENTIAL FOR FLOODING.
OVER THE PAST TWO WEEKS...PORTIONS OF WESTERN ARKANSAS HAVE SEEN
BETWEEN 10 TO 14 INCHES OF RAIN...WHICH IS ROUGHLY 4 TO 6 TIMES
NORMAL. COMBINE THIS WITH DEEP SOUTHERLY FLOW AND PRECIPITABLE WATER
VALUES BETWEEN 1.5 TO OVER 2 INCHES...WHICH IS 1 TO 2 STANDARD
DEVIATIONS ABOVE NORMAL...AND HEAVY RAIN AND LIFE THREATENING FLASH
FLOODING WILL BE LIKELY.
CONTINUES TO LOOK LIKE TWO ROUNDS OF HEAVY RAIN...WITH THE FIRST
ROUND SUNDAY WITH TWO TO FOUR INCHES POSSIBLE WITH THE HEAVIEST RAIN
ACROSS WESTERN ARKANSAS. DO EXPECT THERE WILL BE A LULL IN THE
PRECIPITATION DURING THE DAY ON MONDAY BEFORE THE SECOND ROUND OF
HEAVY RAIN DEVELOPS MONDAY NIGHT THROUGH MID DAY TUESDAY. MODELS
HAVE BEEN CONSISTENT IN SHOWING A PERIOD OF VERY HEAVY RAIN MONDAY
NIGHT. AGAIN...DO EXPECT THAT ANOTHER ROUND OF TWO TO FOUR INCHES
WILL BE POSSIBLE MONDAY NIGHT. AS A RESULT DID GO AND ISSUE AND
EXTEND THE FLASH FLOOD WATCH TO THE ENTIRE AREA AND GO THROUGH 18Z
TUESDAY.
&&
.LONG TERM...THURSDAY THROUGH SATURDAY
MODELS INDC A WEAK UPR RDG WL SET UP ALONG THE MS RVR VALLEY LATE IN
THE WEEK. WITH PLENTY OF LOW LVL MOISTURE RMNG IN PLACE ACRS THE MID
SOUTH...SCTD MAINLY DIURNAL CONVECTION CAN BE EXPECTED EACH DAY. A
STRONGER UPR LVL STORM SYS IS PROGGED TO AFFECT THE LATE IN THE PD.
KEPT POPS IN CHC CAT THIS FAR IN ADVANCE AS CHGS IN TIMING/STRENGTH
ARE LIKELY WITH THIS SYS WITH LATER MODEL RUNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 80 67 78 65 / 70 80 50 80
CAMDEN AR 83 68 82 69 / 70 80 90 90
HARRISON AR 74 65 79 62 / 100 80 40 80
HOT SPRINGS AR 80 67 81 68 / 80 80 80 90
LITTLE ROCK AR 82 68 82 67 / 70 80 60 90
MONTICELLO AR 85 70 83 69 / 60 80 90 90
MOUNT IDA AR 76 68 78 67 / 80 80 80 80
MOUNTAIN HOME AR 75 65 80 64 / 80 80 30 80
NEWPORT AR 81 69 80 67 / 70 80 60 80
PINE BLUFF AR 83 68 81 69 / 70 80 80 90
RUSSELLVILLE AR 79 65 82 66 / 80 80 60 80
SEARCY AR 81 66 80 68 / 70 80 50 80
STUTTGART AR 83 69 82 69 / 70 80 60 80
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 11 AM THIS MORNING TO 9 PM CDT THIS
EVENING FOR ARKANSAS-BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-CLEBURNE-
CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-FULTON-GARLAND-GRANT-
HOT SPRING-INDEPENDENCE-IZARD-JACKSON-JEFFERSON-JOHNSON-LINCOLN-
LOGAN-LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-OUACHITA-PERRY-PIKE-
POLK-POPE-PRAIRIE-PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN
BUREN-WHITE-WOODRUFF-YELL.
FLASH FLOOD WATCH FROM 1 PM CDT THIS AFTERNOON THROUGH TUESDAY
AFTERNOON FOR ARKANSAS-BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-
CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-FULTON-
GARLAND-GRANT-HOT SPRING-INDEPENDENCE-IZARD-JACKSON-JEFFERSON-
JOHNSON-LINCOLN-LOGAN-LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-
OUACHITA-PERRY-PIKE-POLK-POPE-PRAIRIE-PULASKI-SALINE-SCOTT-
SEARCY-SHARP-STONE-VAN BUREN-WHITE-WOODRUFF-YELL.
&&
$$
SHORT TERM...65 / LONG TERM...44
AREA FORECAST DISCUSSION
NWS EUREKA CA
537 AM PDT SUN MAY 24 2015
.SYNOPSIS...DRY WEATHER CONDITIONS WILL CONTINUE TO PREVAIL TODAY
AS HIGH PRESSURE BUILDS TOWARD THE COAST. AN UPPER TROUGH WILL
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO TRINITY COUNTY ON
MONDAY. COASTAL AREAS WILL CONTINUE TO SEE MOSTLY CLOUDS WITH
PARTIAL AFTERNOON CLEARING.
&&
.DISCUSSION...EARLY MORNING SATELLITE IMAGERY SHOWED LOW CLOUDS
COVERING THE COAST AND COASTAL VALLEYS NORTH OF THE CAPE. LOW
CLOUDS HAVE ALSO BEEN REFORMING ALONG THE MENDOCINO COAST ZONE
WITH CLOUDS STARTING TO EXPAND OFFSHORE. THE LOW CLOUD LAYER HAS
BEEN COMPRESSING THROUGH THE NIGHT WITH HIGHER ELEVATION RAWS
SHOWING ABOUT 5 TO 10 DEGREES OF WARMING. WITH MODERATE WARMING
ALOFT TODAY MOST INTERIOR SITES SHOULD SEE HIGHER TEMPERATURES
COMPARED TO YESTERDAY. THE FLOW REMAINS STRONGLY ONSHORE SO COASTAL
VALLEYS EXPOSED TO THE MARINE AIR WILL NOT SEE VERY MUCH...IF
ANY...WARMING TODAY. THE MARINE INVERSION WILL BE STRONGER TODAY.
WITH STRATUS STARTING TO EXPAND OFFSHORE...COASTAL CLOUDS WILL
PROBABLY STICK AROUND LONGER AT THE COAST TODAY. CLEARING IS NOT
LOOKING VERY PROMISING TODAY.
NAM12 CONTINUES TO SHOW WEAK AND SHALLOW INSTABILITY OVER THE
INTERIOR OF TRINITY COUNTY THIS AFTERNOON. THIS MODEL EVEN
GENERATES SOME LIGHT PRECIP WHICH IS PROBABLY OVERDONE. THE GFS
AND ECMWF ARE MUCH DRIER. BASED ON THE NAM12 SOUNDINGS...CONVECTION
IS LOOKING DECENT THIS AFTERNOON AND EVENING WITH LIFTED INDICES
NEAR -2C AND SBCAPE NEAR 1000J/KG. A STRONG CAPPING LAYER AND CIN
WILL SUPPRESS STORM DEVELOPMENT...HOWEVER. AN ISOLATED SHOWER OR
TWO OVER THE TRINITY MOUNTAINS AND YOLLA BOLLYS IS NOT COMPLETELY
OUT OF THE QUESTION. EVEN THE HRRR MODEL INDICATES ISOLATED SHOWER
DEVELOPMENT. OTHERWISE IT IS SHAPING UP TO BE A FINE DAY WITH
PLEASANT AFTERNOON TEMPERATURES AND ABUNDANT SUNSHINE ACROSS THE
INTERIOR TODAY.
AN UPPER TROUGH WILL MOVE ACROSS THE PACIFIC NW ON MONDAY WITH
THE TRAILING EDGE CLIPPING FAR NORTHERN CALIFORNIA. ALL THE
MODELS...GFS...ECMWF AND NAM12 INDICATE PRECIP DEVELOPING WITH
DAYTIME HEATING OVER TRINITY COUNTY. PROFILES LOOK BETTER FOR
STORMS WITH MUCH LESS CAPPING AND HIGHER CAPE ACROSS THE EASTERN
PORTION OF TRINITY COUNTY. MOISTURE IS NOT VERY DEEP SO THERE MAY
NOT BE MUCH IN THE WAY OF CLOUD COVER INITIALLY. PWATS APPROACH 1
INCH BUT NW FLOW ALOFT WILL CARRY THE STORMS QUICKLY TO THE
SOUTHEAST. ISOLATED HEAVY RAIN WILL BE POSSIBLE.
RIDGING OVER THE AREA ON WED AND THU SHOULD BRING DRYING...WARMING
AND INCREASING STABILITY IN THE INTERIOR. BASED ON THE SURFACE
PRESSURE PATTERN AND THE DGEX BOUNDARY LAYER HUMIDITY...COASTAL
AREAS WILL MOST LIKELY SEE LOW CLOUDS AND PERHAPS SOME FOG EACH
DAY AND NIGHT. THE MODELS HAVE BEEN CONSISTENTLY SHOWING FAIRLY
DRY SOUTHWEST FLOW ALOFT AROUND MID WEEK. THE GFS DOES SHOW
CONVECTIVE PARAMETERS FAVORABLE FOR ISOLATED CONVECTION OVER THE
HIGHER TERRAIN ON FRI AND SAT AS A COUPLE OF SHORT WAVES MOVE
TOWARD THE AREA AND INTO THE RIDGE. CONFIDENCE IS NOT HIGH ENOUGH
AT THIS POINT TO ADD STORMS THAT FAR OUT...SO WILL LEAVE THE
FORECAST DRY WITH VERY MINIMAL SHOWER CHANCES OVER THE HIGHER
ELEVATIONS BORDERING SISKIYOU COUNTY.
&&
.AVIATION...OVERNIGHT AND EARLY MORNING CIGS HAVE BEEN BOUNCING
BETWEEN MVFR AND VFR WHILE VSBYS HAVE REMAINED ABOVE 3SM. THIS
SHOULD CONTINUE THROUGH THE MORNING HOURS BEFORE LIFTING BY LATE
MORNING. EXPECT SOME BETTER CLEARING AT THE COASTAL TERMINALS THIS
AFTERNOON BUT AS HAS BEEN THE CASE FOR THE LAST WEEK CLOUDS WILL
FILL IN AGAIN BY EARLY EVENING. INTERIOR AREAS SHOULD SEE VFR
CONDITIONS AGAIN TODAY HOWEVER AN ISOLATED SHOWER IS STILL POSSIBLE
BRIEFLY REDUCING TERMINAL CONDITIONS.
&&
.MARINE...PRESSURE GRADIENT DRIVEN NORTHERLY WINDS WILL PICK UP
AGAIN THIS AFTERNOON AND EVENING CONTRIBUTING TO LOCALLY GENERATED
SHORT PERIOD WAVES GENERALLY 8 TO 10 FT. THE NORTHERLY WINDS AND
STEEP SEAS WILL PERSIST AT LEAST ANOTHER 24-36 HOURS DUE TO AN
OFFSHORE HIGH PRESSURE SYSTEM STRENGTHENING. THE PATTERN BEGINS TO
CHANGE TOWARD WEDNESDAY AS AN UPPER LEVEL LOW PRESSURE SYSTEM MOVES
OVER THE REGION...DIMINISHING THE GRADIENT AND RESULTING WINDS.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 5 AM PDT MONDAY FOR PZZ450.
SMALL CRAFT ADVISORY UNTIL 11 PM PDT TUESDAY FOR PZZ470-475.
SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR PZZ455.
&&
$$
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AREA FORECAST DISCUSSION
NWS PUEBLO CO
709 PM MDT MON MAY 25 2015
.UPDATE...
ISSUED AT 705 PM MDT MON MAY 25 2015
A BIT CONCERNED THAT WX MAY GET A BIT MORE ACTIVE OVER THE REGION
LATER THIS EVENING. HRRR HAS BEEN SHOWING SHOWERS/STORMS WOULD
INCREASE TO OUR NORTH AND WORK SWD AS THE EVENING PROGRESSES.
LATEST RADAR TRENDS AT 7 PM HAVE BEEN SHOWING THIS. BELIEVE THERE
IS A DISTURBANCE OVER THE KDEN AREA AND THIS WEAK PIECE OF ENERGY
WILL MOVE SE THIS EVENING. FOR THIS REASON HAVE ADJUSTED POPS TO
REFLECT THIS POSSIBILITY OVER THE PLAINS FOR THIS EVENING INTO THE
EARLY MORNING HOURS.
PRECIP ACTIVITY SHOULD INCREASE DURING THE NEXT 1-2 HOURS OVER THE
PIKES PEAK REGION AND MOVE EAST-SOUTHEAST WITH TIME. /HODANISH
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 242 PM MDT MON MAY 25 2015
...BACK TO THE SEVENTIES...
REMEMBER THOSE DAYS? WELL...WITH A LITTLE MORE SUN AND H7 TEMPS
CLIMBING TO 7 DEG OR HIGHER TOMORROW...SHOULD GET INTO THE SEVENTIES
TOMORROW OVER THE PLAINS...POSSIBLY NR 80 DEGREES FOR THE WARMEST
SPOTS. RESIDUAL MOISTURE SHOULD KEEP HIGHS FROM REACHING THE GUIDANCE
VALUES...HOWEVER.
REST OF TODAY...MARGINAL THREAT OF SVR HAS SHIFTED TO THE EAST...BUT
STILL AREAS OF 750-1000 CAPE...ESPECIALLY NR THE KS BORDER.
SO...DESPITE MODEST SHEAR...CANNOT RULE OUT SOME MARGINALLY STRONG-
SVR STORMS IN MULTI-CELL CLUSTERS LATE THIS AFTERNOON THRU THIS EVE.
SMALL HAIL WILL BE THE MOST LIKELY THREAT.
SNOW LEVELS REMAIN RELATIVELY HIGH...WITH THE PASSES CURRENTLY
REPORTING MID 30S THIS AFTERNOON. LOW AMPLITUDE UPPER RIDGE WILL
CONTINUE TO BUILD THROUGH TOMORROW...WHILE WEAK DISTURBANCES IN
THE FLOW ST OFF MAINLY DIURNAL SHOWERS AND STORMS. WIND SHEAR
WILL REMAIN MODEST ON TUE...SO SVR THREAT WILL BE LOW. EXTREME
SE CORNER OF THE CWA WILL STILL SEE SOME MARGINALLY SVR PARAMETERS
IN THE AFTERNOON...BUT THE NAM IS INDICATING SUPPRESSED CONVECTION
OVR THAT AREA DUE TO THE UPPER RIDGING. ENJOY THE SEVENTIES! ROSE
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 242 PM MDT MON MAY 25 2015
TUE NIGHT AND WED...THE SHORTWAVE RIDGE OVR THE AREA WL SHIFT
EASTWARD AS AN UPR LOW MOVES INTO ID AND ITS UPR TROF EXTENDS
SOUTHWARD TO BAJA CA. SCT SHOWERS AND TSTMS ARE EXPECTED OVR AND NR
THE MTNS TUE EVENING AND THEN AGAIN ON WED AFTERNOON...WITH MAINLY
JUST SOME ISOLD PCPN OVR THE REST OF THE AREA. IT LOOKS LIKE HIGH
TEMPS ON WED WL BE AROUND AVERAGE...WHICH IS MOSTLY IN THE 70S OVR
THE LOWER ELEVATIONS.
THE UPR TROF IS THEN FORECAST TO MOVE SLOWLY EASTWARD ON WED NIGHT
AND THU...EXTENDING FROM WRN WY INTO AZ BY 00Z FRI. THU LOOKS LIKE
ANOTHER DAY OF SHOWERS AND TSTMS MAINLY OVR AND NR THE MTNS AREAS.
FOR FRI A BAGGY TROF WL LIE OVR THE STATE...AND A FRONT WL MOVE THRU
SERN CO. THE AREA IS EXPECTED TO REALLY MOISTEN UP DURING THE DAY
FRI...WITH WIDESPREAD PCPN DEVELOPING AND CONTINUING FRI NIGHT.
TEMPS ON THU SHOULD DROP BACK TO BELOW AVERAGE AGAIN. THE UPR TROF
AND LOW WL MOVE EAST INTO KS SAT...BUT WRAP AROUND MOISTURE IS
EXPECTED TO KEEP WIDESPREAD PCPN OVR ERN CO ON SAT...WITH THE MTN
AND HIGH VALLEY AREAS HAVING SCT PCPN.
SAT NIGHT THE LOW MOVES FARTHER EAST AND IT LOOKS LIKE THE FORECAST
AREA WL THEN HAVE DRIER WX. ON SUN AN UPR RIDGE BUILDS OVR THE GREAT
BASIN AND THEN MOVE EASTWARD OVR CO ON MONDAY. THERE WL STILL BE
ENOUGH MSTR AROUND FOR SOME MAINLY AFTERNOON AND EVENING SHOWERS AND
TSTMS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 242 PM MDT MON MAY 25 2015
SHOWERS AND A FEW STORMS WILL CONTINUE TO DEVELOP THIS
AFTERNOON...ESPECIALLY VC KPUB ALONG AND S OF HGWY 50. SOME BRIEF
RESTRICTIONS TO VIS WILL BE POSSIBLE WITH SHOWERS/TS. CONVECTION
WILL BE EVEN MORE SUPPRESSED ON TUESDAY AS HIGH PRESSURE BUILDS OVER
SE CO. WILL SEE ISOLD-SCT SHOWERS AND STORMS...MAINLY OVER THE HYR
TRRN. WINDS WILL CONTINUE TO BE RELATIVELY LIGHT EXCEPT VCTS. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HODANISH
SHORT TERM...ROSE
LONG TERM...28
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
949 PM EDT MON MAY 25 2015
.UPDATE...
01Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE EASTERN GULF OF
MEXICO AND FLORIDA PENINSULA UNDERNEATH A LARGE RIDGE OF HIGH
PRESSURE ALOFT. THE RIDGE AXIS IS JUST TO THE EAST OF OUR
AREA...WITH WV IMAGERY SHOWING A LARGE EXPANSE OF VERY DRY
MID/UPPER LEVEL AIR EXTENDING FROM OVER THE FLORIDA EAST COAST OUT
INTO THE ATLANTIC. THIS DRIER AIR WILL SOMEWHAT INFLUENCE OUR
FORECAST FOR TUESDAY AS IT MAKES SOME PROGRESS WESTWARD OVER OUR
ZONES.
AT THE SURFACE...A LARGE 1030+MB ATLANTIC HIGH CENTERED OFF THE
MID- ATLANTIC/NEW ENGLAND COAST RIDGES BACK TO THE SOUTHWEST INTO
THE SOUTHEASTERN STATES. THE FLORIDA PENINSULA IS SITUATED TO THE
SOUTH OF THE RIDGE AXIS...PROVIDING OUR STATE WITH A SYNOPTIC
EASTERLY LOW LEVEL FLOW.
SAW QUITE A BIT OF THUNDERSTORM ACTIVITY TODAY...WITH THE MAJORITY
OF THE ACTIVITY FROM COASTAL PASCO COUNTY SOUTHWARD ALONG THE
SUNCOAST. MORE SCATTERED CONVECTION OCCURRED NORTHWARD THROUGH THE
REST OF THE NATURE COAST AND OVER THE INLAND AREA. MOST OF THE
ACTIVITY HAS NOW ENDED DOWN TOWARD THE FORT MYERS AREA...BUT
AROUND THE GENERAL TAMPA BAY VICINITY...THE LINGERING EFFECTS OF A
LATE DAY SEA-BREEZE/OUTFLOW MERGER CONTINUE TO FIRE OFF STORMS.
MOST OF THIS ACTIVITY IS NOW ON THE WESTERN SIDE OF THE I-75
CORRIDOR...WITH STORMS TRYING TO PUSH OUT INTO THE GULF OF MEXICO.
MAY TAKE ANOTHER HOUR OR TWO FOR THINGS TO REALLY QUITE DOWN
ACROSS PARTS OF MANATEE/PINELLAS COUNTIES...BUT OVERALL...WILL
EXPECT A QUIET/DRY OVERNIGHT OVER THE LAND ZONES AFTER 03-04Z.
STORMS ARE LIKELY TO LINGER LONGER OVER THE MARINE ZONES...AS
SHOWN BY JUST ABOUT ALL HIRES CONVECTION ALLOW GUIDANCE.
FOR TUESDAY...THE RIDGE POSITION SHIFTS SLIGHTLY SOUTHWARD...BUT
STILL REMAINS TO OUR NORTH...THIS SLIGHT SHIFT WILL BRING OUR LOW
LEVEL WINDS OUT OF THE SOUTHEAST. NOW...GENERALLY...GIVEN A NORMAL
ATMOSPHERIC COLUMN FOR THE WARM SEASON...THIS SOUTHEAST FLOW
REGIME IS ONE OF OUR MOST ACTIVE FOR WEST COAST CONVECTION. WHAT
WILL COMPLICATE THE FORECAST LATER TUESDAY WILL BE THE SLOW
ARRIVAL OF MUCH DRIER AIR ALOFT. THE GFS/ECMWF/NAM ALL SHOW OUR
REGION ON THE WESTERN PERIPHERY OF THE REALLY HOSTILE MID/UPPER
LEVEL AIR. AT THE VERY LEAST WE CAN SAY THE ENVIRONMENT ALOFT WILL
NOT BE AS FAVORABLE AS PREVIOUS DAYS. THEREFORE...WE REALLY HAVE A
BATTLE BETWEEN A FAVORABLE LOW LEVEL CONVERGENCE PATTERN TO GET
UPDRAFT GOING...AND A HOSTILE THERMODYNAMIC ENVIRONMENT THAT THE
UPDRAFTS/CONVECTIVE COLUMNS WILL BE GROWING INTO.
MOST OF THE HIRES GUIDANCE MEMBERS ARE SUGGESTING A MORE WIDELY
SCT CONVECTIVE COVERAGE...AND MAINLY NEAR THE COAST THE SECOND
HALF OF TUESDAY AFTERNOON...WITH STORMS DRIFTING WEST/NW INTO THE
GULF. CURRENT FORECASTS PEAK AT 40-50% POPS FOR LATER
TUESDAY...WITH NO LIKELY 60% OR GREATER RAIN CHANCES MENTIONED.
THIS SEEMS REASONABLE GIVEN THE MIX OF GOOD AND BAD TOWARD DEEP
CONVECTION. IF THE DRY AIR MAKES MORE PROGRESS WESTWARD...THEN
THE POPS MAY NEED TO BE NUDGED DOWN A BIT. KEEP IN MIND THAT UPPER
LEVEL MOISTURE IS ONE OF THE POOREST FORECAST VARIABLES BY
NUMERICAL WEATHER PREDICTION. EITHER WAY...IT WILL BE ANOTHER DAY
WHERE BOATERS ON THE COASTAL WATERS NEED TO KEEP A CLOSE EYE ON
THE WEATHER AND BE PREPARED TO REACT TO QUICKLY DEVELOPING STORMS
NEAR THE COAST...SINCE THESE STORMS WILL RAPIDLY MOVE OFFSHORE.
ONE CONCERN FOR THE STORMS THAT DO DEVELOP...IS THE LOWER THETAE
AIR ARRIVING ALOFT THAT MAY ACTUALLY SET UP A SITUATION MORE
FAVORABLE FOR WET MICROBURSTS. THE LOWER THETAE AIR WILL PROMOTE
EVAPORATIVE COOLING THROUGH ENTRAINMENT OF THE AIR INTO THE
CONVECTIVE COLUMN. WAS CHECKING OUT THE VALUES FOR THE WET
MICROBURST SEVERITY INDEX (WMSI) FROM THE LATEST NAM...AND THEY ARE
ACTUALLY QUITE HIGH FOR LATE TUESDAY AFTERNOON. BASICALLY...STORMS
LOOK TO BE MORE PRONE TO DOWNBURST/MICROBURST EVENTS ON TUESDAY
GIVEN THE EXPECTED ENVIRONMENT ALOFT.
STORMS ARE LIKELY TO BE LATE DAY OCCURRENCES ONCE AGAIN. BEFORE
THE STORMS FIRE...OUR POSITION UNDER THE STRONG RIDGE SHOULD AGAIN
ALLOW MANY LOCATIONS AWAY FROM THE IMMEDIATE COAST TO REACH THE
LOWER TO MIDDLE 90S FOR HIGH TEMPERATURES.
&&
.AVIATION...
CONVECTION IS TAKING ITS TIME SETTLING DOWN AROUND THE TAMPA BAY
AREA. KSRQ/KPIE/KTPA/KLAL...WILL CONTINUE AT LEAST A SMALL THREAT
OF A SHOWER OR STORM THROUGH 04Z...AND THEN VFR CONDITIONS SHOULD
GENERALLY PREVAIL THROUGH THE REMAINDER OF THE OVERNIGHT THROUGH
THE EARLY AFTERNOON HOUR TUESDAY. LATE IN THE DAY...WIDELY SCT
STORMS WILL DEVELOP...MAINLY AFTER 19-20Z. ALL TERMINALS WILL RUN
THE RISK OF A BRIEF DOWNPOUR OR ROUND OF GUSTY WINDS...ALTHOUGH
STORM COVERAGE IS EXPECTED TO BE LESS THAN PREVIOUS DAYS.
&&
.MARINE...
EAST TO SOUTHEAST WINDS WILL REMAIN IN PLACE ACROSS THE WATERS
THROUGH TUESDAY...OTHER THAN A TURN ONSHORE DURING THE AFTERNOON
WITH THE SEA BREEZE. AN EASTERLY SURGE TO EXERCISE CAUTION-LEVEL
WINDS IS EXPECTED FOR PORTIONS OF THE GULF WATERS DURING THE LATE
NIGHT AND EARLY MORNING HOURS OF TUESDAY. OTHERWISE...NO
HEADLINES ARE EXPECTED. LATE TUESDAY AFTERNOON...WIDELY SCATTERED
THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE COAST AND THEN
RAPIDLY PUSH WESTWARD INTO THE GULF. BOATERS ON THE COASTAL WATERS
SHOULD KEEP A CLOSE EYE ON THE WEATHER DURING THE LATER AFTERNOON
AND EARLY EVENING HOURS...AND BE PREPARED TO SEEK SAFE HARBOR
QUICKLY SHOULD THREATENING WEATHER APPROACH.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 75 91 74 93 / 50 50 10 30
FMY 74 93 72 94 / 20 40 10 30
GIF 74 93 72 93 / 10 20 0 20
SRQ 74 92 72 92 / 60 50 10 30
BKV 72 93 70 93 / 20 50 10 30
SPG 77 91 77 90 / 60 50 10 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...14/MROCZKA
AREA FORECAST DISCUSSION
NWS MIAMI FL
746 PM EDT MON MAY 25 2015
.AVIATION...
BANDS OF SHOWERS CAN BE SEEN ACROSS THE ATLANTIC WATERS THIS
EVENING DUE TO WEAK LINES OF CONVERGENCE. LATEST HRRR DEPICTS SOME
OF THESE SHOWERS PUSHING ASHORE THROUGH THE NIGHT SO ADDED VCSH
ACROSS THE EAST COAST SITES AFTER 03Z. OTHERWISE...VFR CONDITIONS
SHOULD PREVAIL AT ALL SITES THROUGH THE PERIOD WITH EAST-SOUTHEAST
WINDS REMAINING DOMINANT. SLIGHTLY DRIER AIR IS EXPECTED TO PUSH
INTO SOUTH FLORIDA THROUGH THE DAY ON TUESDAY REDUCING OVERALL
COVERAGE OF SHOWERS AND THUNDERSTORMS. MET GUIDANCE DOES DEPICT A
WEAK GULF BREEZE FORMING BRIEFLY ON TUESDAY AFTERNOON FOR KAPF
BUT NOT SUPPORTED BY OTHER MODEL GUIDANCE SO LEFT EAST-SOUTHEAST
FLOW PREVAILING.
&&
.PREV DISCUSSION... /ISSUED 306 PM EDT MON MAY 25 2015/
DISCUSSION...
HIGH PRESSURE CONTINUES TO HOLD ON OVER THE WESTERN ATLANTIC
THROUGH THE WEEK. HOWEVER, SOME DRIER AIR WILL MOVE OVER SOUTH
FLORIDA FOR THE NEXT COUPLE OF DAYS, REDUCING THE CHANCES FOR
CONVECTION. THIS WILL ALSO KEEP THE EASTERLY FLOW IN PLACE ACROSS
THE CWA. THIS FLOW WILL KEEP AN ELEVATED RISK FOR RIP CURRENTS
THROUGH AT LEAST TOMORROW. IF THE WINDS WEAKEN SOME BY WEDNESDAY,
THE RISK MAY REDUCE SOME, BUT RIP CURRENTS WILL CONTINUE TO BE
POSSIBLE THROUGH AT LEAST MOST OF THE WEEK.
AS FOR CONVECTION, THE SURFACE HIGH DOES LOOK TO STRENGTHEN SOME
OVER THE NEXT COUPLE OF DAYS, AND A 500MB HIGH ALSO REMAINS IN
PLACE OVER THE AREA. ALSO, AS MENTIONED BEFORE, SOME DRIER AIR
DOES WORK ITS WAY OVER THE AREA. THIS WILL REDUCE THE COVERAGE OF
SHOWERS AND ALSO REDUCE THE CHANCES OF ANY THUNDERSTORMS THROUGH
THE MIDDLE OF THE WEEK. THERE WILL STILL BE A CHANCE THAT SOME
SHOWERS MAY DEVELOP AND A VERY SLIGHT CHANCE THAT ANY OF THEM
COULD TURN INTO A THUNDERSTORM. BY THURSDAY AFTERNOON, MOISTURE
BEGINS TO RETURN, AND BY FRIDAY, ENOUGH HAS WORKED ITS WAY BACK IN
TO BRING POPS BACK UP INTO THE CHANCE CATEGORY. GIVEN THE
CONTINUING EASTERLY FLOW, MOST OF THE ACTIVITY WILL BE IN THE
INTERIOR OVER TO THE GULF COAST. CHANCES WILL INCREASE SOME INTO
THE WEEKEND AS WELL AS THE AREAS THAT MAY SEE CONVECTIVE ACTIVITY.
MARINE...
HIGH PRESSURE WILL CONTINUE OVER THE WESTERN ATLANTIC, KEEPING THE
EASTERLY FLOW OVER ALL SOUTH FLORIDA WATERS INTO THE WEEKEND. THIS
MAY KEEP SOME ROUGH SURF ALONG THE ATLANTIC COAST AND CHOPPY
CONDITIONS FOR THE LAKE AND BISCAYNE BAY THIS WEEK. THERE WILL BE
A SLIGHT CHANCE OF SHOWERS FOR THE NEXT COUPLE OF DAYS,AND THEN
INCREASE TO A CHANCE OF SHOWERS AND POSSIBLY SOME THUNDERSTORMS BY
THE END OF THE WEEK, INTO THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 88 77 87 / 20 20 10 20
FORT LAUDERDALE 79 87 78 87 / 20 20 20 20
MIAMI 77 88 77 86 / 20 20 10 20
NAPLES 72 93 72 92 / 10 30 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH TUESDAY AFTERNOON FOR FLZ168-172-
173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...13/SI
LONG TERM....13/SI
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
230 PM CDT SUN MAY 24 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 230 PM CDT SUN MAY 24 2015
THUNDERSTORMS ARE BEGINNING TO BECOME MORE WIDESPREAD ACROSS
CENTRAL/SOUTHERN MISSOURI IN CONJUNCTION WITH A MESOSCALE CONVECTIVE
VORTEX (MCV) GENERATED BY AN UPSTREAM STORM COMPLEX LAST NIGHT.
THESE CELLS ARE LIFTING MAINLY NORTHWARD AND WILL STAY WEST OF THE
MISSISSIPPI RIVER LATE THIS AFTERNOON INTO THE EVENING. FURTHER
EAST...WIDELY SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE
WESTERN HALF OF THE KILX CWA...HOWEVER WEAK WIND SHEAR AND AN
OVERALL LACK OF FORCING WILL KEEP AREAL COVERAGE TO A MINIMUM INTO
THE EARLY EVENING. STRONGER FORCING WILL GRADUALLY ARRIVE AS A
SHORT-WAVE TROUGH EVIDENT ON 19Z/2PM WATER VAPOR IMAGERY ACROSS
TEXAS LIFTS NORTHWARD INTO THE REGION LATER THIS EVENING. HIGH-RES
MODELS CONTINUE TO DELAY THE ONSET OF WIDESPREAD CONVECTION...WITH
THE LATEST HRRR SUGGESTING THAT E/NE PARTS OF THE CWA WILL LIKELY
REMAIN DRY UNTIL AFTER MIDNIGHT. HAVE TAILORED RAIN CHANCES
ACCORDINGLY...WITH LIKELY POPS GRADUALLY OVERSPREADING ALL LOCATIONS
SOUTHWEST OF A BLOOMINGTON TO PARIS LINE DURING THE EVENING...THEN
FURTHER NORTHEAST ACROSS THE REMAINDER OF THE AREA OVERNIGHT.
DESPITE ARRIVAL OF STRONGER LIFT ASSOCIATED WITH TEXAS
WAVE...WANING INSTABILITY AFTER SUNSET WILL PREVENT WIDESPREAD
SEVERE WEATHER FROM MATERIALIZING...ALTHOUGH A FEW CELLS COULD
PRODUCE GUSTY WINDS AND SMALL HAIL.
&&
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 230 PM CDT SUN MAY 24 2015
SHORT-WAVE TROUGH WILL EXTEND FROM NORTHERN MISSOURI TO SOUTHERN
ILLINOIS BY 12Z MON...THEN WILL QUICKLY LIFT NORTHWARD INTO THE
GREAT LAKES BY MIDDAY. ONCE FEATURE PASSES...SHORT-WAVE RIDGING
IN ITS WAKE WILL CREATE SYNOPTIC SUBSIDENCE AND A DRY AFTERNOON.
WILL STILL NEED TO WATCH FOR POTENTIAL MESOSCALE BOUNDARIES FROM
THE OVERNIGHT CONVECTION...AS THESE COULD POSSIBLY TRIGGER
ADDITIONAL STORMS LATER IN THE DAY AS THE AIRMASS BECOMES
MODERATELY UNSTABLE. AT THIS TIME...THINK SUBSIDENCE AND
MID-LEVEL DRYING BEHIND THE WAVE WILL PREVENT CONVECTION...SO
WILL GO WITH A DRY FORECAST IN THE AFTERNOON. MAIN STORY ON
MONDAY WILL BE THE WINDY AND VERY WARM CONDITIONS. MODELS ARE
SHOWING A 50-55KT 925MB JET DEVELOPING FROM THE OZARKS TO THE
SOUTHERN GREAT LAKES LATER TONIGHT. AS MIXING BEGINS TO TAKE
PLACE MONDAY MORNING...SOME OF THIS HIGHER MOMENTUM AIR WILL BE
TRANSFERRED TO THE SURFACE RESULTING IN GUSTS OF 30-35MPH.
THANKS TO THE STRONG SOUTHWESTERLY WINDS AND CLEARING
SKIES...HIGH TEMPERATURES WILL SOAR WELL INTO THE 80S.
THE NEXT UPSTREAM SHORT-WAVE CURRENTLY OVER ARIZONA WILL ROUND THE
BASE OF THE ROCKIES TROUGH AND LIFT INTO ILLINOIS ON TUESDAY.
MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE STRENGTH AND TIMING
OF THIS FEATURE. WILL BRING POPS BACK INTO THE PICTURE AFTER
MIDNIGHT MONDAY NIGHT...THEN WILL GO LIKELY ACROSS THE BOARD ON
TUESDAY. LATEST DAY 3 CONVECTIVE OUTLOOK FROM SPC FEATURES A SLIGHT
RISK FOR SEVERE ALONG/SOUTH OF I-70 ON TUESDAY...HOWEVER WIDESPREAD
CONVECTION IN THE MORNING WILL LIKELY LIMIT INSTABILITY FOR MUCH OF
THE DAY. LATEST NAM SHOWS SBCAPES INCREASING TO 1500J/KG ACROSS THE
SE CWA LATE IN THE DAY...WHILE 0-6KM SHEAR REMAINS QUITE WEAK AT
AROUND 25KT. WHILE ISOLATED STRONG STORMS CANNOT BE RULED
OUT...WIDESPREAD SEVERE WEATHER SEEMS UNLIKELY IN THE OUTLOOK AREA.
ONCE THIS WAVE EXITS THE REGION...FORCING ONCE AGAIN BECOMES MEAGER
FOR THE REMAINDER OF THE WEEK. A SUBTLE WAVE MAY PASS THROUGH
ILLINOIS ON WEDNESDAY...SO HAVE MAINTAINED LOW CHANCE POPS AT THAT
TIME. THURSDAY STILL APPEARS TO BE THE OVERALL DRIEST DAY OF THE
WEEK...WITH ONLY SLIGHT CHANCE POPS AND HIGH TEMPS WELL INTO THE
80S. BY THE END OF THE WEEK...A MORE SIGNIFICANT NORTHERN-STREAM
WAVE WILL BEGIN PUSHING A COLD FRONT TOWARD ILLINOIS. STILL SOME
MODEL DISCREPANCY WITH THE TIMING OF THAT PROCESS...BUT TRENDS ARE
SUGGESTING ENHANCED RAIN CHANCES WILL HOLD OFF UNTIL FRIDAY NIGHT
THROUGH SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1237 PM CDT SUN MAY 24 2015
SHOWERS HAVE REMAINED SCATTERED THUS FAR...AND HRRR MODEL SUGGESTS
THIS SHOULD BE THE CASE A GOOD PART OF THE AFTERNOON WITH SOME
INCREASE BY 21Z OR SO IN WEST CENTRAL ILLINOIS. HAVE GONE WITH
VCTS FOR NOW UNTIL THEY START TO BECOME MORE ORGANIZED. THERE
SHOULD BE A PERIOD EARLY EVENING THAT REMAINS DRY...BEFORE THE
MAIN ARE OF SHOWERS/STORMS ARRIVES AFTER ABOUT 03-04Z AND WORKS
ITS WAY NORTHEAST. OVERALL DIMINISHMENT OF THE CONVECTIVE
ACTIVITY SHOULD BE MID-LATE MONDAY MORNING.
SOUTHERLY WINDS WILL REMAIN GUSTY MUCH OF THE TIME...GUSTING OVER
20 KNOTS...BUT WILL TREND TOWARD THE SOUTHWEST MONDAY MORNING AS
AN AREA OF LOW PRESSURE MOVES FROM SOUTHEAST IOWA INTO WISCONSIN.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1238 PM CDT SUN MAY 24 2015
.UPDATE...
ISSUED AT 1025 AM CDT SUN MAY 24 2015
SOUTHEAST HALF OF THE FORECAST AREA HAS HAD A DECENT AMOUNT OF
SUNSHINE THIS MORNING...AND THIS HAS ALLOWED TEMPERATURES TO
ALREADY RISE INTO THE UPPER 70S TO AROUND 80 DEGREES. THIS AREA IS
IN THE WARM SECTOR SOUTH OF A WARM FRONT...WHICH WAS ROUGHLY ALONG
A MACOMB TO WATSEKA LINE AT 10 AM. CLOUDINESS SHOULD START TO
OVERTAKE THE SOUTHEAST CWA BY EARLY AFTERNOON.
REGIONAL RADAR MOSAICS SHOWING THAT MOST OF THE RAIN HAS BEEN
BYPASSING US THUS FAR EXCEPT FOR A FEW SHOWERS HERE AND
THERE...MAINLY NORTHWEST OF THE ILLINOIS RIVER. THE LARGER RAIN
SHIELD WAS NORTH OF THE FRONT...TIED IN WITH A MESOSCALE VORTEX
OVER WESTERN IOWA...WHILE A SECOND MCV WAS TRACKING NORTHWARD
THROUGH SOUTHEAST KANSAS. SHOWERS OVER EASTERN MISSOURI WERE
INCREASING AND THIS TREND SHOULD CONTINUE THROUGH MIDDAY AS THEY
SPREAD INTO WEST CENTRAL ILLINOIS. HAVE MADE SOME ADJUSTMENTS TO
THE PRECIPITATION TIMING THROUGH TONIGHT...AS FORECAST SOUNDINGS
SHOW A DECENT AMOUNT OF DRY AIR BELOW 800 MB THAT WILL NEED TO BE
OVERCOME. THIS MAY TAKE UNTIL THE EVENING HOURS ACROSS THE EASTERN
CWA. IN THE WEST...LIKELY POP`S ARE IN THE FORECAST FOR THIS
AFTERNOON AND TONIGHT WEST OF I-55...WITH THE HIGHER RAIN CHANCES
BETWEEN I-55 AND I-57 LATER THIS EVENING.
&&
.SHORT TERM...(TODAY)
ISSUED AT 330 AM CDT SUN MAY 24 2015
A NARROW BAND OF SHOWERS HAS DEVELOPED OVER THE NORTHERN PARTS OF
THE CWA EARLY THIS MORNING BUT WILL NOT LAST LONG AS IT IS MOVING
NORTH AND SHOULD BE OUT OF THE CWA LATER THIS MORNING. REMAINDER OF
THE PCPN SHOULD REMAIN WEST OF THE CWA BUT SLOWLY MOVE EAST THIS
MORNING. SO CHANCE POPS THIS MORNING IN THE WEST WILL BECOME LIKELY
LATER THIS MORNING AND CONTINUE INTO THE AFTERNOON...BUT LIKELY POPS
WILL REMAIN WEST OF I-55 TODAY. WILL GO WITH SHOWERS AND ISOLATED
THUNDERSTORMS THIS MORNING ACROSS THE AREA...BUT BELIEVE THIS
AFTERNOON WILL BE SHOWERS AND THUNDERSTORMS. SOUTHEAST WINDS WILL
BECOME SOUTHERLY THIS AFTERNOON AND BECOME A LITTLE GUSTY...WITH
GUSTS TO AROUND 25MPH LATER THIS AFTERNOON. SOUTHERLY WINDS WILL
BEING AN INCREASE IN DEWPOINTS THROUGH THE DAY AS WELL. DAYTIME
HIGHS COULD BE TEMPERED SOME THIS AFTERNOON WHERE THICKER CLOUDS AND
PCPN EXIST...SO WARMER TEMPS WILL BE IN THE EAST WHERE RAIN WILL
HOLD OFF THE LONGEST AND CLOUDS SHOULD BE LITTLE THINNER.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN MAY 24 2015
FORECAST WARM AND MUGGY WITH A LOT OF CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGHOUT. REGION DOMINATED BY SOUTHWESTERLY FLOW AND
A SERIES OF SHORT WAVES EJECTING OUT OF THE UPPER TROF IN THE SW. A
BRIEF BREAK IN THE PATTERN MID WEEK IS ONLY TEMPORARY AS TEMPS
REMAIN WARM WITH PLENTY OF MOISTURE ONLY REINFORCED BY PERIODIC
SHOWERS ENHANCING THE BOUNDARY LAYER RH.
RAIN CHANCES WILL INCREASE GOING INTO THE EVENING HOURS AS THE LOW
OFF TO THE WEST MOVES NORTHWARD INTO THE MIDWEST. RICH MOISTURE AND
WARM TEMPERATURES RESULTING IN A CONTINUATION OF WARM AND MUGGY
WEATHER THROUGH THE OVERNIGHT AND AT LEAST INTO THE FIRST PART OF
MEMORIAL DAY. MODELS STILL SHIFTING THE CONVECTION TO THE EAST FOR
THE SECOND HALF OF THE DAY. EVEN THOUGH THE MODELS ARE MOVING THE
PRECIP THROUGH, THE ATMOSPHERE MAINTAINS A BIT OF INSTABILITY IN THE
AFTERNOON. CONCERNED THAT THE MODELS ARE A LITTLE TOO AGGRESSIVE
WITH THE CLEARING. HOWEVER, THE LACK OF FOCUS/CONVERGENCE IN THE
WAKE OF EXITING STORMS, KEEPING THE FORECAST DRY IN AT LEAST THE
EARLY EVENING. THIS STORY MAY CHANGE QUICKLY WITH ANY MESOSCALE
BOUNDARIES LEFT BEHIND FROM TONIGHT AND TOMORROW EARLY. WITH OR
WITHOUT AFTERNOON STORMS, MONDAY GOING TO BE BREEZY. MOMENTUM
TRANSFER EITHER FROM THE SHOWERS, OR JUST WITH DIURNAL MIXING WILL
RESULT IN GUSTS IN THE 25-30KT RANGE FOR THE AFTERNOON.
ANOTHER SURFACE LOW FINALLY LIFTING INTO THE MIDWEST MOVING ALONG
THE SOUTHWESTERLY FLOW ALOFT ON TUESDAY. MORE SHOWERS ANTICIPATED
FOR TUESDAY/TUESDAY NIGHT WITH THE MUGGY AIRMASS. FRONT ASSOCIATED
WITH THIS SYSTEM WEAK AT BEST AND WILL ONLY SEE A BRIEF SFC WIND
SHIFT TO MORE WESTERLY FROM SOUTHERLY FOR WED AND WED NIGHT
ACCOMPANIED BY A BRIEF PATTERN SHIFT ALOFT. CHANGE IS ONLY
TEMPORARY AS SOUTHERLY SFC WINDS REESTABLISH BY THE END OF THE WEEK
WITH SOUTHWESTERLY FLOW ALOFT SETTING UP FOR YET ANOTHER ROUND OF
ACTIVE WEATHER FOR A WET WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1237 PM CDT SUN MAY 24 2015
SHOWERS HAVE REMAINED SCATTERED THUS FAR...AND HRRR MODEL SUGGESTS
THIS SHOULD BE THE CASE A GOOD PART OF THE AFTERNOON WITH SOME
INCREASE BY 21Z OR SO IN WEST CENTRAL ILLINOIS. HAVE GONE WITH
VCTS FOR NOW UNTIL THEY START TO BECOME MORE ORGANIZED. THERE
SHOULD BE A PERIOD EARLY EVENING THAT REMAINS DRY...BEFORE THE
MAIN ARE OF SHOWERS/STORMS ARRIVES AFTER ABOUT 03-04Z AND WORKS
ITS WAY NORTHEAST. OVERALL DIMINISHMENT OF THE CONVECTIVE
ACTIVITY SHOULD BE MID-LATE MONDAY MORNING.
SOUTHERLY WINDS WILL REMAIN GUSTY MUCH OF THE TIME...GUSTING OVER
20 KNOTS...BUT WILL TREND TOWARD THE SOUTHWEST MONDAY MORNING AS
AN AREA OF LOW PRESSURE MOVES FROM SOUTHEAST IOWA INTO WISCONSIN.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
129 PM CDT SUN MAY 24 2015
...UPDATED AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 631 AM CDT SUN MAY 24 2015
RAIN HAS OVERSPREAD THE CWA FASTER THAN PREVIOUSLY THOUGHT. THE
LINE OF SHOWERS MATCHES WELL TO THE MOISTURE TRANSPORT VECTOR.
BELIEVE THAT WESTERN ZONES WILL SEE THE MOST RAIN THIS MORNING.
THE RAIN BAND WILL SLOWLY MOVE TO THE EAST.M HRRR MODEL RUNS
SUGGESTS THAT THIS AREA OF PRECIP WILL MOVE EAST THROUGH THE DAY
UNTIL THIS AFTERNOON. AS SUCH...HAVE INCREASED PRECIP CHANCES AND
TRIED TO BETTER TIME THE MOVEMENT OF THE RAIN THROUGH THE CWA AND
TAF SITES.
&&
.SYNOPSIS...
ISSUED AT 359 AM CDT SUN MAY 24 2015
EARLY THIS MORNING...A HEAVY RAINFALL EVENT WITH SIGNIFICANT FLASH
FLOODING AND SEVERE WEATHER IS OCCURRING ACROSS PORTIONS OF THE
CENTRAL AND SOUTHERN GREAT PLAINS. A WIDE OPEN GULF AND WEAK
UPPER LEVEL FLOW WAS LEADING TO THE DEVELOPMENT OF RAIN AND
THUNDERSTORMS ACROSS THAT AREA. CLOSER TO HOME...RAIN ASSOCIATED
WITH THE STORMS TO OUR SOUTH IS FINALLY MAKING ITS WAY INTO OUR
AREA. THIS RAIN SHOULD CONTINUE TO SPREAD ACROSS THE AREA THIS
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT SUN MAY 24 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM IS THE RAIN AND IMPACTS
ASSOCIATED WITH POTENTIAL HEAVY RAIN ACROSS THE AREA.
OVERALL...THE GULF IS OPEN AND H5 FLOW IS PERFECT FOR ADVECTING
LARGE AMOUNTS OF PW INTO THE AREA. GEFS M-CLIMATE DATA SUGGESTS
THAT PROGGED PWATS WILL BE IN THE 99 PERCENTILE. THERE WILL BE NO
LACK OF MOISTURE WITH THIS SYSTEM. THE MAIN FORECAST CHALLENGE IS
TIMING AND DETERMINING THE AREAS THAT HAVE THE BEST CHANCES FOR
POSSIBLE FLOODING.
CURRENT THINKING IS THAT WE WILL HAVE RAIN THROUGH THE EARLY
AFTERNOON HOURS. HIRES GUIDANCE SUGGESTS THAT WE HAVE SOME DOWN
TIME THIS AFTERNOON BEFORE A WAVE MOVES THROUGH THE AREA AND LEADS
TO THE DEVELOPMENT OF SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON AND EVENING.
MOISTURE TRANSPORT VECTORS FAVOR AREAS TO OUR WEST THROUGH LATE
MORNING. THE VECTORS THEN SHIFT TO THE EAST AND PAINT OUR WESTERN
ZONES FOR SIGNIFICANT MOISTURE TRANSPORT. THROUGH THE REST OF THE
SHORT TERM. THESE VECTORS SLOWLY TRANSLATE THE BULLS THROUGH OUR
CWA.
UNCERTAINTY REMAINS IN OVERALL FLASH FLOODING COVERAGE. WITH PW
VALUES AT THE TOP OF THE SPECTRUM...ANY CONVECTIVE ELEMENTS THAT
FORM WILL BE VERY EFFICIENT AT PUMPING OUT HEAVY RAIN. AREAS TO
OUR SOUTH IN THE STRATIFORM SHIELD ARE SEEING OVER AN INCH OF RAIN
FROM THOSE SHIELDS. WHAT MAKES THIS A TRICKY FORECAST IS THE
OVERALL LACK OF INSTABILITY. WITHOUT INSTABILITY OVERALL RAINFALL
RATES SHOULD STAY LOW ENOUGH THAT RUNOFF DOES NOT BECOME A
CONCERN. I CANNOT RULE OUT THUNDER COMPLETELY...THIS MEANS THAT
ANY THUNDERSTORM THAT CAN FORM WILL HAVE THE POTENTIAL TO LEAD TO
HEAVY RAINFALL AND RAIN RATES THAT COULD LEAD TO FLOODING. IF
MODELS ARE UNDER FORECASTING THE INSTABILITY...OUR THREAT FOR
FLASH FLOODING WILL GO UP. ANTECEDENT CONDITIONS DO NOT LEND
THEMSELVES WELL TO FLASH FLOODING AS WELL. OVERALL THUNDERSTORM
COVERAGE WILL BE LOW...SO A FLASH FLOOD WATCH WILL NOT BE ISSUED
ON THIS SHIFT.
THIS FORECAST IS FLUID...ANY CHANGES IN HOURLY TRENDS COULD LEAD
TO A DIFFERENT OUTCOME. TODAY IS A DAY TO NOT IGNORE THE WEATHER
AS ANY CHANGES COULD LEAD TO AN INCREASED OR DECREASED THREAT OF
FLASH FLOODING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM CDT SUN MAY 24 2015
CONTINUED ACTIVE/UNSETTLED WITH PERIODIC BOUTS OF PCPN AND TEMPS
NEAR TO SLIGHTLY ABOVE NORMAL.
MEMORIAL DAY AND MONDAY NIGHT... PCPN CHANCES WILL BE DIMINISHING
FROM SOUTHWEST TO NORTHEAST IN THE MORNING AS AN UPPER LEVEL
SHORTWAVE LIFTS INTO THE GREAT LAKES REGION. FOR MEMORIAL DAY
AFTERNOON MODELS SHOW HEIGHTS ALOFT INCREASING AND THIS COMBINED
WITH DRY ADVECTION ON VEERED SOUTHWEST FLOW AND SOME SUGGESTION
OF A BIT OF AN ELEVATED EML PER NAM/GFS BUFR SOUNDINGS SHOULD
MEAN A GENERALLY DRY AFTERNOON. WINDS SHOULD BE RATHER GUSTY FROM
SOUTHWEST AT 15-30+ MPH DUE TO SOME TIGHTENING OF PRESSURE GRADIENT
AND MIX DOWN OF DRYING COLUMN. WITH THE GUSTY SOUTHWEST WINDS AND AT
LEAST PARTIAL SUNSHINE EXPECT HIGHS WIDESPREAD AROUND 80 OR IN THE
LOWER 80S... WITH POTENTIAL FOR FEW MID 80S SOUTHWEST CWA IF MORE
SOLAR INSOLATION. MONDAY NIGHT... PCPN CHANCES WILL BE INCREASING
AHEAD OF WEAK COOL FRONT AND PLAINS SHORTWAVE. BULK SHEAR 0-6 KM OF
30-35 KTS WITH 0-4 KM MUCAPE 1500-2000+ J/KG PARAMETERS SUPPORTIVE
OF AT LEAST ISOLD SEVERE STORM POTENTIAL. THE CHALLENGE IS WHETHER
CONVECTION CAN GROW UPSCALE IN MCS AS SOME MODELS DEPICT SEVERAL MCS
PARAMETERS/INGREDIENTS TO AT LEAST ENTERTAIN POSSIBILITY OF
UPSCALE GROWTH FROM WESTERN INTO CENTRAL IA WHICH IF OCCURS WOULD
PROPAGATE EASTWARD INTO PORTIONS OF CWA LATE MONDAY EVENING AND
OVERNIGHT WITH ROUND OF HEAVY RAIN AS LAYER PWATS SURGE TO OVER 1.5
INCHES. ENOUGH UNCERTAINTY ON THIS OCCURRING TO CAP POPS IN HIGH
CHANCE CATEGORY ATTIM FOR MONDAY NIGHT.
TUESDAY AND TUESDAY NIGHT... CONTINUE TO FOCUS ON TUESDAY AS WET DAY
WITH UPPER LEVEL SHORTWAVE LIFTING THROUGH THE UPPER MIDWEST IN
SOMEWHAT OF A NEGATIVE TILT FASHION. AT LEAST SOME ISOLD SEVERE
POTENTIAL POSSIBLE EASTERN CWA AHEAD OF WEAK FRONT WITH 0-6 KM BULK
SHEAR 30-35 KTS. THE MAIN CHALLENGE WILL BE HOW MUCH INSTABILITY
WILL DEVELOP DURING THE AFTERNOON AND EVENING IN PRESENCE OF LIKELY
CONVECTIVE DEBRIS.
WEDNESDAY AND WEDNESDAY NIGHT... THIS PERIOD IS TRENDING DRIER WITH
WEAK COOL FRONT SETTLING SOUTH OF CWA AND WEAK SURFACE RIDGING
BUILDING IN. HIGHS A BIT WARMER AND MAINLY UPPER 70S TO NEAR 80 WITH
AT LEAST PARTIAL SUNSHINE.
THURSDAY THROUGH SATURDAY... ACTIVE PATTERN APPEARS SET TO RETURN
DURING THE LATTER HALF OF THE WEEK INTO NEXT WEEKEND AS SOUTHEAST
ATLANTIC RIDGE STRENGTHENS WITH GULF MOISTURE INCREASING ON WESTERN
PERIPHERY AHEAD OF NEXT ROUND OF LEE SIDE TROUGHING AND SOUTHWEST
FLOW ALOFT. DUE TO TIMING UNCERTAINTIES UNFORTUNATELY HAVE SEVERAL
PERIODS OF HIGH CHANCE POPS FROM THURSDAY NIGHT THROUGH SATURDAY.
OVERALL... WITH ACTIVE REGIME FEATURING POTENTIAL FOR A FEW PERIODS
OF HEAVY RAIN DURING THE PERIOD WILL HAVE TO WATCH AREA RIVERS IN
THE COMING WEEK AHEAD. ALSO...WILL NEED TO KEEP EYE ON ANY HEAVY
RAINS INTO CENTRAL IA FOR POSSIBLY SOME RISES ON A FEW EASTERN IA
TRIBS DUE TO ROUTING OF SOME WATER. NCRFC ENSEMBLE QPF SCENARIOS
SHOW POTENTIAL FOR SOME TRIBUTARY LOCATIONS NEARING FLOOD STAGE
TOWARD LATE IN THE WEEK AND NEXT WEEKEND...MAINLY THE WAPSIPINICON
AT DEWITT...IOWA RIVER AT MARENGO...SKUNK AT SIGOURNEY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 111 PM CDT SUN MAY 24 2015
MAINLY VFR CONDITIONS ARE FORECAST INTO THE LATE AFTN WITH
BRIEF PERIODS OF MVFR UNDER SHORT-LIVED CONVECTIVE RAIN
SHOWERS.
LATE THIS AFTN AND THIS EVENING INSTABILITY WILL INCREASE
SLIGHTLY AND SCT SHOWERS AND THUNDERSTORMS WILL DEVELOP. INCLUDED
THUNDER AT KMLI AND KBRL WHERE CONFIDENCE IS MUCH HIGHER THAN AT
KCID AND KDBQ. CONDITIONS WILL DETERIORATE LATE THIS EVENING AND
OVERNIGHT AS CIGS GRADUALLY LOWER TO AROUND 1 KFT AGL AND VSBYS TO
2 MILES OR LOWER AT TIMES.
FAIRLY HIGH CONFIDENCE IN A PROLONGED PERIOD OF CONDITIONS AT THE
MVFR/IFR THRESHOLD BETWEEN 05Z-13Z/MONDAY. SW WINDS WILL INCREASE
AFTER 12Z/MONDAY AND CONDITIONS WILL IMPROVE TO MVFR BY MID
MORNING.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...05
AVIATION...UTTECH
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
632 AM CDT SUN MAY 24 2015
.UPDATE...
ISSUED AT 631 AM CDT SUN MAY 24 2015
RAIN HAS OVERSPREAD THE CWA FASTER THAN PREVIOUSLY THOUGHT. THE
LINE OF SHOWERS MATCHES WELL TO THE MOISTURE TRANSPORT VECTOR.
BELIEVE THAT WESTERN ZONES WILL SEE THE MOST RAIN THIS MORNING.
THE RAIN BAND WILL SLOWLY MOVE TO THE EAST.M HRRR MODEL RUNS
SUGGESTS THAT THIS AREA OF PRECIP WILL MOVE EAST THROUGH THE DAY
UNTIL THIS AFTERNOON. AS SUCH...HAVE INCREASED PRECIP CHANCES AND
TRIED TO BETTER TIME THE MOVEMENT OF THE RAIN THROUGH THE CWA AND
TAF SITES.
&&
.SYNOPSIS...
ISSUED AT 359 AM CDT SUN MAY 24 2015
EARLY THIS MORNING...A HEAVY RAINFALL EVENT WITH SIGNIFICANT FLASH
FLOODING AND SEVERE WEATHER IS OCCURRING ACROSS PORTIONS OF THE
CENTRAL AND SOUTHERN GREAT PLAINS. A WIDE OPEN GULF AND WEAK
UPPER LEVEL FLOW WAS LEADING TO THE DEVELOPMENT OF RAIN AND
THUNDERSTORMS ACROSS THAT AREA. CLOSER TO HOME...RAIN ASSOCIATED
WITH THE STORMS TO OUR SOUTH IS FINALLY MAKING ITS WAY INTO OUR
AREA. THIS RAIN SHOULD CONTINUE TO SPREAD ACROSS THE AREA THIS
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT SUN MAY 24 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM IS THE RAIN AND IMPACTS
ASSOCIATED WITH POTENTIAL HEAVY RAIN ACROSS THE AREA.
OVERALL...THE GULF IS OPEN AND H5 FLOW IS PERFECT FOR ADVECTING
LARGE AMOUNTS OF PW INTO THE AREA. GEFS M-CLIMATE DATA SUGGESTS
THAT PROGGED PWATS WILL BE IN THE 99 PERCENTILE. THERE WILL BE NO
LACK OF MOISTURE WITH THIS SYSTEM. THE MAIN FORECAST CHALLENGE IS
TIMING AND DETERMINING THE AREAS THAT HAVE THE BEST CHANCES FOR
POSSIBLE FLOODING.
CURRENT THINKING IS THAT WE WILL HAVE RAIN THROUGH THE EARLY
AFTERNOON HOURS. HIRES GUIDANCE SUGGESTS THAT WE HAVE SOME DOWN
TIME THIS AFTERNOON BEFORE A WAVE MOVES THROUGH THE AREA AND LEADS
TO THE DEVELOPMENT OF SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON AND EVENING.
MOISTURE TRANSPORT VECTORS FAVOR AREAS TO OUR WEST THROUGH LATE
MORNING. THE VECTORS THEN SHIFT TO THE EAST AND PAINT OUR WESTERN
ZONES FOR SIGNIFICANT MOISTURE TRANSPORT. THROUGH THE REST OF THE
SHORT TERM. THESE VECTORS SLOWLY TRANSLATE THE BULLS THROUGH OUR
CWA.
UNCERTAINTY REMAINS IN OVERALL FLASH FLOODING COVERAGE. WITH PW
VALUES AT THE TOP OF THE SPECTRUM...ANY CONVECTIVE ELEMENTS THAT
FORM WILL BE VERY EFFICIENT AT PUMPING OUT HEAVY RAIN. AREAS TO
OUR SOUTH IN THE STRATIFORM SHIELD ARE SEEING OVER AN INCH OF RAIN
FROM THOSE SHIELDS. WHAT MAKES THIS A TRICKY FORECAST IS THE
OVERALL LACK OF INSTABILITY. WITHOUT INSTABILITY OVERALL RAINFALL
RATES SHOULD STAY LOW ENOUGH THAT RUNOFF DOES NOT BECOME A
CONCERN. I CANNOT RULE OUT THUNDER COMPLETELY...THIS MEANS THAT
ANY THUNDERSTORM THAT CAN FORM WILL HAVE THE POTENTIAL TO LEAD TO
HEAVY RAINFALL AND RAIN RATES THAT COULD LEAD TO FLOODING. IF
MODELS ARE UNDER FORECASTING THE INSTABILITY...OUR THREAT FOR
FLASH FLOODING WILL GO UP. ANTECEDENT CONDITIONS DO NOT LEND
THEMSEMLVES WELL TO FLASH FLOODING AS WELL. OVERALL THUNDERSTORM
COVERAGE WILL BE LOW...SO A FLASH FLOOD WATCH WILL NOT BE ISSUED
ON THIS SHIFT.
THIS FORECAST IS FLUID...ANY CHANGES IN HOURLY TRENDS COULD LEAD
TO A DIFFERENT OUTCOME. TODAY IS A DAY TO NOT IGNORE THE WEATHER
AS ANY CHANGES COULD LEAD TO AN INCREASED OR DECREASED THREAT OF
FLASH FLOODING.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM CDT SUN MAY 24 2015
CONTINUED ACTIVE/UNSETTLED WITH PERIODIC BOUTS OF PCPN AND TEMPS
NEAR TO SLIGHTLY ABOVE NORMAL.
MEMORIAL DAY AND MONDAY NIGHT... PCPN CHANCES WILL BE DIMINISHING
FROM SOUTHWEST TO NORTHEAST IN THE MORNING AS AN UPPER LEVEL
SHORTWAVE LIFTS INTO THE GREAT LAKES REGION. FOR MEMORIAL DAY
AFTERNOON MODELS SHOW HEIGHTS ALOFT INCREASING AND THIS COMBINED
WITH DRY ADVECTION ON VEERED SOUTHWEST FLOW AND SOME SUGGESTION
OF A BIT OF AN ELEVATED EML PER NAM/GFS BUFR SOUNDINGS SHOULD
MEAN A GENERALLY DRY AFTERNOON. WINDS SHOULD BE RATHER GUSTY FROM
SOUTHWEST AT 15-30+ MPH DUE TO SOME TIGHTENING OF PRESSURE GRADIENT
AND MIX DOWN OF DRYING COLUMN. WITH THE GUSTY SOUTHWEST WINDS AND AT
LEAST PARTIAL SUNSHINE EXPECT HIGHS WIDESPREAD AROUND 80 OR IN THE
LOWER 80S... WITH POTENTIAL FOR FEW MID 80S SOUTHWEST CWA IF MORE
SOLAR INSOLATION. MONDAY NIGHT... PCPN CHANCES WILL BE INCREASING
AHEAD OF WEAK COOL FRONT AND PLAINS SHORTWAVE. BULK SHEAR 0-6 KM OF
30-35 KTS WITH 0-4 KM MUCAPE 1500-2000+ J/KG PARAMETERS SUPPORTIVE
OF AT LEAST ISOLD SEVERE STORM POTENTIAL. THE CHALLENGE IS WHETHER
CONVECTION CAN GROW UPSCALE IN MCS AS SOME MODELS DEPICT SEVERAL MCS
PARAMETERS/INGREDIENTS TO AT LEAST ENTERTAIN POSSIBILITY OF
UPSCALE GROWTH FROM WESTERN INTO CENTRAL IA WHICH IF OCCURS WOULD
PROPAGATE EASTWARD INTO PORTIONS OF CWA LATE MONDAY EVENING AND
OVERNIGHT WITH ROUND OF HEAVY RAIN AS LAYER PWATS SURGE TO OVER 1.5
INCHES. ENOUGH UNCERTAINTY ON THIS OCCURRING TO CAP POPS IN HIGH
CHANCE CATEGORY ATTIM FOR MONDAY NIGHT.
TUESDAY AND TUESDAY NIGHT... CONTINUE TO FOCUS ON TUESDAY AS WET DAY
WITH UPPER LEVEL SHORTWAVE LIFTING THROUGH THE UPPER MIDWEST IN
SOMEWHAT OF A NEGATIVE TILT FASHION. AT LEAST SOME ISOLD SEVERE
POTENTIAL POSSIBLE EASTERN CWA AHEAD OF WEAK FRONT WITH 0-6 KM BULK
SHEAR 30-35 KTS. THE MAIN CHALLENGE WILL BE HOW MUCH INSTABILITY
WILL DEVELOP DURING THE AFTERNOON AND EVENING IN PRESENCE OF LIKELY
CONVECTIVE DEBRIS.
WEDNESDAY AND WEDNESDAY NIGHT... THIS PERIOD IS TRENDING DRIER WITH
WEAK COOL FRONT SETTLING SOUTH OF CWA AND WEAK SURFACE RIDGING
BUILDING IN. HIGHS A BIT WARMER AND MAINLY UPPER 70S TO NEAR 80 WITH
AT LEAST PARTIAL SUNSHINE.
THURSDAY THROUGH SATURDAY... ACTIVE PATTERN APPEARS SET TO RETURN
DURING THE LATTER HALF OF THE WEEK INTO NEXT WEEKEND AS SOUTHEAST
ATLANTIC RIDGE STRENGTHENS WITH GULF MOISTURE INCREASING ON WESTERN
PERIPHERY AHEAD OF NEXT ROUND OF LEE SIDE TROUGHING AND SOUTHWEST
FLOW ALOFT. DUE TO TIMING UNCERTAINTIES UNFORTUNATELY HAVE SEVERAL
PERIODS OF HIGH CHANCE POPS FROM THURSDAY NIGHT THROUGH SATURDAY.
OVERALL... WITH ACTIVE REGIME FEATURING POTENTIAL FOR A FEW PERIODS
OF HEAVY RAIN DURING THE PERIOD WILL HAVE TO WATCH AREA RIVERS IN
THE COMING WEEK AHEAD. ALSO...WILL NEED TO KEEP EYE ON ANY HEAVY
RAINS INTO CENTRAL IA FOR POSSIBLY SOME RISES ON A FEW EASTERN IA
TRIBS DUE TO ROUTING OF SOME WATER. NCRFC ENSEMBLE QPF SCENARIOS
SHOW POTENTIAL FOR SOME TRIBUTARY LOCATIONS NEARING FLOOD STAGE
TOWARD LATE IN THE WEEK AND NEXT WEEKEND...MAINLY THE WAPSIPINICON
AT DEWITT...IOWA RIVER AT MARENGO...SKUNK AT SIGOURNEY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 631AM CDT SUN MAY 24 2015
MESSY DAY ON THE AVIATION DESK TODAY. IN THE NEXT SIX HOURS MOST
OF THE SITES WILL SEE RAIN AND THEN IT START TO TAPER OFF. AT THAT
TIME SOME BR COULD DEVELOP AT THE TAF SITES. SOME SITES TO THE
WEST ARE ALREADY SHOWING IFR CEILINGS THIS AM. WILL TEMPO IF IFR
SHOWS UP AT CID AS I THINK IT WILL BE TEMPORARY. LATER THIS
AFTERNOON THUNDERSTORMS COULD RETURN WITH THE RAIN. WESTERN TAF
SITES ARE FORECAST TO HAVE CIGS CRASH TO IFR AND POSSIBLY LIFR.
RAIN SHOULD CONTINUE OVERNIGHT THROUGH THE TAF PERIOD.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...05
AVIATION...GIBBS
AREA FORECAST DISCUSSION
NWS WICHITA KS
1100 PM CDT MON MAY 25 2015
...UPDATED FOR 06Z AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 253 PM CDT MON MAY 25 2015
SHORT TERM/HI-RES MODELS SUPPORT THREE AREAS OF CONVECTION LATE THIS
AFTERNOON AND EVENING WITH IMPACTS ON THE FORECAST AREA AND SEEM
REASONABLE GIVEN THE ENVIRONMENTAL INSTABILITY/FORCING/FOCUSING
MECHANISMS. DIURNAL HEATING HAS RESULTED IN A VERY UNSTABLE AIRMASS
OVER SOUTH CENTRAL KANSAS WITH MLCAPES OVER 3000 J/KG. THIS HAS
SUPPORTED RECENT CONVECTION JUST SOUTHWEST OF KICT. THE RAP SHOWED
THIS WELL IN LATEST RUNS. THE HRRR AND RAP ALSO DEVELOP ANOTHER AREA
OF CONVECTION JUST AFTER 00Z SOUTH OF SOUTHWARD SAGGING SURFACE FRONT
MOVING INTO CENTRAL KANSAS THIS EVENING WHERE RETURN MOISTURE FLUX
SHOULD RESULT IN MLCAPES IN EXCESS OF 2500 J/KG FOR A BRIEF TIME.
THIRD AREA IS EXPECTED ON NORTHERN FRINGE OF STRONGER SOUTHERN
PLAINS PV ANOMALY WHICH WILL SWEEP NORTHEAST ACROSS SOUTHEAST
KANSAS LATER THIS EVENING AND OVERNIGHT. DESPITE MODEST DEEP LAYER
SHEAR THE PROGGED INSTABILITY SHOULD SUPPORT MARGINALLY SEVERE
STORMS PRIOR TO MIDNIGHT ACROSS THE FORECAST AREA. WHILE THE DEEP
CONVECTION WILL LEND TO LOCALLY HEAVY RAINFALL...THE OVERALL
COVERAGE/DURATION OF THE EVENT IS NOT EXPECTED TO NECESSITATE A
FLOOD WATCH AT THIS TIME. AS THE MAIN UPPER TROF ROTATES NORTHEAST
ACROSS THE UPPER MIDWEST DURING TUESDAY...A WEAK SHORTWAVE ALOFT
WILL MIGRATE EASTWARD OVER CENTRAL/EASTERN KANSAS IN THE
AFTERNOON/EVENING. THIS MAY SUPPORT RENEWED DIURNAL CONVECTION
ALONG THE SURFACE FRONT WHICH IS EXPECTED TO BECOME QUASI-
STATIONARY ACROSS EAST CENTRAL INTO SOUTH CENTRAL KANSAS. SOME OF
THIS ACTIVITY COULD FESTER INTO PART OF TUESDAY NIGHT ACROSS FAR
SOUTHERN KANSAS. THE QUASI-STATIONARY BOUNDARY LOOKS TO LINGER
ACROSS SOUTHERN KANSAS INTO WEDNESDAY OR POSSIBLY MIGRATE NORTH AS
A WARM FRONT WEDNESDAY NIGHT. DIURNAL HEATING WILL RESULT IN
STRONG INSTABILITY ALONG THIS BOUNDARY ON WEDNESDAY AFTERNOON.
DESPITE SOME WEAK CAPPING POTENTIAL...CONDITIONAL CHANCES FOR
CONVECTION WILL BE MAINTAINED ESPECIALLY ACROSS SOUTHERN KANSAS.
INCREASED POTENTIAL FOR HIGH PLAINS CONVECTION WEDNESDAY EVENING
AND A BETTER LOW LEVEL JET AND MOISTURE IMPINGING INTO CENTRAL
KANSAS WEDNESDAY NIGHT...SHOULD SUPPORT BETTER CHANCES/HIGHER POPS
ACROSS MUCH OF THE AREA WHICH IS REFLECTED IN THE GOING FORECAST.
THURSDAY COULD BE A PERIODICALLY WET/STORMY DAY WITH A COUPLE OF
MIGRATORY SHORTWAVES ALOFT AND CONTINUED MOISTURE TRANSPORT
SUPPORTING CONVECTION.
DARMOFAL
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 253 PM CDT MON MAY 25 2015
THE PINNACLE OF THE NEXT ROUND OF MORE WIDESPREAD CONVECTION AND
HEAVY RAINFALL WILL BE ON FRIDAY INTO SATURDAY...WITH DIMINISHING
CHANCES LATE IN THE WEEKEND AND HOPEFULLY A DRY PERIOD BY SUNDAY
NIGHT INTO MONDAY. THIS SCENARIO IS GENERALLY SUPPORTED IN THE GFS
AND ECMWF...THOUGH THE GFS MAINTAINS A STRONGER UPPER TROF ACROSS
THE PLAINS ON SATURDAY. A STRONG SURFACE COLD FRONT WILL FOCUS
THE HIGHER CONVECTIVE CHANCES/MORE WIDESPREAD RAINFALL FRIDAY
INTO SATURDAY.
KED
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1055 PM CDT MON MAY 25 2015
LINGERING CONVECTION OCCURRING IN CENTRAL/SOUTHEAST KS APPEARS
ASSOCIATED WITH LOCALIZED CONVERGENCE AREAS WITH DIMINISHING
INSTABILITY. MOST OF THE RAIN SHOULD END BY 10-12 UTC. THERE COULD
BE SOME SCATTERED-BROKEN AREAS OF IFR EARLY TUESDAY MORNING GIVEN
RECENT RAINFALL AND LIGHT WINDS. THE MODELS SUGGEST A STRONGLY
UNSTABLE AND UNCAPPED AIRMASS ACROSS THE REGION AGAIN TUESDAY
AFTERNOON. A WEAK BOUNDARY IS PROGGED TO SETTLE INTO CENTRAL KS
WHICH MAY PROVIDE A FOCUS FOR THUNDERSTORM DEVELOPMENT. OTHER
LOCALIZED AREAS OF WEAK CONVERGENCE WILL ALSO LIKELY SET OFF AT
LEAST ISOLATED THUNDERSTORMS. GUSTY WINDS AND VERY HEAVY RAINFALL
RATES WILL BE ASSOCIATED WITH ANY STORM ACTIVITY TUES PM/EVE.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 60 79 61 82 / 60 20 30 30
HUTCHINSON 59 79 60 82 / 70 20 30 30
NEWTON 60 78 60 80 / 70 20 30 30
ELDORADO 60 79 61 82 / 60 20 30 30
WINFIELD-KWLD 60 80 61 82 / 60 20 40 30
RUSSELL 57 78 58 82 / 40 10 20 30
GREAT BEND 57 78 58 81 / 50 10 20 30
SALINA 60 80 59 82 / 70 10 20 20
MCPHERSON 60 79 59 81 / 70 20 20 20
COFFEYVILLE 62 80 62 82 / 50 20 40 30
CHANUTE 62 79 62 82 / 60 20 40 30
IOLA 62 79 62 81 / 60 20 30 30
PARSONS-KPPF 62 80 62 82 / 50 20 40 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
633 PM CDT MON MAY 25 2015
...UPDATED FOR 00Z AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 253 PM CDT MON MAY 25 2015
SHORT TERM/HI-RES MODELS SUPPORT THREE AREAS OF CONVECTION LATE THIS
AFTERNOON AND EVENING WITH IMPACTS ON THE FORECAST AREA AND SEEM
REASONABLE GIVEN THE ENVIRONMENTAL INSTABILITY/FORCING/FOCUSING
MECHANISMS. DIURNAL HEATING HAS RESULTED IN A VERY UNSTABLE AIRMASS
OVER SOUTH CENTRAL KANSAS WITH MLCAPES OVER 3000 J/KG. THIS HAS
SUPPORTED RECENT CONVECTION JUST SOUTHWEST OF KICT. THE RAP SHOWED
THIS WELL IN LATEST RUNS. THE HRRR AND RAP ALSO DEVELOP ANOTHER AREA
OF CONVECTION JUST AFTER 00Z SOUTH OF SOUTHWARD SAGGING SURFACE FRONT
MOVING INTO CENTRAL KANSAS THIS EVENING WHERE RETURN MOISTURE FLUX
SHOULD RESULT IN MLCAPES IN EXCESS OF 2500 J/KG FOR A BRIEF TIME.
THIRD AREA IS EXPECTED ON NORTHERN FRINGE OF STRONGER SOUTHERN
PLAINS PV ANOMALY WHICH WILL SWEEP NORTHEAST ACROSS SOUTHEAST
KANSAS LATER THIS EVENING AND OVERNIGHT. DESPITE MODEST DEEP LAYER
SHEAR THE PROGGED INSTABILITY SHOULD SUPPORT MARGINALLY SEVERE
STORMS PRIOR TO MIDNIGHT ACROSS THE FORECAST AREA. WHILE THE DEEP
CONVECTION WILL LEND TO LOCALLY HEAVY RAINFALL...THE OVERALL
COVERAGE/DURATION OF THE EVENT IS NOT EXPECTED TO NECESSITATE A
FLOOD WATCH AT THIS TIME. AS THE MAIN UPPER TROF ROTATES NORTHEAST
ACROSS THE UPPER MIDWEST DURING TUESDAY...A WEAK SHORTWAVE ALOFT
WILL MIGRATE EASTWARD OVER CENTRAL/EASTERN KANSAS IN THE
AFTERNOON/EVENING. THIS MAY SUPPORT RENEWED DIURNAL CONVECTION
ALONG THE SURFACE FRONT WHICH IS EXPECTED TO BECOME QUASI-
STATIONARY ACROSS EAST CENTRAL INTO SOUTH CENTRAL KANSAS. SOME OF
THIS ACTIVITY COULD FESTER INTO PART OF TUESDAY NIGHT ACROSS FAR
SOUTHERN KANSAS. THE QUASI-STATIONARY BOUNDARY LOOKS TO LINGER
ACROSS SOUTHERN KANSAS INTO WEDNESDAY OR POSSIBLY MIGRATE NORTH AS
A WARM FRONT WEDNESDAY NIGHT. DIURNAL HEATING WILL RESULT IN
STRONG INSTABILITY ALONG THIS BOUNDARY ON WEDNESDAY AFTERNOON.
DESPITE SOME WEAK CAPPING POTENTIAL...CONDITIONAL CHANCES FOR
CONVECTION WILL BE MAINTAINED ESPECIALLY ACROSS SOUTHERN KANSAS.
INCREASED POTENTIAL FOR HIGH PLAINS CONVECTION WEDNESDAY EVENING
AND A BETTER LOW LEVEL JET AND MOISTURE IMPINGING INTO CENTRAL
KANSAS WEDNESDAY NIGHT...SHOULD SUPPORT BETTER CHANCES/HIGHER POPS
ACROSS MUCH OF THE AREA WHICH IS REFLECTED IN THE GOING FORECAST.
THURSDAY COULD BE A PERIODICALLY WET/STORMY DAY WITH A COUPLE OF
MIGRATORY SHORTWAVES ALOFT AND CONTINUED MOISTURE TRANSPORT
SUPPORTING CONVECTION.
DARMOFAL
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 253 PM CDT MON MAY 25 2015
THE PINNACLE OF THE NEXT ROUND OF MORE WIDESPREAD CONVECTION AND
HEAVY RAINFALL WILL BE ON FRIDAY INTO SATURDAY...WITH DIMINISHING
CHANCES LATE IN THE WEEKEND AND HOPEFULLY A DRY PERIOD BY SUNDAY
NIGHT INTO MONDAY. THIS SCENARIO IS GENERALLY SUPPORTED IN THE GFS
AND ECMWF...THOUGH THE GFS MAINTAINS A STRONGER UPPER TROF ACROSS
THE PLAINS ON SATURDAY. A STRONG SURFACE COLD FRONT WILL FOCUS
THE HIGHER CONVECTIVE CHANCES/MORE WIDESPREAD RAINFALL FRIDAY
INTO SATURDAY.
KED
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 630 PM CDT MON MAY 25 2015
INSTABILITY AND LOCALIZED AREAS OF CONVERGENCE WILL KEEP
THUNDERSTORMS IN THE VICINITIES OF RSL...SLN...HUT...AND ICT THIS
EVENING BEFORE THIS ACTIVITY DIMINISHES/DISSIPATES OVERNIGHT.
ANOTHER AREA OF SCATTERED CONVECTION MAY AFFECT CNU TERMINAL FROM
MID EVENING INTO EARLY OVERNIGHT IN ASSOCIATION WITH AN UPPER
LEVEL DISTURBANCE OVER EASTERN OKLAHOMA. POTENTIAL FOR IFR
STRATUS/FOG SEEMS RELATIVELY HIGHER IN SOUTH CENTRAL/SOUTHEAST KS
EARLY TUESDAY MORNING SO HAVE HINTED AT THAT POSSIBILITY IN THE
THE SOUTHERN TAFS.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 60 79 61 82 / 40 20 30 30
HUTCHINSON 59 79 60 82 / 50 20 30 30
NEWTON 60 78 60 80 / 50 20 30 30
ELDORADO 60 79 61 82 / 40 20 30 30
WINFIELD-KWLD 60 80 61 82 / 40 20 40 30
RUSSELL 57 78 58 82 / 50 10 20 30
GREAT BEND 57 78 58 81 / 50 10 20 30
SALINA 60 80 59 82 / 60 10 20 20
MCPHERSON 60 79 59 81 / 60 20 20 20
COFFEYVILLE 62 80 62 82 / 50 20 40 30
CHANUTE 62 79 62 82 / 50 20 40 30
IOLA 62 79 62 81 / 50 20 30 30
PARSONS-KPPF 62 80 62 82 / 50 20 40 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
321 PM CDT Sun May 24 2015
.SHORT TERM...(This Evening through Monday)
Issued at 243 PM CDT SUN MAY 24 2015
The forecast issue tonight is how much rain will fall on the
flooded areas in the southeast part of the forecast area. At 19
UTC, a large-scale upper trough was moving northeast out of the
southern plains. The 12 UTC short-range models were in decent
agreement with the progression of the precipitation this evening.
Heaviest rainfalls should fall across Missouri sparing eastern
Kansas of heavy rainfall. However, it appears likely that a band
of showers and isolated thunderstorms should move through this
evening. The latest HRRR is consistent with previous runs in this
scenario as are the rest of the convective resolving meso-scale
models. Although widespread heavy rainfall is not expected, it
would not take much rainfall to cause more flooding problems.
Therefore, we will keep the flash flood watch going and we can
cancel it early if necessary.
Additional thunderstorms are developing over southeast Colorado
which the hi-res NAM brings east into our west counties late
tonight. Keep a small POP going along with clouds late tonight and
Monday morning.
Both the 12 UTC NAM/GFS bring an EML into northeast KS in the wake
of the ejecting upper trough. Model soundings suggest a decent
cap over the area on Monday with more than modest surface based
CAPE by afternoon. On the synoptic scale, a shortwave should once
again be moving through the southern plains, but it should be too
far south to impact our weather. Meanwhile, the models develop
convection near the synoptic boundary over parts of central KS/NE.
Will keep pops going for late afternoon development over our
northwest counties. The GFS has a deeper 500 mb low over the
central plains by next Sunday while the ECMWF is not as deep and
more progressive.
.LONG TERM...(Monday Night through Sunday)
Issued at 243 PM CDT SUN MAY 24 2015
The weather pattern remains unsettled through the forecast period
and we will have thunderstorms chances almost every period. The
large upper trough over the desert southwest slowly moves into the
central plains during the period. The 12 UTC ECWMF/GFS agree
with the general progression, but there are significant differences
in the details. At the surface, there will be a boundary in the
vicinity which will be heavily influenced by mesoscale influences.
Meanwhile, the Gulf of Mexico will remain open for business with
moisture advection into the central Plains. Will keep
thunderstorms chances going with more humid and warm weather close
to seasonal normal`s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1245 PM CDT SUN MAY 24 2015
Today and early evening, there are a couple mid-level shortwaves
that will impact the TAF sites. Much of this activity will be in
the late afternoon and early evening with the possibility of some
thunderstorm activity developing which could bring some periods of
low end MVFR CIGS/VIS to the terminals. Outside of this, there are
some spotty areas of light showers right now. Not completely
confident any of these will impact the terminals. Therefore, have
left only VCSH for both the afternoon and then again a chance in
the early morning. Lower confidence on the morning showers. But again,
generally expecting VFR outside of some brief periods with the thunderstorms.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through Monday morning FOR KSZ026-039-040-
054>056-058-059.
&&
$$
SHORT TERM...Johnson
LONG TERM...Johnson
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1257 PM CDT Sun May 24 2015
.UPDATE...
Issued at 1108 AM CDT SUN MAY 24 2015
Cancelled the flash flood watch in locations which did not
receive the heavy rain in the past 24 hours. Area of showers
should move into east central Kansas by late morning with more
development this afternoon and evening. 12z model QPF from the NAM
and the most recent HRRR keep heavy QPF southeast of us, but there
is enough QPF on saturated ground and areas that are already in
flood to keep flash flood watch going.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 323 AM CDT SUN MAY 24 2015
After a round of moderate rain over the area, several mainstream
rivers are rising and forecast to flood in the southeast portions of
the forecast area. Flooding also continues in those counties as
widespread rainfall of 2-4 inches fell across the area.
Precipitation chances in a lull in the early morning hours, before
the next wave in the flow begins to increase precipitation chances
from south to north late this morning into the afternoon hours.
Stronger wave over the Big Bend area of Texas lifts northeastward
and moves into the area for the evening hours, and current thinking
is heavier precipitation would fall late afternoon and into the
evening, and primarily across the eastern portions of the forecast
area. Another 1-2 inches of rain are forecast in heavier bands,
with locally higher amounts possible. Subsiding air behind the
departing stronger wave could bring rain to an end from south to
north across eastern Kansas by shortly after midnight, and have
tapered off rain chances as such. Kept high temperatures on the cool
side in the lower 70s and went slightly cooler on lows in the 50s.
.LONG TERM...(Monday through Saturday)
Issued at 323 AM CDT SUN MAY 24 2015
By Monday morning the shortwave responsible for today`s rainfall
will be lifting into the upper Midwest leaving southwest flow aloft
in it`s wake. The next shortwave is forecast to eject over the
region late Monday, while another wave passes over the southern
plains. Lapse rates will steepen as en EML spreads eastward over the
area out ahead of the wave. A boundary will be present across
western and central KS possibly accompanied by a weak surface low
pressure. The morning should be relatively quiet with only slight
chances for light rain showers. During the afternoon and evening the
wave will lift over the boundary where isolated to scattered storms
will be possible. Cape should increase significantly during the day
especially if the clouds begin to scatter out. Deep layer shear
looks marginal at best with a weakness in the mid level winds. The
main uncertainty is will the forcing and convergence along the
boundary be enough to initiate storms. Models are also hinting at
deeper mixing in western KS, which could lead to possible dry
punches in central KS. These could also be locations for surface
convergence and storm development once the cap weakens. Either way
if storms do develop there is a chance they could be strong to
severe given the high instability, but will probably not be well
organized. As of now the better chances for precip appear to be
north central KS during the late afternoon and evening hours.
That shortwave will continue to lift northeastward Monday night and
into Tuesday morning. There are some timing issues among the models
therefore have kept some rain chances during the day Tuesday. The
forecast then becomes somewhat tricky to pin down precip timing as
the large scale flow weakens and small shortwaves traverse across
the center of the country. This west to southwest flow will persist
through late week. It is unlikely that we will be dealing with any
widespread heavy rain events similar to this weekend given this
expected pattern. A few more pronounced shortwaves lift out of
the Rockies late week, which could bring better chances for precip
next weekend. An actual front may come through as these waves
progress eastward to allow for a dry period early next week.
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1245 PM CDT SUN MAY 24 2015
Today and early evening, there are a couple mid-level shortwaves
that will impact the TAF sites. Much of this activity will be in
the late afternoon and early evening with the possibility of some
thunderstorm activity developing which could bring some periods of
low end MVFR CIGS/VIS to the terminals. Outside of this, there are
some spotty areas of light showers right now. Not completely
confident any of these will impact the terminals. Therefore, have
left only VCSH for both the afternoon and then again a chance in
the early morning. Lower confidence on the morning showers. But again,
generally expecting VFR outside of some brief periods with the thunderstorms.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through Monday morning FOR KSZ026-039-040-
054>056-058-059.
&&
$$
UPDATE...Johnson
SHORT TERM...67
LONG TERM...Sanders
AVIATION...Drake
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1115 AM CDT Sun May 24 2015
.UPDATE...
Issued at 1108 AM CDT SUN MAY 24 2015
Cancelled the flash flood watch in locations which did not
receive the heavy rain in the past 24 hours. Area of showers
should move into east central Kansas by late morning with more
development this afternoon and evening. 12z model QPF from the NAM
and the most recent HRRR keep heavy QPF southeast of us, but there
is enough QPF on saturated ground and areas that are already in
flood to keep flash flood watch going.
&&
.SHORT TERM...(Today and Tonight)
Issued at 323 AM CDT SUN MAY 24 2015
After a round of moderate rain over the area, several mainstream
rivers are rising and forecast to flood in the southeast portions of
the forecast area. Flooding also continues in those counties as
widespread rainfall of 2-4 inches fell across the area.
Precipitation chances in a lull in the early morning hours, before
the next wave in the flow begins to increase precipitation chances
from south to north late this morning into the afternoon hours.
Stronger wave over the Big Bend area of Texas lifts northeastward
and moves into the area for the evening hours, and current thinking
is heavier precipitation would fall late afternoon and into the
evening, and primarily across the eastern portions of the forecast
area. Another 1-2 inches of rain are forecast in heavier bands,
with locally higher amounts possible. Subsiding air behind the
departing stronger wave could bring rain to an end from south to
north across eastern Kansas by shortly after midnight, and have
tapered off rain chances as such. Kept high temperatures on the cool
side in the lower 70s and went slightly cooler on lows in the 50s.
.LONG TERM...(Monday through Saturday)
Issued at 323 AM CDT SUN MAY 24 2015
By Monday morning the shortwave responsible for today`s rainfall
will be lifting into the upper Midwest leaving southwest flow aloft
in it`s wake. The next shortwave is forecast to eject over the
region late Monday, while another wave passes over the southern
plains. Lapse rates will steepen as en EML spreads eastward over the
area out ahead of the wave. A boundary will be present across
western and central KS possibly accompanied by a weak surface low
pressure. The morning should be relatively quiet with only slight
chances for light rain showers. During the afternoon and evening the
wave will lift over the boundary where isolated to scattered storms
will be possible. Cape should increase significantly during the day
especially if the clouds begin to scatter out. Deep layer shear
looks marginal at best with a weakness in the mid level winds. The
main uncertainty is will the forcing and convergence along the
boundary be enough to initiate storms. Models are also hinting at
deeper mixing in western KS, which could lead to possible dry
punches in central KS. These could also be locations for surface
convergence and storm development once the cap weakens. Either way
if storms do develop there is a chance they could be strong to
severe given the high instability, but will probably not be well
organized. As of now the better chances for precip appear to be
north central KS during the late afternoon and evening hours.
That shortwave will continue to lift northeastward Monday night and
into Tuesday morning. There are some timing issues among the models
therefore have kept some rain chances during the day Tuesday. The
forecast then becomes somewhat tricky to pin down precip timing as
the large scale flow weakens and small shortwaves traverse across
the center of the country. This west to southwest flow will persist
through late week. It is unlikely that we will be dealing with any
widespread heavy rain events similar to this weekend given this
expected pattern. A few more pronounced shortwaves lift out of
the Rockies late week, which could bring better chances for precip
next weekend. An actual front may come through as these waves
progress eastward to allow for a dry period early next week.
&&
.AVIATION...(For the 12Z TAFs through 12Z Monday Morning)
Issued at 617 AM CDT SUN MAY 24 2015
Tricky aviation forecast this morning. Weak low moving over MHK
likely to hold fog over that area for another hour or so before
lifting. Areas east have mixed out to to VFR and think this will
continue for a few hours before precipitation builds back in from
the south. TSRA to return near terminals late this afternoon with
more widespread convection after around 02z, then clearing quickly
by late in the TAF period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through Monday morning FOR KSZ026-039-040-
054>056-058-059.
&&
$$
UPDATE...Johnson
SHORT TERM...67
LONG TERM...Sanders
AVIATION...67
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
501 PM CDT SUN MAY 24 2015
.DISCUSSION...
HAVE CANCELLED THE TORNADO WATCHES NUMBER 202 AND 204 FOR THE
FOUR STATE REGION WITH ONLY ONE STORM LEFT IN CALDWELL PARISH THAT
WOULD POSE A THREAT TO BECOMING SEVERE. EXPECTING ADDITIONAL
DEVELOPMENT TO OCCUR DURING THE REMAINDER OF THE AFTERNOON AND
INTO THE EVENING OVER PARTS OF EAST AND NORTHEAST TEXAS...
NORTHWEST AND NORTH CENTRAL LOUSIAIANA...AND SOUTHWEST AND SOUTH
CENTRAL ARKANSAS IN WAKE OF THE DEPARTING BAND THAT BROUGH
STRONG TO SEVERE THUNDERSTORMS EARLIER IN THE DAY. THERE MAY BE
SOME LOCALLY HEAVY RAINFALL WITH ANY THUNDERSTORMS THAT DEVELOP
AND WILL KEEP THE FLASH FLOOD WATCH GOING SINCE WE HAD RAIN AT
JUST ABOUT ALL SITES. THE UPPER LEVEL SHORT WAVE THAT HELPED
PRODUCE THE SHOWERS AND THUNDERSTORMS HAS SHIFTED OFF TO THE EAST
AND NORTHEAST BUT ON ITS HEELS ANOTHER ONE OVER NORTH CENTRAL
TEXAS WILL COMBINE WITH AVAILABLE MOISTURE AND REMAINING
UNSTABLE CONDITIONS TO PROVIDE FOR ADDITIONAL DEVELOPMENT.
THERE WILL BE A BREAK LATER DURING THE OVERNIGHT HOURS AND INTO
THE EARLY MORNING HOURS FROM RAIN...BUT ANOTHER STRONG SHORT WAVE
THAT WILL BECOME NEGATIVE TILTED...SHIFT EAST AND NORTHEAST ACROSS
TEXAS AND INTO THE FOUR STATE REGION...AND PRODUCE THE NEXT ROUND
OF SHOWERS AND THUNDERSTORMS. THESE LOOK TO DEVELOP AND START TO
AFFECT PARTS OF EAST TEXAS AND SOUTHEAST OKLAHOMA NEAR MID DAY TO
LATE MORNING AND THEN SPREAD ACROSS THE REMAINDER OF THE FOUR
STATE REION INTO THE AFTERNOON MONDAY AND OVERNIGHT. THE STORMS
WILL BE STRONG TO SEVERE ALONG WITH PRODUCING LOCALLY HEAVY
RAINFLL...WITH STRONG AND DAMAGING WINDS...POSSIBLY LARGE
HAIL...AND ISOLATED TORNADOES MONDAY AFTERNOON AND OVERNIGHT.
ADDITIONAL RAINFALL FROM THIS BAND OF RAIN ON MONDAY AND OVERNIGHT
WILL PROVIDE ADDITIONAL TWO TO FOUR INCHES...WITH A HIGH POTENTIAL
OF FLASH FLOODING DEVELOPING...SINCE GROUNDS WILL STILL BE NEAR
SATURATION AND HIGH WATER IN ALL RIVERS...CREEKS...AND LAKES.
HEAVY RAINFALL WILL BE POSSIBLE INTO THE AFTERNOON TUESDAY FOR THE
DEEP EAST TEXAS LAKES AREA AND ACROSS LOWER PARTS OF NORTHWEST AND
INTO NORTH CENTRAL LOUISIANA. AN UNSETTLED WEATHER PATTERN WILL
CONTINUE THROUGH THE REST OF THE WORK WEEK AS A WEAKLY AMPLIFIED
RIDGE OF HIGH PRESSURE WILL BE AFFECTED BY A SERIES OF WAVES
MOVING INTO THE SYSTEM FROM A TROPICAL DISTURBANCE OFF THE BAJA
COAST AND THEN A LONG WAVE TROUGH THAT DROPS ALONG THE WESTERN
COAST. THROUGH THE LATE WEEK A CLOSED LOW WILL DEVELOP NEAR THE
FOUR CORNERS REGION AND SHIFT OUT INTO THE ROCKIES AND INTO THE
PLAINS THROUGH THE WEEKEND. THIS WILL PROLONG THE THREAT OF
SHOWERS AND THUNDERSTORMS. /06/
&&
.PREV DISCUSSION... /ISSUED 215 PM CDT SUN MAY 24 2015/
UPDATE...
TO INCLUDE TORNADO WATCH NUMBER 204 IN EFFECT UNTIL 8 PM CDT FOR
THE FOUR SOUTHEAST COUNTIES IN THE WARNING AREA.
DISCUSSION...
ONE OF THE LEAD UPPER DISTRUBANCES WAS MOVING ACORSS SOUTHEAST
OKLAHOMA AND INTO NORTHEAST TEXAS AND ACROSS NORTHWEST LOUISIANA
WITH SHOWERS AND THUNDERSTROMS AHEAD OF THIS FEATURE. LATER INTO
LATE AFTERNOON AND EVENING ANOTHER SERIES OF SMALLER DISTURBANCES
WILL SPREAD OVER THE AREA WITH ANOTHER AREA OF SHOWERS AND
THUNDERSTORMS DEVELOPING AND MOVING OVER THE FOUR STATE REGION.
STILL LOOKING FOR ANOTHER STRONG NEGATIVE TROUGH TO MOVE ACROSS
WEST TEXAS AND THE SOUTHERN ROCKIES DURING THE DAY MONDAY
PRODUCING ANOTHER ROUND OF STRONG TO POSSIBLY SEVERE THUNDERSTORMS
MONDAY AND MONDAY NIGHT ACROSS THE FOUR STATE REGION. LOCALLY
HEAVY RAINFALL WILL ALSO ACCOMPANY THIS ROUND OF POSSIBLE SEVERE
WEATHER AND RESULT IN ADDITIONAL TWO TO FOUR INCHES OF RAIN. THIS
HEAVY RAINFALL WILL PRODUCE FLASH FLOODING. /06
PREV DISCUSSION... /ISSUED 101 PM CDT SUN MAY 24 2015/
DISCUSSION...
UPDATED THE FORECAST TO INCLUDE THE TORNADO WATCH NUMBER 202 IN
EFFECT UNTIL 7 PM CDT.
PREV DISCUSSION... /ISSUED 1152 AM CDT SUN MAY 24 2015/
UPDATE...
UPDATED THE FORECAST TO LOWER THE CHANCE OF RAIN FOR THE DEEP EAST
TEXAS AND SOME OF THE OTHER ZONES IN EAST AND NORTHEAST TEXAS WITH
DRIER AIR FOLLOWING IN WAKE OF THE BAND OF SHOWERS AND
THUNDERSTORMS ONGOING. . MADE SOME TEMPERATURE ADJUSTMENTS FOR
THE ENDING RAIN AND DEVELOPING RAINFALL OVER THE EASTERN ZONES.
DISCUSSION...
THE HRRR AND OTHER SHORT TERM MODELS INDICATED THAT ADDITIONAL
DEVELOPMENT IS EXPECTED TO RE-DEVELOP OVER PARTS OF NORTHEAST AND
EAST TEXAS LATER DURING THE AFTERNOON WITH ADDITIONAL DISTURBANCES
MOVING INTO THE AREA /06/
PREV DISCUSSION... /ISSUED 1023 AM CDT SUN MAY 24 2015/
AVIATION...
SCATTERED TO NUMEROUS SHOWERS AND TSTMS OVER MUCH OF E TX CONTINUE
TO MOVE N THIS SUNDAY MORNING. ALSO WIDESPREAD MVFR CEILINGS EXPECTED
TO CONTINUE THROUGHOUT THIS SUNDAY IN A VERY MOIST AND UNSTABLE AIR
MASS.
EXPECT WIDESPREAD MVFR CEILINGS AND SCT TO NUMEROUS SHOWERS AND TSTMS
TO CONTINUE THROUGH MONDAY IN A CONTINUED VERY MOIST AIRMASS. /VIII/.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 70 83 69 85 / 70 70 90 40
MLU 70 83 70 83 / 70 70 90 80
DEQ 69 79 66 83 / 70 70 90 30
TXK 69 81 67 84 / 70 70 90 40
ELD 69 83 68 84 / 70 70 90 80
TYR 71 81 68 85 / 70 80 90 30
GGG 71 82 68 85 / 70 70 90 30
LFK 72 83 70 86 / 70 70 90 50
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ARZ050-051-059>061-
070>073.
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ001>006-010>014-
017>022.
OK...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR OKZ077.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ096-097-108>112-
124>126-136>138-149>153-165>167.
&&
$$
06
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
215 PM CDT SUN MAY 24 2015
.UPDATE...
TO INCLUDE TORNADO WATCH NUMBER 204 IN EFFECT UNTIL 8 PM CDT FOR
THE FOUR SOUTHEAST COUNTIES IN THE WARNING AREA.
&&
.DISCUSSION...
ONE OF THE LEAD UPPER DISTRUBANCES WAS MOVING ACORSS SOUTHEAST
OKLAHOMA AND INTO NORTHEAST TEXAS AND ACROSS NORTHWEST LOUISIANA
WITH SHOWERS AND THUNDERSTROMS AHEAD OF THIS FEATURE. LATER INTO
LATE AFTERNOON AND EVENING ANOTHER SERIES OF SMALLER DISTURBANCES
WILL SPREAD OVER THE AREA WITH ANOTHER AREA OF SHOWERS AND
THUNDERSTORMS DEVELOPING AND MOVING OVER THE FOUR STATE REGION.
STILL LOOKING FOR ANOTHER STRONG NEGATIVE TROUGH TO MOVE ACROSS
WEST TEXAS AND THE SOUTHERN ROCKIES DURING THE DAY MONDAY
PRODUCING ANOTHER ROUND OF STRONG TO POSSIBLY SEVERE THUNDERSTORMS
MONDAY AND MONDAY NIGHT ACROSS THE FOUR STATE REGION. LOCALLY
HEAVY RAINFALL WILL ALSO ACCOMPANY THIS ROUND OF POSSIBLE SEVERE
WEATHER AND RESULT IN ADDITIONAL TWO TO FOUR INCHES OF RAIN. THIS
HEAVY RAINFALL WILL PRODUCE FLASH FLOODING. /06
&&
.PREV DISCUSSION... /ISSUED 101 PM CDT SUN MAY 24 2015/
DISCUSSION...
UPDATED THE FORECAST TO INCLUDE THE TORNADO WATCH NUMBER 202 IN
EFFECT UNTIL 7 PM CDT.
PREV DISCUSSION... /ISSUED 1152 AM CDT SUN MAY 24 2015/
UPDATE...
UPDATED THE FORECAST TO LOWER THE CHANCE OF RAIN FOR THE DEEP EAST
TEXAS AND SOME OF THE OTHER ZONES IN EAST AND NORTHEAST TEXAS WITH
DRIER AIR FOLLOWING IN WAKE OF THE BAND OF SHOWERS AND
THUNDERSTORMS ONGOING. . MADE SOME TEMPERATURE ADJUSTMENTS FOR
THE ENDING RAIN AND DEVELOPING RAINFALL OVER THE EASTERN ZONES.
DISCUSSION...
THE HRRR AND OTHER SHORT TERM MODELS INDICATED THAT ADDITIONAL
DEVELOPMENT IS EXPECTED TO RE-DEVELOP OVER PARTS OF NORTHEAST AND
EAST TEXAS LATER DURING THE AFTERNOON WITH ADDITIONAL DISTURBANCES
MOVING INTO THE AREA /06/
PREV DISCUSSION... /ISSUED 1023 AM CDT SUN MAY 24 2015/
AVIATION...
SCATTERED TO NUMEROUS SHOWERS AND TSTMS OVER MUCH OF E TX CONTINUE
TO MOVE N THIS SUNDAY MORNING. ALSO WIDESPREAD MVFR CEILINGS EXPECTED
TO CONTINUE THROUGHOUT THIS SUNDAY IN A VERY MOIST AND UNSTABLE AIR
MASS.
EXPECT WIDESPREAD MVFR CEILINGS AND SCT TO NUMEROUS SHOWERS AND TSTMS
TO CONTINUE THROUGH MONDAY IN A CONTINUED VERY MOIST AIRMASS. /VIII/.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 82 70 83 69 / 90 60 70 80
MLU 86 70 82 70 / 90 80 70 80
DEQ 78 68 79 67 / 90 60 70 80
TXK 81 69 82 68 / 90 60 70 80
ELD 83 69 82 68 / 90 80 70 80
TYR 79 71 83 69 / 60 40 80 80
GGG 79 71 83 69 / 70 40 70 80
LFK 81 73 83 70 / 60 50 70 80
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ARZ050-051-059>061-
070>073.
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ001>006-010>014-
017>022.
OK...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR OKZ077.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ096-097-108>112-
124>126-136>138-149>153-165>167.
&&
$$
06
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
202 PM CDT SUN MAY 24 2015
.UPDATE...
HAVE UPDATED GRIDS AND ZONES FOR TORNADO WATCH NUMBER 204 ISSUED
BY SPC UNTIL 8 PM FOR A MAJORITY OF THE EASTERN HALF OF THE
FORECAST AREA. AGAIN...DECENT INSTABILITY ALONG WITH LOW LEVEL JET
AND SHEAR IN THE AREA AHEAD OF THE MAIN RAIN BAND ASSOCIATED WITH
EARLIER MCS. SOME ROTATION MAY OCCUR IN THE CELLS DEVELOP AHEAD OF
THIS BAND...THEN ACTIVITY SHOULD BEGIN TO WEAKEN WITH THE LOSS OF
DAYTIME HEATING.
RUA
&&
.PREV DISCUSSION... /ISSUED 1250 PM CDT SUN MAY 24 2015/
AVIATION...
LINE OF NORTH/SOUTH THUNDERSTORMS MARCHING INTO SOUTHWEST
LOUISIANA AT THIS TIME. STORMS WILL MOVE INTO AEX AREA OF
OPERATIONS IN THE NEXT HOUR FOLLOWED BY LFT AND ARA. STORMS ARE
PRODUCING GUSTY SURFACE WINDS...RAINS HEAVY AT TIMES...AND CLOUD
TO CLOUD LIGHTNING. AVIATION INTEREST SHOULD BE AWARE OF LOWER
CEILING NEAR STORM ACTIVITY ALONG WITH RAPIDLY CHANGING WIND
DIRECTION AND SPEED. CONDS ARE BEGINNING TO IMPROVE OVER SE TX AS
THE LINE MOVES EASTWARD.
PREV DISCUSSION... /ISSUED 1156 AM CDT SUN MAY 24 2015/
UPDATE...
ANOTHER QUICK UPDATE BEFORE WE REACH THE NOON HOUR. MCS IS
PLUGGING ALONG SLOWLY TO THE EAST WITH MAIN BAND ALONG THE SABINE
RIVER VALLEY AND NEARING THE GREATER LAKE CHARLES AREA...JUST A
TAD FASTER THAN WHAT THE EARLIER HRRR WAS SHOWING. ATMOSPHERE OVER
SOUTHEAST TEXAS IS EXPECTED TO STABILIZE NOW...REDUCING THE RISK
FOR HEAVY RAINFALL AND FLOODING IN THE NEAR TERM OVER THAT AREA...WITH
MAINLY JUST LIGHT RAIN TO OCCASIONALLY MODERATE RAIN FOR THE
REMAINDER OF THE AFTERNOON.
BEST SURFACE MOISTURE CONVERGENCE IS LOCATED OVER WESTERN
LOUISIANA AND SOUTHWEST LOUISIANA. THIS SHOULD BE THE MAIN FOCUS
FOR THE HEAVY RAINFALL THIS AFTERNOON...FROM EAST OF THE SABINE
RIVER TO ROUGHLY JUST WEST OF ALEXANDRIA TO JENNINGS. THIS IS ALSO
ROUGHLY THE AREA THAT WPC HAS A MODERATE RISK FOR EXCESSIVE
RAINFALL...AND THE AREA THAT WILL HAVE THE BEST CHANCE TO SEE ANY
URBAN FLOOD ADVISORIES OR FLASH FLOOD WARNINGS BEING ISSUED. TIDE
LEVELS ALSO ALONG THE COAST ARE RUNNING A FOOT ABOVE PREDICTED
LEVELS AND NEARING 3 FEET MLLW AT THE CALCASIEU PASS GAUGE. AGAIN
THESE HIGHER TIDES COULD CAUSE BACK-UPS FOR BAYOUS THAT WOULD
NORMALLY DRAIN INTO SYSTEMS THAT GO INTO THE GULF...AND ALLOW
FLOODING TO OCCUR MORE EASILY.
ALSO...A SLIGHT RISK OF SEVERE WEATHER IS NOTED BY SPC ACROSS
SOUTHWEST AND SOUTH CENTRAL LOUISIANA. DECENT HEATING TAKING PLACE
AHEAD OF THE MAIN BAND...ALONG WITH GOOD LOW LEVEL JET WITH JUST
ENOUGH SHEAR THAT POCKETS ALONG THE MAIN BAND OR ISOLATED
CONVECTION AHEAD OF THE BAND COULD TEND TO ROTATE WITH A CHANCE
FOR LOCALIZED DAMAGING WIND GUSTS.
RUA
PREV DISCUSSION... /ISSUED 949 AM CDT SUN MAY 24 2015/
UPDATE...
NOCTURNAL MCS MOVING INTO SOUTHEAST TEXAS BEGINNING TO SLOW UP AND
THIS IS RAISING CONCERNS FOR FLASH FLOODING OVER LOWER SOUTHEAST
TEXAS. MSAS ANALYSIS SHOWS REALLY GOOD SURFACE MOISTURE
CONVERGENCE ALONG THE SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA
COAST TO HELP FEED AND FOCUS CONVECTION. ENVIRONMENT OVER
SOUTHEAST TEXAS RICH WITH MOISTURE WITH PROJECTED PRECIPITABLE
WATER NEAR 2 INCHES AND MEAN RH OVER 90 PERCENT. THEREFORE...THESE
STORMS SHOULD BE EFFICIENT PRECIP PRODUCERS WITH RAINFALL RATES
BETWEEN 1 AND 2 INCHES PER HOUR. TIDE LEVELS NEAR THE COAST ARE
ALSO RUNNING BETWEEN 1/2 AND 1 FOOT ABOVE PREDICTED LEVELS WHICH
WILL HELP KEEP THE BAYOUS AND CREEKS FROM PROPERLY DRAINING. WILL
BE MONITORING THAT AREA CLOSELY FOR POSSIBLE URBAN FLOOD
ADVISORIES OR FLASH FLOOD WARNINGS BEFORE THE MORNING IS UP.
THIS ACTIVITY WILL SLOWLY MOVE EASTWARD WITH HRRR SHOWING THIS
BAND REACHING SOUTHWEST LOUISIANA AROUND 18Z. ALTHOUGH DECENT LOW
LEVEL JET WILL CONTINUE TO HELP DEVELOP ISOLATED TO SCATTERED
ACTIVITY AHEAD OF THE MAIN BAND. WILL MAKE SOME MINOR ADJUSTMENTS
DURING THE FIRST PERIOD TO KEEP UP WITH RADAR AND SHORT TERM
GUIDANCE TRENDS.
RUA
PREV DISCUSSION... /ISSUED 709 AM CDT SUN MAY 24 2015/
DISCUSSION...
FOR 12Z TAF ISSUANCE.
AVIATION...
PRIMARY AVIATION ISSUE THIS MORNING IS TIMING THE ARRIVAL OF
THUNDERSTORMS ASSOCIATED WITH APPROACHING MCV CROSSING METRO
HOUSTON ATTM. EXPECT THIS ACTIVITY TO GET INTO KBPT TOWARD 15Z AND
KLCH 17Z. HRRR SHOWS THIS LINE BREAKING UP AFTER IT PASSES KLCH SO
HAVE ELECTED FOR NOW TO NOT CARRY PREVAILING PRECIP FOR REMAINING
SITES. OTHERWISE PRIMARY ISSUE REMAINS STRONG SRLY WINDS EXPECTED
TO DEVELOP OVER THE NEXT HOUR OR SO AS A TIGHT GRADIENT REMAINS IN
PLACE THANKS TO DEEPENING LOW PRESSURE OVER THE TX/OK PANHANDLE
REGION...AS WELL AS STRONGER WINDS ALOFT MIXING DOWN.
25
PREV DISCUSSION... /ISSUED 445 AM CDT SUN MAY 24 2015/
FLASH FLOOD WATCH IN EFFECT FROM THIS MORNING THROUGH TUESDAY
MORNING...
DISCUSSION...THE FIRST ROUND OF HEAVY RAIN FOR OUR AREA IS
APPROACHING. THE FIRST IN A SERIES OF SHORT WAVES ROTATING AROUND
THE LARGER WEST U.S. TROUGH WILL PUSH INTO THE REGION THIS
MORNING. CURRENTLY OVER TX STORMS ARE STRETCHED FROM BROWNSVILLE
TO DFW. THE PORTION OF WX THAT CONCERNS SE TX AND LA IS MOVING
ACROSS THE CENTRAL TX COAST AND WILL ARRIVE ROUGHLY AT 9 AM TO
JEFFERSON, HARDIN, AND TYLER COUNTIES. ALREADY SATURATED GROUND,
HIGH RAINFALL RATES, AND POTENTIALLY MULTIPLE ROUNDS OF RAIN
PROMPTED THE FLASH FLOOD WATCH ACROSS SE TX, SW AND CENTRAL LA
FROM THIS MORNING THROUGH TUESDAY MORNING, HOWEVER RAIN AND
THUNDERSTORMS MAY STRETCH IN TUESDAY AFTERNOON/EVENING. WITH THE
HIGHER MOISTURE CONTENT AIR MASS AND HIGHER AMOUNT OF FORECASTED
QPF REMAINING JUST WEST OF LOWER ACADIANA THE WATCH WAS NOT EXPANDED
TO THAT AREA, HOWEVER ANY TRAINING STORM, IF IT DOES OCCUR, WILL
HAVE THE POTENTIAL TO PRODUCE FLOODING.
BEHIND THE SHORT WAVE CURRENTLY OVER TX ANOTHER UPPER LOW OVER
SOUTH CA IS ROTATING AROUND THE LARGER TROUGH. THIS WILL CAUSE
RAIN CHANCES TO REMAIN HIGH FROM MONDAY AFTERNOON INTO TUESDAY
MORNING AS THIS DISTURBANCE MOVES ACROSS THE REGION. DURING
TUESDAY THE MAIN TROUGH WILL FINALLY MOVE ACROSS THE REGION WITH
DECREASING RAIN CHANCES THROUGH THE EVENING AS THIS OCCURS. A
SLIGHT DRYING OF THE AIR MASS WILL OCCUR ALOFT AS THE MAIN TROUGH
SHIFTS EAST.
ALSO DURING THE PERIOD OF TODAY THROUGH TUESDAY... WHILE FLOODING
WILL REMAIN THE MAIN THREAT OF THIS EVENT, THERE IS A MARGINAL TO
SLIGHT RISK OF SEVERE WEATHER. INSTABILITY MAY REMAIN LIMITED,
HOWEVER STRONG GUSTY WINDS MAY BE POSSIBLE AS THE LINES OF STORMS
MOVE THROUGH.
MAINLY SCT AFTERNOON THUNDERSTORMS CAN BE EXPECTED WED AND THU
EVEN AS MODEST RIDGING OCCURS. THE MODEST RIDGE IS EXPECTED TO
BREAK DOWN AGAIN BY FRIDAY THROUGH THE WEEKEND WITH ANOTHER, YET
WEAKER, UPPER TROUGH MOVING FROM THE WESTERN STATES INTO THE
PLAINS.
MARINE...A FAIRLY TIGHT PRESSURE GRADIENT IS OCCURRING ACROSS
THE GULF THIS MORNING WITH NEAR SCA CRITERIA WINDS OCCURRING. THE
MODERATE ONSHORE FLOW WILL REMAIN IN PLACE THROUGH MONDAY NIGHT
AND SLOWLY DECREASE THROUGH TUESDAY AS THE SURFACE LOW OVER THE
PLAINS LIFTS NE ACROSS THE GREAT LAKES.
NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS THE COASTAL WATERS
THROUGH TUESDAY MORNING. STRONG GUSTY WINDS, CLOUD TO WATER
LIGHTNING, LOCALLY HIGHER SEAS, AND TORRENTIAL RAINFALL IS
EXPECTED. MARINERS SHOULD REMAIN AWARE OF THE LATEST WEATHER AND
BE PREPARED TO SEEK SHELTER IF A STRONG STORM APPROACHES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 84 70 82 70 / 80 60 70 70
LCH 83 73 84 73 / 80 60 60 70
LFT 85 73 84 73 / 60 60 70 60
BPT 80 74 83 74 / 100 60 70 70
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ027>032-041-042-
073-074.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ180-201-215-216-
259>262.
GM...SMALL CRAFT EXERCISE CAUTION THROUGH MONDAY EVENING FOR GMZ450-
452-455-470-472-475.
SMALL CRAFT EXERCISE CAUTION UNTIL 4 PM CDT THIS AFTERNOON FOR
GMZ435.
&&
$$
PUBLIC...07
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
101 PM CDT SUN MAY 24 2015
.DISCUSSION...
UPDATED THE FORECAST TO INCLUDE THE TORNADO WATCH NUMBER 202 IN
EFFECT UNTIL 7 PM CDT.
&&
.PREV DISCUSSION... /ISSUED 1152 AM CDT SUN MAY 24 2015/
UPDATE...
UPDATED THE FORECAST TO LOWER THE CHANCE OF RAIN FOR THE DEEP EAST
TEXAS AND SOME OF THE OTHER ZONES IN EAST AND NORTHEAST TEXAS WITH
DRIER AIR FOLLOWING IN WAKE OF THE BAND OF SHOWERS AND
THUNDERSTORMS ONGOING. . MADE SOME TEMPERATURE ADJUSTMENTS FOR
THE ENDING RAIN AND DEVELOPING RAINFALL OVER THE EASTERN ZONES.
DISCUSSION...
THE HRRR AND OTHER SHORT TERM MODELS INDICATED THAT ADDITIONAL
DEVELOPMENT IS EXPECTED TO RE-DEVELOP OVER PARTS OF NORTHEAST AND
EAST TEXAS LATER DURING THE AFTERNOON WITH ADDITIONAL DISTURBANCES
MOVING INTO THE AREA /06/
PREV DISCUSSION... /ISSUED 1023 AM CDT SUN MAY 24 2015/
AVIATION...
SCATTERED TO NUMEROUS SHOWERS AND TSTMS OVER MUCH OF E TX CONTINUE
TO MOVE N THIS SUNDAY MORNING. ALSO WIDESPREAD MVFR CEILINGS EXPECTED
TO CONTINUE THROUGHOUT THIS SUNDAY IN A VERY MOIST AND UNSTABLE AIR
MASS.
EXPECT WIDESPREAD MVFR CEILINGS AND SCT TO NUMEROUS SHOWERS AND TSTMS
TO CONTINUE THROUGH MONDAY IN A CONTINUED VERY MOIST AIRMASS. /VIII/.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 82 70 83 69 85 / 90 60 70 80 40
MLU 86 70 82 70 84 / 90 80 70 80 70
DEQ 78 68 79 67 83 / 90 60 70 80 30
TXK 81 69 82 68 84 / 90 60 70 80 40
ELD 83 69 82 68 84 / 90 80 70 80 60
TYR 79 71 83 69 85 / 60 40 80 80 30
GGG 79 71 83 69 85 / 70 40 70 80 30
LFK 81 73 83 70 85 / 60 50 70 80 50
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ARZ050-051-059>061-
070>073.
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ001>006-010>014-
017>022.
OK...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR OKZ077.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ096-097-108>112-
124>126-136>138-149>153-165>167.
&&
$$
06
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1250 PM CDT SUN MAY 24 2015
.AVIATION...
LINE OF NORTH/SOUTH THUNDERSTORMS MARCHING INTO SOUTHWEST
LOUISIANA AT THIS TIME. STORMS WILL MOVE INTO AEX AREA OF
OPERATIONS IN THE NEXT HOUR FOLLOWED BY LFT AND ARA. STORMS ARE
PRODUCING GUSTY SURFACE WINDS...RAINS HEAVY AT TIMES...AND CLOUD
TO CLOUD LIGHTNING. AVIATION INTEREST SHOULD BE AWARE OF LOWER
CEILING NEAR STORM ACTIVITY ALONG WITH RAPIDLY CHANGING WIND
DIRECTION AND SPEED. CONDS ARE BEGINNING TO IMPROVE OVER SE TX AS
THE LINE MOVES EASTWARD.
&&
.PREV DISCUSSION... /ISSUED 1156 AM CDT SUN MAY 24 2015/
UPDATE...
ANOTHER QUICK UPDATE BEFORE WE REACH THE NOON HOUR. MCS IS
PLUGGING ALONG SLOWLY TO THE EAST WITH MAIN BAND ALONG THE SABINE
RIVER VALLEY AND NEARING THE GREATER LAKE CHARLES AREA...JUST A
TAD FASTER THAN WHAT THE EARLIER HRRR WAS SHOWING. ATMOSPHERE OVER
SOUTHEAST TEXAS IS EXPECTED TO STABILIZE NOW...REDUCING THE RISK
FOR HEAVY RAINFALL AND FLOODING IN THE NEAR TERM OVER THAT AREA...WITH
MAINLY JUST LIGHT RAIN TO OCCASIONALLY MODERATE RAIN FOR THE
REMAINDER OF THE AFTERNOON.
BEST SURFACE MOISTURE CONVERGENCE IS LOCATED OVER WESTERN
LOUISIANA AND SOUTHWEST LOUISIANA. THIS SHOULD BE THE MAIN FOCUS
FOR THE HEAVY RAINFALL THIS AFTERNOON...FROM EAST OF THE SABINE
RIVER TO ROUGHLY JUST WEST OF ALEXANDRIA TO JENNINGS. THIS IS ALSO
ROUGHLY THE AREA THAT WPC HAS A MODERATE RISK FOR EXCESSIVE
RAINFALL...AND THE AREA THAT WILL HAVE THE BEST CHANCE TO SEE ANY
URBAN FLOOD ADVISORIES OR FLASH FLOOD WARNINGS BEING ISSUED. TIDE
LEVELS ALSO ALONG THE COAST ARE RUNNING A FOOT ABOVE PREDICTED
LEVELS AND NEARING 3 FEET MLLW AT THE CALCASIEU PASS GAUGE. AGAIN
THESE HIGHER TIDES COULD CAUSE BACK-UPS FOR BAYOUS THAT WOULD
NORMALLY DRAIN INTO SYSTEMS THAT GO INTO THE GULF...AND ALLOW
FLOODING TO OCCUR MORE EASILY.
ALSO...A SLIGHT RISK OF SEVERE WEATHER IS NOTED BY SPC ACROSS
SOUTHWEST AND SOUTH CENTRAL LOUISIANA. DECENT HEATING TAKING PLACE
AHEAD OF THE MAIN BAND...ALONG WITH GOOD LOW LEVEL JET WITH JUST
ENOUGH SHEAR THAT POCKETS ALONG THE MAIN BAND OR ISOLATED
CONVECTION AHEAD OF THE BAND COULD TEND TO ROTATE WITH A CHANCE
FOR LOCALIZED DAMAGING WIND GUSTS.
RUA
PREV DISCUSSION... /ISSUED 949 AM CDT SUN MAY 24 2015/
UPDATE...
NOCTURNAL MCS MOVING INTO SOUTHEAST TEXAS BEGINNING TO SLOW UP AND
THIS IS RAISING CONCERNS FOR FLASH FLOODING OVER LOWER SOUTHEAST
TEXAS. MSAS ANALYSIS SHOWS REALLY GOOD SURFACE MOISTURE
CONVERGENCE ALONG THE SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA
COAST TO HELP FEED AND FOCUS CONVECTION. ENVIRONMENT OVER
SOUTHEAST TEXAS RICH WITH MOISTURE WITH PROJECTED PRECIPITABLE
WATER NEAR 2 INCHES AND MEAN RH OVER 90 PERCENT. THEREFORE...THESE
STORMS SHOULD BE EFFICIENT PRECIP PRODUCERS WITH RAINFALL RATES
BETWEEN 1 AND 2 INCHES PER HOUR. TIDE LEVELS NEAR THE COAST ARE
ALSO RUNNING BETWEEN 1/2 AND 1 FOOT ABOVE PREDICTED LEVELS WHICH
WILL HELP KEEP THE BAYOUS AND CREEKS FROM PROPERLY DRAINING. WILL
BE MONITORING THAT AREA CLOSELY FOR POSSIBLE URBAN FLOOD
ADVISORIES OR FLASH FLOOD WARNINGS BEFORE THE MORNING IS UP.
THIS ACTIVITY WILL SLOWLY MOVE EASTWARD WITH HRRR SHOWING THIS
BAND REACHING SOUTHWEST LOUISIANA AROUND 18Z. ALTHOUGH DECENT LOW
LEVEL JET WILL CONTINUE TO HELP DEVELOP ISOLATED TO SCATTERED
ACTIVITY AHEAD OF THE MAIN BAND. WILL MAKE SOME MINOR ADJUSTMENTS
DURING THE FIRST PERIOD TO KEEP UP WITH RADAR AND SHORT TERM
GUIDANCE TRENDS.
RUA
PREV DISCUSSION... /ISSUED 709 AM CDT SUN MAY 24 2015/
DISCUSSION...
FOR 12Z TAF ISSUANCE.
AVIATION...
PRIMARY AVIATION ISSUE THIS MORNING IS TIMING THE ARRIVAL OF
THUNDERSTORMS ASSOCIATED WITH APPROACHING MCV CROSSING METRO
HOUSTON ATTM. EXPECT THIS ACTIVITY TO GET INTO KBPT TOWARD 15Z AND
KLCH 17Z. HRRR SHOWS THIS LINE BREAKING UP AFTER IT PASSES KLCH SO
HAVE ELECTED FOR NOW TO NOT CARRY PREVAILING PRECIP FOR REMAINING
SITES. OTHERWISE PRIMARY ISSUE REMAINS STRONG SRLY WINDS EXPECTED
TO DEVELOP OVER THE NEXT HOUR OR SO AS A TIGHT GRADIENT REMAINS IN
PLACE THANKS TO DEEPENING LOW PRESSURE OVER THE TX/OK PANHANDLE
REGION...AS WELL AS STRONGER WINDS ALOFT MIXING DOWN.
25
PREV DISCUSSION... /ISSUED 445 AM CDT SUN MAY 24 2015/
FLASH FLOOD WATCH IN EFFECT FROM THIS MORNING THROUGH TUESDAY
MORNING...
DISCUSSION...THE FIRST ROUND OF HEAVY RAIN FOR OUR AREA IS
APPROACHING. THE FIRST IN A SERIES OF SHORT WAVES ROTATING AROUND
THE LARGER WEST U.S. TROUGH WILL PUSH INTO THE REGION THIS
MORNING. CURRENTLY OVER TX STORMS ARE STRETCHED FROM BROWNSVILLE
TO DFW. THE PORTION OF WX THAT CONCERNS SE TX AND LA IS MOVING
ACROSS THE CENTRAL TX COAST AND WILL ARRIVE ROUGHLY AT 9 AM TO
JEFFERSON, HARDIN, AND TYLER COUNTIES. ALREADY SATURATED GROUND,
HIGH RAINFALL RATES, AND POTENTIALLY MULTIPLE ROUNDS OF RAIN
PROMPTED THE FLASH FLOOD WATCH ACROSS SE TX, SW AND CENTRAL LA
FROM THIS MORNING THROUGH TUESDAY MORNING, HOWEVER RAIN AND
THUNDERSTORMS MAY STRETCH IN TUESDAY AFTERNOON/EVENING. WITH THE
HIGHER MOISTURE CONTENT AIR MASS AND HIGHER AMOUNT OF FORECASTED
QPF REMAINING JUST WEST OF LOWER ACADIANA THE WATCH WAS NOT EXPANDED
TO THAT AREA, HOWEVER ANY TRAINING STORM, IF IT DOES OCCUR, WILL
HAVE THE POTENTIAL TO PRODUCE FLOODING.
BEHIND THE SHORT WAVE CURRENTLY OVER TX ANOTHER UPPER LOW OVER
SOUTH CA IS ROTATING AROUND THE LARGER TROUGH. THIS WILL CAUSE
RAIN CHANCES TO REMAIN HIGH FROM MONDAY AFTERNOON INTO TUESDAY
MORNING AS THIS DISTURBANCE MOVES ACROSS THE REGION. DURING
TUESDAY THE MAIN TROUGH WILL FINALLY MOVE ACROSS THE REGION WITH
DECREASING RAIN CHANCES THROUGH THE EVENING AS THIS OCCURS. A
SLIGHT DRYING OF THE AIR MASS WILL OCCUR ALOFT AS THE MAIN TROUGH
SHIFTS EAST.
ALSO DURING THE PERIOD OF TODAY THROUGH TUESDAY... WHILE FLOODING
WILL REMAIN THE MAIN THREAT OF THIS EVENT, THERE IS A MARGINAL TO
SLIGHT RISK OF SEVERE WEATHER. INSTABILITY MAY REMAIN LIMITED,
HOWEVER STRONG GUSTY WINDS MAY BE POSSIBLE AS THE LINES OF STORMS
MOVE THROUGH.
MAINLY SCT AFTERNOON THUNDERSTORMS CAN BE EXPECTED WED AND THU
EVEN AS MODEST RIDGING OCCURS. THE MODEST RIDGE IS EXPECTED TO
BREAK DOWN AGAIN BY FRIDAY THROUGH THE WEEKEND WITH ANOTHER, YET
WEAKER, UPPER TROUGH MOVING FROM THE WESTERN STATES INTO THE
PLAINS.
MARINE...A FAIRLY TIGHT PRESSURE GRADIENT IS OCCURRING ACROSS
THE GULF THIS MORNING WITH NEAR SCA CRITERIA WINDS OCCURRING. THE
MODERATE ONSHORE FLOW WILL REMAIN IN PLACE THROUGH MONDAY NIGHT
AND SLOWLY DECREASE THROUGH TUESDAY AS THE SURFACE LOW OVER THE
PLAINS LIFTS NE ACROSS THE GREAT LAKES.
NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS THE COASTAL WATERS
THROUGH TUESDAY MORNING. STRONG GUSTY WINDS, CLOUD TO WATER
LIGHTNING, LOCALLY HIGHER SEAS, AND TORRENTIAL RAINFALL IS
EXPECTED. MARINERS SHOULD REMAIN AWARE OF THE LATEST WEATHER AND
BE PREPARED TO SEEK SHELTER IF A STRONG STORM APPROACHES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 70 82 70 83 / 80 70 70 70
LCH 73 84 73 85 / 80 60 70 70
LFT 73 84 73 85 / 80 70 60 70
BPT 74 83 74 85 / 80 70 70 60
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ027>032-041-042-
073-074.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ180-201-215-216-
259>262.
GM...SMALL CRAFT EXERCISE CAUTION THROUGH MONDAY EVENING FOR GMZ450-
452-455-470-472-475.
SMALL CRAFT EXERCISE CAUTION UNTIL 4 PM CDT THIS AFTERNOON FOR
GMZ435.
&&
$$
AVIATION...19
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1156 AM CDT SUN MAY 24 2015
.UPDATE...
ANOTHER QUICK UPDATE BEFORE WE REACH THE NOON HOUR. MCS IS
PLUGGING ALONG SLOWLY TO THE EAST WITH MAIN BAND ALONG THE SABINE
RIVER VALLEY AND NEARING THE GREATER LAKE CHARLES AREA...JUST A
TAD FASTER THAN WHAT THE EARLIER HRRR WAS SHOWING. ATMOSPHERE OVER
SOUTHEAST TEXAS IS EXPECTED TO STABILIZE NOW...REDUCING THE RISK
FOR HEAVY RAINFALL AND FLOODING IN THE NEAR TERM OVER THAT AREA...WITH
MAINLY JUST LIGHT RAIN TO OCCASIONALLY MODERATE RAIN FOR THE
REMAINDER OF THE AFTERNOON.
BEST SURFACE MOISTURE CONVERGENCE IS LOCATED OVER WESTERN
LOUISIANA AND SOUTHWEST LOUISIANA. THIS SHOULD BE THE MAIN FOCUS
FOR THE HEAVY RAINFALL THIS AFTERNOON...FROM EAST OF THE SABINE
RIVER TO ROUGHLY JUST WEST OF ALEXANDRIA TO JENNINGS. THIS IS ALSO
ROUGHLY THE AREA THAT WPC HAS A MODERATE RISK FOR EXCESSIVE
RAINFALL...AND THE AREA THAT WILL HAVE THE BEST CHANCE TO SEE ANY
URBAN FLOOD ADVISORIES OR FLASH FLOOD WARNINGS BEING ISSUED. TIDE
LEVELS ALSO ALONG THE COAST ARE RUNNING A FOOT ABOVE PREDICTED
LEVELS AND NEARING 3 FEET MLLW AT THE CALCASIEU PASS GAUGE. AGAIN
THESE HIGHER TIDES COULD CAUSE BACK-UPS FOR BAYOUS THAT WOULD
NORMALLY DRAIN INTO SYSTEMS THAT GO INTO THE GULF...AND ALLOW
FLOODING TO OCCUR MORE EASILY.
ALSO...A SLIGHT RISK OF SEVERE WEATHER IS NOTED BY SPC ACROSS
SOUTHWEST AND SOUTH CENTRAL LOUISIANA. DECENT HEATING TAKING PLACE
AHEAD OF THE MAIN BAND...ALONG WITH GOOD LOW LEVEL JET WITH JUST
ENOUGH SHEAR THAT POCKETS ALONG THE MAIN BAND OR ISOLATED
CONVECTION AHEAD OF THE BAND COULD TEND TO ROTATE WITH A CHANCE
FOR LOCALIZED DAMAGING WIND GUSTS.
RUA
&&
.PREV DISCUSSION... /ISSUED 949 AM CDT SUN MAY 24 2015/
UPDATE...
NOCTURNAL MCS MOVING INTO SOUTHEAST TEXAS BEGINNING TO SLOW UP AND
THIS IS RAISING CONCERNS FOR FLASH FLOODING OVER LOWER SOUTHEAST
TEXAS. MSAS ANALYSIS SHOWS REALLY GOOD SURFACE MOISTURE
CONVERGENCE ALONG THE SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA
COAST TO HELP FEED AND FOCUS CONVECTION. ENVIRONMENT OVER
SOUTHEAST TEXAS RICH WITH MOISTURE WITH PROJECTED PRECIPITABLE
WATER NEAR 2 INCHES AND MEAN RH OVER 90 PERCENT. THEREFORE...THESE
STORMS SHOULD BE EFFICIENT PRECIP PRODUCERS WITH RAINFALL RATES
BETWEEN 1 AND 2 INCHES PER HOUR. TIDE LEVELS NEAR THE COAST ARE
ALSO RUNNING BETWEEN 1/2 AND 1 FOOT ABOVE PREDICTED LEVELS WHICH
WILL HELP KEEP THE BAYOUS AND CREEKS FROM PROPERLY DRAINING. WILL
BE MONITORING THAT AREA CLOSELY FOR POSSIBLE URBAN FLOOD
ADVISORIES OR FLASH FLOOD WARNINGS BEFORE THE MORNING IS UP.
THIS ACTIVITY WILL SLOWLY MOVE EASTWARD WITH HRRR SHOWING THIS
BAND REACHING SOUTHWEST LOUISIANA AROUND 18Z. ALTHOUGH DECENT LOW
LEVEL JET WILL CONTINUE TO HELP DEVELOP ISOLATED TO SCATTERED
ACTIVITY AHEAD OF THE MAIN BAND. WILL MAKE SOME MINOR ADJUSTMENTS
DURING THE FIRST PERIOD TO KEEP UP WITH RADAR AND SHORT TERM
GUIDANCE TRENDS.
RUA
PREV DISCUSSION... /ISSUED 709 AM CDT SUN MAY 24 2015/
DISCUSSION...
FOR 12Z TAF ISSUANCE.
AVIATION...
PRIMARY AVIATION ISSUE THIS MORNING IS TIMING THE ARRIVAL OF
THUNDERSTORMS ASSOCIATED WITH APPROACHING MCV CROSSING METRO
HOUSTON ATTM. EXPECT THIS ACTIVITY TO GET INTO KBPT TOWARD 15Z AND
KLCH 17Z. HRRR SHOWS THIS LINE BREAKING UP AFTER IT PASSES KLCH SO
HAVE ELECTED FOR NOW TO NOT CARRY PREVAILING PRECIP FOR REMAINING
SITES. OTHERWISE PRIMARY ISSUE REMAINS STRONG SRLY WINDS EXPECTED
TO DEVELOP OVER THE NEXT HOUR OR SO AS A TIGHT GRADIENT REMAINS IN
PLACE THANKS TO DEEPENING LOW PRESSURE OVER THE TX/OK PANHANDLE
REGION...AS WELL AS STRONGER WINDS ALOFT MIXING DOWN.
25
PREV DISCUSSION... /ISSUED 445 AM CDT SUN MAY 24 2015/
FLASH FLOOD WATCH IN EFFECT FROM THIS MORNING THROUGH TUESDAY
MORNING...
DISCUSSION...THE FIRST ROUND OF HEAVY RAIN FOR OUR AREA IS
APPROACHING. THE FIRST IN A SERIES OF SHORT WAVES ROTATING AROUND
THE LARGER WEST U.S. TROUGH WILL PUSH INTO THE REGION THIS
MORNING. CURRENTLY OVER TX STORMS ARE STRETCHED FROM BROWNSVILLE
TO DFW. THE PORTION OF WX THAT CONCERNS SE TX AND LA IS MOVING
ACROSS THE CENTRAL TX COAST AND WILL ARRIVE ROUGHLY AT 9 AM TO
JEFFERSON, HARDIN, AND TYLER COUNTIES. ALREADY SATURATED GROUND,
HIGH RAINFALL RATES, AND POTENTIALLY MULTIPLE ROUNDS OF RAIN
PROMPTED THE FLASH FLOOD WATCH ACROSS SE TX, SW AND CENTRAL LA
FROM THIS MORNING THROUGH TUESDAY MORNING, HOWEVER RAIN AND
THUNDERSTORMS MAY STRETCH IN TUESDAY AFTERNOON/EVENING. WITH THE
HIGHER MOISTURE CONTENT AIR MASS AND HIGHER AMOUNT OF FORECASTED
QPF REMAINING JUST WEST OF LOWER ACADIANA THE WATCH WAS NOT EXPANDED
TO THAT AREA, HOWEVER ANY TRAINING STORM, IF IT DOES OCCUR, WILL
HAVE THE POTENTIAL TO PRODUCE FLOODING.
BEHIND THE SHORT WAVE CURRENTLY OVER TX ANOTHER UPPER LOW OVER
SOUTH CA IS ROTATING AROUND THE LARGER TROUGH. THIS WILL CAUSE
RAIN CHANCES TO REMAIN HIGH FROM MONDAY AFTERNOON INTO TUESDAY
MORNING AS THIS DISTURBANCE MOVES ACROSS THE REGION. DURING
TUESDAY THE MAIN TROUGH WILL FINALLY MOVE ACROSS THE REGION WITH
DECREASING RAIN CHANCES THROUGH THE EVENING AS THIS OCCURS. A
SLIGHT DRYING OF THE AIR MASS WILL OCCUR ALOFT AS THE MAIN TROUGH
SHIFTS EAST.
ALSO DURING THE PERIOD OF TODAY THROUGH TUESDAY... WHILE FLOODING
WILL REMAIN THE MAIN THREAT OF THIS EVENT, THERE IS A MARGINAL TO
SLIGHT RISK OF SEVERE WEATHER. INSTABILITY MAY REMAIN LIMITED,
HOWEVER STRONG GUSTY WINDS MAY BE POSSIBLE AS THE LINES OF STORMS
MOVE THROUGH.
MAINLY SCT AFTERNOON THUNDERSTORMS CAN BE EXPECTED WED AND THU
EVEN AS MODEST RIDGING OCCURS. THE MODEST RIDGE IS EXPECTED TO
BREAK DOWN AGAIN BY FRIDAY THROUGH THE WEEKEND WITH ANOTHER, YET
WEAKER, UPPER TROUGH MOVING FROM THE WESTERN STATES INTO THE
PLAINS.
MARINE...A FAIRLY TIGHT PRESSURE GRADIENT IS OCCURRING ACROSS
THE GULF THIS MORNING WITH NEAR SCA CRITERIA WINDS OCCURRING. THE
MODERATE ONSHORE FLOW WILL REMAIN IN PLACE THROUGH MONDAY NIGHT
AND SLOWLY DECREASE THROUGH TUESDAY AS THE SURFACE LOW OVER THE
PLAINS LIFTS NE ACROSS THE GREAT LAKES.
NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS THE COASTAL WATERS
THROUGH TUESDAY MORNING. STRONG GUSTY WINDS, CLOUD TO WATER
LIGHTNING, LOCALLY HIGHER SEAS, AND TORRENTIAL RAINFALL IS
EXPECTED. MARINERS SHOULD REMAIN AWARE OF THE LATEST WEATHER AND
BE PREPARED TO SEEK SHELTER IF A STRONG STORM APPROACHES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 84 70 82 70 / 70 80 70 70
LCH 83 73 84 73 / 80 80 60 70
LFT 85 73 84 73 / 50 80 70 60
BPT 80 74 83 74 / 100 80 70 70
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ027>032-041-042-
073-074.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ180-201-215-216-
259>262.
GM...SMALL CRAFT EXERCISE CAUTION THROUGH MONDAY EVENING FOR GMZ450-
452-455-470-472-475.
SMALL CRAFT EXERCISE CAUTION UNTIL 4 PM CDT THIS AFTERNOON FOR
GMZ435.
&&
$$
PUBLIC...07
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1152 AM CDT SUN MAY 24 2015
.UPDATE...
UPDATED THE FORECAST TO LOWER THE CHANCE OF RAIN FOR THE DEEP EAST
TEXAS AND SOME OF THE OTHER ZONES IN EAST AND NORTHEAST TEXAS WITH
DRIER AIR FOLLOWING IN WAKE OF THE BAND OF SHOWERS AND
THUNDERSTORMS ONGOING. . MADE SOME TEMPERATURE ADJUSTMENTS FOR
THE ENDING RAIN AND DEVELOPING RAINFALL OVER THE EASTERN ZONES.
&&
.DISCUSSION...
THE HRRR AND OTHER SHORT TERM MODELS INDICATED THAT ADDITIONAL
DEVELOPMENT IS EXPECTED TO RE-DEVELOP OVER PARTS OF NORTHEAST AND
EAST TEXAS LATER DURING THE AFTERNOON WITH ADDITIONAL DISTURBANCES
MOVING INTO THE AREA /06/
&&
.PREV DISCUSSION... /ISSUED 1023 AM CDT SUN MAY 24 2015/
AVIATION...
SCATTERED TO NUMEROUS SHOWERS AND TSTMS OVER MUCH OF E TX CONTINUE
TO MOVE N THIS SUNDAY MORNING. ALSO WIDESPREAD MVFR CEILINGS EXPECTED
TO CONTINUE THROUGHOUT THIS SUNDAY IN A VERY MOIST AND UNSTABLE AIR
MASS.
EXPECT WIDESPREAD MVFR CEILINGS AND SCT TO NUMEROUS SHOWERS AND TSTMS
TO CONTINUE THROUGH MONDAY IN A CONTINUED VERY MOIST AIRMASS. /VIII/.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 82 70 83 69 / 90 60 70 80
MLU 86 70 82 70 / 90 80 70 80
DEQ 78 68 79 67 / 90 60 70 80
TXK 81 69 82 68 / 90 60 70 80
ELD 83 69 82 68 / 90 80 70 80
TYR 79 71 83 69 / 60 40 80 80
GGG 79 71 83 69 / 70 40 70 80
LFK 81 73 83 70 / 60 50 70 80
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR ARZ050-051-059>061-
070>073.
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ001>006-010>014-
017>022.
OK...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR OKZ077.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ096-097-108>112-
124>126-136>138-149>153-165>167.
&&
$$
06
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
949 AM CDT SUN MAY 24 2015
.UPDATE...
NOCTURNAL MCS MOVING INTO SOUTHEAST TEXAS BEGINNING TO SLOW UP AND
THIS IS RAISING CONCERNS FOR FLASH FLOODING OVER LOWER SOUTHEAST
TEXAS. MSAS ANALYSIS SHOWS REALLY GOOD SURFACE MOISTURE
CONVERGENCE ALONG THE SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA
COAST TO HELP FEED AND FOCUS CONVECTION. ENVIRONMENT OVER
SOUTHEAST TEXAS RICH WITH MOISTURE WITH PROJECTED PRECIPITABLE
WATER NEAR 2 INCHES AND MEAN RH OVER 90 PERCENT. THEREFORE...THESE
STORMS SHOULD BE EFFICIENT PRECIP PRODUCERS WITH RAINFALL RATES
BETWEEN 1 AND 2 INCHES PER HOUR. TIDE LEVELS NEAR THE COAST ARE
ALSO RUNNING BETWEEN 1/2 AND 1 FOOT ABOVE PREDICTED LEVELS WHICH
WILL HELP KEEP THE BAYOUS AND CREEKS FROM PROPERLY DRAINING. WILL
BE MONITORING THAT AREA CLOSELY FOR POSSIBLE URBAN FLOOD
ADVISORIES OR FLASH FLOOD WARNINGS BEFORE THE MORNING IS UP.
THIS ACTIVITY WILL SLOWLY MOVE EASTWARD WITH HRRR SHOWING THIS
BAND REACHING SOUTHWEST LOUISIANA AROUND 18Z. ALTHOUGH DECENT LOW
LEVEL JET WILL CONTINUE TO HELP DEVELOP ISOLATED TO SCATTERED
ACTIVITY AHEAD OF THE MAIN BAND. WILL MAKE SOME MINOR ADJUSTMENTS
DURING THE FIRST PERIOD TO KEEP UP WITH RADAR AND SHORT TERM
GUIDANCE TRENDS.
RUA
&&
.PREV DISCUSSION... /ISSUED 709 AM CDT SUN MAY 24 2015/
DISCUSSION...
FOR 12Z TAF ISSUANCE.
AVIATION...
PRIMARY AVIATION ISSUE THIS MORNING IS TIMING THE ARRIVAL OF
THUNDERSTORMS ASSOCIATED WITH APPROACHING MCV CROSSING METRO
HOUSTON ATTM. EXPECT THIS ACTIVITY TO GET INTO KBPT TOWARD 15Z AND
KLCH 17Z. HRRR SHOWS THIS LINE BREAKING UP AFTER IT PASSES KLCH SO
HAVE ELECTED FOR NOW TO NOT CARRY PREVAILING PRECIP FOR REMAINING
SITES. OTHERWISE PRIMARY ISSUE REMAINS STRONG SRLY WINDS EXPECTED
TO DEVELOP OVER THE NEXT HOUR OR SO AS A TIGHT GRADIENT REMAINS IN
PLACE THANKS TO DEEPENING LOW PRESSURE OVER THE TX/OK PANHANDLE
REGION...AS WELL AS STRONGER WINDS ALOFT MIXING DOWN.
25
PREV DISCUSSION... /ISSUED 445 AM CDT SUN MAY 24 2015/
.FLASH FLOOD WATCH IN EFFECT FROM THIS MORNING THROUGH TUESDAY
MORNING...
DISCUSSION...THE FIRST ROUND OF HEAVY RAIN FOR OUR AREA IS
APPROACHING. THE FIRST IN A SERIES OF SHORT WAVES ROTATING AROUND
THE LARGER WEST U.S. TROUGH WILL PUSH INTO THE REGION THIS
MORNING. CURRENTLY OVER TX STORMS ARE STRETCHED FROM BROWNSVILLE
TO DFW. THE PORTION OF WX THAT CONCERNS SE TX AND LA IS MOVING
ACROSS THE CENTRAL TX COAST AND WILL ARRIVE ROUGHLY AT 9 AM TO
JEFFERSON, HARDIN, AND TYLER COUNTIES. ALREADY SATURATED GROUND,
HIGH RAINFALL RATES, AND POTENTIALLY MULTIPLE ROUNDS OF RAIN
PROMPTED THE FLASH FLOOD WATCH ACROSS SE TX, SW AND CENTRAL LA
FROM THIS MORNING THROUGH TUESDAY MORNING, HOWEVER RAIN AND
THUNDERSTORMS MAY STRETCH IN TUESDAY AFTERNOON/EVENING. WITH THE
HIGHER MOISTURE CONTENT AIR MASS AND HIGHER AMOUNT OF FORECASTED
QPF REMAINING JUST WEST OF LOWER ACADIANA THE WATCH WAS NOT EXPANDED
TO THAT AREA, HOWEVER ANY TRAINING STORM, IF IT DOES OCCUR, WILL
HAVE THE POTENTIAL TO PRODUCE FLOODING.
BEHIND THE SHORT WAVE CURRENTLY OVER TX ANOTHER UPPER LOW OVER
SOUTH CA IS ROTATING AROUND THE LARGER TROUGH. THIS WILL CAUSE
RAIN CHANCES TO REMAIN HIGH FROM MONDAY AFTERNOON INTO TUESDAY
MORNING AS THIS DISTURBANCE MOVES ACROSS THE REGION. DURING
TUESDAY THE MAIN TROUGH WILL FINALLY MOVE ACROSS THE REGION WITH
DECREASING RAIN CHANCES THROUGH THE EVENING AS THIS OCCURS. A
SLIGHT DRYING OF THE AIR MASS WILL OCCUR ALOFT AS THE MAIN TROUGH
SHIFTS EAST.
ALSO DURING THE PERIOD OF TODAY THROUGH TUESDAY... WHILE FLOODING
WILL REMAIN THE MAIN THREAT OF THIS EVENT, THERE IS A MARGINAL TO
SLIGHT RISK OF SEVERE WEATHER. INSTABILITY MAY REMAIN LIMITED,
HOWEVER STRONG GUSTY WINDS MAY BE POSSIBLE AS THE LINES OF STORMS
MOVE THROUGH.
MAINLY SCT AFTERNOON THUNDERSTORMS CAN BE EXPECTED WED AND THU
EVEN AS MODEST RIDGING OCCURS. THE MODEST RIDGE IS EXPECTED TO
BREAK DOWN AGAIN BY FRIDAY THROUGH THE WEEKEND WITH ANOTHER, YET
WEAKER, UPPER TROUGH MOVING FROM THE WESTERN STATES INTO THE
PLAINS.
MARINE...A FAIRLY TIGHT PRESSURE GRADIENT IS OCCURRING ACROSS
THE GULF THIS MORNING WITH NEAR SCA CRITERIA WINDS OCCURRING. THE
MODERATE ONSHORE FLOW WILL REMAIN IN PLACE THROUGH MONDAY NIGHT
AND SLOWLY DECREASE THROUGH TUESDAY AS THE SURFACE LOW OVER THE
PLAINS LIFTS NE ACROSS THE GREAT LAKES.
NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS THE COASTAL WATERS
THROUGH TUESDAY MORNING. STRONG GUSTY WINDS, CLOUD TO WATER
LIGHTNING, LOCALLY HIGHER SEAS, AND TORRENTIAL RAINFALL IS
EXPECTED. MARINERS SHOULD REMAIN AWARE OF THE LATEST WEATHER AND
BE PREPARED TO SEEK SHELTER IF A STRONG STORM APPROACHES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 70 82 70 83 / 80 70 70 70
LCH 73 84 73 85 / 80 60 70 70
LFT 73 84 73 85 / 80 70 60 70
BPT 74 83 74 85 / 80 70 70 60
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ027>032-041-042-
073-074.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ180-201-215-216-
259>262.
GM...SMALL CRAFT EXERCISE CAUTION THROUGH MONDAY EVENING FOR GMZ450-
452-455-470-472-475.
&&
$$
PUBLIC...07
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
709 AM CDT SUN MAY 24 2015
.DISCUSSION...
FOR 12Z TAF ISSUANCE.
&&
.AVIATION...
PRIMARY AVIATION ISSUE THIS MORNING IS TIMING THE ARRIVAL OF
THUNDERSTORMS ASSOCIATED WITH APPROACHING MCV CROSSING METRO
HOUSTON ATTM. EXPECT THIS ACTIVITY TO GET INTO KBPT TOWARD 15Z AND
KLCH 17Z. HRRR SHOWS THIS LINE BREAKING UP AFTER IT PASSES KLCH SO
HAVE ELECTED FOR NOW TO NOT CARRY PREVAILING PRECIP FOR REMAINING
SITES. OTHERWISE PRIMARY ISSUE REMAINS STRONG SRLY WINDS EXPECTED
TO DEVELOP OVER THE NEXT HOUR OR SO AS A TIGHT GRADIENT REMAINS IN
PLACE THANKS TO DEEPENING LOW PRESSURE OVER THE TX/OK PANHANDLE
REGION...AS WELL AS STRONGER WINDS ALOFT MIXING DOWN.
25
&&
.PREV DISCUSSION... /ISSUED 445 AM CDT SUN MAY 24 2015/
..FLASH FLOOD WATCH IN EFFECT FROM THIS MORNING THROUGH TUESDAY
MORNING...
DISCUSSION...THE FIRST ROUND OF HEAVY RAIN FOR OUR AREA IS
APPROACHING. THE FIRST IN A SERIES OF SHORT WAVES ROTATING AROUND
THE LARGER WEST U.S. TROUGH WILL PUSH INTO THE REGION THIS
MORNING. CURRENTLY OVER TX STORMS ARE STRETCHED FROM BROWNSVILLE
TO DFW. THE PORTION OF WX THAT CONCERNS SE TX AND LA IS MOVING
ACROSS THE CENTRAL TX COAST AND WILL ARRIVE ROUGHLY AT 9 AM TO
JEFFERSON, HARDIN, AND TYLER COUNTIES. ALREADY SATURATED GROUND,
HIGH RAINFALL RATES, AND POTENTIALLY MULTIPLE ROUNDS OF RAIN
PROMPTED THE FLASH FLOOD WATCH ACROSS SE TX, SW AND CENTRAL LA
FROM THIS MORNING THROUGH TUESDAY MORNING, HOWEVER RAIN AND
THUNDERSTORMS MAY STRETCH IN TUESDAY AFTERNOON/EVENING. WITH THE
HIGHER MOISTURE CONTENT AIR MASS AND HIGHER AMOUNT OF FORECASTED
QPF REMAINING JUST WEST OF LOWER ACADIANA THE WATCH WAS NOT EXPANDED
TO THAT AREA, HOWEVER ANY TRAINING STORM, IF IT DOES OCCUR, WILL
HAVE THE POTENTIAL TO PRODUCE FLOODING.
BEHIND THE SHORT WAVE CURRENTLY OVER TX ANOTHER UPPER LOW OVER
SOUTH CA IS ROTATING AROUND THE LARGER TROUGH. THIS WILL CAUSE
RAIN CHANCES TO REMAIN HIGH FROM MONDAY AFTERNOON INTO TUESDAY
MORNING AS THIS DISTURBANCE MOVES ACROSS THE REGION. DURING
TUESDAY THE MAIN TROUGH WILL FINALLY MOVE ACROSS THE REGION WITH
DECREASING RAIN CHANCES THROUGH THE EVENING AS THIS OCCURS. A
SLIGHT DRYING OF THE AIR MASS WILL OCCUR ALOFT AS THE MAIN TROUGH
SHIFTS EAST.
ALSO DURING THE PERIOD OF TODAY THROUGH TUESDAY... WHILE FLOODING
WILL REMAIN THE MAIN THREAT OF THIS EVENT, THERE IS A MARGINAL TO
SLIGHT RISK OF SEVERE WEATHER. INSTABILITY MAY REMAIN LIMITED,
HOWEVER STRONG GUSTY WINDS MAY BE POSSIBLE AS THE LINES OF STORMS
MOVE THROUGH.
MAINLY SCT AFTERNOON THUNDERSTORMS CAN BE EXPECTED WED AND THU
EVEN AS MODEST RIDGING OCCURS. THE MODEST RIDGE IS EXPECTED TO
BREAK DOWN AGAIN BY FRIDAY THROUGH THE WEEKEND WITH ANOTHER, YET
WEAKER, UPPER TROUGH MOVING FROM THE WESTERN STATES INTO THE
PLAINS.
MARINE...A FAIRLY TIGHT PRESSURE GRADIENT IS OCCURRING ACROSS
THE GULF THIS MORNING WITH NEAR SCA CRITERIA WINDS OCCURRING. THE
MODERATE ONSHORE FLOW WILL REMAIN IN PLACE THROUGH MONDAY NIGHT
AND SLOWLY DECREASE THROUGH TUESDAY AS THE SURFACE LOW OVER THE
PLAINS LIFTS NE ACROSS THE GREAT LAKES.
NUMEROUS THUNDERSTORMS ARE EXPECTED ACROSS THE COASTAL WATERS
THROUGH TUESDAY MORNING. STRONG GUSTY WINDS, CLOUD TO WATER
LIGHTNING, LOCALLY HIGHER SEAS, AND TORRENTIAL RAINFALL IS
EXPECTED. MARINERS SHOULD REMAIN AWARE OF THE LATEST WEATHER AND
BE PREPARED TO SEEK SHELTER IF A STRONG STORM APPROACHES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 84 70 82 70 / 80 80 70 70
LCH 83 73 84 73 / 80 80 60 70
LFT 85 73 84 73 / 60 80 70 60
BPT 80 74 83 74 / 80 80 70 70
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR LAZ027>032-041-042-
073-074.
TX...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR TXZ180-201-215-216-
259>262.
GM...SMALL CRAFT EXERCISE CAUTION THROUGH MONDAY EVENING FOR GMZ450-
452-455-470-472-475.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1204 AM CDT SUN MAY 24 2015
.AVIATION...
ISOLD CONVECTION WILL BE POSSIBLE OVERNIGHT...BUT WILL MOST LIKELY
NOT AFFECT ANY TERMINALS UNTIL LATER THIS MORNING. INCREASING
BOUNDARY LAYER MOISTURE WILL BRING LOW CIGS BACK TO AREA TERMINALS
THIS MORNING...WHICH ARE LIKELY TO HOLD ON THROUGH THE PD...AS
CONVECTION BECOMES WIDESPREAD BY THIS AFTERNOON. COVERAGE OF
CONVECTION WILL DECREASE AFTER 00Z THROUGH THE END OF THE PD.
OTHERWISE...EXPECT SELY WINDS AROUND 5 KTS OVERNIGHT TO INCREASE
TO BETWEEN 12 AND 18 KTS WITH HIGHER GUSTS DURING SUNDAY. /12/
&&
.PREV DISCUSSION... /ISSUED 908 PM CDT SAT MAY 23 2015/
DISCUSSION...
INCREDIBLE RAINFALL OCCURRING ACROSS PORTIONS OF CENTRAL TEXAS
AND CENTRAL OKLAHOMA THIS EVENING. DEEP SOUTHWEST FLOW ALOFT
HELPING TO DRIVE THESE UPPER LEVEL DISTURBANCES NORTH AND EAST
INTO THIS REGION. 00Z RAOB FROM FWD SHOWING A NEARLY
UNIDIRECTIONAL WIND PROFILE THIS EVENING AND WITH STRONG DIVERGENT
FLOW ALOFT IN RESPONSE TO RIGHT REAR QUAD OF A NEARLY 100KT UPPER
LEVEL JET ACROSS THE TX HILL COUNTRY...YOU HAVE ALL THE INGREDIENTS
NECESSARY FOR AN EXCESSIVE HEAVY RAINFALL EVENT THROUGH THE
NIGHT. IN FACT...AS THE LOW LEVEL JET CONTINUES TO STRENGTHEN
OVERNIGHT...I WOULD EXPECT TO SEE THE FLOODING TO BECOME MORE
WIDESPREAD...ESPECIALLY ACROSS NORTHERN TEXAS AND FURTHER SOUTH
INTO SOUTHERN OKLAHOMA OR INTO THE MIDDLE RED RIVER BASIN...
EXACTLY WHERE THE RAINFALL IS NOT NEEDED.
THE MILLION DOLLAR QUESTION IS WHEN WILL THIS PRECIPITATION BEGIN
TO MAKE AN APPEARANCE INTO OUR REGION. LATEST OOZ WRF AND
ACCOMPANYING HRRR ARE WANTING TO KEEP A BULK OF THIS PRECIPITATION
OUT OF OUR REGION UNTIL 12Z WHEN THEY FINALLY BEGIN TO BRING SOME
SORT OF LINEAR CONVECTION INTO OUR WESTERN ZONES. GIVEN THAT THE
COLD POOL THAT WAS GENERATED EARLIER WITH THE CENTRAL OK CONVECTION
HAS ALL BUT STALLED WITH THE SEA BREEZE BOUNDARY HAVING MET UP
WITH IT JUST NORTH OF THE RED RIVER...THIS LATER SCENARIO SEEMS
PLAUSIBLE.
OUR FLASH FLOOD WATCH BEGINS AT 4 AM AND THERE MAY NOT BE MUCH
GOING ON ACROSS OUR REGION AT THAT TIME...EXCEPT MAYBE ALONG AND
NORTHWEST OF THE I-30 CORRIDOR. WILL ERR ON THE SIDE OF CAUTION
HOWEVER AND KEEP EVERYTHING AS IS CONCERNING THE TIMING OF THE
WATCH AND THE OVERNIGHT POP FORECAST. MID AND HIGH CLOUD COVER IS
WIDESPREAD AND WE SHOULD BEGIN TO SEE LOWER CEILINGS DEVELOP FROM
THE SOUTH LATER TONIGHT AS WELL. GIVEN THE STRONG PRESSURE
GRADIENT IN PLACE...WOULD NOT EXPECT TO SEE OVERNIGHT TEMPERATURES
FALL TOO MUCH MORE BUT THAT COULD CHANGE IF WE BEGIN TO SEE SOONER
THAN EXPECTED RAINFALL. THEREFORE WILL KEEP CURRENT MIN FCST AS
IS.
NO CHANGES WILL BE MADE TO THE CURRENT FCST ATTM.
13
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 71 81 69 81 / 40 80 80 80
MLU 70 85 70 81 / 30 60 80 70
DEQ 68 75 67 79 / 70 90 80 80
TXK 70 79 69 80 / 60 80 80 80
ELD 69 82 69 80 / 40 70 80 70
TYR 71 77 70 80 / 60 80 70 80
GGG 71 79 70 81 / 50 80 70 80
LFK 73 79 72 81 / 40 80 70 80
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 4 AM CDT SUNDAY THROUGH MONDAY MORNING
FOR ARZ050-051-059>061-070>072.
LA...FLASH FLOOD WATCH FROM 4 AM CDT SUNDAY THROUGH MONDAY MORNING
FOR LAZ001>004-010>012-017-018.
OK...FLASH FLOOD WATCH FROM 4 AM CDT SUNDAY THROUGH MONDAY MORNING
FOR OKZ077.
TX...FLASH FLOOD WATCH FROM 4 AM CDT SUNDAY THROUGH MONDAY MORNING
FOR TXZ096-097-108>112-124>126-136>138-149>153-165>167.
&&
$$
12
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
741 PM EDT MON MAY 25 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 424 PM EDT MON MAY 25 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
MN INTO CO AND A RIDGE OVER THE ERN CONUS RESULTING IN SW FLOW FROM
THE SRN PLAINS TO THE WRN LAKES. A SHORTWAVE TROUGH THAT BROUGHT
WIDESPREAD RAIN ACROSS UPPER MI INTO THE EARLY AFTERNOON WAS LIFTING
NE THROUGH ERN LAKE SUPERIOR LEAVING A PROMINENT DRY SLOT INTO CNTRL
UPPER MI. AT THE SFC...LOW PRES WAS LOCATED OVER W CNTRL UPPER MI
WITH A TROUGH EXTENDING BACK THROUGH CNTRL MN INTO SE SD.
UPSTREAM...ANOTHER WEAKER SHRTWV SUPPORTED SOME TSRA OVER NRN IA.
ENOUGH INSTABILITY HAD DEVELOPED OVER NRN WI FOR SOME ISOLD -SHRA TO
DEVELOP IN THE WAKE OF THE LARGER RAIN AREA.
TONIGHT...MODELS ALONG WITH RADAR/SATELLITE TRENDS SUGGEST THAT THE
NRN IA PCPN MAY SPREAD TOWARD THE S AND E PORTION OF THE CWA BY LATE
THIS EVENING. ALTHOUGH THE MODELS ALSO HINT AT THE POTENTIAL FOR
ADDITIONAL PCPN ASSOCIATED WITH A SHRTWV OVER SE SD THAT COULD MOVE
INTO W UPPER MI...CONFIDENCE IS LOWER. OTHERWISE...MILD CONDITIONS
WITH LOWS IN THE MID50S ARE EXPECTED WITH LIGHT SW WINDS PREVAILING.
TUE...THE SHRTWV OVER NRN TX THAT SUPPORTED A VERY LARGE MCS IS
EXPECTED TO LIFT TOWARD THE WRN LAKES BY LATE TUE BRINGING
INCREASING CHANCES FOR PCPN DURING THE AFTERNOON. THERE IS MORE
UNCERTAINTY ON WHERE THE PCPN WILL DEVELOP AS THE GFS/ECMWF KEEP THE
RAIN FARTHER WEST COMPARED TO THE NAM/REG-GEM. WITH MUCAPE VALUES
INTO THE 500-1000 J/KG RANGE...SOME TSRA WILL BE POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 427 PM EDT MON MAY 25 2015
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AN AREA OF LOW PRESSURE TO
THE SOUTHWEST OF JAMES BAY TUESDAY NIGHT WILL SLIDE INTO NORTHERN
QUEBEC BY WEDNESDAY NIGHT. THIS WILL ALLOW A COLD FRONT TO PASS
ACROSS THE REGION THROUGH WEDNESDAY AFTERNOON. ALOFT...AN ASSOCIATED
SHORTWAVE WILL PASS ACROSS THE UPPER GREAT LAKES REGION AROUND THE
SAME TIME FRAME. THE BEST CHANCES FOR PRECIPITATION WILL BE ALONG
AND AHEAD OF THE COLD FRONT FOR WEST AND CENTRAL AREAS TUESDAY
EVENING...THEN SPREADING INTO CENTRAL AND EASTERN AREAS OVERNIGHT
THROUGH WEDNESDAY MORNING. WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING THE FRONT WILL BE PAST THE CWA...HOWEVER...THE SHORTWAVE
WILL STILL BE NEARBY ALLOWING FOR ADDITIONAL CHANCES OF MORE
ISOLATED SHOWERS AND A FEW THUNDERSTORMS WITH THE COOLER AIR ALOFT.
INSTABILITY WILL BE SIGNIFICANT ENOUGH TO CONTINUE THE MENTION FOR
THUNDERSTORMS DURING THE AFTERNOON WITH VALUES RANGING FROM AROUND
300 J/KG TO AROUND 800 J/KG...AGAIN THE BEST CHANCES FOR RAIN WILL
BE EARLIER IN THE DAY WITH THE FORCING ALONG THE FRONT. SEVERE
WEATHER THREAT DURING THIS TIME PERIOD LOOKS TO BE LIMITED WITH VERY
LITTLE SHEAR ALONG WITH LIMITED CAPE.
THURSDAY THROUGH FRIDAY NIGHT...DURING THE DAY THURSDAY...MUCH OF
THE AREA WILL GET A BREAK FROM THE RAIN SHOWERS AS THE CWA WILL BE
BETWEEN SYSTEMS DURING THAT TIME WITH THE COLD FRONT TO THE EAST AND
A LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT SLIDING INTO THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA. TIMING ISSUES REMAIN
BETWEEN THE GFS/EC THURSDAY NIGHT THROUGH FRIDAY NIGHT ON THE EXACT
LOW POSITION ALONG WITH THE COLD FRONT POSITION. THE GFS IS STILL
MORE PROGRESSIVE WITH THE SYSTEM WHILE THE EC IS MUCH SLOWER AT
MOVING THE SYSTEM THROUGH. EITHER WAY...THURSDAY NIGHT INTO FRIDAY
LOOKS TO BE WET WITH SHOWERS AND THUNDERSTORMS PUSHING THROUGH.
ALOFT...A 500 MB TROUGH WILL PUSH ACROSS THE AREA DURING THE SAME
TIME FRAME...WHILE LINGERING INTO THE OVERNIGHT HOURS FRIDAY NIGHT
AS A RIDGE BEGINS TO BUILD OVER THE WESTERN CONUS. SEVERE WEATHER
WILL BE A POSSIBILITY FRIDAY AFTERNOON IF THE FRONT MOVES IN DURING
THE AFTERNOON...PEAK HEATING HOURS...WHICH IS SUGGESTED BY THE EC.
IF THE GFS SOLUTION VERIFIES...THEN THE FRONT WILL ALREADY BE PAST
MOST OF THE U.P. BY FRIDAY AFTERNOON...HELPING TO LIMIT THE CHANCES.
MUCAPE VALUES RANGE FROM 400-700 J/KG FROM THE GFS TO AROUND 800-
1100 J/KG FROM THE EC. SHEAR VALUES FROM THE EC ARE PROGGED TO BE
AROUND 30 TO 40 KNOTS WITH PERPENDICULAR TO THE FRONT AT THE ONSET.
AGAIN MUCH OF THIS IS CONDITIONAL...DEPENDING LARGELY ON THE OVERALL
TIMING OF THE AFOREMENTIONED UPPER LEVEL AND SURFACE FEATURES. THE
WARMER TEMPERATURES SLIDING ACROSS THE COLD WATERS OF THE GREAT
LAKES WILL ALLOW WIDESPREAD FOG TO FORM THURSDAY NIGHT INTO
FRIDAY...ESPECIALLY WHEN THE RAIN SHOWERS PUSH OVER THE AREA. THE
FAIRLY STRONG TEMPERATURE INVERSION CAN BE NOTED ON BUFKIT SOUNDINGS.
SATURDAY THROUGH THE REMAINING EXTENDED...NICE WEEKEND EXPECTED AS
DRY COOL CANADIAN HIGH PRESSURE IS EXPECTED TO SLIDE ACROSS THE
UPPER GREAT LAKES REGION. THE UPPER LEVEL 500MB TROUGH AXIS IS
EXPECTED TO SLOWLY SHIFT TO THE EAST OF THE AREA BY SUNDAY EVENING.
CALM WINDS ASSOCIATED WITH THE SURFACE HIGH ALONG WITH VERY DRY AIR
IN PLACE WILL ALLOW TEMPERATURES TO DROP BELOW NORMAL...INTO THE 30S
FOR OVERNIGHT LOW TEMPERATURES AND HIGHS IN THE MID 50S TO LOW 60S.
FROST MAY BE POSSIBLE SATURDAY NIGHT INTO SUNDAY MORNING ACROSS
INLAND AREAS. SUNDAY NIGHT THROUGH MONDAY...MODELS BEGIN TO DIFFER
GREATLY WITH THE GFS BRINGING A LOW NORTHWARD INTO THE AREA WHILE
THE EC MAINTAINS THE HIGH PRESSURE SYSTEM. AT THIS POINT...WILL
STICK WITH A CONSENSUS FOR THAT TIME PERIOD DUE TO THE MODEL
DISAGREEMENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 740 PM EDT MON MAY 25 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. WHILE LOWER CLOUDS
WILL LIKELY SCATTER OUT TO VFR AT TIMES THIS EVENING AT KIWD...
EXPECT A TREND FROM MVFR BACK DOWN TO IFR...AND THEN LIFR OVERNIGHT
AS ABUNDANT LOW LEVEL MOISTURE LINGERS. IMPROVEMENT BACK TO MVFR
WILL OCCUR LATE TUE MORNING. AT KCMX...LGT/VRBL WINDS AND LOSS OF
UPSLOPE WIND THIS EVENING SHOULD ALLOW LIFR CONDITIONS TO BOUNCE UP
TO IFR OR EVEN MVFR AT TIMES. HOWEVER...AS LIGHT UPSLOPE WESTERLY
WINDS DEVELOP BY LATE EVENING...EXPECT PREVAILING LIFR CONDITIONS TO
SET IN ONCE AGAIN. IMPROVEMENT TO MVFR WILL OCCUR BY EARLY TUE AFTN.
AT KSAW...SOMEWHAT DRIER AIR AT THE LOW LEVELS ARRIVING ON SW WINDS
SHOULD ALLOW A PREVAILING VFR CONDITION INTO THE OVERNIGHT. MVFR
CIGS SHOULD REDEVELOP LATE TONIGHT. ACROSS THE AREA...SCT/NMRS SHRA
WILL DEVELOP TUE AFTN...WITH PCPN MORE LIKELY TO OCCUR AT KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EDT MON MAY 25 2015
LOW PRESSURE WILL MOVE ACROSS LAKE SUPERIOR TONIGHT SO THE WINDS
WILL SLOWLY DIMINISH. WINDS THE REST OF THE FORECAST PERIOD ARE
EXPECTED TO STAY AT OR BELOW 25 KTS. FOG WILL LINGER THROUGH
WEDNESDAY MORNING AND MAY BE DENSE AT TIMES. ADDITIONAL FOG IS
EXPECTED TO DEVELOP THURSDAY NIGHT AND FRIDAY AHEAD OF THE NEXT LOW
AND ASSOCIATED COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT SUN MAY 24 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 418 PM EDT SUN MAY 24 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
THE WRN CONUS WITH A LOW OVER SRN WY AND A RIDGE FROM THE SE CONUS
TO THE WRN LAKES. ONE SHORTWAVE TROUGH WAS LIFINT TO THE NNE TRHOUGH
FROM ERN IA WHILE ANOTHER TRAILED OVER OK. AT THE SFC...LOW PRES WAS
LOCATED OVER SW IA WITH A WARM FRONT INTO NRN IL. A SURGE OF
MOISTURE (8 G/KG AND 850 MB DEWPONTS AROUND 12C) WITH STRONG 300K-
310K ISENTROPIC LIFT NORTH OF THE WARM FRONT SUPPORTED A LARGE AREA
OF MODERATE TO HEAVY RAIN FROM SE MN THROUGH SRN WI INTO NRN IL.
VIS/IR LOOPS SHOWED THICKENING MID/HIGH CLOUDS INTO UPPER MI NORTH
OF THE AREA OF RAIN. TEMPS HAVE CLIMBED INTO THE MID TO UPPER 70S
BUT HAVE FALLEN OFF N CNTRL AS A LAKE BREEZE MOVED IN.
RADAR TRENDS AND MODELS SUGGEST THAT THE AREA OF RAIN WILL GRADUALLY
SPREAD THROUGH THE CWA FROM S TO N BTWN 23Z-06Z. SUPPORTED BY
MODERATE TO STRONG 700-300 QVECTOR CONV AND UPPER LEVEL DIV WITH THE
RIGHT ENTRANCE OF A JET OVER NRN ONTARIO...WIDESRPEAD MODERATE
RAINFALL AMOUNTS ARE EXPECTED WITH QPF FROM 1.0-1.5 INCHES THROUGH
MON. THE GREATEST AMOUNTS ARE EXEPCTED OVER THE SE WHERE THE
STRONGER MOISTURE TRANSPORT IS FOCUSED.
THE FIRST AREA OF RAIN IS EXPECTED TO TAPER OFF DURING THE MORNING
OVER THE SOUTH AND THE NORTH BY AFTERNOON. HOWEVER...THE TRAILING
SHORTWAVE FROM THE SRN WILL SUPPORT ADDITIONAL RAIN INTO THE WEST BY
MID TO LATE AFTERNOON. NO THUNDER WAS MENTIONED...GIVEN LITTLE OR NO
FCST ELEVATED CAPE AND LACK OF LIGHTNING UPSTREAM.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 358 PM EDT SUN MAY 24 2015
IN THE UPPER LEVELS...TROUGH OVER THE WESTERN CONUS LIFTS ACROSS THE
NORTHERN PLAINS AND UPPER GREAT LAKES EARLY THIS WEEK AS ADDITIONAL
TROUGHING MOVES OVER NORTHWEST CONUS. BY LATE IN THE WEEK...NW CONUS
TROUGH MOVES EAST AND MERGES WITH DEEPER TROUGH MOVING FM CNTRL
CANADA OVER THE GREAT LAKES. AT THE SFC...LOW PRESSURE SYSTEM OVER
LK SUPERIOR ON MONDAY NIGHT WILL DRAG A TROUGH ACROSS UPPER LAKES ON
TUESDAY AS IT MOVES TO QUEBEC. MOST RAIN WILL BE DONE BY 00Z TUESDAY
AS DRY SLOT MOVES IN FM THE SOUTH IN WAKE OF SHORTWAVE AND SFC LOW
MOVING THROUGH. TRACK OF SFC LOW STILL UNCERTAIN...BUT SEEMS IT WILL
BE SOMEWHERE OVER CNTRL OR EASTERN LK SUPERIOR...COMPARED TO FARTHER
WEST TRACK MODELS WERE PREVIOUSLY INDICATING. RESULT WILL BE TO KEEP
EASTERLY COMPONENT WIND OVER THE KEWEENAW INTO THE EVENING AND THUS
A BETTER CHANCE OF FOG OR EVEN SOME DRIZZLE. SSW-SW WINDS ELSEWHERE
WILL LIMIT MOST OF THE FOG VCNTY OF LAKE MICHIGAN SHORE.
NEXT BETTER CHANCES OF RAIN ARRIVE LATER IN THE DAY ON TUESDAY AS
MODELS INDICATE SHORTWAVES CURRENTLY OVER FAR SOUTHERN CA AND IN THE
VCNTY OF UPPER LOW CENTER OVER INTERMOUNTAIN WEST COMBINE TO LIFT
ACROSS UPPER GREAT LAKES. MAY EVEN BE STRONG ENOUGH SYSTEM TO HELP
DEVELOP A SFC LOW PRESSURE. HEAVIEST QPF WILL BE ALONG AND WEST OF
H85-H7 LOWS...WHICH IS NOT QUITE CLEAR. GFS FAVORS FAR WESTERN UPR
MICHIGAN WHILE GEM-NH AND ECMWF ARE MORE OVER CNTRL UPR MICHIGAN.
ELEVATED INSTABILITY PRESENT WITH MUCAPES OF AT LEAST 300 J/KG ECMWF
OR UP OVER 1000J/KG AS THIS WAVE LIFTS THROUGH...SO DID INCLUDE TSRA
MENTION ON TUE/TUE NIGHT. IF FARTHER WEST TRACK VERIFIES...POTENTIAL
IS THERE FOR SFC BASED TSRA TUE AFTN INTO TUE EVENING. MAX TEMPS ON
TUESDAY AHEAD OF THE SYSTEM SHOULD BE ABLE TO REACH 70S INLAND WEST.
HOWEVER...EAST WINDS CLOSER TO LK SUPERIOR AND SOUTH WINDS CLOSER TO
LK MICHIGAN WILL KEEP IT COOLEST IN THOSE AREAS DUE TO ONSHORE FLOW
AND ALSO LINGERING FOG AND LOW CLOUDS.
LOW PRESSURE SYSTEM OR TROUGH SHOULD BE EAST OF UPPER LAKES BY WED.
COULD BE WEAKER WAVE ALOFT MOVING THROUGH THAT INTERACTS WITH SOME
AFTN HEATING TO PRODUCE ISOLD SHRA OR EVEN TSRA...MAINLY WEST. GEM-
NH AND ECMWF HINTING AT THIS...SO KEEP SLIGHT CHANCES EVEN THOUGH
GFS FAVORS DRY CONDITIONS. LIGHTER WEST WINDS WILL ONLY BE LOCALLY
ONSHORE...SO MOST AREAS SHOULD WARM WELL INTO THE 70S AS H85 TEMPS
CLIMB INTO THE LOWER TEENS C.
TROUGH ALOFT SETTLES OVER UPR LAKES ON THURSDAY WHILE MORE ORGANIZED
AREA OF LOW PRESSURE DEVELOPS OVER THE NORTHERN PLAINS AS THE
SHORTWAVE TROUGH MOVES EAST FM THE NORTHWEST CONUS. SFC LOW AND
TROUGH WILL EDGE ACROSS UPPER MISSISSIPPI RIVER VALLEY ON THURSDAY
THEN SLIDE OVER THE UPPER GREAT LAKES FRIDAY INTO FRIDAY NIGHT. THE
TROUGH WILL THEN BE SHOVED SOUTH OVER THE LOWER GREAT LAKES AND OHIO
VALLEY BY NEXT WEEKEND AS CANADIAN HIGH PRESSURE BUILDS OVER THE
NORTHERN PLAINS AND UPR GREAT LAKES. BEST SHOT OF SHRA AND POSSIBLE
TSRA ARRIVES FOR THURSDAY NIGHT OVER THE WEST THEN OVER ALL OF CWA
ON FRIDAY AS THE UPPER AND SFC COLD FRONT SWEEP THROUGH. MODELS ALL
HAVE THE GENERAL IDEA OF COLD FRONTAL PASSAGE...BUT VARY ON WHEN
PASSAGE OCCURS. GFS IS QUICKEST WITH MOST OF AREA DRY BY FRIDAY
AFTN. ECMWF AND GEM-NH ARE SLOWER...BRINGING THE FRONT THROUGH ON
FRIDAY OR EVEN FRIDAY NIGHT. NO MATTER WHICH SOLUTION IS
PREFERRED...APPEARS COOL AND DRY CONDITIONS ARE ON THE WAY NEXT
WEEKEND AS HIGH PRESSURE BUILDS OVERHEAD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 135 PM EDT SUN MAY 24 2015
ALTHOUGH THERE WILL BE AN INCREASE IN MID AND HIGH CLOUDS...DRY AIR
WILL LINGER AT THE LOWER LEVELS THROUGH AT LEAST INTO EARLY THIS
EVENING...RESULTING IN VFR CONDITIONS AT KIWD/KCMX/KSAW. BY LATE
THIS EVENING...AN AREA OF SHOWERS WILL LIFT N INTO THE UPPER GREAT
LAKES...BRINGING DETERIORATING CONDITIONS AT ALL SITES. CONDITIONS
WILL FALL TO IFR OR LOWER AT ALL TERMINALS LATE TONIGHT. IFR/LIFR
CONDITIONS WILL THEN PERSIST THROUGH MONDAY MORNING. MOIST ERLY
UPSLOPE FLOW OFF OF LAKE INTO CMX MAY DROP VSBY DOWN TOWARD VLIFR
MON MORNING BUT WITH RAIN PREVAILING...NOT CONFIDENT IN LOWERING VSBY
BELOW 1SM YET.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EDT SUN MAY 24 2015
LIGHT WINDS INCREASE ON MONDAY AS LOW PRESSURE SYSTEM OVER THE
CENTRAL PLAINS LIFTS TOWARD LK SUPERIOR. EAST WINDS MAY REACH 25
KTS...STRONGEST OVER WESTERN LK SUPERIOR. LOW SLIDES OVERHEAD ON
MONDAY NIGHT SO THE WINDS WILL DIMINISH. WINDS THE REST OF THE
FORECAST PERIOD ARE EXPECTED TO STAY AT OR BLO 20 KTS. FOG IS
EXPECTED TO DEVELOP LATE TONIGHT AND IT SHOULD LINGER THROUGH
WEDNESDAY. THE FOG MAY BE DENSE AT TIMES. ONCE IT IS EVIDENT
HOW EXPANSIVE THE FOG IS...A DENSE FOG ADVISORY MAY BE NEEDED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
106 AM EDT SUN MAY 24 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 409 PM EDT SAT MAY 23 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER
UT...A RIDGE FROM THE SE CONUS INTO THE UPPER MS VALLEY AND A TROUGH
OVER NE CANADA RESULTING IN CONFLUENT WNW FLOW THROUGH THE NRN
LAKES. AT THE SFC...SW TO W WINDS PREVAILED OVER MOST OF UPPER MI
BUT WERE WEAK ENOUGH TO ALLOW A LAKE BREEZE TO MOVE INTO THE N
CNTRL. MIXING AOA 10K FT HAS HELPED DROP DEWPOINTS INTO THE LOW TO
MID 30S. WITH TEMPS ALSO INTO THE UPPER 70S...RH VALUES HAVE DROPPED
INTO THE 20-25 PERCENT RANGE. VIS LOOP INDICATEED SCT DIURNAL CU
ALONG WITH SOME MID/HIGH CLOUDS APPROACHING FROM THE MN/WI.
TONIGHT...WITH PERSISTENT SW WINDS AND INCREASING MID/HIGH
CLOUDS...MIN READINGS WILL REMAIN IN THE UPPER 40S TO MID 50S WITH
THE WARMEST CONDITIONS NEAR LAKE SUPERIOR WHERE DOWNSLOPE FLOW WILL
PREVAIL.
SUNDAY...MODELS SUGGEST THAT THE SFC AND MID LEVEL TROUGH WILL MOVE
INTO THE PLAINS WITH CONTINUED RIDING INTO THE NRN LAKES. HOWEVER SW
TO W MID LEVEL FLOW BRINGING INCREASED MOISTURE WITH 300K-310K
ISENTROPIC ASCENT TOWARD THE AREA WILL BRING A CHANCE OF LIGHT RAIN
TOWARD THE AREA BY LATE IN THE DAY. EXPECT THAT THE ONSET OF THE
PCPN MAY BE DELAYED BY CONTINUE DRY LOW LEVELS. TEMPS SHOULD AGAIN
CLIMB INTO THE MID 70S BUT WILL BE LIMITED BY INCREASING CLOUD
THICKNESS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 357 PM EDT SAT MAY 23 2015
UPPER AIR PATTERN TO START LONG TERM SHOWS LARGER TROUGH FM WESTERN
CANADA INTO THE PLAIN STATES. RIDGE ALOFT CENTERED OVER SE CONUS
EXTENDS RIDGE BACK OVER GREAT LAKES. SHORTWAVE ON LEADING EDGE OF
WESTERN CONUS TROUGH LIFTS TOWARD UPPER MISSISSIPPI RIVER VALLEY ON
SUNDAY NIGHT. SFC LOW AND ASSOCIATED WARM AIR AND MOISTURE ADVECTION
AHEAD OF THE WAVE...SEEN IN H85-H7 MOISTURE TRANSPORT FIELDS...
COMBINES WITH LARGER SCALE ASCENT IN RIGHT ENTRANCE REGION OF 130+
KT JET STREAK FM NORTHERN ONTARIO TO NEW ENGLAND TO BRING A PERIOD
OF SHOWERS ACROSS CWA LATER SUNDAY NIGHT THROUGH EARLY MONDAY AFTN.
SHOWERS SHOULD END FIRST ALONG THE WI BORDER ON MONDAY MORNING AND
THEN ALONG LK SUPERIOR IN THE AFTERNOON. ELEVATED INSTABILITY SHOWS
UP SOME WITH SI/S LOWERING TOWARD 0-1C BUT THAT ARRIVES AFTER MAIN
FORCING MOVES ACROSS. NOT EXPECTING MUCH FOR TSRA AT THIS POINT.
RAIN COULD FALL HEAVY AT TIMES GIVEN PWATS BY 12Z MONDAY AT KGRB
THAT WOULD BE IN THE HIGHEST 5 PCT COMPARED TO CLIMO FOR THE DATE.
ESE-E WINDS AHEAD OF THE LOW AND ASSOCIATED WARM FRONT/ADVECTION OF
HIGHER DWPNTS AND RAIN OVER ALL THE AREA POINTS TO FOG OVER THE GREAT
LAKES/ADJACENT SHORELINES AND ALSO OVER KEWEENAW PENINSULA AND HIGHER
TERRAIN OF CNTRL CWA BTWN KIMT AND MARQUETTE.
UNCERTAINTY IN POPS/WX LATE MONDAY AFTN INTO MONDAY EVENING BUT
GENERALLY EXPECT MAINLY DRY WEATHER DUE TO MID-LEVEL SUBSIDENCE AND
DRYING THAT MOVES OVERHEAD IN WAKE OF PRIMARY SHORTWAVE. LIKELY WILL
BE LINGERING LOW-LEVEL MOISTURE...THOUGH SSW BLYR WINDS DO NOT FAVOR
PERSISTENT LOW CLOUDS SINCE THAT PROVIDES MINIMAL TRAJECTORIES OFF
THE ADDITIONAL MOISTURE FM THE GREAT LAKES. GIVEN THE SSW WINDS ALSO
DIMINISHED FOG ON THE LAND AREAS...AT LEAST AWAY FM LK MICHIGAN AND
THE OPEN WATERS OF LK SUPERIOR. NAM INDICATES ENOUGH ADDITIONAL MID-
LEVEL MOSITURE MOVES IN BY EVENING TO COMBINE WITH INCREASING
INSTABILITY TO PRODUCE CONVECTION. SINCE NAM IS ONLY MODEL
INDICATING THIS AT PRESENT...WILL DISCOUNT THAT IDEA AND CONTINUE TO
DOWNPLAY POPS. TEMPS ON MONDAY DEPEND ON EXTENT OF CLEARING. WILL
NOT TAKE MUCH TO BOOST TEMPS WITH WARM TEMPS ALOFT IN WARM SECTOR OF
SFC LOW THAT WILL BE NW OF LK SUPERIOR BY 00Z TUE. MIXING TO H9
RESULTS IN MAX TEMPS INTO THE 70S...SO INCREASED MAX TEMPS SLIGHTLY.
LATER MONDAY NIGHT INTO TUESDAY...MAIN FRONT SWINGS ACROSS UPPER
GREAT LAKES AS SFC LOW TRACKS NORTH OF LK SUPERIOR. VARYING IDEAS ON
STRENGTH AND WESTWARD EXTENT OF SHORTWAVE LIFTING NORTHEAST ALONG THE
FRONT. GFS MOST AGRESSIVE WITH THAT IDEA WHERE ECMWF AND GEM ARE NOT
AS BULLISH. KEPT IT SIMPLE AND RETAINED LOW CHANCE POPS ALONG AND
AHEAD OF FRONT MOVING THROUGH. BASED ON SW H85 THETA-E ADVECTION
AHEAD OF THE FRONT AND AT LEAST A FEW HUNDRED J/KG OF ELEVATED
CAPE...ADDED SLIGHT CHANCE FOR THUNDER OVER EAST HALF OF CWA MONDAY
NIGHT INTO TUESDAY. BASED ON FORECAST SOUNDINGS...KEPT THE FOG GOING
OVER THE GREAT LAKES AND NEAR LK MICHIGAN AT LEAST FOR THE MORNING ON
TUESDAY. ENOUGH DRYING DEVELOPS LATER IN THE DAY TO DISSIPATE THE
FOG. TEMPS ON TUESDAY COOLEST OVER NW CWA AND NEAR LK MICHIGAN WITH
MORE PRONOUNCED ONSHORE FLOW. EVEN FOR THOSE AREAS THOUGH...TEMPS
WILL BE IN THE 60S. MAX TEMPS REACH MID 70S INLAND TOWARD WI BORDER.
REST OF EXTENDED INDICATES MAINLY DRY WEATHER FOR WEDNESDAY WITH
ANOTHER FRONT BRINGING SMALL CHANCES FOR RAIN THURSDAY INTO FRIDAY.
BASED ON LATEST ECMWF WHICH TRENDED TOWARD LAST COUPLE RUNS OF
GFS...APPEARS THAT NEXT WEEKEND WOULD BE DRIER AS MORE ACTIVE
FRONTAL BOUNDARY SETTLES OVER THE LOWER GREAT LAKES AND OHIO VALLEY.
KEPT LOW CHANCES THAT CONSENSUS GAVE ATTM...BUT IF THESE MODEL
TRENDS CONTINUE...LATER SHIFTS MAY BE ABLE TO REMOVE POPS FM NEXT
SATURDAY. OVERALL TEMPS THROUGH THE WEEK SHOULD BE AROUND NORMAL.
GIVEN THE LACK OF REAL COOLING AT H85 OTHER THAN WITH THE FRONT
MOVING THROUGH ON TUESDAY...COULD SEE TEMPS MOST DAYS TUESDAY
THROUGH THURSDAY PUSH SLIGHTLY ABOVE NORMAL IN THE MID-UPR 70S.
NIGHTTIME LOWS SHOULD STAY SAFELY ABOVE FREEZING...WITH MAINLY 40S
TO AROUND 50 DEGREES EXPECTED. COOLER TEMPS MOVE BACK IN NEXT
WEEKEND AS COOLER CANADIAN HIGH PRESSURE SETTLES OVER THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 106 AM EDT SUN MAY 24 2015
ALTHOUGH THERE WILL BE AN INCREASE IN MID AND HIGH CLOUDS...DRY AIR
WILL LINGER AT THE LOWER LEVELS THRU AT LEAST EARLY THIS EVENING...
RESULTING IN VFR CONDITIONS PREVAILING AT KIWD/KCMX/KSAW. LATE THIS
EVENING AND JUST BEYOND THIS FCST PERIOD...AN AREA OF SHOWERS WILL
LIFT N INTO THE UPPER GREAT LAKES...BRINGING DETERIORATING
CONDITIONS. PCPN SHOULD ADVANCE AS FAR N AND NE AS KIWD JUST BEFORE
THE END OF THIS FCST PERIOD. BEYOND THIS FCST PERIOD...CONDITIONS
WILL LIKELY FALL TO IFR OR LOWER AT ALL TERMINALS BY SUNRISE MON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EDT SAT MAY 23 2015
SW-W WINDS TO 25 KTS...EVEN GREATER THAN 30 KTS AT HIGHER LEVEL
OBSERVATION PLATFORMS...DIMINISHES THROUGH THE EVENING. WINDS THEN
REMAIN LESS THAN 20 KTS INTO SUNDAY NIGHT BEFORE BECOMING EAST TO
SOUTHEAST AND INCREASING TO 20-25 KTS MONDAY AND MONDAY NIGHT AS A
LOW PRESSURE SYSTEM LIFTS TO NORTHWEST LK SUPERIOR. STRONGEST WINDS
SHOULD OCCUR ON MONDAY OVER WESTERN LK SUPERIOR WHERE WINDS WILL
TURN NORTHEAST DUE TO FUNNELLING. FOG SHOULD DEVELOP LATE SUNDAY
NIGHT AND THIS WILL LINGER OVER MUCH OF LK SUPERIOR THROUGH TUESDAY
MORNING. FOG MAY BECOME DENSE AT TIMES. WINDS BEYOND MONDAY NIGHT
DIMINISH TO 20 KTS OR LESS AS PRESSURE GRADIENT WEAKENS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
430 PM CDT SUN MAY 24 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 430 PM CDT SUN MAY 24 2015
TODAY HAS BEEN ABOUT AS MUCH OF A WASHOUT AS YOU CAN GET AS AN
ISENTROPICALLY FORCED RAIN SHIELD LIFTS NORTH ACROSS THE AREA TO THE
NORTH OF A WARM FRONT THAT THIS AFTERNOON WAS APPROACHING I-80 DOWN
IN IOWA. MODELS OF BOTH THE DETERMINISTIC AND CAM VARIETY ARE IN
GOOD AGREEMENT ON THIS BAND SLOWLY LIFTING NORTH THROUGH THE EVENING
BEFORE STALLING OUT OVERNIGHT FROM WEST CENTRAL MN OVER TOWARD NW WI
AS A SFC LOW BEGINS TO TAKE SHAPE OVER SRN MN AS THE WARM FRONT
LIFTS INTO THE STATE. FOLLOWED THE GENERAL IDEA OF THE HOPWRF
MEMBERS AND HRRR WITH THE POPS IN BRINGING SOME LOW CHANCE POPS UP
THROUGH ABOUT THE SRN HALF OF THE AREA TONIGHT AS A DRY PERIOD LOOKS
TO GET ABOUT AS FAR NORTH AS A MONTEVIDEO/TWIN CITIES/EAU CLAIRE LINE.
WHERE A FAIR DEGREE OF UNCERTAINTY LIES IS WHAT HAPPENS AFTER THIS
BAND OF RAIN LIFTS NORTH LATE TONIGHT AND THE STRONG SHORTWAVE
CURRENTLY MOVING OUT OF TEXAS INTO CENTRAL OK MOVES TOWARD WI. THERE
SHOULD BE A BAND OF MOD TO HEAVY RAIN THAT LIFTS NORTH WITH THIS
WAVE LATE TONIGHT THROUGH MONDAY MORNING...BUT WHERE IT GOES IS
WHERE THE UNCERTAINTY LIES. THE GFS AND CANADIAN BRING THIS BAND
ACROSS WRN WI WHILE THE NAM/ECMWF TAKE IT MORE TOWARD GREEN BAY. THE
SHORT TERM MODELS...WHICH NOW END MONDAY MORNING WOULD FAVOR THE ERN
SOLUTION BEING CORRECT. IF THAT IS THAT CASE...THEN A DRY SLOT WILL
RESULT IN A DRY MEMORIAL DAY OUTSIDE OF THE PERSISTENT RAIN BAND
ACROSS CENTRAL MN. THE GFS/CANADIAN SOLUTION WOULD HAVE YET ANOTHER
WASHOUT FOR FOLKS IN WRN WI. HARD TO SPLIT THE DIFFERENCE BET WET OR
DRY...SO JUST REDUCED POPS INTO THE LIKELY CATEGORY IN OUR EAST
MONDAY MORNING GIVEN THE UNCERTAINTY.
OTHER CHANGE FOR THE SHORT TERM WAS TO REMOVE MOST OF THE THUNDER
MENTION AS WE JUST DO NOT SEE ANY INSTABILITY DEVELOP. THE LONE
EXCEPTION TO THIS IS FOR SOUTH CENTRAL MN MONDAY AFTERNOON WHERE
TEMPERATURES WILL WARM TO AROUND 70...ALLOWING FOR A FEW HUNDRED
J/KG OF CAPE TO DEVELOP. CAMS ALSO SHOW THE TRAILING COLD FRONT
FIRING OFF STORMS IN WRN IOWA MONDAY AFTERNOON...WHICH MAY START
GETTING NEAR THE I-90 CORRIDOR BY THE END OF THE SHORT TERM PERIOD.
FOR TEMPERATURES...EXTENSIVE CLOUD COVER TONIGHT WILL KEEP
TEMPERATURES PRETTY MUCH STEADY THROUGH THE NIGHT. FOR HIGHS
TOMORROW...WITH CONTINUED LIGHT RAIN AND CLOUDS ACROSS CENTRAL MN
EXPECTED...DID DROP HIGHS DOWN TO JUST THE LOW 60S THERE...WHILE THE
RETURN OF SW WINDS DURING THE AFTERNOON IN SRN MN SHOULD ALLOW FOR
TEMPERATURES TO WARM CLOSER TO LATE MAY NORMALS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 430 PM CDT SUN MAY 24 2015
WE PICK UP THE LONG TERM ON MONDAY NIGHT. THE SHORT TERM
DISCUSSION ABOVE MENTIONED THE THREAT FOR THUNDER IN FAR SOUTHERN
MN MONDAY AFTERNOON. THERE IS STILL SOME QUESTION AS TO EXACTLY
HOW FAR NORTH STORMS WILL END UP. THERE IS GOOD AGREEMENT AMONG
THE 12Z AND 18Z GUIDANCE THAT THE WARM FRONT WILL MAKE IT INTO
SOUTHERN MINNESOTA TOMORROW WITH WEAK TO MODERATE ELEVATED
INSTABILITY ARRIVING IN THE SOUTHERN FORECAST AREA BETWEEN 21Z-
00Z. THE AVAILABLE CAM GUIDANCE /WRF-ARW...WRF-NMM...NAM NEST/
SUPPORTS A HEALTHY EAST-WEST ORIENTATED LINE OF CONVECTION
BREAKING OUT IN THE LATE AFTERNOON SOMEWHERE NEAR THE IA/MN IN
RESPONSE TO BUILDING INSTABILITY AND THE ARRIVAL OF A SHORTWAVE
TROUGH OUT OF THE CENTRAL PLAINS. A COUPLE STRONG TO SEVERE STORMS
CAN`T RE RULED OUT AT THIS POINT.
THE FRONTAL BOUNDARY IS SLOW TO CLEAR THE EASTERN FORECAST ON
TUESDAY...SO WE FELT IT WAS BEST TO LINGER THE CHANCE FOR SHOWERS
AND STORMS ACROSS EASTERN MN AND WEST CENTRAL WI UNTIL BUILDING
HEIGHTS KICK THE FRONT TO THE EAST TUESDAY NIGHT INTO WEDNESDAY.
THEREFORE...THE MIDDLE OF THIS COMING WEEK LOOKS DRY AT THE
MOMENT. BEYOND WEDNESDAY...THE PATTERN REMAINS ACTIVE WITH
SOUTHWEST FLOW AND ANOTHER TROUGH MAKING ITS WAY THROUGH MN/WI
LATE IN THE WEEK. THURSDAY AND FRIDAY COULD SEE A COUPLE ROUNDS OF
SHOWERS AND STORMS WITH THE POTENTIAL FOR HEAVY RAIN FALL GIVEN
ANOTHER SLOW FRONTAL PASSAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 119 PM CDT SUN MAY 24 2015
WHAT IS A CERTAINTY IS RAIN AT ALL TERMINALS FOR THE FIRST 6 HOURS
OF THE TAF. RAIN SHIELD MOVING ACROSS THE AREA NOW WILL BECOME
ANCHORED TONIGHT FROM WC MN TOWARD NW WI...WITH PRECIP LIKELY
ENDING AFTER 6Z FOR RWF AND POSSIBLY MSP. ALSO A CERTAINTY ARE
CIGS GOING UNDER VFR AND EVENTUALLY IFR OVERNIGHT. CURRENT TAFS
ARE PROBABLY A BIT OPTIMISTIC ON WHEN MVFR/IFR CIGS MOVE IN...AS
MVFR/IFR CIGS ARE STARTING TO MAKE A BIT MORE NRN PROGRESS INTO
SRN MN. WIND DIRECTIONS WILL BE A BIT DIFFICULT OVERNIGHT AS A
SFC LOW BY MONDAY MORNING WILL BE CENTERED NEAR EAU. WITH THE LOW
PASSING OVERHEAD...WINDS WILL REMAIN LIGHT...BUT DIRECTION WILL
GET A BIT TRICKY TO PIN DOWN...BUT FOLLOWED THE TREND OF THE SREF
FOR DIRECTIONS WITH THE 18Z TAFS.
KMSP...SREF PROBS FOR IFR CIGS AFTER 6Z INCREASE TO ALMOST
100%...SO FEEL CONFIDENT IN CIGS STARTING OFF MONDAY UNDER 1K FT.
CONFIDENT IN RAIN FALLING AS WELL THROUGH ABOUT 4Z...BUT AFTER
THAT IT MAY BE MOSTLY DRY AT MSP FOR THE REST OF THE TAF PERIOD AS
PRECIP STAYS NORTH AND EAST OF THE FIELD.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS SW 10 KTS.
WED...VFR. WINDS SW 5-10 KTS.
THU...VFR. CHC SHRA/-TSRA. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS JACKSON MS
437 PM CDT SUN MAY 24 2015
.DISCUSSION...
SHORT TERM...SHOWERS AND STORMS HAVE BECOME MORE WIDESPREAD ACROSS
THE AREA WITH DAYTIME HEATING AND AIDED BY BROAD UPPER TROUGHING OVER
THE WESTERN 2/3RDS OF THE COUNTRY AND A MID LEVEL SHORTWAVE PASSING
THROUGH THE RED RIVER VALLEY. WHILE CONVECTION HASN`T BEEN
PARTICULARLY DEEP SO FAR TODAY...SOME OF THE STORMS HAVE STILL BEEN
EFFICIENT WIND PRODUCERS. TORNADO WATCH 204 HAS BEEN POSTED FOR ALL
OF OUR LA PARISHES/AR COUNTIES AND PORTIONS OF WEST/CENTRAL MS.
HOWEVER THE OVERALL TORNADO THREAT APPEARS TO BE ON THE LOW END...
ESPECIALLY WITH EASTWARD EXTENT. LATEST SPC MESOANALYSIS SHOWS
RATHER MARGINAL SRH AND MID LEVEL LAPSE RATES ACROSS MOST OF THE
CWA...WITH NEITHER EXPECTED TO SUBSTANTIALLY INCREASE OVER THE NEXT
FEW HOURS PER SPC SSEO/RECENT RAP RUNS. BUFR SOUNDING ANALYSIS/VWPS
ARE MOSTLY UNIDIRECTIONAL. HOWEVER DEEP LAYER/EFFECTIVE BULK SHEAR IS
INCREASING OVER MUCH OF THE DELTA...SO THERE IS GREATER CONCERN FOR
POTENTIAL DAMAGING WINDS THROUGH THE REMAINDER OF THE AFTERNOON INTO
THE EVENING.
EVEN AS THE SHORTWAVE PULLS AWAY FROM THE REGION...SCATTERED
CONVECTION WILL REMAIN POSSIBLE OVERNIGHT INTO MONDAY AS MID/UPPER
FLOW WILL BE NEARLY MERIDIONAL THUS NOT GIVING ACTIVITY MUCH OF AN
EASTWARD PUSH OUT OF OUR AREA. ANOTHER MID LEVEL SHORTWAVE WILL SWING
ACROSS THE LOWER PLAINS/MS VALLEY MONDAY NIGHT INTO EARLY TUESDAY.
BEST POTENTIAL FOR SEVERE WEATHER INCLUDING SOME POSSIBILITY FOR A
TORNADO OR TWO WOULD BE ACROSS THE DELTA...WHERE THE BEST OVERLAY OF
STRONGER DEEP LAYER SHEAR AND HELICITY IS PROGGED. SIMILARLY WE MAY
SOME CONVECTION BECOME REINVIGORATED FARTHER EAST ACROSS A LARGER
PORTION OF THE CWA DURING THE DAYTIME TUESDAY AS STRONGER FORCING
SPREADS EASTWARD.
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE THIS AFTERNOON AND EVENING
ESPECIALLY OVER THE WESTERN HALF OF THE AREA AS PWATS INCREASE TO
AROUND 1 3/4 INCH. IT APPEARS WIDESPREAD AMOUNTS WILL BE LOW ENOUGH
TO PRECLUDE A NOTABLE FLOOD THREAT OVER THE NEXT 24 HOURS. HOWEVER
FLOODING COULD BECOME A GREATER CONCERN MONDAY INTO TUESDAY AS THE
ATMOSPHERE REMAINS VERY MOIST (PWATS INCREASING TO AROUND 2 IN) AND
THE GROUND WILL HAVE BECOME MORE SATURATED DUE TO RAIN FROM
TODAY/TONIGHT. /DL/
LONG TERM...AS WE GO INTO THE REST OF THE PERIOD WE WILL SEE SOME
HEIGHT RISES AS WE GO TOWARD A MORE DIURNAL DRIVEN REGIME FOR MAINLY
AFTERNOON AND EARLY EVENING CONVECTION. THE MEAN RIDGE WILL FLUCTUATE
SOME DURING THE REST OF THE PERIOD./17/
&&
.AVIATION...VFR CONDITIONS AND OCCASIONALLY GUSTY SOUTH TO SOUTHEAST
WINDS ARE EXPECTED THROUGH THE REMAINDER OF THE AFTERNOON AT MOST
TAF SITES ACROSS THE REGION. HOWEVER...THERE WILL BE SCATTERED TO
NUMEROUS SHOWERS AND STORMS MOVING FROM SOUTH TO NORTH THROUGH
TONIGHT AND SOME OF THESE STORMS WILL BRING BRIEF POTENTIAL FOR
CEILINGS AND VIS RESTRICTION IFR OR WORSE...AND ALSO SOME VERY GUSTY
WINDS. EVEN AWAY FROM THE STORMS EXPECT RATHER WIDESPREAD MVFR/IFR
CONDITIONS AT ALL SITES AFTER MIDNIGHT TONIGHT. EXPECT ADDITIONAL
NUMEROUS STORMS TOMORROW WITH OF COURSE POTENTIAL HAZARDS FOR
EXCLUSIVELY VFR TRAFFIC. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 71 81 70 81 / 64 62 46 76
MERIDIAN 69 80 69 80 / 39 60 40 79
VICKSBURG 71 84 71 81 / 73 60 67 79
HATTIESBURG 71 81 71 82 / 56 66 42 73
NATCHEZ 71 84 71 81 / 70 66 66 77
GREENVILLE 70 83 70 80 / 83 69 74 78
GREENWOOD 71 83 70 79 / 79 66 58 79
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/17/BB
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1210 AM MDT SUN MAY 24 2015
.DISCUSSION...
UPDATE FORTHCOMING. HAVE MADE SOME MINOR ADJUSTMENTS TO THE POP AND
QPF GRIDS THIS MORNING. UPPER LOW OVER SOUTHERN WYOMING COUNTIES TO
PROVIDE A MOIST LOW LEVEL EASTERLY FLOW ACROSS THE AREA. LIGHT RAIN
CONTINUES AT LEWISTOWN AND OVER PORTIONS OF EASTERN JUDITH BASIN
COUNTY AND IS REFLECTED IN HIGHER POPS. SPC PLACES THE AREA UNDER A
GENERAL THUNDERSTORM RISK AND HRRR ANALYSIS INDICATES ISOLATED
SHOWER ACTIVITY AFTER 18Z. TEMPERATURES LOOK GOOD.
&&
.AVIATION...
UPDATED 1810Z.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE THROUGH
03Z MONDAY. SKIES WILL BECOME PARTLY CLOUDY OVERNIGHT...WITH MOSTLY
VFR CONDITIONS EXPECTED. BRUSDA
&&
.PREV DISCUSSION...ISSUED 354 AM MDT SUN MAY 24 2015
TODAY THROUGH TUESDAY...A BROAD UPPER LOW CONTINUES TO SPIN SLOWLY
THROUGH THE CENTRAL ROCKIES...MAINTAINING A WEAK LOW TO MID LEVEL
EASTERLY FLOW ACROSS NORTH CENTRAL AND SOUTHWEST MONTANA. ISOLATED
SHOWERS ARE DISSIPATING THIS MORNING...BUT IR SATELLITE AND
SURFACE OBSERVATIONS INDICATE VARIABLE LOW CLOUDS. AREAS OF FOG
ARE POSSIBLE THIS MORNING IN THE MOIST AND CALM ENVIRONMENT. SHORT
TERM MODELS SUPPORT ANOTHER ROUND OF AFTERNOON SHOWERS AND
THUNDERSTORMS ON SUNDAY...BUT GENERALLY LESS WIDESPREAD THAN
OBSERVED ON SATURDAY. A SHORTWAVE RIDGE SETTLES OVER THE REGION ON
MONDAY AFTERNOON...SUPPRESSING ALL BUT ISOLATED SHOWERS AND
THUNDERSTORMS. MODELS REMAIN CONSISTENT IN BRINGING SHORTWAVE
TROUGH THROUGH THE PACIFIC NORTHWEST MONDAY NIGHT. THIS WILL
GENERATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LIFTING FROM
SOUTHWEST TO NORTHEAST ON TUESDAY AFTERNOON. INCREASING SHEAR AND
INSTABILITY WILL SUPPORT A FEW STRONGER STORMS COMPARED TO THOSE
OF THE LAST FEW DAYS. NUTTER
TUESDAY NIGHT THROUGH SUNDAY...THE PERIOD WILL START OFF UNSETTLED.
AN UPPER LOW OVER THE PACIFIC NORTHWEST TUESDAY WILL WEAKEN INTO AN
UPPER TROUGH AND SLOWLY MOVE EAST AND FINALLY BE EAST OF THE
FORECAST AREA BY THURSDAY NIGHT. SEVERAL ROUNDS OF SHOWERS AND
LIKELY A FEW THUNDERSTORMS WILL AFFECT THE FORECAST AREA THROUGH
THURSDAY NIGHT. THEN AN UPPER RIDGE OVER THE PACIFIC NORTHWEST
FRIDAY WILL MOVE EAST AND BE OVER THE FORECAST AREA BY SUNDAY. EVEN
WITH THE INFLUENCE OF THE UPPER RIDGE DAYTIME HEATING SHOULD BE
ENOUGH TO RESULT IN A FEW SHOWERS OR THUNDERSTORMS. AND SPEAKING OF
HEATING HIGH TEMPERATURES WILL RISE OVER THE WEEKEND WITH
READING IN THE MID 70S TO NEAR 80 BY SUNDAY. BLANK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 64 44 70 48 / 20 10 10 30
CTB 67 40 70 46 / 20 0 10 30
HLN 65 45 72 50 / 20 20 20 40
BZN 59 40 67 44 / 60 30 20 30
WEY 56 33 60 37 / 30 20 40 50
DLN 61 40 68 44 / 30 20 30 50
HVR 72 43 75 47 / 20 10 10 20
LWT 61 44 67 46 / 40 30 20 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1010 AM MDT SUN MAY 24 2015
.DISCUSSION...
UPDATE FORTHCOMING. HAVE MADE SOME MINOR ADJUSTMENTS TO THE POP AND
QPF GRIDS THIS MORNING. UPPER LOW OVER SOUTHERN WYOMING COUNTIES TO
PROVIDE A MOIST LOW LEVEL EASTERLY FLOW ACROSS THE AREA. LIGHT RAIN
CONTINUES AT LEWISTOWN AND OVER PORTIONS OF EASTERN JUDITH BASIN
COUNTY AND IS REFLECTED IN HIGHER POPS. SPC PLACES THE AREA UNDER A
GENERAL THUNDERSTORM RISK AND HRRR ANALYSIS INDICATES ISOLATED
SHOWER ACTIVITY AFTER 18Z. TEMPERATURES LOOK GOOD.
&&
.AVIATION...
UPDATED 1145Z.
EXPECT VFR CONDITIONS EXCEPT FOR SOME PATCHY MVFR/IFR CONDITIONS IN
FOG AND LOW CLOUDS OVER THE EAST SLOPES UNTIL 15Z. THERE IS ALSO A
CHANCE OF PATCHY MVFR/IFR CONDITIONS IN FOG AND LOW CLOUDS IN THE
SOUTHWEST VALLEYS ALSO UNTIL 15Z. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL DEVELOP LATER THIS MORNING AND EARLY AFTERNOON
AND AFFECT CENTRAL AND SOUTHWEST MONTANA. SHOWERS WILL BE VERY
ISOLATED ALONG THE U.S. ROUTE 2 CORRIDOR. SHOWERS WILL GRADUALLY
DISSIPATE THIS EVENING THROUGH AFTER MIDNIGHT. BLANK
&&
.PREV DISCUSSION...ISSUED 354 AM MDT SUN MAY 24 2015
TODAY THROUGH TUESDAY...A BROAD UPPER LOW CONTINUES TO SPIN SLOWLY
THROUGH THE CENTRAL ROCKIES...MAINTAINING A WEAK LOW TO MID LEVEL
EASTERLY FLOW ACROSS NORTH CENTRAL AND SOUTHWEST MONTANA. ISOLATED
SHOWERS ARE DISSIPATING THIS MORNING...BUT IR SATELLITE AND
SURFACE OBSERVATIONS INDICATE VARIABLE LOW CLOUDS. AREAS OF FOG
ARE POSSIBLE THIS MORNING IN THE MOIST AND CALM ENVIRONMENT. SHORT
TERM MODELS SUPPORT ANOTHER ROUND OF AFTERNOON SHOWERS AND
THUNDERSTORMS ON SUNDAY...BUT GENERALLY LESS WIDESPREAD THAN
OBSERVED ON SATURDAY. A SHORTWAVE RIDGE SETTLES OVER THE REGION ON
MONDAY AFTERNOON...SUPPRESSING ALL BUT ISOLATED SHOWERS AND
THUNDERSTORMS. MODELS REMAIN CONSISTENT IN BRINGING SHORTWAVE
TROUGH THROUGH THE PACIFIC NORTHWEST MONDAY NIGHT. THIS WILL
GENERATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS LIFTING FROM
SOUTHWEST TO NORTHEAST ON TUESDAY AFTERNOON. INCREASING SHEAR AND
INSTABILITY WILL SUPPORT A FEW STRONGER STORMS COMPARED TO THOSE
OF THE LAST FEW DAYS. NUTTER
TUESDAY NIGHT THROUGH SUNDAY...THE PERIOD WILL START OFF UNSETTLED.
AN UPPER LOW OVER THE PACIFIC NORTHWEST TUESDAY WILL WEAKEN INTO AN
UPPER TROUGH AND SLOWLY MOVE EAST AND FINALLY BE EAST OF THE
FORECAST AREA BY THURSDAY NIGHT. SEVERAL ROUNDS OF SHOWERS AND
LIKELY A FEW THUNDERSTORMS WILL AFFECT THE FORECAST AREA THROUGH
THURSDAY NIGHT. THEN AN UPPER RIDGE OVER THE PACIFIC NORTHWEST
FRIDAY WILL MOVE EAST AND BE OVER THE FORECAST AREA BY SUNDAY. EVEN
WITH THE INFLUENCE OF THE UPPER RIDGE DAYTIME HEATING SHOULD BE
ENOUGH TO RESULT IN A FEW SHOWERS OR THUNDERSTORMS. AND SPEAKING OF
HEATING HIGH TEMPERATURES WILL RISE OVER THE WEEKEND WITH
READING IN THE MID 70S TO NEAR 80 BY SUNDAY. BLANK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 64 44 70 48 / 20 10 10 30
CTB 67 40 70 46 / 20 0 10 30
HLN 65 45 72 50 / 20 20 20 40
BZN 59 40 67 44 / 60 30 20 30
WEY 56 33 60 37 / 30 20 40 50
DLN 61 40 68 44 / 30 20 30 50
HVR 72 43 75 47 / 20 10 10 20
LWT 61 44 67 46 / 40 30 20 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
314 PM CDT SUN MAY 24 2015
.SHORT TERM...(TONIGHT)
UPPER LOW CONTINUES TO SPIN ACROSS THE CENTRAL ROCKIES. A VERY WEAK
WARM FRONT HAD LIFTED INTO THE FORECAST AREA RESULTING IN WIDESPREAD
SHOWERS THIS MORNING...BUT THOSE HAVE LIFTED NORTH OF THE AREA.
ADDITIONAL SHOWERS WERE MOVING INTO SOUTHEAST NEBRASKA LATE THIS
AFTERNOON FROM NORTHEAST KANSAS...AND THIS WILL THE PRIMARY ACTIVITY
THROUGH THE EVENING. INSTABILITY IS AGAIN MARGINAL TODAY AND THIS
WILL MOSTLY BE SHOWERS...ALTHOUGH THERE APPEARS TO BE A COUPLE
HUNDRED JOULES OF CAPE IN SOUTHEAST NEBRASKA. THE BETTER FORCING AND
MOISTURE TRANSPORT WILL BE SOUTH AND EAST OF THE AREA AS A UPPER
LEVEL WAVE MOVES OUT OF THE SOUTHERN PLAINS. THE RAP KEEPS THE BEST
PRECIP CHANCES IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA...AS WELL AS
WESTERN NEBRASKA CLOSER TO THE UPPER LOW. WILL PLAY POPS THAT WAY
EARLY IN THE PERIOD. OVERNIGHT...WITH WEAK ISENTROPIC LIFT ACROSS
THE REGION...AND MARGINALLY UNSTABLE CONDITIONS...SCATTERED SHOWERS
COULD DEVELOP...ESPECIALLY AS A REINFORCING WARM FRONT MOVES INTO
THE REGION THROUGH THE NIGHT. AGAIN...SHOULD MOSTLY BE SHOWERS...BUT
A FEW HUNDRED JOULES OF CAPE AND WEAKLY NEGATIVE LIFTED INDICES
COULD RESULT IN AN ISOLATED RUMBLE OF THUNDER.
.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM CDT SUN MAY 24 2015
OTHER THAN SOME MINOR POP MODIFICATIONS...GOING FCST LOOKS ON TRACK
THROUGH EARLY THIS WEEK. FORTUNATELY MODELS ARE IN QUITE GOOD
AGREEMENT BULK OF ACCUMULATING PCPN WILL BE FOUND WELL EAST OF THE
CWA. NEVERTHELESS...POTENTIAL FOR SOME PCPN WILL STILL EXIST EARLY
ON IN THE FCST PD.
BEGINNING MONDAY AFTN...MODELS IN AGREEMENT ADVERTISING
INCREASING BNDRY LYR THETA-E ADVECTION COUPLED WITH VIGOROUS
LITTLE VORT MAX WILL ALLOW FOR QUICK ENVIRONMENTAL DESTABILIZATION
OVER THE REGION. CONVECTIVE INITIATION ENSUES JUST NW OF THE CWA
ALONG AXIS OF LLVL THETA-E CONVG/INVERTED SFC TROF BEFORE ACTIVITY
QUICKLY EXPANDS EWD INTO THE CWA MONDAY NIGHT/TUESDAY MORNING.
EARLY TUESDAY EVENING...EXPECT PCPN TO EXIT THE CWA AS UPPER VORT
MAX TAKES BEST LIFT/MOISTURE INTO THE UPPER MIDWEST.
TURNING TO WEDNESDAY...UPPER SHORTWAVE RIDGE OVER THE CNTRL PLAINS
WILL FINALLY BRING PLEASANT CONDITIONS BACK THE REGION WITH PARTLY CLOUDY
SKIES AND HIGHS TOPPING OUT AROUND 80.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM CDT SUN MAY 24 2015
LARGE SCALE FLOW PER ECM/GFS ARE IN REASONABLE AGREEMENT HEADING
INTO NEXT WEEKEND SHOWING A LONGWAVE TROF OVER THE WRN CONUS
GRADUALLY MIGRATING EAST AND EVENTUALLY REACHING THE CNTRL PLAINS ON
FRIDAY. CONVECTIVE CHANCES ARE ON TAP THE MAJORITY OF THE EXTENDED
PDS IN RESPONSE TO PROLONGED MOIST UPGLIDE AND INCREASING UPPER
SUPPORT VIA APPROACHING LONGWAVE TROF. AS FOR TEMPS...HIGHS SHOULD
BE ABLE TO PUSH INTO THE UPPER 70S BEFORE THE NEXT COLD FRONT SWEEPS
THRU FRIDAY NIGHT RESULTING IN BELOW NORMAL TEMPS AND HIGHS ONLY IN
THE MID/UPPER 60S SATURDAY AND SUNDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1223 PM CDT SUN MAY 24 2015
CHALLENGING FORECAST. MVFR CLOUDS AT KLNK AND IFR AT KOMA/KLNK
COULD VERY WELL LIFT TO VFR THIS AFTERNOON AS HIGHER CEILINGS
POISED JUST TO THE SOUTH CONTINUE TO SPREAD NORTHWARD INTO THE
AREA AS A REINFORCING WARM FRONT LIFTS NORTH. BEST CHANCES FOR
SHOWER ACTIVITY APPEAR TO BE AT KOMA/KOFK 03-09Z...BUT STILL NOT
CONFIDENT IN THAT DEVELOPMENT. EXPECTING CONDITIONS TO DROP BACK
TO MVFR AND EVENTUALLY LIFR AT KOFK BY 10Z...THEN BACK TO MVFR
LATER MONDAY MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
TONIGHT...DEWALD
SHORT TERM...DEE
LONG TERM...DEE
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1103 PM CDT SAT MAY 23 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 250 PM CDT SAT MAY 23 2015
TONIGHT
REGIONAL 88D MOSAIC SHOWING AREA OF TSRA OVER KS QUICKLY APPROACHING
THE SRN CWA. THE LAST SEVERAL RUNS OF THE HRRR SEEM TO HAVE A GOOD
HANDLE TIMING THE PCPN WITH THE LATEST INDICATING THE LEADING EDGE
OF THE ACTIVITY PUSHING INTO THE SRN CWA SOMETIME BTWN 22Z-24Z LATE
THIS AFTN. RAP13 SUGGESTING RATHER STRONG 305K UPGLIDE/INFLUX OF
MOISTURE SHOULD AID IN MAINTAINING THE PCPN ACTIVITY THEN THRU THE
MAJORITY OF THE OVERNIGHT HOURS. INSTABILITY WILL BE MINIMAL AT
BEST...THUS EXPECT ANY THUNDER TO BE ISOLATED IN NATURE.
AT THIS POINT...VERY GOOD AGREEMENT SEEN BTWN THE HRRR/RAP13/AWR-NMM
WITH HIGHEST QPF FOUND OVER THE SRN CWA WHERE MAX OMEGA WILL BE
REALIZED OVERNIGHT. GENERAL CONSENSUS AMONGST THE SHORT TERM MODELS
GIVE AMOUNTS GENERALLY AROUND 1.5" BY 12Z SUN SOUTH OF THE I-80
CORRIDOR. MEANWHILE OVER THE REST OF THE CWA...AMOUNTS ANYWHERE FROM
AROUND A TENTH OF AN INCH UP TO HALF AN INCH BY SUN MORNING LOOK
POSSIBLE. IN ADDITION...CHANCE OF FLASH FLOODING TO THE SOUTH LOOKS
RELATIVELY SMALL PER LATEST FLASH FLOOD GUIDANCE.
SUNDAY THROUGH TUESDAY
SHOWERS MAY BE ONGOING ALONG/EAST OF THE MISSOURI RIVER SUNDAY
MORNING...MAY WANE BY LATE MORNING...BUT THEN COULD REDEVELOP BY
SUNDAY AFTERNOON ALONG/SOUTH OF I80 AS THE NEXT UPPER LEVEL
IMPULSE BEGINS TO MOVE INTO REGION. INSTABILITY WILL ALSO RETURN
WITH MUCAPES INCREASING TO 1000-1500 J/KG DURING THE AFTERNOON. A
DRY SLOT COULD ALSO AFFECT PORTIONS OF CENTRAL/EASTERN NEBRASKA
WHICH COULD MAKE THUNDERSTORM ACTIVITY PRETTY SPARSE. A SECONDARY
WARM FRONT LIFTING NORTH THROUGH THE AREA SUNDAY NIGHT COULD BRING
A FEW STORMS...ESPECIALLY SUNDAY EVENING...THEN LIFTING NORTH
AFTER MIDNIGHT.
COULD SEE PRECIP WANE AGAIN MONDAY MORNING AS WEAK UPPER LEVEL
RIDGING MOVES INTO THE AREA. WITH WARM FRONT WELL NORTH OF THE
REGION...TEMPS SHOULD BE MUCH WARMER BACK INTO THE MID TO UPPER
70S. THIS WILL RESULT IN VERY UNSTABLE CONDITIONS DEVELOPING FOR
MONDAY AFTERNOON AND EVENING. THIS WILL BE WITHIN THE AREA WELL
AHEAD OF A WEAK COLD FRONT THAT SHOULD MOVE ACROSS THE REGION
MONDAY NIGHT. BEST THREAT FOR SEVERE STORMS AND POTENTIAL HEAVY
RAIN APPEARS TO BE MONDAY EVENING ALONG/SOUTH OF I80.
COLD FRONT IS STILL MOVING THROUGH THE REGION TUESDAY THUS STILL
HAVE A CHANCE OF PRECIP ALONG SOUTH OF THE FRONT...WITH PRECIP
CHANCES WINDING DOWN TUESDAY NIGHT.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 250 PM CDT SAT MAY 23 2015
WILL CONTINUE A DRY FORECAST WEDNESDAY AS WE SHOULD IN BETWEEN
SYSTEMS. NEXT TROUGH COMES OFF THE ROCKIES WEDNESDAY NIGHT INTO
THURSDAY BRINGING THE NEXT CHANCE FOR THUNDERSTORMS. A COUPLE MORE
IMPULSES MOVE ACROSS THE PLAINS THURSDAY NIGHT THROUGH SATURDAY
BRINGING ADDITIONAL HIGH CHANCE TO LIKELY POPS TO THE REGION.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1056 PM CDT SAT MAY 23 2015
MVFR/IFR/LIFR CONDITIONS WILL CONTINUE OVERNIGHT WITH PERIODS OF
DRIZZLE/LIGHT RAIN AND FOG THROUGH SUNDAY MORNING. POTENTIAL FOR
ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS SUNDAY AFTERNOON AND
SUNDAY EVENING.FOR NOW INCLUDED LATE IN THE AFTERNOON/EVENING AT
KOMA WITH INCREASING 45KT LOW LEVEL JET AND CONTINUED FAVORABLE
MOISTURE TRANSPORT AND CONTINUED LIFT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DEE/DEWALD
LONG TERM...DEWALD
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BISMARCK ND
949 PM CDT MON MAY 25 2015
.UPDATE...
ISSUED AT 939 PM CDT MON MAY 25 2015
A FEW STRONGER THUNDERSTORMS OVER THE SOUTH CENTRAL EARLIER THIS
EVENING CONTINUE TO DISSIPATE AS THEY MOVE SOUTHWEST THROUGH
EMMONS AND MCINTOSH COUNTIES. THERE HAS BEEN NO LIGHTNING WITH
THESE CELLS OVER THE PAST HOUR OR SO. ELSEWHERE A FEW SHOWERS WERE
LOCATED OVER THE NORTHEAST FORECAST AREA IN EASTERN ROLETTE AND
PIERCE COUNTIES...AND OVER WESTERN MCKENZIE COUNTY. THERE COULD
YET BE A PASSING SPRINKLE OR SHOWER OVERNIGHT ACROSS THE
NORTH ASSOCIATED WITH A WEAK SHORTWAVE SLIDING SOUTHEAST FROM
SASKATCHEWAN...BUT IN GENERAL HAVE SIGNIFICANTLY LOWERED OR
REMOVED POPS MOST AREAS FOR THE REMAINDER OF THE NIGHT. DID KEEP
THE PATCHY FOG IN THE GRIDDED FORECAST ACROSS THE WEST AND CENTRAL
WITH SOME MORNING SHOWERS...AND CLEAR TO PARTLY CLOUDY SKIES AND
LIGHT WINDS EXPECTED TONIGHT. OTHERWISE NO CHANGES TO THE GOING
FORECAST.
UPDATE ISSUED AT 550 PM CDT MON MAY 25 2015
WEAK SURFACE PRESSURE PATTERN OVER WESTERN AND CENTRAL NORTH
DAKOTA...WITH SOME RATHER IMPRESSIVE LOW LEVEL MOISTURE OVER SOUTH
CENTRAL INTO EASTERN NORTH DAKOTA AS DEWPOINTS WERE IN THE MIDDLE
50S. WEAK MID TO UPPER LEVEL TROUGH FROM NEBRASKA PANHANDLE INTO
WEST CENTRAL MINNESOTA. AFTERNOON INSTABILITY HAS PRODUCED
SCATTERED SHOWERS ACROSS THE FORECAST AREA AND EXPECT THESE TO
DIMINISH AS WE HEAD TOWARDS SUNSET. LOW TO MID LEVEL CIRCULATION
AND STEEP LAPSE RATES HAVE HEIGHTENED THE SPC NON SUPERCELL
TORNADO PARAMETER OVER SOUTH CENTRAL NORTH DAKOTA. DID HAVE A
REPORT OF A FUNNEL EARLIER TODAY NEAR JUD AND CANNOT RULE OUT
ADDITIONAL FUNNELS FOR THE NEXT FEW HOURS. THERE HAS BEEN NO
LIGHTNING THIS AFTERNOON AND THESE FUNNELS ARE USUALLY SHORT LIVED
AND RARELY REACH THE GROUND. THEY ARE NOT ASSOCIATED WITH SEVERE
THUNDERSTORMS. DID MAKE SOME SLIGHT ADJUSTMENTS TO POPS BASED ON
LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING
FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 331 PM CDT MON MAY 25 2015
SHOWER AND THUNDERSTORM CHANCES THIS AFTERNOON AND EARLY EVENING
HIGHLIGHT THE SHORT TERM FORECAST.
AS DEPICTED WELL BY THE HRRR RUNS FROM THIS MORNING AND THROUGH
THE AFTERNOON...ISOLATED TO SCATTERED SURFACE BASED CONVECTION
CONTINUES TO DEVELOP ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA THIS AFTERNOON. GIVEN WEAK INSTABILITY...ANY THUNDERSTORMS
ARE EXPECTED TO BE MUCH MORE ISOLATED COMPARED TO THE MORE
DOMINANT RAIN SHOWER MODE. GIVEN THE DIURNAL NATURE OF THIS
CONVECTION AND LACK OF STRONG FORCING...SHOWERS AND THUNDERSTORMS
WILL FADE WITH SUNSET. SEVERE WEATHER IS NOT EXPECTED.
OTHERWISE FOR TONIGHT...DID ADD A PATCHY FOG MENTION TO THE SOUTH
CENTRAL AND SOUTHWEST WITH RAINFALL FROM EARLIER TODAY...CLEARING
SKIES TONIGHT AND LIGHT WINDS ASSOCIATED WITH A WEAK SURFACE HIGH.
A MILD TUESDAY IS EXPECTED WITH HIGHS IN THE MID 70S TO LOWER 80S
IN A RATHER DEFUSE SURFACE PRESSURE PATTERN. THERE IS A CHANCE OF
THUNDERSTORMS ACROSS THE TURTLE MOUNTAINS AND UPPER JAMES RIVER
VALLEY DURING THE AFTERNOON IN ASSOCIATION WITH WEAK IMPULSES
EMBEDDED IN NORTHWEST FLOW ALOFT. ONCE AGAIN GIVEN WEAK
INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 331 PM CDT MON MAY 25 2015
A PERSISTING REX BLOCKING PATTERN...OVER THE PACIFIC NORTHWEST...IS
PROJECTED WITHIN THE CURRENT ENSEMBLE AND DETERMINISTIC MODELS TO
REMAIN IN PLACE THROUGH MUCH OF THE EXTENDED. SPLIT FLOW ALOFT WILL
RESULT AND CONTINUE OVER NORTH DAKOTA INTO THE WEEKEND.
THEREAFTER...A TRANSITION TO ZONAL FLOW IS PROJECTED BY THE LONG
TERM MODELS. OVERALL...SEVERAL EMBEDDED SHORTS WAVES WITHIN THE
NORTHERN STREAM ALOFT WILL RESULT IN SEVERAL CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THE LONG TERM. AS OF NOW...THE GREATEST
CHANCES FOR PRECIPITATION ARE WEDNESDAY NIGHT THROUGH EARLY FRIDAY
MORNING. ALTHOUGH THE COMPLEXITY OF THE UPPER LEVEL FLOW HAS
RESULTED IN HIGHER THAN NORMAL MODEL UNCERTAINTY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 939 PM CDT MON MAY 25 2015
VFR MID LEVEL CLOUDS CONTINUE TO DIMINISH ACROSS THE AREA THIS
EVENING. EXPECT CLEAR TO PARTLY CLOUDY SKIES TONIGHT AND THROUGH
TUESDAY WITH A LIGHT AND VARIABLE SURFACE FLOW. WILL NEED TO
MONITOR FOR SOME PATCHY FOG EARLY TUESDAY MORNING BUT AT THIS
TIME CERTAINTY TOO LOW FOR A MENTION IN ANY INDIVIDUAL TAF SITE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AC
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
604 PM CDT MON MAY 25 2015
.UPDATE...
ISSUED AT 550 PM CDT MON MAY 25 2015
WEAK SURFACE PRESSURE PATTERN OVER WESTERN AND CENTRAL NORTH
DAKOTA...WITH SOME RATHER IMPRESSIVE LOW LEVEL MOISTURE OVER SOUTH
CENTRAL INTO EASTERN NORTH DAKOTA AS DEWPOINTS WERE IN THE MIDDLE
50S. WEAK MID TO UPPER LEVEL TROUGH FROM NEBRASKA PANHANDLE INTO
WEST CENTRAL MINNESOTA. AFTERNOON INSTABILITY HAS PRODUCED
SCATTERED SHOWERS ACROSS THE FORECAST AREA AND EXPECT THESE TO
DIMINISH AS WE HEAD TOWARDS SUNSET. LOW TO MID LEVEL CIRCULATION
AND STEEP LAPSE RATES HAVE HEIGHTENED THE SPC NON SUPERCELL
TORNADO PARAMETER OVER SOUTH CENTRAL NORTH DAKOTA. DID HAVE A
REPORT OF A FUNNEL EARLIER TODAY NEAR JUD AND CANNOT RULE OUT
ADDITIONAL FUNNELS FOR THE NEXT FEW HOURS. THERE HAS BEEN NO
LIGHTNING THIS AFTERNOON AND THESE FUNNELS ARE USUALLY SHORT LIVED
AND RARELY REACH THE GROUND. THEY ARE NOT ASSOCIATED WITH SEVERE
THUNDERSTORMS. DID MAKE SOME SLIGHT ADJUSTMENTS TO POPS BASED ON
LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING
FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 331 PM CDT MON MAY 25 2015
SHOWER AND THUNDERSTORM CHANCES THIS AFTERNOON AND EARLY EVENING
HIGHLIGHT THE SHORT TERM FORECAST.
AS DEPICTED WELL BY THE HRRR RUNS FROM THIS MORNING AND THROUGH
THE AFTERNOON...ISOLATED TO SCATTERED SURFACE BASED CONVECTION
CONTINUES TO DEVELOP ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA THIS AFTERNOON. GIVEN WEAK INSTABILITY...ANY THUNDERSTORMS
ARE EXPECTED TO BE MUCH MORE ISOLATED COMPARED TO THE MORE
DOMINANT RAIN SHOWER MODE. GIVEN THE DIURNAL NATURE OF THIS
CONVECTION AND LACK OF STRONG FORCING...SHOWERS AND THUNDERSTORMS
WILL FADE WITH SUNSET. SEVERE WEATHER IS NOT EXPECTED.
OTHERWISE FOR TONIGHT...DID ADD A PATCHY FOG MENTION TO THE SOUTH
CENTRAL AND SOUTHWEST WITH RAINFALL FROM EARLIER TODAY...CLEARING
SKIES TONIGHT AND LIGHT WINDS ASSOCIATED WITH A WEAK SURFACE HIGH.
A MILD TUESDAY IS EXPECTED WITH HIGHS IN THE MID 70S TO LOWER 80S
IN A RATHER DEFUSE SURFACE PRESSURE PATTERN. THERE IS A CHANCE OF
THUNDERSTORMS ACROSS THE TURTLE MOUNTAINS AND UPPER JAMES RIVER
VALLEY DURING THE AFTERNOON IN ASSOCIATION WITH WEAK IMPULSES
EMBEDDED IN NORTHWEST FLOW ALOFT. ONCE AGAIN GIVEN WEAK
INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 331 PM CDT MON MAY 25 2015
A PERSISTING REX BLOCKING PATTERN...OVER THE PACIFIC NORTHWEST...IS
PROJECTED WITHIN THE CURRENT ENSEMBLE AND DETERMINISTIC MODELS TO
REMAIN IN PLACE THROUGH MUCH OF THE EXTENDED. SPLIT FLOW ALOFT WILL
RESULT AND CONTINUE OVER NORTH DAKOTA INTO THE WEEKEND.
THEREAFTER...A TRANSITION TO ZONAL FLOW IS PROJECTED BY THE LONG
TERM MODELS. OVERALL...SEVERAL EMBEDDED SHORTS WAVES WITHIN THE
NORTHERN STREAM ALOFT WILL RESULT IN SEVERAL CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THE LONG TERM. AS OF NOW...THE GREATEST
CHANCES FOR PRECIPITATION ARE WEDNESDAY NIGHT THROUGH EARLY FRIDAY
MORNING. ALTHOUGH THE COMPLEXITY OF THE UPPER LEVEL FLOW HAS
RESULTED IN HIGHER THAN NORMAL MODEL UNCERTAINTY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 550 PM CDT MON MAY 25 2015
VFR CUMULUS FIELDS WILL DIMINISH ACROSS THE AREA THIS EVENING.
POSSIBLY AN ISOLATED SHOWER THROUGH 02 UTC. OTHERWISE CLEAR TO
PARTLY CLOUDY WITH A LIGHT SURFACE FLOW THROUGH THE FORECAST
PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...AC
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
924 PM EDT MON MAY 25 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE EAST COAST OF THE US WILL CONTINUE TO
INCREASE MOISTURE LEVELS FROM THE GULF OF MEXICO THROUGH THE
MIDDLE OF THE WEEK. SEVERAL PIECES OF JET ENERGY WILL MOVE ACROSS
THE REGION THROUGH THE WEEK BRINGING INCREASED CHANCES OF SHOWERS
AND THUNDERSTORMS. A WEAK COLD FRONT WILL MOVE ACROSS THE LOWER
GREAT LAKES WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
PATCH OF CONVECTION THAT HRRR TRIES TO DEVELOP AROUND CLE NOT
MATERIALIZING. WILL STICK WITH PLAN TO ALLOW ONLY WIDELY SCT WEAK
CONVECTION TO DEVELOP AROUND THE EASTERN PART OF THE AREA THE REST
OF THE NIGHT WITH QPF UNDER A TENTH OF AN INCH.
IT WILL BE ANOTHER WARM NIGHT WITH LOWS ONLY DIPPING BACK INTO THE
MIDDLE 60S AS DEBRIS CLOUDS PERSIST AT MID AND UPPER LEVELS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
THE MORNING SHOWERS AND POSSIBLE RUMBLE OF THUNDER SHOULD DRIFT
EASTWARD OR DISSIPATE WITH THE MORNING MIX. THE APPROACHING WAVE
FROM THE MIDWEST SHOULD HELP TO INCREASE THE LIFT LATE AFTERNOON
INTO THE EVENING HOURS. THE INCREASED LIFT AND CONTINUED FLOW OF
MOISTURE INTO THE REGION SHOULD GENERATE THUNDERSTORMS OVER
INDIANA/NW OHIO AND POSSIBLY ACROSS THE EASTERN COUNTY WARNING
AREA TUESDAY AFTERNOON. THE WESTERN CONVECTION WILL HAVE A CHANCE
TO SWEEP ACROSS THE COUNTY WARNING AREA TUESDAY EVENING. AT THIS
POINT CONFIDENCE IS HIGH ENOUGH TO MENTION LIKELY POPS. THERE
SHOULD BE A LULL IN THE THUNDER FOR A FEW HOURS WEDNESDAY MORNING
BUT A WEAK FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION DURING THE
AFTERNOON. THIS SHOULD BE A FOCUS FOR THUNDERSTORMS WEDNESDAY
AFTERNOON INTO THE EVENING HOURS. SLIGHTLY DRIER AIR RETURNS ON
THURSDAY WITH THE UPPER LEVEL RIDGE ATTEMPTING TO INCREASE SLIGHTLY.
OF NOTE THROUGH THE WEEK IS THE FACT THAT UPPER LEVEL HEIGHTS WILL
BE RATHER HIGH. THIS MAY END UP LIMITING THE COVERAGE OF
THUNDERSTORMS EACH AFTERNOON AND EVENING.
TEMPERATURES WILL CONTINUE TO BE ABOVE SEASONAL AVERAGES THROUGH
THE WEEK WITH HIGHS GENERALLY IN THE LOWER 80S. LOWS WILL BE IN
THE 60S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM BEGINS FRIDAY WITH THE MODELS SHOWING HIGH PRESSURE
ACROSS THE SOUTHEAST COAST...LOW PRESSURE ACROSS QUEBEC AND A
FRONTAL SYSTEM SOUTHWEST FROM THE LOW ACROSS THE CENTRAL LAKES TO
TEXAS. THIS FRONTAL SYSTEM WILL EVENTUALLY GET INTO THE AREA BUT FOR
FRIDAY THERE WILL BE A GENERAL LACK OF FORCING. WITH THAT SAID WILL
HAVE SLIGHT CHANCE POPS FOR MAINLY DIURNAL SHOWER OR THUNDERSTORM.
MODELS A BIT BETTER ON TIMING TODAY WITH BOTH THE GFS AN ECMWF
BRINGING THE FRONT THROUGH ON SATURDAY. THE FRONT WILL STALL IN THE
TENNESSEE OR LOWER OHIO VALLEY SUNDAY BEFORE LIKELY MOVING BACK
NORTH ON MONDAY. THE FRONT WILL BRING ITS OWN MOISTURE WITH IT BUT
WILL ALSO GET AN INFLUX OF GLFMX MOISTURE AS IT WAFFLES THROUGH THE
AREA DURING THE WEEKEND. THIS OF COURSE IF A FAIRLY WET PATTERN
SUGGESTING HIGH CHANCE TO LIKELY POPS WILL BE NEEDED SATURDAY
THROUGH SUNDAY WITH CHANCE POPS CONTINUING MONDAY. ABOVE NORMAL
TEMPS FRIDAY AND NEAR NORMAL SATURDAY THROUGH MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE SHOWERS THAT DEVELOPED EARLIER ARE JUST ABOUT GONE. SOME OF
THE GUIDANCE IS SHOWING ANOTHER WAVE OF PRECIP CLIPPING THE
EASTERN END OF THE AREA TOWARD DAYBREAK. TILL THEN IT WILL BE DRY
AS DIURNAL CLOUDS DISSIPATE. WILL HOWEVER SEE SOME MID LEVEL CIGS
OVERSPREAD THE AREA TONIGHT WITH MVFR CIGS POSSIBLE LATE
TONIGHT...ESPECIALLY AT THE EASTERN TAF SITES. SOME PATCHY MVFR
FOG/HAZE IS ALSO POSSIBLE. WILL MENTION A VICINITY OF SHOWERS AT
KYNG AND KERI LATE TONIGHT. FOR THE DAYLIGHT HOURS...A LOT OF
UNCERTAINTY REMAINS. DO THINK PRECIP WILL BREAK OUT BEGINNING
AROUND MIDDAY. WILL MENTION SOME SHOWERS MOST AREAS BUT NO THUNDER
GIVEN UNCERTAINTY. EXPECT S TO SW WINDS TO QUICKLY DIMINISH AFTER
00Z WITH SPEEDS LESS THAN 10 KNOTS ALL AREAS BY 02Z.
.OUTLOOK...NON VFR POSSIBLE TUESDAY EVENING THROUGH WEDNESDAY IN SCT
SHRA AND TSRA.
&&
.MARINE...
WILL CONTINUE WITH A SMALL CRAFT ADVISORY PRIMARILY FOR WINDS WEST
THIRD. WINDS SHOULD DECREASE FURTHER OFF SHORE GIVEN STABILIZING
EFFECTS OF THE COOLER WATER BUT CLOSE TO SHORE WINDS SHOULD CONTINUE
GUSTING INTO THE MID 20 KNOT RANGE INTO EARLY EVENING. NO HEADLINES
EXPECTED THROUGH THE REMAINDER OF THE FORECAST. WINDS WILL REMAIN
PRIMARILY FROM THE SOUTH TO SOUTHWEST AT 10 TO 20 KNOTS OR LESS
THROUGH WEDNESDAY NIGHT. THURSDAY AND FRIDAY WINDS WILL BECOME LIGHT
AND VARIABLE. BEST CHANCE FOR THUNDERSTORMS WILL COME TUESDAY AND
TUESDAY NIGHT
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>145.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...MULLEN
SHORT TERM...MULLEN
LONG TERM...TK
AVIATION...KUBINA
MARINE...TK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
805 PM EDT MON MAY 25 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE EAST COAST WILL KEEP A WARM AND INCREASINGLY
HUMID AIRFLOW IN PLACE FOR MUCH OF THE UPCOMING WEEK. A STRONG
COLD FRONT WILL PUSH ACROSS THE STATE SATURDAY AFTERNOON OR
NIGHT...USHERING IN COOLER AND LESS HUMID CONDITIONS FOR THE
REMAINDER OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A COUPLE OF VERY SMALL SHOWERS CAN BE SEEN OVER ERIE
COUNTY...OTHERWISE THE FIRST EVENING OF THE TRADITIONAL SUMMER IS
A PERFECT ONE FOR COOKING OUT WITH MILD TEMPS AND STILL TOLERABLE
HUMIDITY.
PWATS WILL INCREASE TO AROUND 1.5 INCHES THROUGH THE
OVERNIGHT...LEADING TO A NOTICEABLE INCREASE IN THE HUMIDITY.
THERE WILL BE A SMALL CHANCE OF A SHOWER OR THUNDERSTORM OVER
ABOUT THE NWRN 1/3 OR SO OF THE FORECAST AREA...BUT MOST LOCATIONS
WILL REMAIN FAIR AND DRY OVERNIGHT.
OVERNIGHT LOWS WILL AVERAGE IN THE LOW TO MID 60S...OR SOME 10 TO
NEARLY 20 DEG ABOVE NORMAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
PWATS CONTINUE TO RISE THROUGH THE SHORT TERM AND WILL GET ABOVE
1.75 INCHES BY TUESDAY AFTERNOON. THE DEEP SOUTHWESTERLY FLOW WILL
TRANSPORT REMNANT MCV/S AND CLUSTERS OF SHOWERS/SCTD TSRA FROM THE
VERY ACTIVE SRN PLAINS STATES AND LOWER MISS VALLEY CONVECTION.
THESE WEAK AND DIFFICULT TO CAPTURE FEATURES WILL TRIGGER
SOME SHRA/TSRA AS THEY CROSS THE AREA. MODELS HAVE A TOUGH TIME
CAPTURING/TIMING THE IMPACTS OF SUCH WEAK SHORTWAVES DURING THE
OVERNIGHT AND MORNING HOURS...WHILE FORECASTS OF PEAK INSTABILITY
DURING THE AFTERNOON HOURS PROVIDE MUCH GREATER CONFIDENCE IN AT
LEAST SCTD SHRA/TSRA BETWEEN 17Z-01Z.
SPC CONTINUES TO PAINT A MARGINAL RISK UP AND OVER THE WRN HALF TO
TWO-THIRDS OF THE CWA FOR DAY 2 - TUES AFTERNOON AND TUES NIGHT.
WILL MENTION THIS IN THE HWO.
MEAN SREF CAPES TOP OUT BETWEEN 1500-2000 J/KG 18-23Z
TUESDAY...AND 0-3KM SHEAR IS WEAK-MDT WITH A GENERALLY LINEAR
PROFILE. A FEW MARGINALLY SEVERE MULTI-CELL TSRA ARE POSSIBLE
TUESDAY AFTERNOON/EVENING ACROSS THE CWA.
MAX TEMPS MAY ACTUALLY BE A DEG OR TWO COOLER ON TUES WITH MORE
CLOUDS THAN WE HAD DURING THE DAY TODAY /MONDAY/.
HIGH CHC POPS WILL BE PAINTED TUESDAY WITH A WIDESPREAD 40-50 PCT
OVER MOST OF THE AREA. WILL KEEP THEM LOWER IN THE SE - WHERE THEY
WILL BE FARTHER FROM THE FORCING AND UNDER WARMER TEMPS ALOFT AND
MORE SUPPRESSIVE INFLUENCE FROM THE NEARBY UPPER RIDGE AXIS .
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THE MID TO LONG RANGE MODELS CONTINUE TO SHOW AGREEMENT IN
POSITION AND MOVEMENT OF THE UPPER LEVEL RIDGE. THE LOW WILL
CONTINUE TO DIG INTO THE GREAT LAKES REGION...AND A LINE OF
SHOWERS AND THUNDERSTORMS SHOULD FORM OUT AHEAD OF THE APPROACHING
COLD FRONT. EXPECT MOIST SOUTHEASTERLY FLOW TO CONTINUE WEDNESDAY
INTO THURSDAY. PRECIPITATION CHANCES SHOULD INCREASE WEDNESDAY AND
THURSDAY.
THE MODELS BEGIN TO DIVERGE THROUGHOUT THE LATTER HALF OF THE
WEEK AND INTO NEXT WEEKEND. THERE SHOULD BE A BOUNDARY THAT COULD
PERSIST ACROSS THE NEW YORK BORDER...WHICH COULD BRING DAILY
CHANCES FOR RAIN THROUGH THE WEEKEND. THE MODELS CONTINUE TO TREND
COOLER TEMPERATURES AND HAVE ADJUSTED MAX AND MIN TEMPERATURES AS
SUCH...BUT EXPECT TEMPS TO REMAIN ABOVE NORMAL THROUGH THE WORK
WEEK.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
RADAR SHOWS ISOLD SHOWERS DEVELOPING JUST OUTSIDE OF CENTRAL PA
AIRSPACE JUST EAST OF YNG-ERI-DKK LINE. LATEST HRRR STILL
SUGGESTS ISOLD SHOWER ACTIVITY POSSIBLY REACHING BFD VCNTY AROUND
00Z BUT CONFIDENCE IS LOW AND DURATION WOULD BE VERY BRIEF. VFR
SHOULD CONTINUE AT MOST SITES DURING THE OVERNIGHT AND EARLY
MORNING PERIOD...HOWEVER MVFR CIGS AT BFD AND VISBYS AT MDT/LNS
ARE POSSIBLE AROUND DAYBREAK. HIGHEST CONFIDENCE IS AT MDT/LNS
GIVEN INCREASING DEWPOINTS AND PERSISTENCE. ALSO CUT BACK MENTION
OF VCTS EARLY TOMORROW BUT WILL LKLY RE-INTRODUCE FOR THE AFTN.
OVERALL...THE FLIGHT CATEGORY WILL PREDOMINANTLY REMAIN VFR
THROUGH MUCH OF THE UPCOMING WEEK. ANY RESTRICTIONS WILL LKLY BE
LIMITED TO PREDAWN/EARLY MORNING FOG AND/OR ISOLATED-SCATTERED
AFTERNOON THUNDERSTORMS.
OUTLOOK...
TUE-FRI...PATCHY A.M. MVFR FOG/BR. ISOLD-SCT P.M. TSTMS.
SAT-SUN...PATCHY A.M. MVFR FOG/BR. SCT-NMRS P.M TSTMS W/COLD
FROPA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...CERU/MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
958 PM CDT MON MAY 25 2015
.UPDATE...
PER SHWRS LEAVING THE MID STATE...AND WITH NO INDICATIONS FROM SHORT
RANGE MODELS OF SHWRS/TSTMS MOVING BACK INTO MID STATE UNTIL LATE
TONIGHT...REMOVED MENTION OF EVENING SHWRS FROM THE SUITE OF FORECAST
PRODUCTS. OTHERWISE...FORECAST REMAINS ON TRACK.
&&
.PREV DISCUSSION.../ISSUED 709 PM CDT MON MAY 25 2015/
UPDATE...
PER REGIONAL RADAR...SATELLITE...AND SFC OBSERVATIONS TRENDS...ALONG
WITH SHORT RANGE MODEL CONSENSUS...SOME LINGERING SHWRS ACROSS THE FAR
MOST ERN PLATEAU COUNTIES THRU THE EVENING HRS...WITH DRY CONDITIONS
REMAINDER OF MID STATE. BELIEVE WITH WINDS DYING DOWN AFTER MIDNIGHT...
PATCHY FOG DEVELOPMENT COULD OCCUR. THERE COULD BE SOME LINGERING SHWRS
ACROSS UPPER CUMBERLAND REGION THRU THE FIRST FEW HRS AFTER MIDNIGHT ALSO.
NEXT ROUND OF SHWRS/TSTMS SHOULD APPROACH THE TN RIVER VALLEY SHORTLY AFTER
SUNRISE. TWEAKED HRLY TEMP...DEWPOINT...SKY CONDITION...AND WIND SPEED
/DIRECTION GRIDS. HAVE UPDATED THE SUITE OF FORECAST PRODUCTS ACCORDINGLY...
INCLUDING REMOVING THE THROUGH LATE AFTERNOON ZONE GROUPING FROM THE ZONE
FORECAST PRODUCT.
PREV DISCUSSION.../ISSUED 637 PM CDT MON MAY 25 2015/
UPDATE...FOR AVIATION.
AVIATION...
00Z TAFS...UNSETTLED WX WILL CONTINUE. ONE WAVE OF SHRA/TSRA WAS
MOVING OFF TO THE EAST OF MID TN THIS EVENING. WE DO NOT EXPECT
MUCH MORE SHOWER ACTIVITY OVERNIGHT. LOTS OF RESIDUAL
MOISTURE...SO PERIODS OF MVFR CIGS/VSBYS WITH BR CAN BE EXPECTED
OVERNIGHT. THE NEXT WAVE OF SHRA/TSRA WILL ARRIVE TUESDAY
MORNING WITH MAINLY MVFR THROUGH MIDDAY. S WINDS WILL
CONTINUE...AROUND 08KT OVERNIGHT...AND 10G22KT TUESDAY.
13
PREV DISCUSSION.../ISSUED 221 PM CDT MON MAY 25 2015/
DISCUSSION...A PERSISTENT BAND OF SHOWERS CONTINUES TO MOVE
SLOWLY EASTWARD ACROSS MIDDLE TENNESSEE, WITH A FEW STRONGER
CELLS PASSING THROUGH SOUTHERN PARTS. HRRR HAS PERFORMED QUITE
WELL TODAY, AND THE SHORT-RANGE MODEL HAS CONSISTENTLY SHOWN A
DECREASE IN THE ACTIVITY FROM LATE AFTERNOON THROUGH EVENING, SO
AM SPLITTING TONIGHT`S POP GRID INTO 6-HOUR INCREMENTS, WITH
REDUCED POP`S FROM 00Z THROUGH 06Z. NAM SHOWS A WEAK TROUGH MOVING
INTO MIDDLE TENNESSEE TOMORROW MORNING ALONG WITH THE NEXT WAVE OF
MOISTURE, THEREBY PUSHING THE DRY WEDGE NORTHWARD AND BRINGING
LIKELY TO CATEGORICAL POP`S BACK IN. SPC IS KEEPING THE ENTIRE MID
STATE UNDER A SLIGHT RISK OF SEVERE STORMS TOMORROW AND TOMORROW
NIGHT, AND A MARGINAL RISK FOR DAY 3. MODEL SOUNDINGS CONTINUE TO
SHOW GOOD INSTABILITY FOR THE NEXT SEVERAL DAYS, MAINLY DURING
PEAK HEATING HOURS, WITH VERY LITTLE AIR MASS CHANGE FOR THE
FORESEEABLE FUTURE. FOLLOWING WEDNESDAY`S ANTICIPATED SHORTWAVE
PASSAGE, THE UPPER PATTERN BREAKS DOWN INTO A MUCH WEAKER FLOW,
WITH HIGH PRESSURE ESTABLISHING ITSELF OFF THE EAST COAST, VERY
SUMMER-LIKE. WE MAY SEE A FRONTAL PASSAGE EARLY NEXT WEEK, BUT AT
THIS POINT THE GFS AND ECMWF SOLUTIONS DIVERGE TO THE POINT THAT
ANY CONFIDENCE REGARDING TIMING IS LOW. TEMPERATURES WILL
GRADUALLY WARM THROUGHOUT THE WEEK, WITH READINGS SEVERAL DEGREES
ABOVE NORMAL FROM WEDNESDAY ON.
ROSE
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
709 PM CDT MON MAY 25 2015
.UPDATE...
PER REGIONAL RADAR...SATELLITE...AND SFC OBSERVATIONS TRENDS...ALONG
WITH SHORT RANGE MODEL CONSENSUS...SOME LINGERING SHWRS ACROSS THE FAR
MOST ERN PLATEAU COUNTIES THRU THE EVENING HRS...WITH DRY CONDITIONS
REMAINDER OF MID STATE. BELIEVE WITH WINDS DYING DOWN AFTER MIDNIGHT...
PATCHY FOG DEVELOPMENT COULD OCCUR. THERE COULD BE SOME LINGERING SHWRS
ACROSS UPPER CUMBERLAND REGION THRU THE FIRST FEW HRS AFTER MIDNIGHT ALSO.
NEXT ROUND OF SHWRS/TSTMS SHOULD APPROACH THE TN RIVER VALLEY SHORTLY AFTER
SUNRISE. TWEAKED HRLY TEMP...DEWPOINT...SKY CONDITION...AND WIND SPEED
/DIRECTION GRIDS. HAVE UPDATED THE SUITE OF FORECAST PRODUCTS ACCORDINGLY...
INCLUDING REMOVING THE THROUGH LATE AFTERNOON ZONE GROUPING FROM THE ZONE
FORECAST PRODUCT.
&&
.PREV DISCUSSION.../ISSUED 637 PM CDT MON MAY 25 2015/
UPDATE...FOR AVIATION.
AVIATION...
00Z TAFS...UNSETTLED WX WILL CONTINUE. ONE WAVE OF SHRA/TSRA WAS
MOVING OFF TO THE EAST OF MID TN THIS EVENING. WE DO NOT EXPECT
MUCH MORE SHOWER ACTIVITY OVERNIGHT. LOTS OF RESIDUAL
MOISTURE...SO PERIODS OF MVFR CIGS/VSBYS WITH BR CAN BE EXPECTED
OVERNIGHT. THE NEXT WAVE OF SHRA/TSRA WILL ARRIVE TUESDAY
MORNING WITH MAINLY MVFR THROUGH MIDDAY. S WINDS WILL
CONTINUE...AROUND 08KT OVERNIGHT...AND 10G22KT TUESDAY.
13
PREV DISCUSSION.../ISSUED 221 PM CDT MON MAY 25 2015/
DISCUSSION...A PERSISTENT BAND OF SHOWERS CONTINUES TO MOVE
SLOWLY EASTWARD ACROSS MIDDLE TENNESSEE, WITH A FEW STRONGER
CELLS PASSING THROUGH SOUTHERN PARTS. HRRR HAS PERFORMED QUITE
WELL TODAY, AND THE SHORT-RANGE MODEL HAS CONSISTENTLY SHOWN A
DECREASE IN THE ACTIVITY FROM LATE AFTERNOON THROUGH EVENING, SO
AM SPLITTING TONIGHT`S POP GRID INTO 6-HOUR INCREMENTS, WITH
REDUCED POP`S FROM 00Z THROUGH 06Z. NAM SHOWS A WEAK TROUGH MOVING
INTO MIDDLE TENNESSEE TOMORROW MORNING ALONG WITH THE NEXT WAVE OF
MOISTURE, THEREBY PUSHING THE DRY WEDGE NORTHWARD AND BRINGING
LIKELY TO CATEGORICAL POP`S BACK IN. SPC IS KEEPING THE ENTIRE MID
STATE UNDER A SLIGHT RISK OF SEVERE STORMS TOMORROW AND TOMORROW
NIGHT, AND A MARGINAL RISK FOR DAY 3. MODEL SOUNDINGS CONTINUE TO
SHOW GOOD INSTABILITY FOR THE NEXT SEVERAL DAYS, MAINLY DURING
PEAK HEATING HOURS, WITH VERY LITTLE AIR MASS CHANGE FOR THE
FORESEEABLE FUTURE. FOLLOWING WEDNESDAY`S ANTICIPATED SHORTWAVE
PASSAGE, THE UPPER PATTERN BREAKS DOWN INTO A MUCH WEAKER FLOW,
WITH HIGH PRESSURE ESTABLISHING ITSELF OFF THE EAST COAST, VERY
SUMMER-LIKE. WE MAY SEE A FRONTAL PASSAGE EARLY NEXT WEEK, BUT AT
THIS POINT THE GFS AND ECMWF SOLUTIONS DIVERGE TO THE POINT THAT
ANY CONFIDENCE REGARDING TIMING IS LOW. TEMPERATURES WILL
GRADUALLY WARM THROUGHOUT THE WEEK, WITH READINGS SEVERAL DEGREES
ABOVE NORMAL FROM WEDNESDAY ON.
ROSE
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
637 PM CDT MON MAY 25 2015
.UPDATE...FOR AVIATION.
&&
.AVIATION...
00Z TAFS...UNSETTLED WX WILL CONTINUE. ONE WAVE OF SHRA/TSRA WAS
MOVING OFF TO THE EAST OF MID TN THIS EVENING. WE DO NOT EXPECT
MUCH MORE SHOWER ACTIVITY OVERNIGHT. LOTS OF RESIDUAL
MOISTURE...SO PERIODS OF MVFR CIGS/VSBYS WITH BR CAN BE EXPECTED
OVERNIGHT. THE NEXT WAVE OF SHRA/TSRA WILL ARRIVE TUESDAY
MORNING WITH MAINLY MVFR THROUGH MIDDAY. S WINDS WILL
CONTINUE...AROUND 08KT OVERNIGHT...AND 10G22KT TUESDAY.
13
&&
.PREV DISCUSSION... /ISSUED 221 PM CDT MON MAY 25 2015/
DISCUSSION...A PERSISTENT BAND OF SHOWERS CONTINUES TO MOVE
SLOWLY EASTWARD ACROSS MIDDLE TENNESSEE, WITH A FEW STRONGER
CELLS PASSING THROUGH SOUTHERN PARTS. HRRR HAS PERFORMED QUITE
WELL TODAY, AND THE SHORT-RANGE MODEL HAS CONSISTENTLY SHOWN A
DECREASE IN THE ACTIVITY FROM LATE AFTERNOON THROUGH EVENING, SO
AM SPLITTING TONIGHT`S POP GRID INTO 6-HOUR INCREMENTS, WITH
REDUCED POP`S FROM 00Z THROUGH 06Z. NAM SHOWS A WEAK TROUGH MOVING
INTO MIDDLE TENNESSEE TOMORROW MORNING ALONG WITH THE NEXT WAVE OF
MOISTURE, THEREBY PUSHING THE DRY WEDGE NORTHWARD AND BRINGING
LIKELY TO CATEGORICAL POP`S BACK IN. SPC IS KEEPING THE ENTIRE MID
STATE UNDER A SLIGHT RISK OF SEVERE STORMS TOMORROW AND TOMORROW
NIGHT, AND A MARGINAL RISK FOR DAY 3. MODEL SOUNDINGS CONTINUE TO
SHOW GOOD INSTABILITY FOR THE NEXT SEVERAL DAYS, MAINLY DURING
PEAK HEATING HOURS, WITH VERY LITTLE AIR MASS CHANGE FOR THE
FORESEEABLE FUTURE. FOLLOWING WEDNESDAY`S ANTICIPATED SHORTWAVE
PASSAGE, THE UPPER PATTERN BREAKS DOWN INTO A MUCH WEAKER FLOW,
WITH HIGH PRESSURE ESTABLISHING ITSELF OFF THE EAST COAST, VERY
SUMMER-LIKE. WE MAY SEE A FRONTAL PASSAGE EARLY NEXT WEEK, BUT AT
THIS POINT THE GFS AND ECMWF SOLUTIONS DIVERGE TO THE POINT THAT
ANY CONFIDENCE REGARDING TIMING IS LOW. TEMPERATURES WILL
GRADUALLY WARM THROUGHOUT THE WEEK, WITH READINGS SEVERAL DEGREES
ABOVE NORMAL FROM WEDNESDAY ON.
ROSE
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1125 PM CDT SAT MAY 23 2015
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 923 PM CDT SAT MAY 23 2015/
UPDATE...
CLOUDS CONTINUE TO SPREAD INTO THE AREA THIS EVENING. THE CLOUDS
ARE ASSOCIATED WITH THE LARGE CONVECTIVE COMPLEXES OVER OKLAHOMA
AND TEXAS. LATEST HRRR SHOWS REMNANT SHOWERS FROM THESE COMPLEXES
MOVING INTO EASTERN ARKANSAS JUST BEFORE SUNRISE. CURRENT FORECAST
HAS A GOOD HANDLE. NO UPDATES ARE EXPECTED.
KRM
DISCUSSION... /ISSUED 259 PM CDT SAT MAY 23 2015/
SKIES REMAIN MOSTLY SUNNY ACROSS MUCH OF THE FORECAST AREA THIS
AFTERNOON WITH TEMPERATURES RANGING FROM THE MID 70S TO LOWER 80S.
THE AREA OF LIGHT RAIN WHICH WAS MOVING THROUGH NORTH CENTRAL
ARKANSAS THIS MORNING HAS NOW REACHED SOUTHEAST MISSOURI AND IS
OUT OF THE FORECAST AREA.
CURRENTLY A WARM FRONT EXTENDS FROM CENTRAL OKLAHOMA THROUGH
NORTHERN LOUISIANA AND INTO SOUTH MISSISSIPPI. THIS WARM FRONT IS
EXPECTED TO LIFT NORTH TONIGHT AND MOVE INTO SOUTHERN ARKANSAS BY
SUNDAY MORNING. SOME SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP ALONG AND AHEAD OF THE WARM FRONT AND SOME OF THIS
ACTIVITY MAY REACH WESTERN SECTIONS OF THE FORECAST AREA
OVERNIGHT. TEMPERATURES WILL REMAIN MILDER THAN THEY HAVE BEEN THE
LAST COUPLE OF NIGHTS WITH LOWS SUNDAY MORNING IN THE MID TO UPPER
60S.
ON SUNDAY...THE WARM FRONT WILL CONTINUE TO LIFT NORTH AND REACH
INTO NORTHERN MISSOURI BY SUNDAY EVENING. AS A RESULT MORE SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO DEVELOP WITH THE BEST CHANCE OF
THUNDERSTORMS OVER FAR NORTHWEST SECTIONS OF THE FORECAST AREA.
TEMPERATURES WILL BE FAIRLY WARM WITH HIGH IN THE LOWER TO MID
80S. BY SUNDAY NIGHT A UPPER LEVEL TROUGH WILL MOVE THROUGH THE
REGION PRODUCING MORE SHOWERS AND THUNDERSTORMS. IT WILL REMAIN
WARM SUNDAY NIGHT WITH LOW TEMPERATURES MONDAY MORNING AROUND 70
DEGREES.
ON MONDAY...ANOTHER UPPER LEVEL TROUGH APPROACHES THE REGION
BRINGING MORE SHOWERS AND THUNDERSTORMS. THIS SYSTEM COULD BRING
SOME LOCALLY HEAVY RAINFALL TO PARTS OF EAST ARKANSAS AND A FLASH
FLOOD WATCH MAY BE NEEDED BUT A LITTLE TOO EARLY TO ISSUE IT YET
AS SOME UNCERTAINTY REMAINS AS TO HOW MUCH RAIN IS EXPECTED. WITH
MORE CLOUDS AND RAIN TEMPERATURES WILL BE A LITTLE COOLER WITH
HIGHS AROUND 80 DEGREES.
THIS UPPER LEVEL TROUGH WILL BE SLOW TO MOVE SO THERE WILL BE MORE
SHOWERS AND THUNDERSTORMS FOR MONDAY NIGHT AND TUESDAY WITH LOCALLY
HEAVY RAINFALL ALSO POSSIBLE. THIS UPPER LEVEL TROUGH WILL FINALLY
MOVE AWAY FROM THE REGION TUESDAY NIGHT AND EARLY WEDNESDAY SO
THE THREAT OF THUNDERSTORMS WILL DIMINISH FROM WEST TO EAST DURING
THIS PERIOD.
THURSDAY WILL SEE WEATHER MORE LIKE SUMMER WITH A FEW AFTERNOON
THUNDERSTORMS THAT DEVELOP IN THE HEAT OF THE DAY. ANOTHER UPPER
LEVEL TROUGH WILL START TO MOVE SLOWLY TOWARD THE REGION STARTING
THURSDAY NIGHT AND CONTINUING THROUGH NEXT SATURDAY. THIS WILL SET
UP MORE SHOWERS AND THUNDERSTORM ACTIVITY FOR THE FORECAST AREA
DURING THIS PERIOD.
ARS
&&
.AVIATION...
06Z TAF CYCLE
VFR THROUGH MOST OF THE PERIOD. A FEW SHRAS ARE POSSIBLE AT KMEM
AND KJBR LATE TONIGHT/EARLY SUNDAY. THOSE WILL LIFT NORTH BY
24/14Z WITH VFR AND BREEZY CONDS DURING THE DAY. SE WINDS WILL
INCREASE SLIGHTLY OVERNIGHT THEN VEER SOUTH AND CONTINUE TO
INCREASE TO 10-15 KTS WITH HIGHER GUSTS BY SUNDAY AFTERNOON. AN
UPPER LEVEL DISTURBANCE WILL PUSH INTO THE MIDSOUTH SUNDAY EVENING
RESULTING IN SHRAS AND TSRAS AT KJBR AND KMEM BY 25/03Z.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1039 PM CDT MON MAY 25 2015
.UPDATE...
SOME OF THE HI-RES MODELS...MOST NOTABLY THE LAST FEW HRRR AND RAP
RUNS...ARE GENERATING BACKBUILDING STORMS IN MEXICO THAT MAY
DEVELOP INTO A LARGER COMPLEX OVERNIGHT AFTER 8-9Z...MAINLY ALONG
AND SOUTH OF HIGHWAY 90. A PRONOUNCED OUTFLOW BOUNDARY MOVING
SOUTHWEST...WEAK ISENTROPIC ASCENT...AND A TONGUE OF MOIST AIR
EVIDENT ON WV IMAGERY SANDWICHED BETWEEN VERY DRY AIR ON BOTH
SIDES OF IT MAY HELP IN INITIATING THESE STORMS. THIS AREA DID NOT
RECEIVE CONVECTION EARLIER...SO IT MAY NOT BE WORKED OVER DESPITE
THE MESOANALYSIS SUGGESTING A CAP. ANY WEAK SHORTWAVE ROTATING
AROUND THE LARGER SCALE TROUGH TO THE WEST COULD TRIGGER NEW
CONVECTION...SO WILL BE INCREASING POPS ALONG AND SOUTH OF HIGHWAY
90 TO ACCOUNT FOR SCATTERED SHOWERS AND THUNDERSTORMS.
IN ADDITION...ISOLATED SHOWERS AND THUNDERSTORMS ARE FORMING IN THE
HILL COUNTRY ALONG REMNANT OUTFLOW BOUNDARIES ORIENTED WEST TO
EAST...WITH A STRONGER CELL OVER BLANCO COUNTY. IT IS CONCERNING
THAT THESE STORMS ARE STILL ABLE TO FORM DESPITE AN ENVIORMENT
THAT SHOULD BE FAIRLY WORKED OVER FROM AN INSTABILITY
STANDPOINT...BUT SOME HI- RES MODELS DO SUGGEST THAT THE CAP IS
ERODING AND CAPPING WAS VIRTUALLY NONEXISTENT ON THE 00Z DRT
SOUNDING. THUS...WILL BE INCREASING POPS TO ACCOUNT FOR THIS AS
WELL. THESE STORMS WOULD MOVE VERY SLOWLY AND THE FLASH FLOOD
GUIDANCE IS WELL BELOW ONE INCH PER HOUR IN SOME PLACES DUE TO
HEAVY RAINFALL FROM TODAY AND THE PAST FEW WEEKS...SO WILL HAVE
TO MONITOR RADAR TRENDS TO SEE IF A NEW FLASH FLOOD WATCH NEEDS TO
BE ISSUED FOR THE OVERNIGHT HOURS.
FINALLY...A TORNADO WATCH WAS LOCALLY EXTENDED TO 11 PM CDT FOR
KARNES...DEWITT...AND LAVACA COUNTIES TO ACCOUNT FOR CURRENT RADAR
TRENDS...BUT WE DO NOT EXPECT TO EXTEND THIS WATCH FURTHER.
&&
.PREV DISCUSSION... /ISSUED 717 PM CDT MON MAY 25 2015/
AVIATION.../00Z TAFS/
STORMS HAVE CLEARED ALL TAF SITES...BUT WILL INCLUDE VCTS THROUGH
01Z FOR SAT/SSF/AUS IN CASE BACKBUILDING STORMS PRODUCE A ROGUE
LIGHTNING STRIKE. A MESO LOW HAS FORMED BEHIND THIS LINE...WHICH
WILL CAUSE VARIABLE WINDS BELOW 10 KTS AT SAT/SSF/AUS FOR THE NEXT
FEW HOURS...WILL HANDLE THIS WITH AMENDMENTS IF THEY INCREASE
ABOVE 10 KTS. DRY AIR EVIDENT ON WV IMAGERY WILL HELP DRY OUT THE
MID AND UPPER LEVELS...BUT MOIST LOW LEVEL SE FLOW WILL ALLOW VFR
CIGS TO LOWER TO IFR BY 7Z AT SAT/SSF/AUS AND MVFR BY 9Z AT DRT.
MODEL GUIDANCE SUGGESTS LIFR CIGS COULD DEVELOP BETWEEN 10-14Z AT
SAT/SSF/AUS...BUT WILL REEVALUATE THIS WITH THE 06Z TAF PACKAGE.
PREV DISCUSSION... /ISSUED 447 PM CDT MON MAY 25 2015/
.SIGNIFICANT FLASH FLOODING ONGOING ACROSS THE NORTHERN AND
CENTRAL PARTS OF SOUTH CENTRAL TEXAS...
SHORT TERM (TODAY THROUGH TUESDAY)...
A STRONG NEGATIVELY TILTED UPPER LEVEL TROUGH HAS CAUSED A
SIGNIFICANT SEVERE WEATHER EVENT THAT HAS ALREADY PRODUCED A FEW
TORNADOES IN THE HILL COUNTRY AND WIDESPREAD FLASH FLOODING IN THE
HILL COUNTRY AND I-35 CORRIDOR IS ONGOING THIS AFTERNOON. A FLASH
FLOOD EMERGENCY HAS ALSO BEEN ISSUED FOR EASTERN WILLIAMSON AND
TRAVIS COUNTIES AFTER 3 TO 5 INCHES OF RAIN FELL IN TWO HOURS. THE
PRIMARY THREAT FOR THE NEXT SEVERAL HOURS WILL CONTINUE TO BE
SIGNIFICANT FLASH AND RIVER FLOODING...WITH THE LATTER CONTINUING
INTO AT LEAST THE OVERNIGHT HOURS. RAINFALL RATES UP TO 4 INCHES
PER HOUR HAVE OCCURRED THIS AFTERNOON...BUT THESE RATES SHOULD
BEGIN TO DECREASE SLIGHTLY AS THESE STORMS CONTINUE TO MERGE INTO
A LINE OVER THE I-35 CORRIDOR FROM THE SAN ANTONIO METRO AND AREAS
NORTH BEFORE PUSHING EAST ACROSS OUR CWA. DRY AIR MOVING IN FROM
THE WEST EVIDENT ON WV IMAGERY SHOULD CONTINUE TO CAUSE PWAT
VALUES TO DECREASE AND END THE HEAVY RAINFALL THREAT FROM WEST TO
EAST AS WE MOVE INTO THE EVENING AND OVERNIGHT HOURS. THUS...THE
FLASH FLOOD WATCH HAS BEEN CANCELLED FOR OUR WESTERNMOST
COUNTIES...BUT CONTINUES FOR THE VAST MAJORITY OF SOUTH CENTRAL
TEXAS THROUGH 1 AM CDT TUESDAY.
ALTHOUGH SHEAR VALUES HAVE DECREASED SLIGHTLY FROM THE 50-55 KT
SEEN EARLIER THIS AFTERNOON IN THE HILL COUNTRY...HELICITY VALUES
ABOVE 200-300 M^2/S^2 AND LOW LCLS ALONG AND EAST OF I-35 WILL
LIKELY CONTINUE THE TORNADO THREAT FOR THIS AREA FOR AT LEAST THE
NEXT FEW HOURS. TORNADOES WILL BE POSSIBLE WITHIN MORE DISCRETE
CELLS WITHIN THE LINE OF STORMS CURRENTLY CENTERED OVER THE I-35
CORRIDOR NORTH OF SAN ANTONIO AND EXPANDING INTO NE TX AND SE
OK. THUS...A TORNADO WATCH CONTINUES UNTIL 10 PM CDT FOR THE
EASTERN HILL COUNTRY...AND ALL COUNTIES ALONG AND NORTH OF THE
I-10 CORRIDOR AND ALONG AND EAST OF THE I-35 CORRIDOR NORTHEAST OF
THE SAN ANTONIO METRO.
DRY AIR WILL GRACIOUSLY FILL INTO THE ENTIRE CWA BY EARLY TUESDAY
MORNING...BUT ANOTHER WEAK SHORTWAVE ROTATING AROUND THE
PERSISTENT LONGWAVE TROUGH TO OUR WEST MAY TRIGGER ISOLATED
THUNDERSTORMS TUESDAY AFTERNOON IN THE SERRENIAS DEL BURRO THAT
MOVE INTO THE RIO GRANDE PLAINS. ELSEWHERE...AMPLE BOUNDARY LAYER
AND SOIL MOISTURE WITH DAYTIME TEMPERATURES RISING INTO THE UPPER
80S MAY STILL ALLOW FOR VERY ISOLATED AFTERNOON SHOWERS AND
THUNDERSTORMS...BUT DRY AIR SHOULD PREVENT DEVELOPMENT. IN
ADDITION...WEAK SHORTWAVE RIDING SHOULD BEGIN TO BUILD IN BY LATE
TUESDAY NIGHT TO LIMIT OUR RAIN CHANCES.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
A BRIEF PERIOD OF SHORTWAVE RIDGING WITH RELATIVELY DRY AIR WILL
CONTINUE THROUGH EARLY THURSDAY...GIVING THE REGION A MUCH NEEDED
BREAK FROM THE HEAVY RAINFALL PATTERN WE HAVE BEEN IN FOR SEVERAL
WEEKS FOR A FEW DAYS. HOWEVER...WILL STILL CARRY ISOLATED
AFTERNOON SHOWERS AND THUNDERSTORMS FOR WEDNESDAY DUE TO AMPLE
BOUNDARY LAYER MOISTURE AND SOIL MOISTURE WITH HIGHS NEARING 90
DEGREES. ANOTHER UPPER LEVEL TROUGH APPROACHES THE REGION ON
THURSDAY TO BREAK DOWN THIS RIDGE...INCREASING THE COVERAGE OF
AFTERNOON SHOWERS AND THUNDERSTORMS...PARTICULARLY IN THE RIO
GRANDE PLAINS. MODELS GENERALLY AGREE THAT THE MAIN ENERGY FROM
THIS UPPER LEVEL TROUGH SHOULD REMAIN TO OUR NORTH...BUT ALSO
SUGGEST THAT IT WILL NOT BE VERY PROGRESSIVE AND STICK AROUND
UNTIL AT LEAST SUNDAY. CONSIDERING THAT A FEW WEAK BOUNDARIES MAY
SLIP INTO THE REGION TO PROVIDE AN ADDITIONAL FOCUS FOR
CONVECTION...RAINFALL CHANCES WILL LIKELY CONTINUE THROUGH FRIDAY
AND THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 70 88 73 89 / 80 30 20 20 20
AUSTIN BERGSTROM INTL AIRPORT 81 70 88 73 89 / 80 30 20 20 20
NEW BRAUNFELS MUNI AIRPORT 82 71 88 73 89 / 70 30 20 20 20
BURNET MUNI AIRPORT 80 69 87 72 88 / 80 20 20 20 20
DEL RIO INTL AIRPORT 90 71 91 74 91 / 60 10 10 20 20
GEORGETOWN MUNI AIRPORT 80 70 87 71 88 / 80 30 20 20 20
HONDO MUNI AIRPORT 84 72 87 74 89 / 60 10 20 20 20
SAN MARCOS MUNI AIRPORT 81 71 87 73 89 / 70 30 20 20 20
LA GRANGE - FAYETTE REGIONAL 82 70 88 75 90 / 80 50 20 20 20
SAN ANTONIO INTL AIRPORT 83 73 88 74 89 / 70 30 20 20 20
STINSON MUNI AIRPORT 82 73 88 74 89 / 70 30 20 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 AM CDT TUESDAY FOR THE FOLLOWING
COUNTIES: BASTROP...CALDWELL...DE WITT...FAYETTE...GONZALES...
GUADALUPE...KARNES...LAVACA...LEE...WILSON.
&&
$$
MESOSCALE/AVIATION...99
SYNOPTIC/GRIDS...01
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION...UPDATED
NWS HOUSTON/GALVESTON TX
344 PM CDT SUN MAY 24 2015
.DISCUSSION...
SEEING SOME SCT TSRA REDEVELOP ACROSS N PARTS OF THE AREA WHERE
HEATING AND RRQ OF DEPARTING JET ARE WORKING THEIR MAGIC.
ANTICIPATE THESE TO TAPER OFF SHORTLY AFTER SUNSET. IN THE
MEANTIME...CAN STILL SEE SOME ISO STRONG STORMS/DOWNPOURS THAT`LL
NEED TO BE MONITORED.
OVERNIGHT SYSTEM MADE MUCH QUICKER EWD PROGRESS THAN EXPECTED
YDAY AND IS WELL INTO CNTL LA. (FASTER NAM12 ACTUALLY DID A
RESPECTABLE JOB). ALSO SEE NO LINGERING SFC BOUNDARY ALONG I-10
ON CURRENT SFC OBSERVATIONS THAT SOME MODELS WERE INDICATING FOR
TONIGHT - SERVING AS A FOCUS FOR POSSIBLE OVERNIGHT CONVECTION AS
ONSHORE FLOW AND LLJ FEEDS INTO IT. ONLY CANADIAN AND POSSIBLY LATER
SPC HRRR RUNS DEPICT SUCH A SCENARIO NOW - THE REST (INCLUDING
ECMWF) KEEP THE REGION MOSTLY DRY OVERNIGHT. THIS GIVES US A BIT
MORE CONFIDENCE IN A DRIER OVERNIGHT PERIOD THAN EARLIER - BUT
STILL NO GUARANTY. HAVE SLIGHTLY LOWERED POPS IN RESPONSE.
NEXT IMPULSE SEEN ON W/V IMAGERY IN SRN NEVADA WILL MOVE ACROSS
THE STATE MONDAY. EXPECT THIS DISTURBANCE TO TRIGGER ANOTHER SHOWER AND
THUNDERSTORM COMPLEX TO OUR WEST. THIS SYSTEM SHOULD BE MOVING
INTO WESTERN PARTS OF THE AREA TOWARD MID MORNING AND ACROSS THE
REMAINDER OF THE REGION THROUGH THE AFTERNOON HOURS. ISSUED
ANOTHER FF WATCH FROM MID MORNING INTO THE EVENING MON FOR
LOCATIONS GENERALLY ALONG AND NORTH OF I-10. THERE IS SOME UNCERTAINTY
REGARDING HOW FAST THE SYSTEM WILL MOVE OUT AND SOME LOCATIONS
MIGHT SEE PRECIPITATION CONTINUE INTO THE EVENING. IN GENERAL...EXPECT
1 TO 3 INCH RAINFALL AMOUNTS IN THE WATCH AREA AND LESS SO FURTHER
SOUTH. LOCALIZED HIGHER TOTALS ARE POSSIBLE WHERE TRAINING CELLS
OCCUR...AND ALSO IF THE EVENT DRAGS ON INTO THE EVENING HOURS.
THIS WATCH WILL NEED TO BE EXPANDED IN TIME IF IT DOES.
IN ADDITION TO TRAINING STORMS...DYNAMICS W/ THIS SYSTEM ALSO
LOOK FAVORABLE FOR SOME STRONG/SEVERE STORMS WITH WIND DAMAGE AND
TORNADOES BEING THE PRIMARY THREAT. GROUNDS ARE WET AND TREES ARE
MORE PRONE TO BE BLOWN DOWN WITH LESS INTENSE WINDS THAN THEY
MIGHT OTHERWISE.
SPOKE ABOUT THE UNCERTAINTY ABOUT MON NIGHT REGARDING TIMING OF
THE EXIT OF PRECIP. WILL JUST NEED TO WATCH TRENDS. REMAINDER OF
THE WORK WEEK WOULD ANTICIPATE SCT (MAINLY AFTN/EVNG) PRECIP EACH
DAY ACROSS INLAND AREAS. ANOTHER TROF APPROACHES THE NEIGHBORHOOD
GOING INTO NEXT WEEKEND...ALONG W/ HIGHER POPS UNFORTUNATELY. 47
&&
MARINE...
LOOKS LIKE A REPRISE FROM WIDESPREAD THUNDERSTORMS OVER THE BAYS AND
GULF WATERS UNTIL AT LEAST LATER TONIGHT AND LIKELY UNTIL MONDAY.
THE PRESSURE GRADIENT LOOKS TO WEAKEN A BIT TONIGHT...BUT THEN
TIGHTEN BACK UP ON MONDAY BEFORE WEAKENING AGAIN MONDAY EVENING. FOR
THE MOST PART EXPECT ADVISORY CONDITIONS THROUGH MONDAY
AFTERNOON...ALTHOUGH THE WINDS COULD DIMINISH SLIGHTLY BELOW 21
KNOTS TONIGHT AT LEAST OVER THE BAYS AND NEARSHORE WATERS.
REGARDING THE TIDES...GALVESTON CHANNEL AND THE NORTH JETTY BOTH
RECORDED TIDE LEVELS OF ABOUT REACHED ABOUT 1.2 FEET ABOVE NORMAL
LEVELS DURING THE TIME OF THE ASTRONOMICAL HIGH TIDE EARLIER TODAY.
TIDE LEVELS ARE EXPECTED TO BE SLIGHTLY LOWER LATE TOMORROW MORNING
DURING THE HIGH TIDE TIME. EVEN SO...WAVE RUN UP COULD STILL PRESENT
SOME PROBLEMS WITH MINOR FLOODING ON LOW LYING AREAS ALONG THE GULF
FACING BEACHES OF THE BOLIVAR PENINSULA FROM LATE MORNING TO EARLY
AFTERNOON ON MONDAY. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 84 71 87 74 / 50 90 70 30 20
HOUSTON (IAH) 74 84 72 87 74 / 30 80 60 40 20
GALVESTON (GLS) 78 84 78 85 78 / 30 80 60 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
THE FOLLOWING ZONES: AUSTIN...BRAZOS...BURLESON...
COLORADO...GRIMES...HARRIS...HOUSTON...LIBERTY...MADISON...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON.
HIGH RIP CURRENT RISK THROUGH MONDAY EVENING FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT MONDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
338 PM CDT SUN MAY 24 2015
.DISCUSSION...
SEEING SOME SCT TSRA REDEVELOP ACROSS N PARTS OF THE AREA WHERE
HEATING AND RRQ OF DEPARTING JET ARE WORKING THEIR MAGIC.
ANTICIPATE THESE TO TAPER OFF SHORTLY AFTER SUNSET. IN THE
MEANTIME...CAN STILL SEE SOME ISO STRONG STORMS/DOWNPOURS THAT`LL
NEED TO BE MONITORED.
OVERNIGHT SYSTEM MADE MUCH QUICKER EWD PROGRESS THAN EXPECTED
YDAY AND IS WELL INTO CNTL LA. (FASTER NAM12 ACTUALLY DID A
RESPECTABLE JOB). ALSO SEE NO LINGERING SFC BOUNDARY ALONG I-10
ON CURRENT SFC OBSERVATIONS THAT SOME MODELS WERE INDICATING FOR
TONIGHT - SERVING AS A FOCUS FOR POSSIBLE OVERNIGHT CONVECTION AS
ONSHORE FLOW AND LLJ FEEDS INTO IT. ONLY CANADIAN AND POSSIBLY LATER
SPC HRRR RUNS DEPICT SUCH A SCENARIO NOW - THE REST (INCLUDING
ECMWF) KEEP THE REGION MOSTLY DRY OVERNIGHT. THIS GIVES US A BIT
MORE CONFIDENCE IN A DRIER OVERNIGHT PERIOD THAN EARLIER - BUT
STILL NO GUARANTY. HAVE SLIGHTLY LOWERED POPS IN RESPONSE.
NEXT IMPULSE SEEN ON W/V IMAGERY IN SRN NEVADA WILL MOVE ACROSS
THE STATE MONDAY. EXPECT THIS DISTURBANCE TO TRIGGER ANOTHER SHOWER AND
THUNDERSTORM COMPLEX TO OUR WEST. THIS SYSTEM SHOULD BE MOVING
INTO WESTERN PARTS OF THE AREA TOWARD MID MORNING AND ACROSS THE
REMAINDER OF THE REGION THROUGH THE AFTERNOON HOURS. ISSUED
ANOTHER FF WATCH FROM MID MORNING INTO THE EVENING MON FOR
LOCATIONS GENERALLY ALONG AND NORTH OF I-10. THERE IS SOME UNCERTAINTY
REGARDING HOW FAST THE SYSTEM WILL MOVE OUT AND SOME LOCATIONS
MIGHT SEE PRECIPITATION CONTINUE INTO THE EVENING. IN GENERAL...EXPECT
1 TO 3 INCH RAINFALL AMOUNTS IN THE WATCH AREA AND LESS SO FURTHER
SOUTH. LOCALIZED HIGHER TOTALS ARE POSSIBLE WHERE TRAINING CELLS
OCCUR...AND ALSO IF THE EVENT DRAGS ON INTO THE EVENING HOURS.
THIS WATCH WILL NEED TO BE EXPANDED IN TIME IF IT DOES.
IN ADDITION TO TRAINING STORMS...DYNAMICS W/ THIS SYSTEM ALSO
LOOK FAVORABLE FOR SOME STRONG/SEVERE STORMS WITH WIND DAMAGE AND
TORNADOES BEING THE PRIMARY THREAT. GROUNDS ARE WET AND TREES ARE
MORE PRONE TO BE BLOWN DOWN WITH LESS INTENSE WINDS THAN THEY
MIGHT OTHERWISE.
SPOKE ABOUT THE UNCERTAINTY ABOUT TUES NIGHT REGARDING TIMING OF
THE EXIT OF PRECIP. WILL JUST NEED TO WATCH TRENDS. REMAINDER OF
THE WORK WEEK WOULD ANTICIPATE SCT (MAINLY AFTN/EVNG) PRECIP EACH
DAY ACROSS INLAND AREAS. ANOTHER TROF APPROACHES THE NEIGHBORHOOD
GOING INTO NEXT WEEKEND...ALONG W/ HIGHER POPS UNFORTUNATELY. 47
&&
.MARINE...
LOOKS LIKE A REPRISE FROM WIDESPREAD THUNDERSTORMS OVER THE BAYS AND
GULF WATERS UNTIL AT LEAST LATER TONIGHT AND LIKELY UNTIL MONDAY.
THE PRESSURE GRADIENT LOOKS TO WEAKEN A BIT TONIGHT...BUT THEN
TIGHTEN BACK UP ON MONDAY BEFORE WEAKENING AGAIN MONDAY EVENING. FOR
THE MOST PART EXPECT ADVISORY CONDITIONS THROUGH MONDAY
AFTERNOON...ALTHOUGH THE WINDS COULD DIMINISH SLIGHTLY BELOW 21
KNOTS TONIGHT AT LEAST OVER THE BAYS AND NEARSHORE WATERS.
REGARDING THE TIDES...GALVESTON CHANNEL AND THE NORTH JETTY BOTH
RECORDED TIDE LEVELS OF ABOUT REACHED ABOUT 1.2 FEET ABOVE NORMAL
LEVELS DURING THE TIME OF THE ASTRONOMICAL HIGH TIDE EARLIER TODAY.
TIDE LEVELS ARE EXPECTED TO BE SLIGHTLY LOWER LATE TOMORROW MORNING
DURING THE HIGH TIDE TIME. EVEN SO...WAVE RUN UP COULD STILL PRESENT
SOME PROBLEMS WITH MINOR FLOODING ON LOW LYING AREAS ALONG THE GULF
FACING BEACHES OF THE BOLIVAR PENINSULA FROM LATE MORNING TO EARLY
AFTERNOON ON MONDAY. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 84 71 87 74 / 50 90 70 30 20
HOUSTON (IAH) 74 84 72 87 74 / 30 80 60 40 20
GALVESTON (GLS) 78 84 78 85 78 / 30 80 60 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR
THE FOLLOWING ZONES: AUSTIN...BRAZOS...BURLESON...
COLORADO...GRIMES...HARRIS...HOUSTON...LIBERTY...MADISON...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON.
HIGH RIP CURRENT RISK THROUGH MONDAY EVENING FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT MONDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
322 PM CDT SUN MAY 24 2015
.SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...
THE SHORT BREAK FROM PRECIPITATION CONTINUES LATE THIS AFTERNOON
INTO THE OVERNIGHT HOURS. A FEW SHOWERS AND AN ISOLATED
THUNDERSTORMS ARE STILL POSSIBLE LATER THIS AFTERNOON. HAVE SEEN A
FEW ISOLATED SHOWERS BEGINNING TO FORM UP IN WILLIAMSON COUNTY.
THIS SUPPORTS WHAT THE HRRR SHOWS THROUGH THE EVENING HOURS.
DRY AIR HAS FILTERED IN BEHIND THE TWO LINES OF CONVECTION THIS
MORNING. ALL OF THE MODELS HAVE SOUTH CENTRAL TEXAS REMAINING DRY
OVERNIGHT WITH ONLY THE NAM SHOWING ANY CONVECTION/QPF OVERNIGHT.
WILL DISCOUNT THE NAM FOR NOW.
THE NEXT UPPER LEVEL DISTURBANCE IS NOW ALONG THE
CALIFORNIA/ARIZONA BORDER. THIS WILL APPROACH THE AREA MONDAY.
MODELS ARE A BIT SPLIT ON TIMING OF THE SHOWERS AND THUNDERSTORMS
TOMORROW...BUT THEY ARE IN FAIRLY GOOD AGREEMENT ON QPF AMOUNTS.
THE NAM...GFS...AND ECMWF ALL CONCENTRATE QPF ACROSS THE NORTHERN
I-35 CORRIDOR AND POINTS EAST WITH LESSER AMOUNTS ACROSS THE HILL
COUNTRY AND BEXAR COUNTY AREA. STILL THOUGH MODELS ARE SHOWING 1
TO 3 INCHES ACROSS AREAS THAT NOT ONLY HAD 1 TO 3...OR IN SOME
CASES A LOT MORE...INCHES OF A RAIN LAST NIGHT BUT HAVE ALSO HAD
SEVERAL HEAVY RAIN EVENTS OVER THE LAST FEW WEEKS...LIKE THE
BASTROP AND LEE COUNTY AREAS. THE HEAVIER STORMS TOMORROW COULD
PRODUCE LOCALLY HEAVY RAINFALL UP TO 5 INCHES. THIS SHOULD BE
ENOUGH TO CAUSE MORE FLOODING CONCERNS SO FOR THAT REASON WE WILL
BE ISSUING A FLASH FLOOD WATCH FROM 10 AM MONDAY THROUGH 1 AM ON
TUESDAY. AGAIN ALTHOUGH QPF AMOUNTS ARE EXPECTED TO BE LOWER
TOMORROW THAN THEY WERE LAST NIGHT THE ALREADY SATURATED GROUND
CANNOT TAKE ANYMORE RAINFALL LEADING TO THE ENHANCED FLASH FLOOD
RISK. THE LINE OF STORMS WILL BE FAST MOVING SO PRECIPITATION
SHOULD BE ENDING BY LATE MONDAY NIGHT.
MOST OF THE MESOSCALE MODELS BEGIN CONVECTION ACROSS THE EDWARDS
PLATEAU AS EARLY AS 7 TO 10 AM TOMORROW. EARLY ON STORMS SHOULD BE
MORE CELLULAR. EVENTUALLY THESE STORMS WILL FORM INTO A LINE OF
SHOWERS AND THUNDERSTORMS MUCH LIKE WHAT WE SAW COME THROUGH LAST
NIGHT. THIS LINE WOULD APPROACH THE I-35 CORRIDOR MID TO LATE
AFTERNOON TOMORROW. SEVERE WEATHER PARAMETERS ARE AGAIN IMPRESSIVE
FOR TOMORROW WITH FORECAST SOUNDINGS SHOWING PLENTY OF INSTABILITY
AND SHEAR TO SUPPORT NOT ONLY THE THREAT FOR LARGE HAIL AND
DAMAGING WINDS...BUT ALSO A FEW ISOLATED TORNADOES. SIMILAR TO
YESTERDAY AFTERNOON AND OVERNIGHT THE STORM MODE THAT THE STORMS
TAKE WILL MOST LIKELY DETERMINE THE MAIN THREATS. THE LONGER THE
STORMS STAY CELLULAR THE BETTER THE CHANCES FOR TORNADOES. WITH
MOST MODELS SHOWING A LINEAR SYSTEM COMING ACROSS THE I-35
CORRIDOR THE MAIN THREATS WILL BE STRAIGHTLINE WINDS...SOME
ISOLATED HAIL...AND THE POSSIBILITY OF A QLCS TORNADO OR TWO. WE
SAW SEVERAL CIRCULATIONS OR SPIN UPS ALONG THE LINE OF
THUNDERSTORMS LAST NIGHT AS IT PROGRESSED ACROSS THE AREA. A STORM
SURVEY TEAM IS CURRENT EN ROUTE TO GO DETERMINE IF THERE WERE ANY
TORNADOES OR IF THE DAMAGE WAS CAUSED BY STAIGHTLINE WINDS. MODELS
HAVE THE LINE OF STORMS THROUGH THE AREA BY 10 PM TO MIDNIGHT
MONDAY INTO EARLY TUESDAY MORNING.
IN SUMMARY...QUIET NIGHT TONIGHT...CONVECTION STARTING EARLY
TOMORROW...FLASH FLOOD WATCH STARTING AT 10 AM...CONVECTION
APPROACHING THE I-35 CORRIDOR MID TO LATE AFTERNOON WITH A THREAT
FOR LOCALLY HEAVY RAIN AND SEVERE WEATHER...MOVING OUT OF THE
AREA LATE MONDAY NIGHT INTO TUESDAY.
&&
.LONG TERM (TUESDAY THROUGH SUNDAY)...
MID WEEK SHOULD SEE A LULL IN PRECIPITATION FOR TUESDAY THROUGH
THURSDAY MORNING AS THE UPPER LEVEL PATTERN BECOMES MORE ZONAL AND
EVEN SOME WEAK RIDGING TAKES PLACE ACROSS SOUTH TEXAS. WHILE THE
PATTERN BECOMES MORE PROGRESSIVE ANOTHER TROUGH DROPS ACROSS THE
WESTERN U.S. WITH ANOTHER DISTURBANCE TRACKING ACROSS THE
SOUTHWEST U.S. BY LATE THURSDAY INTO FRIDAY. THIS WILL UP
RAIN CHANCES AGAIN INTO THE WEEKEND AS THE TROUGH ALSO DRAGS A
BOUNDARY ACROSS THE AREA. THE WET AND RAINY PATTERN LOOKS TO
CONTINUE. ANOTHER FACTOR THAT MAY PLAY INTO THE WEATHER LATE NEXT
WEEK IS THAT MODELS ARE FORMING A TROPICAL SYSTEM IN THE PACIFIC
THAT COULD SEND MOISTURE UP OUR DIRECTION.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 72 82 69 88 72 / 20 80 40 20 20
AUSTIN BERGSTROM INTL AIRPORT 72 82 68 87 72 / 20 80 40 20 20
NEW BRAUNFELS MUNI AIRPORT 72 83 70 87 73 / 20 80 30 20 20
BURNET MUNI AIRPORT 70 80 67 87 71 / 20 80 30 20 20
DEL RIO INTL AIRPORT 70 90 68 93 74 / 20 50 20 10 20
GEORGETOWN MUNI AIRPORT 72 80 69 87 72 / 20 80 30 20 20
HONDO MUNI AIRPORT 71 84 70 88 73 / 20 80 30 20 20
SAN MARCOS MUNI AIRPORT 73 82 70 87 72 / 20 80 40 20 20
LA GRANGE - FAYETTE REGIONAL 74 82 72 87 74 / 30 80 50 20 20
SAN ANTONIO INTL AIRPORT 73 83 72 88 73 / 20 80 30 20 20
STINSON MUNI AIRPORT 73 84 72 88 74 / 20 80 30 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
THE FOLLOWING COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...
BLANCO...BURNET...CALDWELL...COMAL...DE WITT...DIMMIT...FAYETTE...
FRIO...GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...
KERR...LAVACA...LEE...LLANO...MEDINA...REAL...TRAVIS...UVALDE...
WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
114 AM CDT SUN MAY 24 2015
.AVIATION... /06Z TAF UPDATE/
CONVECTION HAS WEAKENED OVER AUS TEMPORARILY BUT WILL CONTINUE TO
REDEVELOP OVER SAT/SSF FOR SEVERAL MORE HOURS. TSRA SHOULD BE MORE
ISOLATED AROUND DRT AND WILL KEEP ONLY A MENTION OF VCSH FOR THE
REST OF THE OVERNIGHT. A STRONG CONVECTIVE BAND MOVING THROUGH THE
HILL COUNTRY SHOULD IMPACT SAT/SSF IN THE NEXT 2 TO 4 HOURS AND IN
THE AUS AREA AS LATE AS 11Z. SOME WEAKENING OF THESE CELLS MAY
DEVELOP AS THEY MOVE INTO DOWNDRAFT INFLUENCED AIR ALONG I-35. BY
12Z CONVECTION COULD BECOME MORE SCATTERED AND MAINLY EAST OF
I-35 WITH MESOSCALE MODELS SUGGESTING SLIGHTLY INCREASED STABILITY
BY MIDDAY. WILL LEAVE OUT THE SCATTERED AFTERNOON STORM THREAT FOR
NOW AND FOCUS ON THE MORE LIKELY EXPECTATION FOR LOWERING CIGS
TOMORROW EVENING.
&&
.PREV DISCUSSION... /ISSUED 226 PM CDT SAT MAY 23 2015/
SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
AN ACTIVE AND COMPLEX FORECAST IS SHAPING UP OVER SOUTH CENTRAL
TEXAS THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK WITH BOTH
SEVERE WEATHER AND FLASH FLOODING POSSIBLE. FLASH FLOOD WATCH IS
IN EFFECT THROUGH 7 PM ON SUNDAY.
IN ADDITION TO THE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY
THAT IS ONGOING CURRENTLY ACROSS THE TEXAS HILL COUNTRY AND I-35
CORRIDOR CONVECTION HAS BEGUN ACROSS NORTHERN MEXICO AND THE BIG
BEND REGION. THIS IS THE START OF A LARGE LINEAR MCS THAT ALL OF
THE MESOSCALE MODELS SHOW MOVING ACROSS THE STATE THIS EVENING
INTO EARLY TOMORROW MORNING. THE UPPER LEVEL LOW PRESSURE THAT HAS
BEEN SITTING OVER THE WESTERN UNITED STATES WILL MOVE TO THE EAST
AND NORTHEAST THIS AFTERNOON AND OVERNIGHT PROVIDING THE LIFT FOR
THIS MCS. THERE IS PLENTY OF MOISTURE IN PLACE WITH DEWPOINTS IN
THE LOW 70S AND PRECIPITABLE WATER VALUES BETWEEN 1.75 AND 2
INCHES. THERE IS ALSO PLENTY OF INSTABILITY OVER THE AREA WITH
THE MORNING DRT AND CRP SOUNDINGS BOTH HAVING 2000 - 3000 J/KG OF
CAPE. A GOOD AMOUNT OF LOW LEVEL AND BULK SHEAR IS ALSO EVIDENT
ACCORDING TO THE MODELS. THIS MEANS THAT ALL OF THE INGREDIENTS
ARE IN PLACE FOR BOTH HEAVY RAINFALL AND SEVERE WEATHER THIS
AFTERNOON THROUGH THE OVERNIGHT HOURS INTO TOMORROW. WILL
BREAKDOWN THE THREATS AND THE TIME PERIODS IN THE REST OF THE
SHORT TERM AFD.
FOR TONIGHT...AS ALREADY DISCUSSED...THE MESOSCALE MODELS DEVELOP
A COMPLEX OF STORMS THAT WILL SWEEP ACROSS THE STATE OVERNIGHT
TONIGHT. TIMING FOR THIS CONTINUES TO GET EARLIER. THE NSSL WRF
AND ARM BOTH HAVE THE LINE APPROACHING THE I-35 CORRIDOR BY THE
LATE AFTERNOON. THE TEXAS TECH WRF AND HRRR AND NMM ALL SAY THAT
THE LINE WILL BE MOVING THROUGH THE HILL COUNTRY AND APPROACHING
THE I-35 CORRIDOR BY 9PM AND SLOWLY PUSHING EAST THROUGH THE EARLY
MORNING HOURS. BASED ON CURRENT SATELLITE TRENDS THE EARLIER
TIMING IS BEGINNING TO LOOK MORE LIKELY. MODELS ARE STILL HOLDING
ONTO 1-3 INCH RAINFALL TOTALS WITH THIS INITIAL WAVE OF
CONVECTION. THIS...ON TOP OF ADDITIONAL RAINS THAT HAVE ALREADY
FALLEN TODAY...AND THE FACT THAT SOILS ARE SATURATED WILL LEAD TO
THE THREAT OF BOTH RIVER FLOODING AND FLASH FLOODING. THE SEVERE
WEATHER THREAT WILL ALSO BE PRESENT. WHILE CONVECTION GROUPING
TOGETHER LIKE THIS TYPICAL MEANS THE THREAT FOR SEVERE WEATHER IS
A LITTLE BIT LESS...CONVECTIVE PARAMETERS ARE VERY FAVORABLE. THE
MAIN CONCERNS WILL BE FIRST DAMAGING THUNDERSTORM WINDS WITHIN
BOWING SECTIONS OF THE LINE. THE HRRR ACTUAL SUPPORTS THIS WITH
SEVERAL BOWING SECTIONS BEING SHOWN IN THE MODEL REFLECTIVITY.
THERE IS ALSO SUFFICIENT SURFACE WIND SHEAR AND HELICITY VALUES
TO RESULT IN AN ISOLATED TORNADO THREAT AS WINDS PROFILES TURN
WITH HEIGHT.
DURING THE OVERNIGHT HOURS IT IS IMPERATIVE THAT THOSE OUT AND
ABOUT FOR THE HOLIDAY WEEKEND...ESPECIALLY THOSE ON LOCAL RIVERS
AND LAKES...MONITOR THE WEATHER AND BE READY TO ACT SHOULD A
WARNING BE ISSUED FOR THEIR AREA. HAVE MULTIPLE WAYS TO RECEIVE
WEATHER INFORMATION...HAVE A PLAN TO SEEK SHELTER OR GET TO SAFETY
SHOULD SEVERE WEATHER OR FLOODING OCCUR...AND ALWAYS REMEMBER TO
TURN AROUND...DONT DROWN.
AS WE GET INTO EARLY SUNDAY MORNING THE LINE WILL CONTINUE TO
PUSH ACROSS THE I-35 CORRIDOR INTO OUR EASTERN COUNTIES WITH
CONTINUED RISK FOR FLASH FLOODING AND SEVERE WEATHER. MODELS NOW
SHOW THE LINE MOVING OUT OF OUR CWA BY 09Z TO 12Z (4 TO 7 AM).
BEHIND THE LINE THE ATMOSPHERE WILL BE SOME WHAT WORKED OVER FROM
THE NIGHT OF STORMS. ALTHOUGH MODEL SOUNDINGS SHOW OVER 3000 J/KG
OF CAPE...SIGNIFICANT INSTABILITY...DURING THE AFTERNOON HOURS
ALONG THE I-35 CORRIDOR. THE SAME SOUNDINGS SHOW SIGNIFICANT LOW
AND UPPER LEVEL DRYING OF THE ATMOSPHERE. THIS SHOULD LIMIT SHOWER
AND THUNDERSTORM ACTIVITY SUNDAY AFTERNOON INTO THE OVERNIGHT
HOURS SUNDAYS. MESOSCALE MODELS LIKE THE ARM/NMM/NSSL WRF DO SHOW
SOME ISOLATED ACTIVITY SUNDAY AFTERNOON BUT COVERAGE SHOULD BE
LIMITED.
TO SUMMARIZE THE NEXT 24 HOURS...1 TO 4 INCHES OF RAINFALL ARE
EXPECTED WITH A LINE OF SHOWERS AND STORMS THAT WILL SLOWLY MOVE
ACROSS THE AREA THIS EVENING INTO THE OVERNIGHT HOURS. FLASH FLOOD
WATCH IN EFFECT. THE LINE SHOULD BE PUSHING OUT OF OUR AREA
EARLY SUNDAY MORNING. THE THREAT FOR SEVERE THUNDERSTORM WINDS
ALONG WITH AN ISOLATED TORNADO EXIST WITH THE LINE. BY TOMORROW
AFTERNOON ONLY AN ISOLATED SHOWER OR THUNDERSTORM IS EXPECTED
THROUGH THE AFTERNOON AND OVERNIGHT HOURS. EVERYONE SHOULD BE
WEATHER AWARE FOR THIS WEEKEND...ESPECIALLY THOSE OUT AND ABOUT ON
AREA RIVERS AND LAKES.
LONG TERM (MONDAY THROUGH SATURDAY)...
THE BREAK FROM THE SHOWER AND THUNDERSTORM ACTIVITY WILL BE SHORT
LIVED AS ANOTHER UPPER LEVEL DISTURBANCE APPROACHES ON MONDAY.
THIS DISTURBANCE...CURRENTLY SEEN ON WATER VAPOR ACROSS NORTHERN
CALIFORNIA WILL ROTATE AROUND THE BASE OF THE LARGER UPPER LEVEL
TROUGH AND GIVE SOUTH CENTRAL TEXAS ANOTHER SHOT OF RAIN AND
STORMS. MODELS INDICATE THAT THE BEST TIMING FOR ANOTHER WAVE OF
PRECIPITATION WILL BE FROM AROUND LUNCH TIME THROUGH THE
AFTERNOON. MODEL QPF (FROM THE GFS AND ECMWF) FOR THIS TIME PERIOD
SUGGEST ANOTHER 1 TO 2 INCHES POSSIBLE. PRECIPITABLE WATER VALUES
REMAIN OVER 1.5 INCHES AS WELL. LATER SHIFTS WOULD POSSIBLE NEED
TO CONSIDER EXTENDING THE FLASH FLOOD WATCH INTO MONDAY AS
CONFIDENCE INCREASES. THE CHANCE FOR SEVERE WEATHER WILL ALSO
RETURN ON MONDAY. SPC HAS THE AREA CURRENTLY BLANKETED IN A DAY 3
SLIGHT RISK. MODEL SOUNDINGS AGAIN SHOW CAPE AND SHEAR VALUES
SUPPORTIVE OF HAIL...DAMAGING WINDS AND ISOLATED TORNADOES. STORM
MODE AND COVERAGE OF STORMS WILL DETERMINE THE OVERALL THREAT OF
TORNADOES AS CHANCES ARE BETTER WITH ISOLATED SUPERCELLS RATHER
THAN WIDESPREAD CONVECTION OR MCS STORM MODES. WILL HAVE TO
MONITOR THE THREAT FOR SEVERE WEATHER MONDAY CLOSELY. STRESSING
AGAIN...ANYONE WITH OUTDOOR PLANS FOR THE HOLIDAY NEEDS TO MAKE
SURE THEY ARE WEATHER AWARE AND HAVE A PLAN TO SEEK SHELTER SHOULD
SEVERE WEATHER DEVELOP.
THE UPPER LEVEL FLOW FOR TUESDAY IS MORE ZONAL WITH SOME SLIGHT
RIDGING FOR WEDNESDAY. THIS WILL BRING ANOTHER REDUCTION IN POP
CHANCES FOR MID-WEEK. BY THE END OF THE WEEK ANOTHER LARGE UPPER
LEVEL TROUGH SETS UP ACROSS THE WEST RETURNING THE AREA TO A
SIMILAR PATTERN THAT WE HAVE BEEN IN FOR THE LAST FEW WEEKS WITH A
LARGE UPPER TROUGH SENDING A SERIES OF DISTURBANCES ACROSS THE
AREA. RAIN CHANCES WILL BE ON THE RISE AGAIN LATE NEXT WEEK INTO
NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 70 81 69 87 / 80 40 80 60 30
AUSTIN BERGSTROM INTL AIRPORT 82 69 81 68 87 / 80 40 80 60 30
NEW BRAUNFELS MUNI AIRPORT 83 69 81 70 87 / 70 40 80 50 30
BURNET MUNI AIRPORT 81 69 80 67 85 / 60 30 80 50 20
DEL RIO INTL AIRPORT 90 71 89 69 90 / 20 20 60 20 -
GEORGETOWN MUNI AIRPORT 80 69 80 68 86 / 70 30 80 50 20
HONDO MUNI AIRPORT 85 70 83 69 87 / 50 30 80 40 20
SAN MARCOS MUNI AIRPORT 82 69 81 69 86 / 80 40 80 60 30
LA GRANGE - FAYETTE REGIONAL 82 71 82 71 86 / 90 50 80 70 40
SAN ANTONIO INTL AIRPORT 84 71 82 71 87 / 60 30 80 50 20
STINSON MUNI AIRPORT 84 71 83 71 88 / 60 40 80 50 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING COUNTIES:
ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...CALDWELL...
COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...GILLESPIE...
GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...KINNEY...
LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...UVALDE...
VAL VERDE...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...OAKS
SYNOPTIC/GRIDS...HAMPSHIRE
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
924 PM CDT MON MAY 25 2015
.UPDATE...
THE NEW NAM SHOWS AN UPPER LEVEL 250 MB WIND MAX OVER THE CENTRAL
PLAINS TO NORTHERN IOWA...WILL LIFT INTO NORTHERN WISCONSIN AND
SOUTHEAST MINNESOTA BY MIDNIGHT...AS A SECOND WIND MAX LIFTS INTO
THE UPPER MISSISSIPPI VALLEY. THE UPPER DIVERGENCE INCREASES OVER
SOUTH CENTRAL WISCONSIN LATE TONIGHT AS A 500 MB TROUGH LIFTS
NORTHEAST INTO WESTERN MISSOURI AND EASTERN IOWA BY SUNRISE. THE
700 MB UPWARD MOTION INCREASES ACROSS THE SOUTH TOWARDS SUNRISE.
THE NAM BRINGS SHOWERS AND ISOLATED THUNDERSTORMS INTO MAINLY
SOUTH CENTRAL WISCONSIN BETWEEN 4 AM AND 6 AM. THE 01Z HRRR IS
JUST A FEW HOURS LATER...BUT MAY NOT HAVE THE NEW 00Z UPPER AIR
DATA.
&&
.AVIATION/06Z TAFS/...
SOUTH WINDS WILL WEAKEN SOMEWHAT TONIGHT INTO TUESDAY...AS A
SURFACE TROUGH MOVES TOWARD THE AREA FROM THE WEST. CHANCES FOR
SHOWERS AND STORMS WILL GRADUALLY INCREASE LATER TONIGHT INTO
TUESDAY. VICINITY THUNDERSTORM WORDING WILL BE USED FOR TUESDAY AT
MADISON...IN THE AFTERNOON IN THE EASTERN SITES. THERE IS SOME
UNCERTAINTY WITH AREAL COVERAGE AND TIMING OF ANY OF THESE
SHOWERS/STORMS. MVFR CEILINGS/VISIBILITIES ARE POSSIBLE IN ANY
HEAVIER SHOWERS/STORMS.
.MARINE...
AS THE DEW POINTS REMAIN REASONABLY ABOVE THE WATER
TEMPERATURES FOR THE NEXT FEW DAYS...FOG MAY DEVELOP BUT FOR NOW
WITH AN OFF SHORE FLOW ANY FOG WILL BE MORE LIKELY TOWARD THE OPEN
WATERS.
THE SMALL CRAFT ADVISORY WILL BE CANCELLED AT 10 PM. WINDS HAVE
DIMINISHED. HIGHEST WAVES WILL BE TOWARD THE OPEN WATERS.
&&
.PREV DISCUSSION... /ISSUED 337 PM CDT MON MAY 25 2015/
TONIGHT AND TUESDAY...FORECAST CONFIDENCE IS MEDIUM.
A FEW SHOWERS ARE STILL DEVELOPING AND DISSIPATING ACROSS PORTIONS
OF THE AREA THIS AFTERNOON...AS 500 MB VORTICITY MAXIMUM PASSES
THROUGH. THIS FEATURE WILL MOVE NORTHEASTWARD BY SUNSET.
HOWEVER...MORE SHOWERS AND STORMS HAVE FORMED NEAR THE
MINNESOTA/IOWA BORDER REGION THIS AFTERNOON. THESE ARE BEING DRIVEN
BY THE 850 MB LOW LEVEL JET AND ANOTHER WEAKER 500 MB VORTICITY
MAXIMUM. MESOSCALE MODELS ARE MIXED WITH THEIR HANDLING OF THE
CURRENT ACTIVITY. BEST ONES TAKE MOST OF THIS PRECIPITATION EAST
NORTHEAST AND MISS THE AREA.
THESE MODELS TRY TO DEVELOP MORE SHOWERS AND STORMS LATER THIS
EVENING AND OVERNIGHT...AS THE LOW LEVEL JET AXIS AND WARM CONVEYOR
BELT SHIFTS INTO THE AREA. 500 MB SHORTWAVE TROUGH ALSO APPROACHES
THE REGION. BEST SETUP APPEARS TO BE IN THE NORTHWEST PARTS OF THE
AREA. THUS...CONTINUED TO RAMP UP POPS TONIGHT.
SPC HAS PARTS OF AREA IN MARGINAL SEVERE RISK TONIGHT...WITH ENOUGH
ELEVATED CAPE AND EFFECTIVE SHEAR TO BRING A RISK FOR SOME HAIL.
HOWEVER...THIS SHOULD BE ISOLATED IN NATURE...DUE TO LACK OF FOCUSED
UPWARD VERTICAL MOTION. LOWS SHOULD DROP ONLY INTO THE MID 60S.
BETTER UPWARD VERTICAL MOTION COMES INTO THE AREA TUESDAY...AS
SEVERAL 500 MB VORTICITY MAXIMA PUSH NORTHEAST THROUGH THE AREA. THE
SURFACE TROUGH ALSO PUSHES EASTWARD TOWARD THE AREA. GOOD MIXING IN
THE LOW LEVELS ELIMINATES CAP...WITH WEAK MEAN LAYER CAPE WITH GOOD
DEEP LAYER SHEAR. NAM LOOKS OVERDONE WITH CAPE WITH DEW POINTS TOO
HIGH...WITH THE MORE CONSERVATIVE MEAN LAYER CAPE ON THE GFS MORE
REALISTIC. CONTINUED THE LIKELY THUNDER POPS FOR TUESDAY. HIGHS
SHOULD REACH THE UPPER 70S INLAND...WITH A POSSIBLE LAKE BREEZE
IN THE AFTERNOON KEEPING THINGS COOLER NEAR THE LAKE.
TUESDAY NIGHT - CONFIDENCE...MEDIUM
500 MILLIBAR SHORTWAVE COMBINED WITH SFC/850 TROUGH AXIS EXPECTED
TO KEEP SCT SHRA/TSRA GOING THIS PERIOD. SOME DIURNAL DROPOFF
POSSIBLE BUT ENOUGH FORCING MECHANISMS AT PLAY TO KEEP THE CHANCE
GOING. SOUNDINGS CONTINUE TO SHOW A TALLER AND SKINNIER CAPE
PROFILE. MBE VELOCITIES ARE ALSO LESS THAN 10 KNOTS. SO POTENTIAL
FOR EFFICIENT RAIN MAKERS.
WEDNESDAY - CONFIDENCE...MEDIUM
MID LEVEL SHORTWAVE AND LOW LEVEL TROUGH AXIS MOVE SLOW ENOUGH TO
KEEP THE CHANCE FOR SHRA/TSRA GOING FOR AT LEAST THE MORNING
HOURS. MAY GET INTO SOME SUBSIDENCE FOR THE AFTERNOON AS SHORTWAVE
MOVES EAST OF THE AREA. BRIEF 925 COOLING ASSOCIATED WITH TROUGH
BUT 925 TEMPS MODIFY BACK TO 18-20C DURING THE AFTERNOON.
WEDNESDAY NIGHT AND THURSDAY - CONFIDENCE...MEDIUM
WILL GO WITH A QUIET PERIOD IS MID LEVEL RIDGING AND SURFACE HIGH
DOMINATE. RETURN FLOW LLJ SETS UP TO THE WEST OF THE AREA ON
THURSDAY. SOUTHERLY WINDS DO PICK UP A BIT WITH 925 TEMPS
19-21C...SO WARM DAY EXPECTED WITH LAKE BREEZE CIRCULATION
GENERATING AN ONSHORE COMPONENT.
THURSDAY NIGHT - CONFIDENCE...MEDIUM
LEAD VORT MAXES AND EASTWARD TRANSLATION OF 850 JET SUGGEST
PRECIP DEVELOPMENT MAY OCCUR WITH AN UPTICK IN MOISTURE ADVECTION
AS WELL.
FRIDAY THROUGH SATURDAY - CONFIDENCE...LOW TO MEDIUM
LOOKS LIKE AN ACTIVE PERIOD WITH SURFACE/850 FRONTS SLOWLY
SAGGING INTO SRN WI. MOISTURE/INSTABILITY LIKELY PLENTIFUL WITH
GRADUALLY INCREASING 500 MILLIBAR DYNAMICS AS WELL. BIGGER MODEL
DISCREPANCY COMES WITH HOW MUCH PRECIP LINGERS IN A POST FRONTAL
FASHION INTO SATURDAY. THE GEM IS THE MOST AGGRESSIVE BU THE ECMWF
IS NOT TOO FAR BEHIND. THE GFS TENDS TO SUPPRESS THIS FURTHER
SOUTH WITH MORE INFLUENCE OF THE COOL HIGH PRESSURE BUILDING IN.
IN FACT A NE WIND REGIME LOOKS LIKELY IN THE WAKE OF THE FRONT
WITH 925 WINDS RAMPING UP TO 35 KNOTS. SO A BIG DOWNTURN IN TEMPS
FROM FRIDAY APPEARS LIKELY.
SUNDAY AND MONDAY - CONFIDENCE...LOW
MODELS CONTINUE TO DIVERGE WITH THE GFS SHOWING MORE PRECIP WITH
THE NEWD MOVEMENT OF PLAINS UPPER LOW INTO THE GREAT LAKES KEEPING
RAIN CHANCES ALIVE. MEANWHILE THE ECMWF SHOWS THE HIGH DOMINATING
WITH QUIET WX AND THE INFLUENCE OF THE LOW REMAINING SOUTH OF WI.
WILL CARRY SMALL PRECIP CHANCES PER THE SUPERBLEND GUID TO HANDLE
THIS DIFFERENCE.
AVIATION/00Z TAFS/...A FEW RAIN SHOWERS LINGERING IN THE AREA SHOULD
MOVE OUT BY EVENING. GUSTY SOUTHWEST WINDS ARE EXPECTED INTO EARLY
THIS EVENING...WITH GUSTS TO AROUND 25 KNOTS. SCATTERED CUMULUS
ALSO WILL LINGER UNTIL EARLY EVENING.
SOUTHWEST WINDS AT 1500 TO 2000 FEET ABOVE GROUND LEVEL WILL
APPROACH THE 35 TO 40 KNOT RANGE FOR A TIME LATER THIS EVENING INTO
THE OVERNIGHT HOURS. LEFT OUT OF TAFS DUE TO BORDERLINE NATURE...BUT
MAY NEED TO BE ADDED LATER IF THESE VALUES INCREASE.
SOUTH WINDS WILL WEAKEN SOMEWHAT TONIGHT INTO TUESDAY...AS A SURFACE
TROUGH MOVES TOWARD THE AREA FROM THE WEST. CHANCES FOR SHOWERS AND
STORMS WILL GRADUALLY INCREASE LATER TONIGHT INTO TUESDAY. VICINITY
THUNDERSTORM WORDING WILL BE USED FOR TUESDAY AT MADISON...IN THE
AFTERNOON IN THE EASTERN SITES. THERE IS SOME UNCERTAINTY WITH AREAL
COVERAGE AND TIMING OF ANY OF THESE SHOWERS/STORMS. MVFR
CEILINGS/VISIBILITIES ARE POSSIBLE IN ANY HEAVIER SHOWERS/STORMS.
MARINE...AS THE DEW POINTS REMAIN REASONABLY ABOVE THE WATER
TEMPERATURES FOR THE NEXT FEW DAYS...FOG MAY DEVELOP AT TIMES.
THIS WOULD BE ESPECIALLY TRUE TOWARD THE OPEN WATERS...MORE UNDER
THE INFLUENCE OF THE MARINE INVERSION. DENSE FOG IS POSSIBLE AT
NIGHT...IF WINDS GET LIGHT ENOUGH.
SMALL CRAFT ADVISORY CONTINUES ACROSS THE NEARSHORE WATERS UNTIL 09Z
TUESDAY...AS A TIGHT PRESSURE GRADIENT CONTINUES ACROSS THE AREA.
GUSTY SOUTHWEST WINDS ARE EXPECTED UNTIL EARLY EVENING...THEN
WEAKENING. GUSTS TO AROUND 25 KNOTS ARE EXPECTED INTO EARLY THIS
EVENING. HIGHEST WAVES WILL BE TOWARD THE OPEN WATERS. THE WINDS AND
WAVES WILL SUBSIDE BY LATER TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD
TUESDAY NIGHT THROUGH MONDAY...COLLAR
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1149 PM MDT SAT MAY 23 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 530 PM MDT SAT MAY 23 2015
THE UPPER LOW IS SITUATED ALONG THE CO/UT BORDER THIS AFTERNOON
WITH A SHORTWAVE MOVING NORTH ACROSS EASTERN COLORADO IN SOUTHERLY
FLOW ALOFT. STRENGTHENING EAST-SOUTHEAST SFC FLOW AHEAD OF THIS
SYSTEM COMBINED WITH PLENTIFUL MID LEVEL ENERGY AND UPPER LEVEL
DIFFLUENCE IS ALLOWING FOR A FAIRLY BROAD COVERAGE OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. THE INITIAL WAVE OF STORMS
OCCURRED SHORTLY AFTER THE NOON HOUR OVER THE HIGH COUNTRY WHERE
SKIES WHERE MOSTLY CLEAR. FURTHER EAST...CLOUDS NEVER FULLY BROKE
ACROSS THE MUCH OF THE PLAINS BUT SEEMED TO BE ENOUGH TO
DESTABILIZE THE AREA FOR MODERATE THUNDERSTORMS TO DEVELOP WITHIN
STRONG UPPER LEVEL FORCING. ALTHOUGH OVERALL DEEP LAYER SHEAR HAS
NOT BEEN ON THE WHOLE IMPRESSIVE AT 30 TO 40 KTS...LOCALIZED
POCKETS OF HIGHER LOW LEVEL SHEAR LIKELY DEVELOPED ALONG
BOUNDARIES NEAR TERRAIN FEATURES SUCH AS THE CHEYENNE RIDGE NEAR
SIDNEY AND JUST WEST OF THE LARAMIE RANGE NEAR BOSLER WITHIN THE
SOUTHEASTERLY FLOW...AND LIKELY CONTRIBUTED TO BRIEF TORNADO
TOUCHDOWNS AND FUNNEL CLOUDS IN THESE AREAS.
HOWEVER...FOCUS HAS TRANSITIONED MORE TO POSSIBLE HEAVY RAINFALL
IN SHOWERS AND THUNDERSTORMS ACROSS THE PLAINS DUE TO CONTINUED
BOUNDARY ACTION...MOISTURE ADVECTION IN UPSLOPE FLOW AND WAA. WENT
AHEAD AND ISSUED A FLASH FLOOD WATCH FOR THE SOUTHERN NEBRASKA
PANHANDLE AND PLATTE...GOSHEN...AND LARAMIE COUNTIES IN WYOMING
FOR THIS AFTERNOON THROUGH MIDNIGHT WITH HEAVY RAINFALL FROM
STORMS EXPECTED TO CONTINUE THROUGH THIS PERIOD AS THE SHORTWAVE
MOVES ACROSS THE AREA. WITH ALREADY SATURATED GROUNDS...WILL NOT
TAKE MUCH FOR FLOODING TO OCCUR IN THESE AREAS. FOR
TONIGHT...GUIDANCE SHOWS ISENTROPIC LIFT INCREASING ACROSS
SOUTHEAST WYOMING ALONG THE INVERTED SFC TROUGH SETTING UP ALONG
THE MOUNTAINS...AND WITHIN WRAP AROUND MOISTURE AND CONTINUED
UPPER FORCING AS THE LOW SLOWLY MOVES NORTHEAST ACROSS WYOMING. SO
EXPECT TO SEE MODERATE TO HEAVY RAIN CONTINUE OVERNIGHT ACROSS
NORTHERN AND WEST PORTIONS OF THE FORECAST AREA...ALTHOUGH CANT
RULE OUT A FEW HEAVIER RAIN SHOWERS FURTHER SOUTH ACROSS THE
PLAINS AS WELL. THE FOCUS FOR BEST FORCING WILL BE ALONG A LINE
FROM EAST-CENTRAL WYOMING TO SOUTH-CENTRAL WYOMING WHERE THE
MID LEVEL TROUGH WILL SET UP AND AT THE NOSE OF THE INVERTED
TROUGH...SO WENT WITH A FLASH FLOOD WATCH FOR TONIGHT AND TOMORROW
ALONG THIS AREA WHICH INCLUDES CONVERSE...NORTHERN ALBANY...AND
NORTHERN CARBON COUNTIES FOR EXPECTED MODERATE TO HEAVY RAIN TO
PERSIST. LOOKING AT 1 TO 3 INCHES OF RAINFALL FOR NOW...BUT
LOCALLY HEAVIER AMOUNTS ARE POSSIBLE AS WELL ESPECIALLY ALONG
FAVORED TERRAIN FEATURES.
THE UPPER LOW WILL WEAKEN SUNDAY AND BECOME AN OPEN WAVE BY
MONDAY. COLD AIR WILL REMAIN OVERHEAD THROUGH THIS TIME WHILE A
SFC COLD FRONT SHIFTS SOUTHEAST ACROSS THE CWA LATE SUNDAY.
CONTINUED SOUTHEAST FLOW ACROSS THE PLAINS TONIGHT AND SUNDAY
AHEAD OF THE FRONT WILL REDEVELOP THE STRATUS/FOG DECK WHICH
SHOULD STRUGGLE TO BREAK AGAIN ON SUNDAY...BUT GUIDANCE DOES SHOW
SOME HIGHER INSTABILITY ACROSS THE PANHANDLE SO PERHAPS THERE
WILL BE MORE CLEARING IN THIS AREA. THUS WOULDN`T BE SURPRISED IF
A FEW STRONGER THUNDERSTORMS DEVELOPED ONCE AGAIN IN ACROSS THE
PLAINS WITHIN THE POCKETS OF CLEARING WITHIN MODEST SHEAR. THE
UPPER TROUGH WILL FINALLY BEGIN TO SHIFT EAST OF THE FORECAST AREA
ON MONDAY ALTHOUGH SLOW ENOUGH TO MAINTAIN CHANCES FOR INSTABILITY
SHOWERS AND THUNDERSTORMS THROUGH THE DAY. WEAK WINDS ALOFT WILL
PROMOTE MODERATE TO HEAVY RAIN PRODUCERS AS PLENTIFUL MOISTURE
WILL REMAIN OVER THE REGION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 530 PM MDT SAT MAY 23 2015
THE PATTERN WILL BECOME MORE TYPICAL FOR LATE MAY TUESDAY THRU
SATURDAY AS A SERIES OF SHORTWAVES EMBEDDED WITHIN RELATIVELY WEAK
FLOW PASS THRU THE INTERMOUNTAIN WEST. THUNDERSTORM COVERAGE WILL
BE ISOLATED TO SCATTERED AND GENERALLY CONFINED TO THE AFTERNOON
AND EVENING HOURS. ALTHOUGH CLOUDS WILL STILL BE AROUND...EXPECT
TO SEE MORE SUN NEXT WEEK THAN THE PAST FEW. MORE SUNSHINE WILL
ALLOW FOR WARMER DAYTIME TEMPERATURES WHICH WILL BE THE CULPRIT
FOR AFTERNOON/EVENING INSTABILITY AND RESULTANT CONVECTIVE
CHANCES. BRIEF TRANSITORY RIDGE EARLY TUESDAY WILL GIVE WAY TO
BACKING FLOW AS UPSTREAM SHORTWAVE ENERGY SWINGS INTO THE PACIFIC
NW. MODELS PUT THE TRANSITORY RIDGE AXIS IN THE VICINITY OF THE
WY/NE STATELINE WHICH WILL BE A GOOD MEASURE OF THE EASTERN EXTENT
OF THE CONVECTION ON TUESDAY. UPSTREAM SHORTWAVE WILL INCH CLOSER
FOR WEDNESDAY...SO EXPECT CONVECTIVE COVERAGE TO INCREASE TO MORE
SCATTERED COMPARED TO TUESDAY. THERE MAY BE A FEW STRONG STORMS ON
WEDNESDAY AS SBCAPES ARE PROGGED TO CLIMB TO AROUND 600-1000
J/KG. UPSTREAM SHORTWAVE FINALLY REACHES WRN WY BY THURSDAY...BUT
EXPECT A GENERAL REPEAT FOR THURSDAY. THE SHORTWAVE FINALLY PASSES
THRU FRIDAY...GIVING WAY TO...AT LEAST IF YOU BELIEVE THE ECMWF
MODEL...A BUILDING RIDGE AND DRYING CONDITIONS FOR NEXT WEEKEND.
AFTERNOON HIGH TEMPERATURES WILL BE NOTICEABLY WARMER NEXT
WEEK...WITH GENERALLY 60S OVR SE WY AND LOW/MID 70S ACROSS THE WRN
NEBRASKA PANHANDLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM MDT SAT MAY 23 2015
LATEST HRRR AND NAM MODELS LOWER CEILINGS AND VISIBILITIES TO
IFR/LIFR ALONG AND EAST OF THE LARAMIE RANGE OVERNIGHT THROUGH
SUNDAY MORNING...WITH AREAS OF LIGHT DRIZZLE...RAIN AND FOG.
LARAMIE AND RAWLINS CAN EXPECT MVFR CEILINGS AND VISIBILITIES
THROUGH SUNDAY MORNING. ISOLATED TSTORMS WILL REDEVELOP SUNDAY
AFTERNOON WITH VCTS AT ALL TERMINALS.
&&
.FIRE WEATHER...
ISSUED AT 530 PM MDT SAT MAY 23 2015
SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH MUCH OF THE WEEK
AND WILL BRING MODERATE TO HEAVY RAINFALL AT TIMES ACROSS THE DISTRICT.
WITH PLENTIFUL MOISTURE ANTICIPATED...NO FIRE WEATHER CONCERNS ARE
EXPECTED.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR WYZ106>108-118-
119.
FLASH FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR WYZ101-103>105-
109.
NE...FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR NEZ019>021-054-
055.
&&
$$
SHORT TERM...RJM
LONG TERM...CAH
AVIATION...MAJ
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1112 PM MDT MON MAY 25 2015
.UPDATE...
ISSUED AT 705 PM MDT MON MAY 25 2015
A BIT CONCERNED THAT WX MAY GET A BIT MORE ACTIVE OVER THE REGION
LATER THIS EVENING. HRRR HAS BEEN SHOWING SHOWERS/STORMS WOULD
INCREASE TO OUR NORTH AND WORK SWD AS THE EVENING PROGRESSES.
LATEST RADAR TRENDS AT 7 PM HAVE BEEN SHOWING THIS. BELIEVE THERE
IS A DISTURBANCE OVER THE KDEN AREA AND THIS WEAK PIECE OF ENERGY
WILL MOVE SE THIS EVENING. FOR THIS REASON HAVE ADJUSTED POPS TO
REFLECT THIS POSSIBILITY OVER THE PLAINS FOR THIS EVENING INTO THE
EARLY MORNING HOURS.
PRECIP ACTIVITY SHOULD INCREASE DURING THE NEXT 1-2 HOURS OVER THE
PIKES PEAK REGION AND MOVE EAST-SOUTHEAST WITH TIME. /HODANISH
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 242 PM MDT MON MAY 25 2015
...BACK TO THE SEVENTIES...
REMEMBER THOSE DAYS? WELL...WITH A LITTLE MORE SUN AND H7 TEMPS
CLIMBING TO 7 DEG OR HIGHER TOMORROW...SHOULD GET INTO THE SEVENTIES
TOMORROW OVER THE PLAINS...POSSIBLY NR 80 DEGREES FOR THE WARMEST
SPOTS. RESIDUAL MOISTURE SHOULD KEEP HIGHS FROM REACHING THE GUIDANCE
VALUES...HOWEVER.
REST OF TODAY...MARGINAL THREAT OF SVR HAS SHIFTED TO THE EAST...BUT
STILL AREAS OF 750-1000 CAPE...ESPECIALLY NR THE KS BORDER.
SO...DESPITE MODEST SHEAR...CANNOT RULE OUT SOME MARGINALLY STRONG-
SVR STORMS IN MULTI-CELL CLUSTERS LATE THIS AFTERNOON THRU THIS EVE.
SMALL HAIL WILL BE THE MOST LIKELY THREAT.
SNOW LEVELS REMAIN RELATIVELY HIGH...WITH THE PASSES CURRENTLY
REPORTING MID 30S THIS AFTERNOON. LOW AMPLITUDE UPPER RIDGE WILL
CONTINUE TO BUILD THROUGH TOMORROW...WHILE WEAK DISTURBANCES IN
THE FLOW ST OFF MAINLY DIURNAL SHOWERS AND STORMS. WIND SHEAR
WILL REMAIN MODEST ON TUE...SO SVR THREAT WILL BE LOW. EXTREME
SE CORNER OF THE CWA WILL STILL SEE SOME MARGINALLY SVR PARAMETERS
IN THE AFTERNOON...BUT THE NAM IS INDICATING SUPPRESSED CONVECTION
OVR THAT AREA DUE TO THE UPPER RIDGING. ENJOY THE SEVENTIES! ROSE
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 242 PM MDT MON MAY 25 2015
TUE NIGHT AND WED...THE SHORTWAVE RIDGE OVR THE AREA WL SHIFT
EASTWARD AS AN UPR LOW MOVES INTO ID AND ITS UPR TROF EXTENDS
SOUTHWARD TO BAJA CA. SCT SHOWERS AND TSTMS ARE EXPECTED OVR AND NR
THE MTNS TUE EVENING AND THEN AGAIN ON WED AFTERNOON...WITH MAINLY
JUST SOME ISOLD PCPN OVR THE REST OF THE AREA. IT LOOKS LIKE HIGH
TEMPS ON WED WL BE AROUND AVERAGE...WHICH IS MOSTLY IN THE 70S OVR
THE LOWER ELEVATIONS.
THE UPR TROF IS THEN FORECAST TO MOVE SLOWLY EASTWARD ON WED NIGHT
AND THU...EXTENDING FROM WRN WY INTO AZ BY 00Z FRI. THU LOOKS LIKE
ANOTHER DAY OF SHOWERS AND TSTMS MAINLY OVR AND NR THE MTNS AREAS.
FOR FRI A BAGGY TROF WL LIE OVR THE STATE...AND A FRONT WL MOVE THRU
SERN CO. THE AREA IS EXPECTED TO REALLY MOISTEN UP DURING THE DAY
FRI...WITH WIDESPREAD PCPN DEVELOPING AND CONTINUING FRI NIGHT.
TEMPS ON THU SHOULD DROP BACK TO BELOW AVERAGE AGAIN. THE UPR TROF
AND LOW WL MOVE EAST INTO KS SAT...BUT WRAP AROUND MOISTURE IS
EXPECTED TO KEEP WIDESPREAD PCPN OVR ERN CO ON SAT...WITH THE MTN
AND HIGH VALLEY AREAS HAVING SCT PCPN.
SAT NIGHT THE LOW MOVES FARTHER EAST AND IT LOOKS LIKE THE FORECAST
AREA WL THEN HAVE DRIER WX. ON SUN AN UPR RIDGE BUILDS OVR THE GREAT
BASIN AND THEN MOVE EASTWARD OVR CO ON MONDAY. THERE WL STILL BE
ENOUGH MSTR AROUND FOR SOME MAINLY AFTERNOON AND EVENING SHOWERS AND
TSTMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1109 PM MDT MON MAY 25 2015
KPUB...
WILL SEE SOME PASSING LIGHT SHOWERS EARLY IN THE FCST PD...THEN
VFR THROUGH MID TO LATE AFTERNON TUESDAY. COULD SEE SOME BRIEF
HEAVIER TSRA LATER TOMORROW AFTERNOON WHICH COULD BRING CIGS/VIS
TO MVFR. VFR EXPECTED BY TOMORROW EVENING.
KCOS AND KALS...
VFR NEXT 24H EXCEPT FOR MID TO EARLY EVENING TSRA AT THE TAF
SITES. BRIEF PDS OF MVFR POSSIBLE ALONG WITH GUSTY WINDS
ASSOCIATED WITH TSRA.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HODANISH
SHORT TERM...ROSE
LONG TERM...28
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS ALBANY NY
523 AM EDT TUE MAY 26 2015
.SYNOPSIS...
WARM AND HUMID WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY
DURING THE AFTERNOON INTO THE EARLY EVENING THROUGH MID WEEK. SOME
STORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE REGION IS IN A WARM AND HUMID AIRMASS WITH RIDGING ALONG THE
EASTERN SEABOARD. A SHORT WAVE TROUGH WILL MOVE INTO THE WESTERN
GREAT LAKES TODAY WITH THE RIDGE OVER THE NORTHEAST HOLDING
STEADY. GUIDANCE INCLUDING THE MESOSCALE HRRR INDICATE DIURNALLY
DRIVEN CONVECTION SHOULD INITIATE ACROSS THE CENTRAL AND SOUTHERN
PORTION OF THE FORECAST AREA THIS AFTERNOON. WITH PRECIPITABLE
WATER VALUES RISING TO 1.5+ INCHES STORMS WILL BE CAPABLE OF
PRODUCING HEAVY DOWNPOURS.
TODAY WILL BE MORE HUMID THAN MONDAY WITH DEW POINTS IN THE MAINLY
IN THE UPPER 50S TO LOWER 60S. IT WILL BE VERY WARM/HOT WITH HIGHS
IN THE 80S...WITH MID/UPPER 80S UP THE HUDSON VALLEY. ACROSS THE
HIGHER TERRAIN OF THE WESTERN ADIRONDACKS...EASTERN CATSKILLS AND
SOUTHERN GREENS HIGHS SHOULD GET INTO THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
BETTER AND MORE WIDESPREAD CHANCES FOR CONVECTION EXPECTED
WEDNESDAY. THE SHORT WAVE TROUGH WILL MOVE ACROSS THE GREAT LAKES
REGION AND HEIGHTS WILL FALL SOME ACROSS THE NORTHEAST. HOWEVER
LARGE SCALE FORCING WILL REMAIN TO OUR NORTH AS THE RIGHT-REAR
QUADRANT OF THE UPPER LEVEL JET STREAK WILL BE LOCATED OVER
EASTERN CANADA AND MOVING TO THE NORTHEAST. ACROSS THE REGION
WE WILL HAVE DEW POINTS IN THE 60S AND MODEST SOUTHWESTERLY DEEP
LAYER SHEAR SO STRONG STORMS WITH GUSTY WINDS ARE POSSIBLE. THE
STORM PREDICTION CENTER CONTINUES TO KEEP OUR AREA UNDER MARGINAL
RISK FOR SEVERE WEATHER...HOWEVER DOES NOTE THAT IF GREATER
INSTABILITY IS EXPECTED THEN AN UPGRADE TO A SLIGHT RISK MAY BE
NEEDED. CONTINUE TO HAVE MENTION OF STRONG STORMS POSSIBLE FOR
WEDNESDAY IN OUR HAZARDOUS WEATHER OUTLOOK AND ADDED GUSTY WINDS.
HIGH TEMPERATURES SHOULD BE A COUPLE/FEW DEGREES LOWER WEDNESDAY
THAN THURSDAY DUE TO MORE CLOUD COVER AND THE CONVECTION...MID
70S TO MID 80S.
THE SHORT WAVE TROUGH WILL CONTINUE TO PRESS EASTWARD INTO THE
RIDGE WEDNESDAY NIGHT AND THURSDAY SHEARING OUT WITH TIME. ALONG
WITH TROUGH A WEAK COLD FRONTAL BOUNDARY WILL MOVE INTO AND ACROSS
THE REGION THROUGH THURSDAY NIGHT. CHANCES FOR CONVECTION WILL
PERSIST UNTIL THE SHORT WAVE MOVES OFF TO THE EAST AND BOUNDARY
SHIFTS THROUGH BUT DECREASE IN TIME AS THE FEATURES WEAKEN. IT
WILL NOT BE AS HOT OR HUMID THURSDAY HOWEVER ABOVE NORMAL
TEMPERATURES WILL CONTINUE...HIGHS LOWER 70S TO LOWER 80S.
WITH PRECIPITABLE WATER VALUES OF 1.5+ INCHES STORMS WILL BE
CAPABLE OF PRODUCING HEAVY DOWNPOURS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE EXTENDED FORECAST OPENS WITH HIGH PRESSURE BRIEFLY BUILDING
IN OVER ERN NY AND NEW ENGLAND IN THE WAKE OF A WEAK COLD FRONTAL
PASSAGE. THE GFS/ECMWF/CAN GGEM HAVE TRENDED DRIER FOR THIS DAY.
THE FRONTAL BOUNDARY MAY STALL CLOSE ENOUGH TO THE SRN NEW ENGLAND
AND NJ COAST FOR SOME ISOLD-SCT SHOWERS AND THUNDERSTORMS
ESPECIALLY SOUTH OF THE INTERSTATE 90 CORRIDOR. A SLIGHT TO LOW
CHC THREAT WAS KEPT IN FOR THE AFTERNOON TIME FRAME FOR THE FCST
AREA WITH LOW CHANCE POPS SOUTH OF THE CAPITAL REGION. H850 TEMPS
WILL STILL BE IN THE +13C TO +15C RANGE WITH MEAN UPPER RIDING
OVER THE REGION. EXPECT HIGHS IN THE LOWER TO M80S IN THE
VALLEYS...AND M70S TO NEAR 80F OVER THE HILLS AND MTNS. ANY SHOWER
OR THUNDERSTORMS ACTIVITY SHOULD WANE WITH THE LOSS OF THE DIURNAL
HEATING. LOWS WILL BE IN THE 60-65F RANGE IN THE LOWER
ELEVATIONS...AND M50S TO 60F OVER THE HIGHER TERRAIN.
SAT-SUN...A PROGRESSIVE UPPER LEVEL TROUGH WILL BE MOVING ACROSS
CNTRL CANADA...THE UPPER MIDWEST...AND THE GREAT LAKES REGION. BROAD
SW FLOW ALOFT ASSOCIATED WITH THE HIGH AMPLITUDE RIDGE OVER THE EAST
COAST WILL KEEP THE HUMID AIR MASS AROUND FOR THE FIRST HALF OF THE
WEEKEND. THE COLD FRONT WILL BE APPROACHING ON SATURDAY WITH AN
UNSTABLE AIR MASS AHEAD OF IT...ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS IS POSSIBLE. SOME OF THE THUNDERSTORMS COULD BE
STRONG DEPENDING ON THE EXACT AMOUNT OF INSTABILITY AVAILABLE. THE
LATEST GFS HAS SFC DEWPTS WELL INTO THE 60S WITH SBCAPES OF 1000-
2000 J/KG. PWATS INCREASE BACK TO 1.33-1.75 INCHES OVER THE FCST
AREA. SOME HEAVY DOWNPOURS WILL BE LIKELY WITH ANY CONVECTION. WE
EXPECT THE SCT SHOWERS AND THUNDERSTORM TO CONTINUE INTO THE
OVERNIGHT PERIOD AHEAD OF THE FRONT. HIGHS ON SATURDAY WILL BE IN
THE MID AND U80S OVER THE VALLEY AREAS...AND M70S TO L80S IN THE
MTNS. MUCH COOLER TEMPS ARE EXPECTED ON SUNDAY WITH THE FRONTAL
BOUNDARY STALLING NEAR THE REGION. OCCASIONAL SHOWERS AND SOME
ISOLD THUNDERSTORMS MAY LINGER ON THE 2ND HALF OF THE WEEKEND NOW.
HIGHS WILL BE MAINLY IN THE 60S TO L70S OVER THE FCST AREA.
SUN NIGHT TO MONDAY...THE MEDIUM RANGE GUIDANCE DIVERGES ON WHERE
THE FRONT GOES TO START NEXT WEEK. THE ECMWF PUSHES THE FRONT SOUTH
OF THE FCST AREA WITH A 1032 HPA SFC ANTICYCLONE RIDGING IN FROM SRN
QUEBEC. COOLER AND DRIER WEATHER WOULD PREVAIL. THE WPC GUIDANCE
IS STARTING TO LEAN TOWARDS THE ECMWF SCENARIO WITH THE SFC RIDGE
WINNING OUT...AND THE FRONT STALLING NEAR DC AND THE MID ATLANTIC
REGION. THE GFS HAS A SOAKER FOR THE START OF THE WORK WEEK WITH A
WAVE MOVING ALONG THE FRONT...AND A STRONG LOW-LEVEL BAROCLINIC ZONE
BTWN THE WAVE AND SFC HIGH. OVERALL...WE KEPT A LOW CHC OF SHOWERS
IN FOR MOST OF THE AREA SUNDAY NIGHT...AND THEN WENT LOW CHC SOUTH
OF THE CAPITAWARM TEMPERATURES AND INCREASINGLY HUMID CONDITIONS ARE
FORECAST FOR THIS WEEK WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...
ESPECIALLY MID WEEK.
RH VALUES TONIGHT RECOVER BETWEEN 70 AND 90 PERCENT TONIGHT...THEN
EXPECTED TO RANGE BETWEEN 40 AND 60 PERCENT TUESDAY AFTERNOON WITH
VALUES BETWEEN 50 AND 70 PERCENT WEDNESDAY AFTERNOON.
THE BETTER CHANCES FOR THUNDERSTORMS WILL BE DURING THE AFTERNOON
INTO EARLY EVENING HOURS.L REGION ON MONDAY...AND SLIGHT CHC TO THE
NORTH AND WEST. THIS FCST WOULD NEED FINE TUNING IF THE GFS IS
RIGHT. TEMPS WILL BE RUNNING SLIGHTLY BELOW NORMAL TO OPEN THE WEEK.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
A WARM FRONT HAS LIFTED NORTH OF THE FORECAST AREA INTO NORTHERN
NEW ENGLAND AND SOUTHERN QUEBEC. MOST OF THE FORECAST AREA WILL BE
IN A WARM SECTOR WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC
OCEAN TODAY INTO TOMORROW.
MID AND HIGH LEVEL CLOUDS PREVAIL FOR KGFL/KALB/KPSF/KPOU THIS
MORNING WITH VFR CONDITIONS. A FEW SHOWERS MAY GET CLOSE TO KGFL SO
A VCSH GROUP WAS USED. THE CLOUDS WILL THIN LATE THIS MORNING WITH
MAINLY SOME HIGH CLOUDS AROUND WITH SCT-BKN CUMULUS FOR THE PM.
SOME POP-UP SHOWERS OR THUNDERSTORMS MAY DEVELOP BY THE MID TO LATE
PM IN THE HUMID AIR MASS. VCSH GROUPS AND CIGS BKN050-060 WERE
USED.
CONFIDENCE WAS NOT HIGH ENOUGH TO PLACE PROB30 GROUPS IN FOR
THUNDERSTORMS. MID AND HIGH CLOUDS WILL LINGER INTO THE OVERNIGHT
PERIOD.
THE WINDS WILL BE FROM SOUTH AT 5-12 KTS THIS MORNING WITH SOME
GUSTS AROUND 20 KTS AT KALB/KPSF. THE WINDS WILL CONTINUE FROM THE
S TO SW AT 10-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KALB/KPSF IN
THE AFTERNOON.
OUTLOOK...
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRIDAY TO FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF
SHRA...TSRA. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
WARM AND HUMID WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY
DURING THE AFTERNOON INTO THE EARLY EVENING.
MINIMUM RH VALUES THIS AFTERNOON WILL BE IN THE LOWER 40S TO LOWER
50S...WITH MINIMUMS WEDNESDAY AND THURSDAY AFTERNOONS IN THE 50S.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS EXPECTED THIS WEEK...HOWEVER
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS.
THE U.S. DROUGHT MONITOR HAS MUCH OF EASTERN NEW YORK AND WESTERN
NEW ENGLAND IN THE D1 CATEGORY...WHICH IS CONSIDERED MODERATE
DROUGHT AT THIS TIME.
WARM AND HUMID WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY
DURING THE AFTERNOON INTO THE EARLY EVENING. THE BETTER AND MORE
WIDESPREAD CHANCES ARE EXPECTED WEDNESDAY AFTERNOON INT0 THE EVENING.
PRECIPITABLE WATER VALUES OF 1.5+ INCHES ARE EXPECTED SO STORMS WILL
BE CAPABLE OF PRODUCING HEAVY DOWNPOURS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
502 AM EDT TUE MAY 26 2015
.SYNOPSIS...
WARM AND HUMID WITH CHANCES FOR SHOWERS AND
THUNDERSTORMS...MAINLY DURING THE AFTERNOON INTO THE EARLY EVENING
THROUGH MID WEEK. SOME STORMS WILL BE CAPABLE OF PRODUCING HEAVY
DOWNPOURS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE REGION IS IN A WARM AND HUMID AIRMASS WITH RIDGING ALONG THE
EASTERN SEABOARD. A SHORT WAVE TROUGH WILL MOVE INTO THE WESTERN
GREAT LAKES TODAY WITH THE RIDGE OVER THE NORTHEAST HOLDING
STEADY. GUIDANCE INCLUDING THE MESOSCALE HRRR INDICATE DIURNALLY
DRIVEN CONVECTION SHOULD INITIATE ACROSS THE CENTRAL AND SOUTHERN
PORTION OF THE FORECAST AREA THIS AFTERNOON.
TODAY WILL BE MORE HUMID THAN MONDAY WITH DEW POINTS IN THE MAINLY
IN THE UPPER 50S TO LOWER 60S. IT WILL BE VERY WARM/HOT WITH HIGHS
IN THE 80S...WITH MID/UPPER 80S UP THE HUDSON VALLEY. ACROSS THE
HIGHER TERRAIN OF THE WESTERN ADIRONDACKS...EASTERN CATSKILLS AND
SOUTHERN GREENS HIGHS SHOULD GET INTO THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
BETTER AND MORE WIDESPREAD CHANCES FOR CONVECTION EXPECTED
WEDNESDAY. THE SHORT WAVE TROUGH WILL MOVE ACROSS THE GREAT LAKES
REGION AND HEIGHTS WILL FALL SOME ACROSS THE NORTHEAST. HOWEVER
LARGE SCALE FORCING WILL REMAIN TO OUR NORTH AS THE RIGHT-REAR
QUADRANT OF THE UPPER LEVEL JET STREAK WILL BE LOCATED OVER
EASTERN CANADA. ACROSS THE REGION WILL HAVE HIGH DEW POINTS
IN THE 60S AND MODEST SOUTHWESTERLY DEEP-LAYER SHEAR. THE STORM
PREDICTION CENTER CONTINUES TO KEEP OUR AREA UNDER MARGINAL RISK
FOR SEVERE WEATHER. MORE TO COME...
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE EXTENDED FORECAST OPENS WITH HIGH PRESSURE BRIEFLY BUILDING
IN OVER ERN NY AND NEW ENGLAND IN THE WAKE OF A WEAK COLD FRONTAL
PASSAGE. THE GFS/ECMWF/CAN GGEM HAVE TRENDED DRIER FOR THIS DAY.
THE FRONTAL BOUNDARY MAY STALL CLOSE ENOUGH TO THE SRN NEW ENGLAND
AND NJ COAST FOR SOME ISOLD-SCT SHOWERS AND THUNDERSTORMS
ESPECIALLY SOUTH OF THE INTERSTATE 90 CORRIDOR. A SLIGHT TO LOW
CHC THREAT WAS KEPT IN FOR THE AFTERNOON TIME FRAME FOR THE FCST
AREA WITH LOW CHANCE POPS SOUTH OF THE CAPITAL REGION. H850 TEMPS
WILL STILL BE IN THE +13C TO +15C RANGE WITH MEAN UPPER RIDING
OVER THE REGION. EXPECT HIGHS IN THE LOWER TO M80S IN THE
VALLEYS...AND M70S TO NEAR 80F OVER THE HILLS AND MTNS. ANY SHOWER
OR THUNDERSTORMS ACTIVITY SHOULD WANE WITH THE LOSS OF THE DIURNAL
HEATING. LOWS WILL BE IN THE 60-65F RANGE IN THE LOWER
ELEVATIONS...AND M50S TO 60F OVER THE HIGHER TERRAIN.
SAT-SUN...A PROGRESSIVE UPPER LEVEL TROUGH WILL BE MOVING ACROSS
CNTRL CANADA...THE UPPER MIDWEST...AND THE GREAT LAKES REGION. BROAD
SW FLOW ALOFT ASSOCIATED WITH THE HIGH AMPLITUDE RIDGE OVER THE EAST
COAST WILL KEEP THE HUMID AIR MASS AROUND FOR THE FIRST HALF OF THE
WEEKEND. THE COLD FRONT WILL BE APPROACHING ON SATURDAY WITH AN
UNSTABLE AIR MASS AHEAD OF IT...ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS IS POSSIBLE. SOME OF THE THUNDERSTORMS COULD BE
STRONG DEPENDING ON THE EXACT AMOUNT OF INSTABILITY AVAILABLE. THE
LATEST GFS HAS SFC DEWPTS WELL INTO THE 60S WITH SBCAPES OF 1000-
2000 J/KG. PWATS INCREASE BACK TO 1.33-1.75 INCHES OVER THE FCST
AREA. SOME HEAVY DOWNPOURS WILL BE LIKELY WITH ANY CONVECTION. WE
EXPECT THE SCT SHOWERS AND THUNDERSTORM TO CONTINUE INTO THE
OVERNIGHT PERIOD AHEAD OF THE FRONT. HIGHS ON SATURDAY WILL BE IN
THE MID AND U80S OVER THE VALLEY AREAS...AND M70S TO L80S IN THE
MTNS. MUCH COOLER TEMPS ARE EXPECTED ON SUNDAY WITH THE FRONTAL
BOUNDARY STALLING NEAR THE REGION. OCCASIONAL SHOWERS AND SOME
ISOLD THUNDERSTORMS MAY LINGER ON THE 2ND HALF OF THE WEEKEND NOW.
HIGHS WILL BE MAINLY IN THE 60S TO L70S OVER THE FCST AREA.
SUN NIGHT TO MONDAY...THE MEDIUM RANGE GUIDANCE DIVERGES ON WHERE
THE FRONT GOES TO START NEXT WEEK. THE ECMWF PUSHES THE FRONT SOUTH
OF THE FCST AREA WITH A 1032 HPA SFC ANTICYCLONE RIDGING IN FROM SRN
QUEBEC. COOLER AND DRIER WEATHER WOULD PREVAIL. THE WPC GUIDANCE
IS STARTING TO LEAN TOWARDS THE ECMWF SCENARIO WITH THE SFC RIDGE
WINNING OUT...AND THE FRONT STALLING NEAR DC AND THE MID ATLANTIC
REGION. THE GFS HAS A SOAKER FOR THE START OF THE WORK WEEK WITH A
WAVE MOVING ALONG THE FRONT...AND A STRONG LOW-LEVEL BAROCLINIC ZONE
BTWN THE WAVE AND SFC HIGH. OVERALL...WE KEPT A LOW CHC OF SHOWERS
IN FOR MOST OF THE AREA SUNDAY NIGHT...AND THEN WENT LOW CHC SOUTH
OF THE CAPITAWARM TEMPERATURES AND INCREASINGLY HUMID CONDITIONS ARE
FORECAST FOR THIS WEEK WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...
ESPECIALLY MID WEEK.
RH VALUES TONIGHT RECOVER BETWEEN 70 AND 90 PERCENT TONIGHT...THEN
EXPECTED TO RANGE BETWEEN 40 AND 60 PERCENT TUESDAY AFTERNOON WITH
VALUES BETWEEN 50 AND 70 PERCENT WEDNESDAY AFTERNOON.
THE BETTER CHANCES FOR THUNDERSTORMS WILL BE DURING THE AFTERNOON
INTO EARLY EVENING HOURS.L REGION ON MONDAY...AND SLIGHT CHC TO THE
NORTH AND WEST. THIS FCST WOULD NEED FINE TUNING IF THE GFS IS
RIGHT. TEMPS WILL BE RUNNING SLIGHTLY BELOW NORMAL TO OPEN THE WEEK.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
A WARM FRONT HAS LIFTED NORTH OF THE FORECAST AREA INTO NORTHERN
NEW ENGLAND AND SOUTHERN QUEBEC. MOST OF THE FORECAST AREA WILL BE
IN A WARM SECTOR WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC
OCEAN TODAY INTO TOMORROW.
MID AND HIGH LEVEL CLOUDS PREVAIL FOR KGFL/KALB/KPSF/KPOU THIS
MORNING WITH VFR CONDITIONS. A FEW SHOWERS MAY GET CLOSE TO KGFL SO
A VCSH GROUP WAS USED. THE CLOUDS WILL THIN LATE THIS MORNING WITH
MAINLY SOME HIGH CLOUDS AROUND WITH SCT-BKN CUMULUS FOR THE PM.
SOME POP-UP SHOWERS OR THUNDERSTORMS MAY DEVELOP BY THE MID TO LATE
PM IN THE HUMID AIR MASS. VCSH GROUPS AND CIGS BKN050-060 WERE
USED.
CONFIDENCE WAS NOT HIGH ENOUGH TO PLACE PROB30 GROUPS IN FOR
THUNDERSTORMS. MID AND HIGH CLOUDS WILL LINGER INTO THE OVERNIGHT
PERIOD.
THE WINDS WILL BE FROM SOUTH AT 5-12 KTS THIS MORNING WITH SOME
GUSTS AROUND 20 KTS AT KALB/KPSF. THE WINDS WILL CONTINUE FROM THE
S TO SW AT 10-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KALB/KPSF IN
THE AFTERNOON.
OUTLOOK...
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRIDAY TO FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF
SHRA...TSRA. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
WARM AND HUMID WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY
DURING THE AFTERNOON INTO THE EARLY EVENING.
MINIMUM RH VALUES THIS AFTERNOON WILL BE IN THE LOWER 40S TO LOWER
50S...WITH MINIMUMS WEDNESDAY AND THURSDAY AFTERNOONS IN THE 50S.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS EXPECTED THIS WEEK...HOWEVER
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS.
THE U.S. DROUGHT MONITOR HAS MUCH OF EASTERN NEW YORK AND WESTERN
NEW ENGLAND IN THE D1 CATEGORY...WHICH IS CONSIDERED MODERATE
DROUGHT AT THIS TIME.
WARM AND HUMID WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY
DURING THE AFTERNOON INTO THE EARLY EVENING. THE BETTER AND MORE
WIDESPREAD CHANCES ARE EXPECTED WEDNESDAY AFTERNOON INT0 THE EVENING.
PRECIPITABLE WATER VALUES OF 1.5+ INCHES ARE EXPECTED SO STORMS
STORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
400 AM CDT Tue May 26 2015
.SHORT TERM...(Today and Tonight)
Issued at 258 AM CDT TUE MAY 26 2015
Precipitation persists over much of the area, though becoming
steadily more scattered in nature and generally rather low rates.
Appears more vigorous convection in western locations is long
upper trough axis, with whole upper system good northeast progress
through eastern Kansas with warming cloud tops.
Have a hard time ruling out precip for much of today and tonight.
Short-range models seem a bit too fast with main deformation
precip`s exit this morning, with latest HRRR runs similar in
isolated to scattered convection making its way southeast around
the low into northern areas in the late morning to early
afternoon. Still seeing best lower-level forcing in southern areas
late today into tonight were somewhat better convergence exists.
There is also decent larger-scale model similarity in another wave
rotating (perhaps taking shape in western Nebraska early this
morning) passing through over this same period, although heights
are still rising. Moisture through the column not up to recent
levels, but dewpoints into the lower 60s still support some
instability developing in peak heating. Fairly unidirectional and
modest wind speeds keep severe storm concerns low.
.LONG TERM...(Wednesday through Monday)
Issued at 258 AM CDT TUE MAY 26 2015
Surface high pressure moves into the Central Plains on Wednesday,
with the frontal boundary slowing over southern Kansas under
generally west southwest upper flow. Think more stable surface air
plus mid level ridging will keep northern areas dry on Wednesday
but could see some rumbles south depending on how far south the
front progresses. Next in a series of shortwave trofs moves over
eastern Kansas overnight into Thursday morning, and draws rain
chances back over our area. Have continued chances into Thursday,
although features driving rain chances are more mesoscale in
nature and timing will likely need adjustment.
Better model agreement on a slightly larger scale shortwave
feature lifting out of the southwest US and across eastern Kansas
for Friday, and will keep higher rain chances as a result. Front
slides southeast across the area through early Saturday morning,
cooling things down and bringing decreasing rain chances through
Sunday from northwest to southeast. If pattern persists, may be
able to end chances sooner. High temperatures Wednesday through
Friday are forecast in the upper 70s near 80, falling into the 60s
for the weekend behind the front, with lows in the 60s then
falling to the 50s late week.
&&
.AVIATION...(For the 06Z TAFs through 06Z Tuesday Night)
Issued at 1147 PM CDT MON MAY 25 2015
Showers and thunderstorms should continue at TOP and FOE until
about 09Z with things slowly drying out after that. MVFR
conditions expected in the precipitation. MHK should have just
some light rain until about 09Z, with VFR conditions throughout.
After that, expect dry conditions and VFR for the day into the
evening. There is a small chance of evening thunderstorms in east
central KS this evening, but not enough confidence to put in TAF.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...GDP
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1205 AM CDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 1205 AM CDT TUE MAY 26 2015
UPDATED AVIATION SECTION FOR 06Z TAF PACKAGE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 304 PM CDT MON MAY 25 2015
BEST WARMING THIS AFTERNOON HAS BEEN TO THE WEST OF THE CIRRUS
SHIELD OVER SOUTHEAST MISSOURI. A LAPS SOUNDING FROM NEAR VAN
BUREN MISSOURI INDICATES THAT THERE IS VERY DRY AIR IN THE MID AND
UPPER LEVELS...AND LOW-LEVEL MOISTURE IS RATHER LACKING AS WELL.
THERE MAY BE JUST ENOUGH MOISTURE TO GET DEEP CONVECTION...BUT
FIGURE THAT IT WILL BE DIFFICULT TO SUSTAIN FOR LONG. WILL KEEP AT
LEAST A SLIGHT CHANCE THROUGHOUT THE AREA THROUGH 00Z...BUT
FIGURE MOST AREAS WILL STAY DRY.
ALL EYES ARE ON THE MASSIVE CONVECTIVE COMPLEX RAKING ACROSS TEXAS
AND SOUTHERN OKLAHOMA THIS AFTERNOON. THE NMM AND ARW WRF BOTH
WIPE IT OUT AS IT APPROACHES OUR AREA OVERNIGHT TONIGHT...AND THE
LATEST HRRR APPEARS TO BE TRENDING THAT WAY TOO. LIKE WPC QPF AND
FOLLOWED IT CLOSELY THROUGH TUESDAY. NOT SURE ABOUT THE LIKELY TO
CATEGORICAL POPS ASSOCIATED WITH THIS AREA LATE TONIGHT AND
TUESDAY. BOTTOM-LINE IS THAT THE HEAVY RAINFALL THREAT IS RATHER
LOW.
WOULD NOT BE SURPRISED TO SEE CONVECTION BEGIN TO INCREASE AS THE
OUTFLOW BOUNDARY PUSHES INTO THE PENNYRILE REGION OF WEST KENTUCKY
AROUND MIDDAY TUESDAY. FIGURE THAT THE SEVERE THREAT TUESDAY WILL
BE GREATEST TO THE EAST OF OUR AREA.
REALLY FEEL THAT TUESDAY NIGHT AND WEDNESDAY MORNING WILL BE
DRY...BUT HAVE CHANCY POPS IN THERE ANYWAY. A WEAK MID/UPPER-LEVEL
TROUGH WILL BE APPROACHING THE AREA FROM THE WEST BY 12Z WEDNESDAY
AND THIS MAY BE ABLE TO TOUCH OFF SOME SHOWERS AND STORMS.
THE BEST CHANCE FOR CONVECTIVE DEVELOPMENT WEDNESDAY WILL BE
ACROSS THE NORTH IN THE AFTERNOON...AS THIS TROUGH MOVES BY. THE
MODELS HAVE BEEN HITTING THIS DEVELOPMENT CONSISTENTLY FOR AT
LEAST 3 DAYS NOW...SO AT LEAST SCATTERED SHOWERS AND STORMS SEEMS
LIKE A GOOD BET AT THIS TIME. THE MODELS DEVELOP THAT ACTIVITY
SOUTHWARD THROUGH THE REMAINDER OF THE AREA IN THE EVENING.
TEMPERATURES WILL BE HIGHLY DEPENDENT ON CONVECTION AND ASSOCIATED
CLOUD COVER. HELD TEMPERATURES DOWN A BIT FOR HIGHS TUESDAY...WITH
LITTLE SUNSHINE EXPECTED. WEDNESDAY MAY SEE HIGHS BACK UP IN THE
80S...ESPECIALLY IF CONVECTION CAN HOLD OFF UNTIL THE AFTERNOON.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 304 PM CDT MON MAY 25 2015
BY THURSDAY INTO FRIDAY..THE UPPER FLOW WEAKENS AND UPPER HEIGHTS
SLOWLY RISE AS A RIDGE TRIES TO BUILD ACROSS THE REGION. ENOUGH
MOISTURE WILL BE IN PLACE HOWEVER TO WARRANT SOME LOW CHANCES FOR
AFTERNOON CONVECTION AS WE REMAIN IN A WARM...MOIST...AND UNCAPPED
ENVIRONMENT.
SOUTHWEST FLOW STRENGTHENS ACROSS THE AREA FRIDAY NIGHT INTO
SATURDAY AS A TROUGH OVER THE WESTERN CONUS MOVES INTO THE CENTRAL
PLAINS. A FRONTAL BOUNDARY WILL BE IN ASSOCIATION WITH THIS SYSTEM
AND IT WILL MOVE IN OUR DIRECTION FOR THE WEEKEND. HOW EXACTLY THIS
SFC LOW AND FRONT WILL EVOLVE AS WE HEAD INTO THE WEEKEND AND EARLY
NEXT WEEK IS STILL IN QUESTION. HOWEVER...THIS DOES APPEAR TO BE OUR
BEST CHANCE FOR MORE WIDESPREAD CONVECTION. THEREFORE...WILL
ADVERTISE HIGHEST POPS DURING THESE PERIODS.
IT WILL CERTAINLY CONTINUE TO BE WARM AND HUMID...AS HIGHS IN THE
FIRST PART OF THE EXTENDED WILL BE IN THE MID 80S...DROPPING DOWN
INTO THE LOW 80S WITH THE CLOUDS/PRECIP AROUND OVER THE WEEKEND.
DEWPOINTS WILL BE RATHER HIGH AS WELL...WITH READINGS IN THE MID TO
UPPER 60S...MAKING IT FEEL PRETTY STICKY OUTSIDE WITH HEAT INDEX
READINGS IN THE UPPER 80S IN MANY LOCATIONS EARLY ON IN THE
EXTENDED.
&&
.AVIATION...
ISSUED AT 1205 AM CDT TUE MAY 26 2015
AREA OF SHOWERS EXPECTED TO SPREAD ACROSS KCGI/KPAH BETWEEN 8-10Z,
AND KEVV/KOWB BETWEEN 10-12Z. VFR CIGS/VSBYS WILL DROP TO MVFR
WITH SHOWERS. SHOWER CHANCES WILL DROP OFF AT KCGI/KPAH AROUND
15Z, AND AROUND 17Z AT KEVV/KOWB, AND CONDITIONS WILL IMPROVE TO
VFR. WINDS WILL BE SOUTHEAST AT 6 TO 12 KTS OVERNIGHT, THEN
INCREASE FROM THE SOUTH/SOUTHWEST AFTER 14Z TO 10 TO 15 KTS WITH
GUSTS AROUND 20 KTS. PRECIP CHANCES AFTER 18Z TOO LOW TO INCLUDE
IN TAFS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...CW
AVIATION...RST
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
113 AM EDT TUE MAY 26 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 424 PM EDT MON MAY 25 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
MN INTO CO AND A RIDGE OVER THE ERN CONUS RESULTING IN SW FLOW FROM
THE SRN PLAINS TO THE WRN LAKES. A SHORTWAVE TROUGH THAT BROUGHT
WIDESPREAD RAIN ACROSS UPPER MI INTO THE EARLY AFTERNOON WAS LIFTING
NE THROUGH ERN LAKE SUPERIOR LEAVING A PROMINENT DRY SLOT INTO CNTRL
UPPER MI. AT THE SFC...LOW PRES WAS LOCATED OVER W CNTRL UPPER MI
WITH A TROUGH EXTENDING BACK THROUGH CNTRL MN INTO SE SD.
UPSTREAM...ANOTHER WEAKER SHRTWV SUPPORTED SOME TSRA OVER NRN IA.
ENOUGH INSTABILITY HAD DEVELOPED OVER NRN WI FOR SOME ISOLD -SHRA TO
DEVELOP IN THE WAKE OF THE LARGER RAIN AREA.
TONIGHT...MODELS ALONG WITH RADAR/SATELLITE TRENDS SUGGEST THAT THE
NRN IA PCPN MAY SPREAD TOWARD THE S AND E PORTION OF THE CWA BY LATE
THIS EVENING. ALTHOUGH THE MODELS ALSO HINT AT THE POTENTIAL FOR
ADDITIONAL PCPN ASSOCIATED WITH A SHRTWV OVER SE SD THAT COULD MOVE
INTO W UPPER MI...CONFIDENCE IS LOWER. OTHERWISE...MILD CONDITIONS
WITH LOWS IN THE MID50S ARE EXPECTED WITH LIGHT SW WINDS PREVAILING.
TUE...THE SHRTWV OVER NRN TX THAT SUPPORTED A VERY LARGE MCS IS
EXPECTED TO LIFT TOWARD THE WRN LAKES BY LATE TUE BRINGING
INCREASING CHANCES FOR PCPN DURING THE AFTERNOON. THERE IS MORE
UNCERTAINTY ON WHERE THE PCPN WILL DEVELOP AS THE GFS/ECMWF KEEP THE
RAIN FARTHER WEST COMPARED TO THE NAM/REG-GEM. WITH MUCAPE VALUES
INTO THE 500-1000 J/KG RANGE...SOME TSRA WILL BE POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 427 PM EDT MON MAY 25 2015
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AN AREA OF LOW PRESSURE TO
THE SOUTHWEST OF JAMES BAY TUESDAY NIGHT WILL SLIDE INTO NORTHERN
QUEBEC BY WEDNESDAY NIGHT. THIS WILL ALLOW A COLD FRONT TO PASS
ACROSS THE REGION THROUGH WEDNESDAY AFTERNOON. ALOFT...AN ASSOCIATED
SHORTWAVE WILL PASS ACROSS THE UPPER GREAT LAKES REGION AROUND THE
SAME TIME FRAME. THE BEST CHANCES FOR PRECIPITATION WILL BE ALONG
AND AHEAD OF THE COLD FRONT FOR WEST AND CENTRAL AREAS TUESDAY
EVENING...THEN SPREADING INTO CENTRAL AND EASTERN AREAS OVERNIGHT
THROUGH WEDNESDAY MORNING. WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING THE FRONT WILL BE PAST THE CWA...HOWEVER...THE SHORTWAVE
WILL STILL BE NEARBY ALLOWING FOR ADDITIONAL CHANCES OF MORE
ISOLATED SHOWERS AND A FEW THUNDERSTORMS WITH THE COOLER AIR ALOFT.
INSTABILITY WILL BE SIGNIFICANT ENOUGH TO CONTINUE THE MENTION FOR
THUNDERSTORMS DURING THE AFTERNOON WITH VALUES RANGING FROM AROUND
300 J/KG TO AROUND 800 J/KG...AGAIN THE BEST CHANCES FOR RAIN WILL
BE EARLIER IN THE DAY WITH THE FORCING ALONG THE FRONT. SEVERE
WEATHER THREAT DURING THIS TIME PERIOD LOOKS TO BE LIMITED WITH VERY
LITTLE SHEAR ALONG WITH LIMITED CAPE.
THURSDAY THROUGH FRIDAY NIGHT...DURING THE DAY THURSDAY...MUCH OF
THE AREA WILL GET A BREAK FROM THE RAIN SHOWERS AS THE CWA WILL BE
BETWEEN SYSTEMS DURING THAT TIME WITH THE COLD FRONT TO THE EAST AND
A LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT SLIDING INTO THE
NORTHERN PLAINS AND SOUTH CENTRAL CANADA. TIMING ISSUES REMAIN
BETWEEN THE GFS/EC THURSDAY NIGHT THROUGH FRIDAY NIGHT ON THE EXACT
LOW POSITION ALONG WITH THE COLD FRONT POSITION. THE GFS IS STILL
MORE PROGRESSIVE WITH THE SYSTEM WHILE THE EC IS MUCH SLOWER AT
MOVING THE SYSTEM THROUGH. EITHER WAY...THURSDAY NIGHT INTO FRIDAY
LOOKS TO BE WET WITH SHOWERS AND THUNDERSTORMS PUSHING THROUGH.
ALOFT...A 500 MB TROUGH WILL PUSH ACROSS THE AREA DURING THE SAME
TIME FRAME...WHILE LINGERING INTO THE OVERNIGHT HOURS FRIDAY NIGHT
AS A RIDGE BEGINS TO BUILD OVER THE WESTERN CONUS. SEVERE WEATHER
WILL BE A POSSIBILITY FRIDAY AFTERNOON IF THE FRONT MOVES IN DURING
THE AFTERNOON...PEAK HEATING HOURS...WHICH IS SUGGESTED BY THE EC.
IF THE GFS SOLUTION VERIFIES...THEN THE FRONT WILL ALREADY BE PAST
MOST OF THE U.P. BY FRIDAY AFTERNOON...HELPING TO LIMIT THE CHANCES.
MUCAPE VALUES RANGE FROM 400-700 J/KG FROM THE GFS TO AROUND 800-
1100 J/KG FROM THE EC. SHEAR VALUES FROM THE EC ARE PROGGED TO BE
AROUND 30 TO 40 KNOTS WITH PERPENDICULAR TO THE FRONT AT THE ONSET.
AGAIN MUCH OF THIS IS CONDITIONAL...DEPENDING LARGELY ON THE OVERALL
TIMING OF THE AFOREMENTIONED UPPER LEVEL AND SURFACE FEATURES. THE
WARMER TEMPERATURES SLIDING ACROSS THE COLD WATERS OF THE GREAT
LAKES WILL ALLOW WIDESPREAD FOG TO FORM THURSDAY NIGHT INTO
FRIDAY...ESPECIALLY WHEN THE RAIN SHOWERS PUSH OVER THE AREA. THE
FAIRLY STRONG TEMPERATURE INVERSION CAN BE NOTED ON BUFKIT SOUNDINGS.
SATURDAY THROUGH THE REMAINING EXTENDED...NICE WEEKEND EXPECTED AS
DRY COOL CANADIAN HIGH PRESSURE IS EXPECTED TO SLIDE ACROSS THE
UPPER GREAT LAKES REGION. THE UPPER LEVEL 500MB TROUGH AXIS IS
EXPECTED TO SLOWLY SHIFT TO THE EAST OF THE AREA BY SUNDAY EVENING.
CALM WINDS ASSOCIATED WITH THE SURFACE HIGH ALONG WITH VERY DRY AIR
IN PLACE WILL ALLOW TEMPERATURES TO DROP BELOW NORMAL...INTO THE 30S
FOR OVERNIGHT LOW TEMPERATURES AND HIGHS IN THE MID 50S TO LOW 60S.
FROST MAY BE POSSIBLE SATURDAY NIGHT INTO SUNDAY MORNING ACROSS
INLAND AREAS. SUNDAY NIGHT THROUGH MONDAY...MODELS BEGIN TO DIFFER
GREATLY WITH THE GFS BRINGING A LOW NORTHWARD INTO THE AREA WHILE
THE EC MAINTAINS THE HIGH PRESSURE SYSTEM. AT THIS POINT...WILL
STICK WITH A CONSENSUS FOR THAT TIME PERIOD DUE TO THE MODEL
DISAGREEMENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 113 AM EDT TUE MAY 26 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. WITH ABUNDANT LOW-
LEVEL MOISTURE OVER THE AREA...LIFR CONDITIONS WILL LIKELY CONTINUE
TO PREVAIL OVERNIGHT AT KIWD/KCMX. EXPECT FOG/STRATUS TO DEVELOP AT
KSAW AS WELL...BRINGING CONDITIONS DOWN TO LIFR LATER IN THE NIGHT.
ALL TERMINALS SHOULD IMPROVE TO MVFR BY AFTN. NEXT DISTURBANCE
APPROACHING FROM THE S AND SW WILL BRING SHRA TO THE AREA THIS
AFTN/EVENING WITH KSAW MOST LIKELY TO SEE PCPN. NOT OUT OF THE
QUESTION FOR SOME TSRA TO OCCUR IN CNTRL UPPER MI AS WELL. IFR/LIFR
CONDITIONS WILL PROBABLY SET IN AGAIN THIS EVENING AT ALL TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EDT MON MAY 25 2015
LOW PRESSURE WILL MOVE ACROSS LAKE SUPERIOR TONIGHT SO THE WINDS
WILL SLOWLY DIMINISH. WINDS THE REST OF THE FORECAST PERIOD ARE
EXPECTED TO STAY AT OR BELOW 25 KTS. FOG WILL LINGER THROUGH
WEDNESDAY MORNING AND MAY BE DENSE AT TIMES. ADDITIONAL FOG IS
EXPECTED TO DEVELOP THURSDAY NIGHT AND FRIDAY AHEAD OF THE NEXT LOW
AND ASSOCIATED COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
456 AM CDT Tue May 26 2015
.DISCUSSION...
Issued at 455 AM CDT TUE MAY 26 2015
Today - Wednesday:
Vorticity max which lifted out of West TX yesterday and helped
generate the MCC that roared through east TX has attempted to merge
with the NE/KS upper trough. Hard to say if this process has been
successful. Operational models appear to wash out the vorticity max
currently over east central KS while allowing a separate h7
vorticity max to rotate east through the NE/KS upper trough and
across northern MO this afternoon.
Near term portion of forecast is tied to radar trends which shows a
fairly expansive region of tropical type showers with a few
thunderstorms. The entire region of rain is starting to lift
northeast. Have followed the trend of the HRRR and gone with
categorical PoPs for much of northern and west central MO this
morning. Think we`ll see scattered afternoon convection over
northern MO in response to the above mentioned h7 vorticity max
spinning through that area. A weak cold front/convergent zone is
expected to drift south through the CWA tonight and will provide
additional lift for scattered convection.
Also watching area of loosely organized convection coming out of NM
and into the TX Panhandle. Can see some rotation in water vapor
imagery. NAM and SREF seem to have best handle of this feature and
they both lift it northeast today. Am expecting to see scattered
convection reform with this feature and likely affect at least the
far southern counties this evening/overnight. So have upped PoPs
this region.
Wednesday should be relatively quiet with low chance PoPs tied to
weak convergence with whatever is left of the weak cold front.
Thursday - Weekend:
Very unsettled pattern as upper flow backs to the southwest and a
series of weak embedded disturbances lift northeast through the
Central Plains. Eventually a broad upper trough will shift east out
of the Central Rockies over the weekend and enhance precipitation
chances for at least Saturday. Deep moisture from the Gulf of Mexico
will once again flow northward and gradually result in a tropical
environment by Thursday night. Medium range models have been hitting
the PoPs hard with only minor run-to-run changes. See no reason to
deviate from likely PoPs during this period. Due to recent heavy
rains leaving sub-soil saturated will need to be watchful for
flooding issues as progged soundings once again are suggestive of
warm-rain processes.
Have some concern that the model PoPs are too low as both the
GFS/ECMWF still have the upper trough just passing through MO. Think
the model blended PoPs have not picked up on this. Sunday is looking
a bit chilly since we`ll be under an extensive cloud shield with
scattered convection.
Monday:
Finally should see the start of drying out as the upper trough
should have passed east of the region with subsidence overspreading
the region.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1158 PM CDT MON MAY 25 2015
Scattered thunderstorms will continue to lift north northwest over
the next few hours, impacting all TAF sites through 06z at IXD to
07z at MKC and MCI, to 08z or later at STJ. A few showers and
possibly an embedded storm could sweep back through the area between
09z and 12z, but this is less likely and coverage should be less,
warranting a VCTS group for this period at all locations. By 12z, all
sites should return to VFR, and variable wind direction due to storm
outflow will end, allowing winds to increase out of the southwest.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH until 10 AM CDT this morning FOR KSZ102.
MO...FLASH FLOOD WATCH until 10 AM CDT this morning FOR MOZ001>005-
011-012.
&&
$$
DISCUSSION...MJ
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1223 AM CDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 1221 AM CDT TUE MAY 26 2015
JUST A FEW CHANGES MADE FOR THIS UPDATE. LOWERED SKY COVER ACROSS
THE AREA AND LOW TEMPERATURES ACROSS THE WEST. CLEAR SKIES AND
LIGHT WINDS ARE ALLOWING TEMPERATURES TO FALL A LITTLE FASTER THAN
PREVIOUSLY FORECAST. OTHERWISE THE ONGOING FORECAST IS IN GOOD
SHAPE.
UPDATE ISSUED AT 939 PM CDT MON MAY 25 2015
A FEW STRONGER THUNDERSTORMS OVER THE SOUTH CENTRAL EARLIER THIS
EVENING CONTINUE TO DISSIPATE AS THEY MOVE SOUTHWEST THROUGH
EMMONS AND MCINTOSH COUNTIES. THERE HAS BEEN NO LIGHTNING WITH
THESE CELLS OVER THE PAST HOUR OR SO. ELSEWHERE A FEW SHOWERS WERE
LOCATED OVER THE NORTHEAST FORECAST AREA IN EASTERN ROLETTE AND
PIERCE COUNTIES...AND OVER WESTERN MCKENZIE COUNTY. THERE COULD
YET BE A PASSING SPRINKLE OR SHOWER OVERNIGHT ACROSS THE
NORTH ASSOCIATED WITH A WEAK SHORTWAVE SLIDING SOUTHEAST FROM
SASKATCHEWAN...BUT IN GENERAL HAVE SIGNIFICANTLY LOWERED OR
REMOVED POPS MOST AREAS FOR THE REMAINDER OF THE NIGHT. DID KEEP
THE PATCHY FOG IN THE GRIDDED FORECAST ACROSS THE WEST AND CENTRAL
WITH SOME MORNING SHOWERS...AND CLEAR TO PARTLY CLOUDY SKIES AND
LIGHT WINDS EXPECTED TONIGHT. OTHERWISE NO CHANGES TO THE GOING
FORECAST.
UPDATE ISSUED AT 550 PM CDT MON MAY 25 2015
WEAK SURFACE PRESSURE PATTERN OVER WESTERN AND CENTRAL NORTH
DAKOTA...WITH SOME RATHER IMPRESSIVE LOW LEVEL MOISTURE OVER SOUTH
CENTRAL INTO EASTERN NORTH DAKOTA AS DEWPOINTS WERE IN THE MIDDLE
50S. WEAK MID TO UPPER LEVEL TROUGH FROM NEBRASKA PANHANDLE INTO
WEST CENTRAL MINNESOTA. AFTERNOON INSTABILITY HAS PRODUCED
SCATTERED SHOWERS ACROSS THE FORECAST AREA AND EXPECT THESE TO
DIMINISH AS WE HEAD TOWARDS SUNSET. LOW TO MID LEVEL CIRCULATION
AND STEEP LAPSE RATES HAVE HEIGHTENED THE SPC NON SUPERCELL
TORNADO PARAMETER OVER SOUTH CENTRAL NORTH DAKOTA. DID HAVE A
REPORT OF A FUNNEL EARLIER TODAY NEAR JUD AND CANNOT RULE OUT
ADDITIONAL FUNNELS FOR THE NEXT FEW HOURS. THERE HAS BEEN NO
LIGHTNING THIS AFTERNOON AND THESE FUNNELS ARE USUALLY SHORT LIVED
AND RARELY REACH THE GROUND. THEY ARE NOT ASSOCIATED WITH SEVERE
THUNDERSTORMS. DID MAKE SOME SLIGHT ADJUSTMENTS TO POPS BASED ON
LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING
FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 331 PM CDT MON MAY 25 2015
SHOWER AND THUNDERSTORM CHANCES THIS AFTERNOON AND EARLY EVENING
HIGHLIGHT THE SHORT TERM FORECAST.
AS DEPICTED WELL BY THE HRRR RUNS FROM THIS MORNING AND THROUGH
THE AFTERNOON...ISOLATED TO SCATTERED SURFACE BASED CONVECTION
CONTINUES TO DEVELOP ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA THIS AFTERNOON. GIVEN WEAK INSTABILITY...ANY THUNDERSTORMS
ARE EXPECTED TO BE MUCH MORE ISOLATED COMPARED TO THE MORE
DOMINANT RAIN SHOWER MODE. GIVEN THE DIURNAL NATURE OF THIS
CONVECTION AND LACK OF STRONG FORCING...SHOWERS AND THUNDERSTORMS
WILL FADE WITH SUNSET. SEVERE WEATHER IS NOT EXPECTED.
OTHERWISE FOR TONIGHT...DID ADD A PATCHY FOG MENTION TO THE SOUTH
CENTRAL AND SOUTHWEST WITH RAINFALL FROM EARLIER TODAY...CLEARING
SKIES TONIGHT AND LIGHT WINDS ASSOCIATED WITH A WEAK SURFACE HIGH.
A MILD TUESDAY IS EXPECTED WITH HIGHS IN THE MID 70S TO LOWER 80S
IN A RATHER DEFUSE SURFACE PRESSURE PATTERN. THERE IS A CHANCE OF
THUNDERSTORMS ACROSS THE TURTLE MOUNTAINS AND UPPER JAMES RIVER
VALLEY DURING THE AFTERNOON IN ASSOCIATION WITH WEAK IMPULSES
EMBEDDED IN NORTHWEST FLOW ALOFT. ONCE AGAIN GIVEN WEAK
INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 331 PM CDT MON MAY 25 2015
A PERSISTING REX BLOCKING PATTERN...OVER THE PACIFIC NORTHWEST...IS
PROJECTED WITHIN THE CURRENT ENSEMBLE AND DETERMINISTIC MODELS TO
REMAIN IN PLACE THROUGH MUCH OF THE EXTENDED. SPLIT FLOW ALOFT WILL
RESULT AND CONTINUE OVER NORTH DAKOTA INTO THE WEEKEND.
THEREAFTER...A TRANSITION TO ZONAL FLOW IS PROJECTED BY THE LONG
TERM MODELS. OVERALL...SEVERAL EMBEDDED SHORTS WAVES WITHIN THE
NORTHERN STREAM ALOFT WILL RESULT IN SEVERAL CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THE LONG TERM. AS OF NOW...THE GREATEST
CHANCES FOR PRECIPITATION ARE WEDNESDAY NIGHT THROUGH EARLY FRIDAY
MORNING. ALTHOUGH THE COMPLEXITY OF THE UPPER LEVEL FLOW HAS
RESULTED IN HIGHER THAN NORMAL MODEL UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1221 AM CDT TUE MAY 26 2015
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. PATCHY FOG IS
POSSIBLE...BUT THERE IS TOO MUCH UNCERTAINTY TO PLACE FOG IN ANY
TAF.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...AYD
LONG TERM...AC
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
153 AM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE EAST COAST OF THE US WILL CONTINUE TO
INCREASE MOISTURE LEVELS FROM THE GULF OF MEXICO THROUGH THE
MIDDLE OF THE WEEK. SEVERAL PIECES OF JET ENERGY WILL MOVE ACROSS
THE REGION THROUGH THE WEEK BRINGING INCREASED CHANCES OF SHOWERS
AND THUNDERSTORMS. A WEAK COLD FRONT WILL MOVE ACROSS THE LOWER
GREAT LAKES WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PATCH OF CONVECTION THAT HRRR TRIES TO DEVELOP AROUND CLE NOT
MATERIALIZING. WILL STICK WITH PLAN TO ALLOW ONLY WIDELY SCT WEAK
CONVECTION TO DEVELOP AROUND THE EASTERN PART OF THE AREA THE REST
OF THE NIGHT WITH QPF UNDER A TENTH OF AN INCH.
IT WILL BE ANOTHER WARM NIGHT WITH LOWS ONLY DIPPING BACK INTO THE
MIDDLE 60S AS DEBRIS CLOUDS PERSIST AT MID AND UPPER LEVELS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
THE MORNING SHOWERS AND POSSIBLE RUMBLE OF THUNDER SHOULD DRIFT
EASTWARD OR DISSIPATE WITH THE MORNING MIX. THE APPROACHING WAVE
FROM THE MIDWEST SHOULD HELP TO INCREASE THE LIFT LATE AFTERNOON
INTO THE EVENING HOURS. THE INCREASED LIFT AND CONTINUED FLOW OF
MOISTURE INTO THE REGION SHOULD GENERATE THUNDERSTORMS OVER
INDIANA/NW OHIO AND POSSIBLY ACROSS THE EASTERN COUNTY WARNING
AREA TUESDAY AFTERNOON. THE WESTERN CONVECTION WILL HAVE A CHANCE
TO SWEEP ACROSS THE COUNTY WARNING AREA TUESDAY EVENING. AT THIS
POINT CONFIDENCE IS HIGH ENOUGH TO MENTION LIKELY POPS. THERE
SHOULD BE A LULL IN THE THUNDER FOR A FEW HOURS WEDNESDAY MORNING
BUT A WEAK FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION DURING THE
AFTERNOON. THIS SHOULD BE A FOCUS FOR THUNDERSTORMS WEDNESDAY
AFTERNOON INTO THE EVENING HOURS. SLIGHTLY DRIER AIR RETURNS ON
THURSDAY WITH THE UPPER LEVEL RIDGE ATTEMPTING TO INCREASE SLIGHTLY.
OF NOTE THROUGH THE WEEK IS THE FACT THAT UPPER LEVEL HEIGHTS WILL
BE RATHER HIGH. THIS MAY END UP LIMITING THE COVERAGE OF
THUNDERSTORMS EACH AFTERNOON AND EVENING.
TEMPERATURES WILL CONTINUE TO BE ABOVE SEASONAL AVERAGES THROUGH
THE WEEK WITH HIGHS GENERALLY IN THE LOWER 80S. LOWS WILL BE IN
THE 60S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM BEGINS FRIDAY WITH THE MODELS SHOWING HIGH PRESSURE
ACROSS THE SOUTHEAST COAST...LOW PRESSURE ACROSS QUEBEC AND A
FRONTAL SYSTEM SOUTHWEST FROM THE LOW ACROSS THE CENTRAL LAKES TO
TEXAS. THIS FRONTAL SYSTEM WILL EVENTUALLY GET INTO THE AREA BUT FOR
FRIDAY THERE WILL BE A GENERAL LACK OF FORCING. WITH THAT SAID WILL
HAVE SLIGHT CHANCE POPS FOR MAINLY DIURNAL SHOWER OR THUNDERSTORM.
MODELS A BIT BETTER ON TIMING TODAY WITH BOTH THE GFS AN ECMWF
BRINGING THE FRONT THROUGH ON SATURDAY. THE FRONT WILL STALL IN THE
TENNESSEE OR LOWER OHIO VALLEY SUNDAY BEFORE LIKELY MOVING BACK
NORTH ON MONDAY. THE FRONT WILL BRING ITS OWN MOISTURE WITH IT BUT
WILL ALSO GET AN INFLUX OF GLFMX MOISTURE AS IT WAFFLES THROUGH THE
AREA DURING THE WEEKEND. THIS OF COURSE IF A FAIRLY WET PATTERN
SUGGESTING HIGH CHANCE TO LIKELY POPS WILL BE NEEDED SATURDAY
THROUGH SUNDAY WITH CHANCE POPS CONTINUING MONDAY. ABOVE NORMAL
TEMPS FRIDAY AND NEAR NORMAL SATURDAY THROUGH MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
REGIONAL RADARS SHOW A SMALL AREA OF SHOWERS MOVING TOWARDS
NORTHEAST OHIO AND WILL LIKELY CLIP CAK/YNG FOR AN HOUR OR TWO
BETWEEN 07-10Z. OTHERWISE EXPECTING AN MVFR CLOUD DECK TO TRY TO
FILL IN AT MOST SITES EXCEPT ERIE FROM AROUND 10-15Z BUT THERE
IS ABOUT A 40 PERCENT CHANCE THIS WILL NOT DEVELOP. SCT-BKN
CLOUDS AROUND 3500 FEET WILL LINGER FOR MUCH OF THE DAY ON TUESDAY
WITH CHANCES OF SHOWERS AND THUNDERSTORMS ARRIVING IN NW OHIO
TOWARDS 22Z. CHANCES OF SHOWERS AND THUNDERSTORMS WILL PUSH
EASTWARD DURING THE EVENING. WINDS WILL REMAIN OUT OF THE SOUTH
AND MAY BECOME BREEZY WITH GUSTS TO AROUND 22 KNOTS AT SOME
LOCATIONS DURING THE AFTERNOON.
.OUTLOOK...NON VFR POSSIBLE TUESDAY EVENING THROUGH WEDNESDAY IN SCT
SHRA AND TSRA...THEN RETURNING AGAIN ON SATURDAY.
&&
.MARINE...
WILL CONTINUE WITH A SMALL CRAFT ADVISORY PRIMARILY FOR WINDS WEST
THIRD. WINDS SHOULD DECREASE FURTHER OFF SHORE GIVEN STABILIZING
EFFECTS OF THE COOLER WATER BUT CLOSE TO SHORE WINDS SHOULD CONTINUE
GUSTING INTO THE MID 20 KNOT RANGE INTO EARLY EVENING. NO HEADLINES
EXPECTED THROUGH THE REMAINDER OF THE FORECAST. WINDS WILL REMAIN
PRIMARILY FROM THE SOUTH TO SOUTHWEST AT 10 TO 20 KNOTS OR LESS
THROUGH WEDNESDAY NIGHT. THURSDAY AND FRIDAY WINDS WILL BECOME LIGHT
AND VARIABLE. BEST CHANCE FOR THUNDERSTORMS WILL COME TUESDAY AND
TUESDAY NIGHT
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...MULLEN
SHORT TERM...MULLEN
LONG TERM...TK
AVIATION...KEC
MARINE...TK
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
257 AM CDT TUE MAY 26 2015
.DISCUSSION...
RADAR IMAGERY THIS MORNING SHOWS THE MID STATE CLEAR OF
CONVECTION. HOWEVER...REGIONAL MOSAIC IMAGERY SHOWS A LARGE BUT
WEAKENING MCS STRETCHING FROM EASTERN ARKANSAS INTO WESTERN
MISSISSIPPI. CURRENT SPEED OF MCS BRINGS IT INTO SOUTHWEST ZONES
AROUND 12Z...WHICH IS IN LINE WITH 06Z HRRR TIMING/DEPICTION OF
MCS FALLING APART AS IT ENTERS THE MID STATE. LATEST THINKING
REMAINS SIMILAR TO PREVIOUS FORECASTS WITH WEAKENING MCS AFFECTING
WESTERN ZONES IN THE MORNING...THEN ADDITIONAL SCATTERED TO
NUMEROUS SHOWERS AND STORMS REDEVELOPING LATE MORNING/AFTERNOON
AREAWIDE. WILL SHOW POPS IN THE LIKELY CATEGORY VERSUS CATEGORICAL
DUE TO COVERAGE CONCERNS...AND HAVE KEPT TEMPS NEAR THE SUPERBLEND
CONSENSUS IN THE UPPER 70S TO LOWER 80S. SPC DAY 1 OUTLOOK HAS
TRIMMED BACK THE SLIGHT RISK TO JUST NORTHERN SECTIONS OF THE MID
STATE...AND SEVERE THREAT STILL APPEARS MARGINAL DUE TO NEAR
MOIST ADIABATIC PROFILES AND LACKLUSTER CAPE. STILL...A FEW
STRONG OR BORDERLINE SEVERE STORMS WITH STRONG WINDS CANNOT BE
RULED OUT...MAINLY IN THE AFTERNOON HOURS AND PARTICULARLY OVER
THE NORTHEAST TWO-THIRDS OF THE CWA.
ACTIVITY WILL DIMINISH THIS EVENING INTO TONIGHT WITH POPS
DECREASING FROM WEST TO EAST. REMAINDER OF FORECAST PERIOD FROM
WEDNESDAY INTO THE WEEKEND WILL SEE A MORE SUMMER LIKE PATTERN
WITH MIDDLE TENNESSEE ON THE BORDERLINE BETWEEN A WESTERN CONUS
TROUGH AND EASTERN CONUS RIDGE. THUS ANTICIPATED ABOVE AVERAGE
TEMPS WELL INTO THE 80S WITH SCATTERED DIURNAL SHOWERS AND STORMS
DEVELOPING EACH DAY BEFORE DECREASING AT NIGHT. A FEW STRONG
PULSE/MULTICELL STORMS WITH POTENTIAL MICROBURST WIND/HAIL RISK
COULD BE SEEN EACH DAY AS CAPE WILL BE SUBSTANTIAL BUT BULK SHEAR
WEAK. MORE WIDESPREAD SHOWERS AND STORMS APPEAR POSSIBLE SUNDAY
AND MONDAY AS A COLD FRONT APPROACHES FROM THE NORTH...BUT 00Z
GUIDANCE DIFFERS ON HOW FAR SOUTH FRONT WILL PUSH INTO THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 81 66 86 66 / 70 40 40 30
CLARKSVILLE 79 65 84 65 / 70 30 40 30
CROSSVILLE 77 64 80 64 / 70 60 50 30
COLUMBIA 79 65 83 65 / 70 40 40 30
LAWRENCEBURG 78 65 82 65 / 70 40 40 30
WAVERLY 78 66 84 65 / 70 30 40 30
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
233 AM EDT TUE MAY 26 2015
.SHORT TERM (TODAY THROUGH THURSDAY NIGHT)...
RADAR TRENDS SUPPORT THE LATEST HRRR DEPICTIONS OF CONVECTION
DEVELOPING OVER NE GA AND MOVING N-NE THROUGH THE MORNING...SO
INITIALLY THE HIGHEST POPS TODAY WILL BE NE. THE VORT MAX/SHORTWAVE
TROUGH ASSOCIATED WITH CONVECTION NEAR THE MS RIVER THIS MORNING
WILL MOVE INTO MIDDLE TN THIS AFTERNOON...SHIFTING THE HIGHERST
PRECIP CHANCES TO THE PLATEAU AND SOUTHERN VALLEY AREAS. WILL HAVE
CATEGORICAL POPS IN THESE AREAS...WITH LIKELY POPS ELSEWHERE
THROUGH THE EVENING AS THE VORT MAX MOVES EAST. A FEW STRONG STORMS
CANNOT BE RULED OUT...BUT THE THREAT FOR SEVERE LOOKS LOW WITH A
SKINNY CAPE AREA SEEN IN FORECAST SOUNDINGS. HEAVY RAIN FROM
TRAINING CELLS WILL BE A BIGGER THREAT THAT WILL BEAR WATCHING.
THE GENERAL PATTERN THROUGH THE REST OF THE SHORT TERM WILL BE A
DEEP SOUTHERLY FLOW OF MOISTURE WITH PW VALUES OVER 1.5
INCHES...WITH MIDLEVEL DISTURBANCES PASSING ACROSS THE AREA. VARIOUS
MODELS DISAGREE WITH THE TIMING AND STRENGTH OF THESE
DISTURBANCES...WHICH WILL BE KEY TO PINPOINTING THE AREA AND TIMING
OF HIGHEST POPS AND QPF. WITH CONFIDENCE BEING LOW WITH THESE FINER
FEATURES...WILL PAINT THE POP/WX/QPF GRIDS WITH A BROAD BRUSH.
LIKELY POPS ARE WARRANTED EACH DAY...WITH CHANCE POPS OVERNIGHT. NO
SEVERE THREAT IS EXPECTED DUE TO THE LACK OF SHEAR AND
INSTABILITY...BUT LOCALLY HEAVY RAIN MAY BE POSSIBLE AT TIMES.
- KMEM 260623
WRKAFD
.LONG TERM (FRIDAY THROUGH MONDAY)...
WIDELY SCATTERED TO SCATTERED DIURNAL CONVECTION WILL BE THE RULE
FRIDAY AND SATURDAY BEHIND THE DEPARTING MID WEEK SHORT WAVE AS
SOUTHERLY FLOW CONTINUES AROUND THE WESTERN ATLANTIC RIDGE.
PROBABILITY OF PRECIPITATION INCHES UP JUST A LITTLE LATER IN THE
WEEKEND INTO THE BEGINNING OF THE WORK WEEK TO ACCOUNT FOR THE
POSSIBILITY OF THE PASSAGE OF A SHORT WAVE FEATURE ALONG WITH A
SYNOPTIC COLD FRONT SHIFTING SLOWLY SOUTHEAST TOWARD THE
APPALACHIAN REGION. MAX AND MIN FORECAST TEMPERATURES WILL BE JUST
A LITTLE AHEAD OF CLIMATOLOGY FOR LATE MAY AND EARLY JUNE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 80 66 82 66 / 80 80 70 50
KNOXVILLE MCGHEE TYSON AIRPORT, TN 81 65 81 64 / 70 70 70 50
OAK RIDGE, TN 80 65 81 65 / 70 70 70 50
TRI CITIES AIRPORT, TN 82 64 79 62 / 60 70 70 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
24/99
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1144 PM CDT MON MAY 25 2015
.UPDATE...FOR AVIATION.
&&
AVIATION...
06Z TAFS...RESIDUAL MOISTURE WILL CAUSE SOME AREAS OF BR AND LOW
STRATUS CLOUDS TO FORM OVERNIGHT...MAINLY FOR CKV AND CSV. EXPECT
MAINLY MVFR AT CKV/CSV...WITH CIGS BRIEFLY DROPPING TO IFR.
A SHORTWAVE TROUGH WILL MOVE INTO THE AREA ON TUESDAY WITH A GOOD
CHANCE FOR SHRA/TSRA AFTER 12Z...RESULTING IN PERIODS OF MVFR. WINDS
WILL REMAIN OUT OF THE SOUTH...WITH GUSTS OVER 20KT AT TIMES.
MOST PRECIP WILL EXIT THE AREA BY 27/00Z...WITH AREAS OF BR
FORMING BY 27/06Z.
13
&&
.PREV DISCUSSION... /ISSUED 958 PM CDT MON MAY 25 2015/
UPDATE...
PER SHWRS LEAVING THE MID STATE...AND WITH NO INDICATIONS FROM SHORT
RANGE MODELS OF SHWRS/TSTMS MOVING BACK INTO MID STATE UNTIL LATE
TONIGHT...REMOVED MENTION OF EVENING SHWRS FROM THE SUITE OF FORECAST
PRODUCTS. OTHERWISE...FORECAST REMAINS ON TRACK.
31
PREV DISCUSSION.../ISSUED 709 PM CDT MON MAY 25 2015/
UPDATE...
PER REGIONAL RADAR...SATELLITE...AND SFC OBSERVATIONS TRENDS...ALONG
WITH SHORT RANGE MODEL CONSENSUS...SOME LINGERING SHWRS ACROSS THE FAR
MOST ERN PLATEAU COUNTIES THRU THE EVENING HRS...WITH DRY CONDITIONS
REMAINDER OF MID STATE. BELIEVE WITH WINDS DYING DOWN AFTER MIDNIGHT...
PATCHY FOG DEVELOPMENT COULD OCCUR. THERE COULD BE SOME LINGERING SHWRS
ACROSS UPPER CUMBERLAND REGION THRU THE FIRST FEW HRS AFTER MIDNIGHT ALSO.
NEXT ROUND OF SHWRS/TSTMS SHOULD APPROACH THE TN RIVER VALLEY SHORTLY AFTER
SUNRISE. TWEAKED HRLY TEMP...DEWPOINT...SKY CONDITION...AND WIND SPEED
/DIRECTION GRIDS. HAVE UPDATED THE SUITE OF FORECAST PRODUCTS ACCORDINGLY...
INCLUDING REMOVING THE THROUGH LATE AFTERNOON ZONE GROUPING FROM THE ZONE
FORECAST PRODUCT.
31
PREV DISCUSSION.../ISSUED 221 PM CDT MON MAY 25 2015/
DISCUSSION...A PERSISTENT BAND OF SHOWERS CONTINUES TO MOVE
SLOWLY EASTWARD ACROSS MIDDLE TENNESSEE, WITH A FEW STRONGER
CELLS PASSING THROUGH SOUTHERN PARTS. HRRR HAS PERFORMED QUITE
WELL TODAY, AND THE SHORT-RANGE MODEL HAS CONSISTENTLY SHOWN A
DECREASE IN THE ACTIVITY FROM LATE AFTERNOON THROUGH EVENING, SO
AM SPLITTING TONIGHT`S POP GRID INTO 6-HOUR INCREMENTS, WITH
REDUCED POP`S FROM 00Z THROUGH 06Z. NAM SHOWS A WEAK TROUGH MOVING
INTO MIDDLE TENNESSEE TOMORROW MORNING ALONG WITH THE NEXT WAVE OF
MOISTURE, THEREBY PUSHING THE DRY WEDGE NORTHWARD AND BRINGING
LIKELY TO CATEGORICAL POP`S BACK IN. SPC IS KEEPING THE ENTIRE MID
STATE UNDER A SLIGHT RISK OF SEVERE STORMS TOMORROW AND TOMORROW
NIGHT, AND A MARGINAL RISK FOR DAY 3. MODEL SOUNDINGS CONTINUE TO
SHOW GOOD INSTABILITY FOR THE NEXT SEVERAL DAYS, MAINLY DURING
PEAK HEATING HOURS, WITH VERY LITTLE AIR MASS CHANGE FOR THE
FORESEEABLE FUTURE. FOLLOWING WEDNESDAY`S ANTICIPATED SHORTWAVE
PASSAGE, THE UPPER PATTERN BREAKS DOWN INTO A MUCH WEAKER FLOW,
WITH HIGH PRESSURE ESTABLISHING ITSELF OFF THE EAST COAST, VERY
SUMMER-LIKE. WE MAY SEE A FRONTAL PASSAGE EARLY NEXT WEEK, BUT AT
THIS POINT THE GFS AND ECMWF SOLUTIONS DIVERGE TO THE POINT THAT
ANY CONFIDENCE REGARDING TIMING IS LOW. TEMPERATURES WILL
GRADUALLY WARM THROUGHOUT THE WEEK, WITH READINGS SEVERAL DEGREES
ABOVE NORMAL FROM WEDNESDAY ON.
ROSE
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
207 AM CDT TUE MAY 26 2015
.UPDATE...
QUICK UPDATE TO REMOVE THE FLASH FLOOD WATCH FROM THE FORECAST.
ALL THE HEAVY RAIN HAS MOVED OFF TO THE EAST AND ONLY ISOLATED
SHOWERS REMAIN AND THOSE ARE DISSIPATING. WE LET THE FLASH FLOOD
WATCH EXPIRE.
&&
.PREV DISCUSSION... /ISSUED 1241 AM CDT TUE MAY 26 2015/
AVIATION DISCUSSION...FOR 06Z TAF PACKAGE...
CONCERNED WITH REDEVELOPMENT OF TSRA IN THE VICINITY OF KDRT
OVERNIGHT RESULTING IN LOWERED VIS. IN THE MEANTIME...IFR AND LIFR
CIGS ARE LIKELY TO DEVELOP AT THE I35 CORRIDOR TERMINALS DUE TO
VERY MOIST LOW LEVEL ENVIRONMENTS. UNSURE HOW FAR EAST THE TSRA
WILL SPREAD BUT INCLUDED A TEMPO MENTION IN KSAT/KSSF FOR TIME
FRAME IN WHICH IT WOULD OCCUR. AMENDMENTS MAY BE NEEDED. AFTER
18Z...VFR CONDITIONS SHOULD RETURN AND PREVAIL.
PREV DISCUSSION... /ISSUED 1039 PM CDT MON MAY 25 2015/
UPDATE...
SOME OF THE HI-RES MODELS...MOST NOTABLY THE LAST FEW HRRR AND RAP
RUNS...ARE GENERATING BACKBUILDING STORMS IN MEXICO THAT MAY
DEVELOP INTO A LARGER COMPLEX OVERNIGHT AFTER 8-9Z...MAINLY ALONG
AND SOUTH OF HIGHWAY 90. A PRONOUNCED OUTFLOW BOUNDARY MOVING
SOUTHWEST...WEAK ISENTROPIC ASCENT...AND A TONGUE OF MOIST AIR
EVIDENT ON WV IMAGERY SANDWICHED BETWEEN VERY DRY AIR ON BOTH
SIDES OF IT MAY HELP IN INITIATING THESE STORMS. THIS AREA DID NOT
RECEIVE CONVECTION EARLIER...SO IT MAY NOT BE WORKED OVER DESPITE
THE MESOANALYSIS SUGGESTING A CAP. ANY WEAK SHORTWAVE ROTATING
AROUND THE LARGER SCALE TROUGH TO THE WEST COULD TRIGGER NEW
CONVECTION...SO WILL BE INCREASING POPS ALONG AND SOUTH OF HIGHWAY
90 TO ACCOUNT FOR SCATTERED SHOWERS AND THUNDERSTORMS.
IN ADDITION...ISOLATED SHOWERS AND THUNDERSTORMS ARE FORMING IN THE
HILL COUNTRY ALONG REMNANT OUTFLOW BOUNDARIES ORIENTED WEST TO
EAST...WITH A STRONGER CELL OVER BLANCO COUNTY. IT IS CONCERNING
THAT THESE STORMS ARE STILL ABLE TO FORM DESPITE AN ENVIORMENT
THAT SHOULD BE FAIRLY WORKED OVER FROM AN INSTABILITY
STANDPOINT...BUT SOME HI- RES MODELS DO SUGGEST THAT THE CAP IS
ERODING AND CAPPING WAS VIRTUALLY NONEXISTENT ON THE 00Z DRT
SOUNDING. THUS...WILL BE INCREASING POPS TO ACCOUNT FOR THIS AS
WELL. THESE STORMS WOULD MOVE VERY SLOWLY AND THE FLASH FLOOD
GUIDANCE IS WELL BELOW ONE INCH PER HOUR IN SOME PLACES DUE TO
HEAVY RAINFALL FROM TODAY AND THE PAST FEW WEEKS...SO WILL HAVE
TO MONITOR RADAR TRENDS TO SEE IF A NEW FLASH FLOOD WATCH NEEDS TO
BE ISSUED FOR THE OVERNIGHT HOURS.
FINALLY...A TORNADO WATCH WAS LOCALLY EXTENDED TO 11 PM CDT FOR
KARNES...DEWITT...AND LAVACA COUNTIES TO ACCOUNT FOR CURRENT RADAR
TRENDS...BUT WE DO NOT EXPECT TO EXTEND THIS WATCH FURTHER.
PREV DISCUSSION... /ISSUED 717 PM CDT MON MAY 25 2015/
AVIATION.../00Z TAFS/
STORMS HAVE CLEARED ALL TAF SITES...BUT WILL INCLUDE VCTS THROUGH
01Z FOR SAT/SSF/AUS IN CASE BACKBUILDING STORMS PRODUCE A ROGUE
LIGHTNING STRIKE. A MESO LOW HAS FORMED BEHIND THIS LINE...WHICH
WILL CAUSE VARIABLE WINDS BELOW 10 KTS AT SAT/SSF/AUS FOR THE NEXT
FEW HOURS...WILL HANDLE THIS WITH AMENDMENTS IF THEY INCREASE
ABOVE 10 KTS. DRY AIR EVIDENT ON WV IMAGERY WILL HELP DRY OUT THE
MID AND UPPER LEVELS...BUT MOIST LOW LEVEL SE FLOW WILL ALLOW VFR
CIGS TO LOWER TO IFR BY 7Z AT SAT/SSF/AUS AND MVFR BY 9Z AT DRT.
MODEL GUIDANCE SUGGESTS LIFR CIGS COULD DEVELOP BETWEEN 10-14Z AT
SAT/SSF/AUS...BUT WILL REEVALUATE THIS WITH THE 06Z TAF PACKAGE.
PREV DISCUSSION... /ISSUED 447 PM CDT MON MAY 25 2015/
SIGNIFICANT FLASH FLOODING ONGOING ACROSS THE NORTHERN AND
CENTRAL PARTS OF SOUTH CENTRAL TEXAS...
SHORT TERM (TODAY THROUGH TUESDAY)...
A STRONG NEGATIVELY TILTED UPPER LEVEL TROUGH HAS CAUSED A
SIGNIFICANT SEVERE WEATHER EVENT THAT HAS ALREADY PRODUCED A FEW
TORNADOES IN THE HILL COUNTRY AND WIDESPREAD FLASH FLOODING IN THE
HILL COUNTRY AND I-35 CORRIDOR IS ONGOING THIS AFTERNOON. A FLASH
FLOOD EMERGENCY HAS ALSO BEEN ISSUED FOR EASTERN WILLIAMSON AND
TRAVIS COUNTIES AFTER 3 TO 5 INCHES OF RAIN FELL IN TWO HOURS. THE
PRIMARY THREAT FOR THE NEXT SEVERAL HOURS WILL CONTINUE TO BE
SIGNIFICANT FLASH AND RIVER FLOODING...WITH THE LATTER CONTINUING
INTO AT LEAST THE OVERNIGHT HOURS. RAINFALL RATES UP TO 4 INCHES
PER HOUR HAVE OCCURRED THIS AFTERNOON...BUT THESE RATES SHOULD
BEGIN TO DECREASE SLIGHTLY AS THESE STORMS CONTINUE TO MERGE INTO
A LINE OVER THE I-35 CORRIDOR FROM THE SAN ANTONIO METRO AND AREAS
NORTH BEFORE PUSHING EAST ACROSS OUR CWA. DRY AIR MOVING IN FROM
THE WEST EVIDENT ON WV IMAGERY SHOULD CONTINUE TO CAUSE PWAT
VALUES TO DECREASE AND END THE HEAVY RAINFALL THREAT FROM WEST TO
EAST AS WE MOVE INTO THE EVENING AND OVERNIGHT HOURS. THUS...THE
FLASH FLOOD WATCH HAS BEEN CANCELLED FOR OUR WESTERNMOST
COUNTIES...BUT CONTINUES FOR THE VAST MAJORITY OF SOUTH CENTRAL
TEXAS THROUGH 1 AM CDT TUESDAY.
ALTHOUGH SHEAR VALUES HAVE DECREASED SLIGHTLY FROM THE 50-55 KT
SEEN EARLIER THIS AFTERNOON IN THE HILL COUNTRY...HELICITY VALUES
ABOVE 200-300 M^2/S^2 AND LOW LCLS ALONG AND EAST OF I-35 WILL
LIKELY CONTINUE THE TORNADO THREAT FOR THIS AREA FOR AT LEAST THE
NEXT FEW HOURS. TORNADOES WILL BE POSSIBLE WITHIN MORE DISCRETE
CELLS WITHIN THE LINE OF STORMS CURRENTLY CENTERED OVER THE I-35
CORRIDOR NORTH OF SAN ANTONIO AND EXPANDING INTO NE TX AND SE
OK. THUS...A TORNADO WATCH CONTINUES UNTIL 10 PM CDT FOR THE
EASTERN HILL COUNTRY...AND ALL COUNTIES ALONG AND NORTH OF THE
I-10 CORRIDOR AND ALONG AND EAST OF THE I-35 CORRIDOR NORTHEAST OF
THE SAN ANTONIO METRO.
DRY AIR WILL GRACIOUSLY FILL INTO THE ENTIRE CWA BY EARLY TUESDAY
MORNING...BUT ANOTHER WEAK SHORTWAVE ROTATING AROUND THE
PERSISTENT LONGWAVE TROUGH TO OUR WEST MAY TRIGGER ISOLATED
THUNDERSTORMS TUESDAY AFTERNOON IN THE SERRENIAS DEL BURRO THAT
MOVE INTO THE RIO GRANDE PLAINS. ELSEWHERE...AMPLE BOUNDARY LAYER
AND SOIL MOISTURE WITH DAYTIME TEMPERATURES RISING INTO THE UPPER
80S MAY STILL ALLOW FOR VERY ISOLATED AFTERNOON SHOWERS AND
THUNDERSTORMS...BUT DRY AIR SHOULD PREVENT DEVELOPMENT. IN
ADDITION...WEAK SHORTWAVE RIDING SHOULD BEGIN TO BUILD IN BY LATE
TUESDAY NIGHT TO LIMIT OUR RAIN CHANCES.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
A BRIEF PERIOD OF SHORTWAVE RIDGING WITH RELATIVELY DRY AIR WILL
CONTINUE THROUGH EARLY THURSDAY...GIVING THE REGION A MUCH NEEDED
BREAK FROM THE HEAVY RAINFALL PATTERN WE HAVE BEEN IN FOR SEVERAL
WEEKS FOR A FEW DAYS. HOWEVER...WILL STILL CARRY ISOLATED
AFTERNOON SHOWERS AND THUNDERSTORMS FOR WEDNESDAY DUE TO AMPLE
BOUNDARY LAYER MOISTURE AND SOIL MOISTURE WITH HIGHS NEARING 90
DEGREES. ANOTHER UPPER LEVEL TROUGH APPROACHES THE REGION ON
THURSDAY TO BREAK DOWN THIS RIDGE...INCREASING THE COVERAGE OF
AFTERNOON SHOWERS AND THUNDERSTORMS...PARTICULARLY IN THE RIO
GRANDE PLAINS. MODELS GENERALLY AGREE THAT THE MAIN ENERGY FROM
THIS UPPER LEVEL TROUGH SHOULD REMAIN TO OUR NORTH...BUT ALSO
SUGGEST THAT IT WILL NOT BE VERY PROGRESSIVE AND STICK AROUND
UNTIL AT LEAST SUNDAY. CONSIDERING THAT A FEW WEAK BOUNDARIES MAY
SLIP INTO THE REGION TO PROVIDE AN ADDITIONAL FOCUS FOR
CONVECTION...RAINFALL CHANCES WILL LIKELY CONTINUE THROUGH FRIDAY
AND THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 87 73 87 72 86 / 20 20 20 20 30
AUSTIN BERGSTROM INTL AIRPORT 86 72 87 71 86 / 20 20 20 20 30
NEW BRAUNFELS MUNI AIRPORT 87 73 88 72 87 / 20 20 20 20 30
BURNET MUNI AIRPORT 86 69 86 70 84 / 10 20 20 20 30
DEL RIO INTL AIRPORT 90 74 89 74 86 / 30 20 20 20 40
GEORGETOWN MUNI AIRPORT 86 70 87 71 86 / 20 20 20 20 30
HONDO MUNI AIRPORT 87 73 88 73 86 / 30 20 20 20 40
SAN MARCOS MUNI AIRPORT 86 73 87 72 85 / 20 20 20 20 30
LA GRANGE - FAYETTE REGIONAL 87 74 88 73 87 / 30 20 20 20 40
SAN ANTONIO INTL AIRPORT 88 74 88 73 86 / 30 20 20 20 30
STINSON MUNI AIRPORT 88 74 88 73 87 / 30 20 20 20 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...TB3
SYNOPTIC/GRIDS...05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1241 AM CDT TUE MAY 26 2015
.AVIATION DISCUSSION...FOR 06Z TAF PACKAGE...
CONCERNED WITH REDEVELOPMENT OF TSRA IN THE VICINITY OF KDRT
OVERNIGHT RESULTING IN LOWERED VIS. IN THE MEANTIME...IFR AND LIFR
CIGS ARE LIKELY TO DEVELOP AT THE I35 CORRIDOR TERMINALS DUE TO
VERY MOIST LOW LEVEL ENVIRONMENTS. UNSURE HOW FAR EAST THE TSRA
WILL SPREAD BUT INCLUDED A TEMPO MENTION IN KSAT/KSSF FOR TIME
FRAME IN WHICH IT WOULD OCCUR. AMENDMENTS MAY BE NEEDED. AFTER
18Z...VFR CONDITIONS SHOULD RETURN AND PREVAIL.
&&
.PREV DISCUSSION... /ISSUED 1039 PM CDT MON MAY 25 2015/
UPDATE...
SOME OF THE HI-RES MODELS...MOST NOTABLY THE LAST FEW HRRR AND RAP
RUNS...ARE GENERATING BACKBUILDING STORMS IN MEXICO THAT MAY
DEVELOP INTO A LARGER COMPLEX OVERNIGHT AFTER 8-9Z...MAINLY ALONG
AND SOUTH OF HIGHWAY 90. A PRONOUNCED OUTFLOW BOUNDARY MOVING
SOUTHWEST...WEAK ISENTROPIC ASCENT...AND A TONGUE OF MOIST AIR
EVIDENT ON WV IMAGERY SANDWICHED BETWEEN VERY DRY AIR ON BOTH
SIDES OF IT MAY HELP IN INITIATING THESE STORMS. THIS AREA DID NOT
RECEIVE CONVECTION EARLIER...SO IT MAY NOT BE WORKED OVER DESPITE
THE MESOANALYSIS SUGGESTING A CAP. ANY WEAK SHORTWAVE ROTATING
AROUND THE LARGER SCALE TROUGH TO THE WEST COULD TRIGGER NEW
CONVECTION...SO WILL BE INCREASING POPS ALONG AND SOUTH OF HIGHWAY
90 TO ACCOUNT FOR SCATTERED SHOWERS AND THUNDERSTORMS.
IN ADDITION...ISOLATED SHOWERS AND THUNDERSTORMS ARE FORMING IN THE
HILL COUNTRY ALONG REMNANT OUTFLOW BOUNDARIES ORIENTED WEST TO
EAST...WITH A STRONGER CELL OVER BLANCO COUNTY. IT IS CONCERNING
THAT THESE STORMS ARE STILL ABLE TO FORM DESPITE AN ENVIORMENT
THAT SHOULD BE FAIRLY WORKED OVER FROM AN INSTABILITY
STANDPOINT...BUT SOME HI- RES MODELS DO SUGGEST THAT THE CAP IS
ERODING AND CAPPING WAS VIRTUALLY NONEXISTENT ON THE 00Z DRT
SOUNDING. THUS...WILL BE INCREASING POPS TO ACCOUNT FOR THIS AS
WELL. THESE STORMS WOULD MOVE VERY SLOWLY AND THE FLASH FLOOD
GUIDANCE IS WELL BELOW ONE INCH PER HOUR IN SOME PLACES DUE TO
HEAVY RAINFALL FROM TODAY AND THE PAST FEW WEEKS...SO WILL HAVE
TO MONITOR RADAR TRENDS TO SEE IF A NEW FLASH FLOOD WATCH NEEDS TO
BE ISSUED FOR THE OVERNIGHT HOURS.
FINALLY...A TORNADO WATCH WAS LOCALLY EXTENDED TO 11 PM CDT FOR
KARNES...DEWITT...AND LAVACA COUNTIES TO ACCOUNT FOR CURRENT RADAR
TRENDS...BUT WE DO NOT EXPECT TO EXTEND THIS WATCH FURTHER.
PREV DISCUSSION... /ISSUED 717 PM CDT MON MAY 25 2015/
AVIATION.../00Z TAFS/
STORMS HAVE CLEARED ALL TAF SITES...BUT WILL INCLUDE VCTS THROUGH
01Z FOR SAT/SSF/AUS IN CASE BACKBUILDING STORMS PRODUCE A ROGUE
LIGHTNING STRIKE. A MESO LOW HAS FORMED BEHIND THIS LINE...WHICH
WILL CAUSE VARIABLE WINDS BELOW 10 KTS AT SAT/SSF/AUS FOR THE NEXT
FEW HOURS...WILL HANDLE THIS WITH AMENDMENTS IF THEY INCREASE
ABOVE 10 KTS. DRY AIR EVIDENT ON WV IMAGERY WILL HELP DRY OUT THE
MID AND UPPER LEVELS...BUT MOIST LOW LEVEL SE FLOW WILL ALLOW VFR
CIGS TO LOWER TO IFR BY 7Z AT SAT/SSF/AUS AND MVFR BY 9Z AT DRT.
MODEL GUIDANCE SUGGESTS LIFR CIGS COULD DEVELOP BETWEEN 10-14Z AT
SAT/SSF/AUS...BUT WILL REEVALUATE THIS WITH THE 06Z TAF PACKAGE.
PREV DISCUSSION... /ISSUED 447 PM CDT MON MAY 25 2015/
SIGNIFICANT FLASH FLOODING ONGOING ACROSS THE NORTHERN AND
CENTRAL PARTS OF SOUTH CENTRAL TEXAS...
SHORT TERM (TODAY THROUGH TUESDAY)...
A STRONG NEGATIVELY TILTED UPPER LEVEL TROUGH HAS CAUSED A
SIGNIFICANT SEVERE WEATHER EVENT THAT HAS ALREADY PRODUCED A FEW
TORNADOES IN THE HILL COUNTRY AND WIDESPREAD FLASH FLOODING IN THE
HILL COUNTRY AND I-35 CORRIDOR IS ONGOING THIS AFTERNOON. A FLASH
FLOOD EMERGENCY HAS ALSO BEEN ISSUED FOR EASTERN WILLIAMSON AND
TRAVIS COUNTIES AFTER 3 TO 5 INCHES OF RAIN FELL IN TWO HOURS. THE
PRIMARY THREAT FOR THE NEXT SEVERAL HOURS WILL CONTINUE TO BE
SIGNIFICANT FLASH AND RIVER FLOODING...WITH THE LATTER CONTINUING
INTO AT LEAST THE OVERNIGHT HOURS. RAINFALL RATES UP TO 4 INCHES
PER HOUR HAVE OCCURRED THIS AFTERNOON...BUT THESE RATES SHOULD
BEGIN TO DECREASE SLIGHTLY AS THESE STORMS CONTINUE TO MERGE INTO
A LINE OVER THE I-35 CORRIDOR FROM THE SAN ANTONIO METRO AND AREAS
NORTH BEFORE PUSHING EAST ACROSS OUR CWA. DRY AIR MOVING IN FROM
THE WEST EVIDENT ON WV IMAGERY SHOULD CONTINUE TO CAUSE PWAT
VALUES TO DECREASE AND END THE HEAVY RAINFALL THREAT FROM WEST TO
EAST AS WE MOVE INTO THE EVENING AND OVERNIGHT HOURS. THUS...THE
FLASH FLOOD WATCH HAS BEEN CANCELLED FOR OUR WESTERNMOST
COUNTIES...BUT CONTINUES FOR THE VAST MAJORITY OF SOUTH CENTRAL
TEXAS THROUGH 1 AM CDT TUESDAY.
ALTHOUGH SHEAR VALUES HAVE DECREASED SLIGHTLY FROM THE 50-55 KT
SEEN EARLIER THIS AFTERNOON IN THE HILL COUNTRY...HELICITY VALUES
ABOVE 200-300 M^2/S^2 AND LOW LCLS ALONG AND EAST OF I-35 WILL
LIKELY CONTINUE THE TORNADO THREAT FOR THIS AREA FOR AT LEAST THE
NEXT FEW HOURS. TORNADOES WILL BE POSSIBLE WITHIN MORE DISCRETE
CELLS WITHIN THE LINE OF STORMS CURRENTLY CENTERED OVER THE I-35
CORRIDOR NORTH OF SAN ANTONIO AND EXPANDING INTO NE TX AND SE
OK. THUS...A TORNADO WATCH CONTINUES UNTIL 10 PM CDT FOR THE
EASTERN HILL COUNTRY...AND ALL COUNTIES ALONG AND NORTH OF THE
I-10 CORRIDOR AND ALONG AND EAST OF THE I-35 CORRIDOR NORTHEAST OF
THE SAN ANTONIO METRO.
DRY AIR WILL GRACIOUSLY FILL INTO THE ENTIRE CWA BY EARLY TUESDAY
MORNING...BUT ANOTHER WEAK SHORTWAVE ROTATING AROUND THE
PERSISTENT LONGWAVE TROUGH TO OUR WEST MAY TRIGGER ISOLATED
THUNDERSTORMS TUESDAY AFTERNOON IN THE SERRENIAS DEL BURRO THAT
MOVE INTO THE RIO GRANDE PLAINS. ELSEWHERE...AMPLE BOUNDARY LAYER
AND SOIL MOISTURE WITH DAYTIME TEMPERATURES RISING INTO THE UPPER
80S MAY STILL ALLOW FOR VERY ISOLATED AFTERNOON SHOWERS AND
THUNDERSTORMS...BUT DRY AIR SHOULD PREVENT DEVELOPMENT. IN
ADDITION...WEAK SHORTWAVE RIDING SHOULD BEGIN TO BUILD IN BY LATE
TUESDAY NIGHT TO LIMIT OUR RAIN CHANCES.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
A BRIEF PERIOD OF SHORTWAVE RIDGING WITH RELATIVELY DRY AIR WILL
CONTINUE THROUGH EARLY THURSDAY...GIVING THE REGION A MUCH NEEDED
BREAK FROM THE HEAVY RAINFALL PATTERN WE HAVE BEEN IN FOR SEVERAL
WEEKS FOR A FEW DAYS. HOWEVER...WILL STILL CARRY ISOLATED
AFTERNOON SHOWERS AND THUNDERSTORMS FOR WEDNESDAY DUE TO AMPLE
BOUNDARY LAYER MOISTURE AND SOIL MOISTURE WITH HIGHS NEARING 90
DEGREES. ANOTHER UPPER LEVEL TROUGH APPROACHES THE REGION ON
THURSDAY TO BREAK DOWN THIS RIDGE...INCREASING THE COVERAGE OF
AFTERNOON SHOWERS AND THUNDERSTORMS...PARTICULARLY IN THE RIO
GRANDE PLAINS. MODELS GENERALLY AGREE THAT THE MAIN ENERGY FROM
THIS UPPER LEVEL TROUGH SHOULD REMAIN TO OUR NORTH...BUT ALSO
SUGGEST THAT IT WILL NOT BE VERY PROGRESSIVE AND STICK AROUND
UNTIL AT LEAST SUNDAY. CONSIDERING THAT A FEW WEAK BOUNDARIES MAY
SLIP INTO THE REGION TO PROVIDE AN ADDITIONAL FOCUS FOR
CONVECTION...RAINFALL CHANCES WILL LIKELY CONTINUE THROUGH FRIDAY
AND THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 73 89 72 84 / 20 20 20 20 30
AUSTIN BERGSTROM INTL AIRPORT 88 73 89 71 86 / 20 20 20 20 30
NEW BRAUNFELS MUNI AIRPORT 88 73 89 73 87 / 20 20 20 20 30
BURNET MUNI AIRPORT 87 72 88 71 84 / 20 20 20 20 30
DEL RIO INTL AIRPORT 91 74 91 73 86 / 20 20 20 30 40
GEORGETOWN MUNI AIRPORT 87 71 88 71 84 / 20 20 20 20 30
HONDO MUNI AIRPORT 87 74 89 73 86 / 20 20 20 20 30
SAN MARCOS MUNI AIRPORT 87 73 89 72 85 / 20 20 20 20 30
LA GRANGE - FAYETTE REGIONAL 88 75 90 74 87 / 20 20 20 20 40
SAN ANTONIO INTL AIRPORT 88 74 89 73 86 / 20 20 20 20 30
STINSON MUNI AIRPORT 88 74 89 74 86 / 20 20 20 20 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING COUNTIES: BASTROP...CALDWELL...DE WITT...FAYETTE...
GONZALES...GUADALUPE...KARNES...LAVACA...LEE...WILSON.
&&
$$
MESOSCALE/AVIATION...TB3
SYNOPTIC/GRIDS...05
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
849 AM PDT TUE MAY 26 2015
.SYNOPSIS...COOLER THAN NORMAL CONDITIONS WILL CONTINUE THROUGH
WEDNESDAY ALONG WITH WIDESPREAD CLOUDS. WARMER CONDITIONS ARE
EXPECTED DURING THE SECOND HALF OF THE WEEK...ESPECIALLY FOR
INLAND AREAS. HOWEVER...COASTAL AREAS WILL SEE ONLY LIMITED
WARMING AS AN ONSHORE FLOW REMAINS IN PLACE.
&&
.DISCUSSION...AS OF 08:36 AM PDT TUESDAY...MORNING DRIZZLE IN MANY
AREAS THIS MORNING WITH A FEW HUNDRETHS OF AN INCH REPORTED AT
VARIOUS SITES. MARINE LAYER ABOUT 3000 FEET DEEP WITH CLOUD
THICKNESS BASED ON SATELLITE DATA AROUND 1000 FEET. WEAK TROF
INLAND CONTINUING TO DISRUPT MARINE LAYER WITH SOME BREAKS IN
CLOUDS IN MONTEREY BAY. ELSEWHERE CLOUDS HAVE PUSHED WELL INLAND
AND ARE QUITE EXTENSIVE. UPDATED SKY GRID FOR TODAY TO BETTER
REFLECT SHORT TERM CONDITIONS.
MORNING TEMPERATURES SIMILAR TO YESTERDAY WITH MOSTLY 50S IN
VALLEYS AND BAY AREA. NOT MUCH CHANGE IN AFTERNOON TEMPERATURES
EXPECTED TODAY...THEN INTERIOR WARMING TREND COMMENCES WEDNESDAY
AS RIDGE BUILDS ALONG COAST AND LOW LATITUDE PACIFIC DISTURBANCE
EJECTS INLAND ACROSS SOUTHERN CALIFORNIA. MAIN IMPACT FROM THE
RIDGING WILL BE A SHALLOWER MARINE LAYER...THOUGH ONSHORE FLOW
WILL CONTINUE WITH COASTAL NW WINDS INCREASING SOMEWHAT. NO OTHER
CHANGES PLANNED TO EARLY MORNING FORECAST PACKAGE AT THIS TIME.
&&
.PREV DISCUSSION...AS OF 3:00 AM TUESDAY...BROKEN RECORD FORECAST THIS
MORNING AS OVERNIGHT SATELLITE ALONG WITH SURFACE OBS INDICATE
WIDESPREAD CLOUDS THROUGH VIRTUALLY ALL OF OUR AREA. FORT ORD
PROFILER ALSO SHOWS LITTLE CHANGE FROM YESTERDAY AND IS AROUND
3000 FEET. WITH A MODERATE WESTERLY FLOW AT THE SURFACE DO NOT SEE
ANY REASON WE WILL DEVIATE MUCH FROM CONDITIONS ON MONDAY. IN
FACT...24 HOUR TEMPERATURE CHANGE RIGHT NOW HAS VIRTUALLY ALL
SPOTS WITHIN A DEGREE. WILL LIKELY SEE CLOUDS AT MANY COASTAL
LOCATIONS HANGING THROUGH THE ENTIRE DAY. HIGHS WILL RANGE FROM
THE MID 50S TO MID 60S AT THE COAST TO MID 60S TO MID 70S FOR MOST
INLAND SPOTS.
FOR TOMORROW A FEW DEGREES OF WARMER IS FORECAST...ESPECIALLY
INLAND...AS A RIDGE OF HIGH PRESSURE STARTS TO BUILD INTO OUR AREA
ALONG WITH SLIGHTLY WARMER TEMPERATURES ALOFT. HOWEVER...A NEARLY
PERSISTENT WESTERLY FLOW AT THE SURFACE COMBINED WITH SST VALUES
IN THE LOWER TO MID 50S WILL KEEP COASTAL SPOTS COOL. EVEN WITH
THE SLIGHT WARMING...ALL PLACES SHOULD STILL BE COOLER THAN
NORMAL. GUIDANCE IS SUGGESTING FEWER CLOUDS BY TOMORROW AFTERNOON
WITH SOME SUNSHINE DOWN TO THE COAST. AFTER MULTIPLE GREY
DAYS...THAT WOULD BE A WELCOME CHANGE FOR MANY PEOPLE.
THE RIDGE WILL CONTINUE TO BUILD TOWARD OUR AREA FOR THURSDAY
THROUGH SATURDAY WHILE 850 MB TEMPS ALSO INCREASE. THIS WILL LEAD
TO A MORE COMPRESSED MARINE LAYER PLUS MUCH WARMER INLAND TEMPS.
STILL NO SIGNS OF AN OFFSHORE WIND EVENT SO COASTAL SPOTS WILL SEE
MUCH LESS WARMING. BY FRIDAY WE WILL LIKELY SEE HIGHS AT THE COAST
MOSTLY IN THE 60S WITH 80S TO LOWER 90S INLAND. IN OTHER WORDS..A
MORE TYPICAL TEMPERATURE GRADIENT FOR THIS TIME OF YEAR.
TEMPERATURES WILL COOL A BIT GOING INTO NEXT WEEK AS AN UPPER
LEVEL LOW MOVES INTO NORTHERN CALIFORNIA. ALL ASSOCIATED RAINFALL
SHOULD BE WELL TO THE NORTH SO THE ONLY EXPECTED IMPACT WILL BE
COOLER TEMPERATURES...ESPECIALLY FOR INLAND SPOTS.
THE FLOW IS FORECAST TO BE PROGRESSIVE ENOUGH TO KICK THE LOW TO
THE EAST WHILE THE RIDGE STARTS TO BUILD BACK IN. LONGER RANGE
GUIDANCE FOR NEXT WEEK DOES SHOW WARMER THAN NORMAL TEMPS RETURNING
TO OUR AREA.
&&
.AVIATION...AS OF 4:45 AM PDT TUESDAY...FOR 12Z TAFS. STRATUS
INTRUSION INLAND ONCE AGAIN THIS MORNING WITH WIDESPREAD MVFR AND
LOCAL IFR CIGS OBSERVED. BOTH RUC AND WRF SHORT TERM GUIDANCE
LEANING TOWARDS EARLIER MIXING OUT OF MARINE DECK THIS MORNING
VERSUS PREVIOUS MORNINGS... WITH SCT POSBL BTWN 18-20Z THIS MORN
AT MANY LOCATIONS. LIGHT TO MODERATE ONSHORE FLOW THROUGH LATE
MORNING AND AFTERNOON WITH A FEW GUSTS UP TO 20 KT POSBL. DRIZZLE
MAY LEAD TO WET RUNWAYS AT COASTAL AIRPORTS THIS MORNING.
VICINITY OF KSFO... MVFR CIGS THROUGH 18 TO 20Z WITH VFR/SCT THIS
AFTERNOON EXPECTED PER LATEST SHORT TERM GUIDANCE. MVFR CIGS
RETURN 03-04Z WED. ONSHORE FLOW AOA 15 KT. SPOTTY DRIZZLE.
KSFO BRIDGE APPROACH...SIMILAR TO TERMINAL...EXCEPT CLEARING FROM
THE SOUTH A BIT EARLIER ON TUESDAY.
MONTEREY BAY AREA TERMINALS... MVFR CIGS WITH BRIEF IFR CIGS AND
SPOTTY DRIZZLE POSBL THIS MORNING. VFR CIGS WITH FEW TO SCT CLOUDS
LATER THIS AFTERNOON.
&&
.MARINE...AS OF 3:00 AM PDT TUESDAY...HIGH PRESSURE OVER THE EXTREME
EASTERN PACIFIC IS LEADING TO PREDOMINATELY GENTLE SEAS AND LIGHT
WINDS. WINDS VEER TOWARDS THE NORTHWEST AND INCREASE FROM MIDWEEK
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: KBB
AVIATION: BLIER
MARINE: DRP
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
439 AM PDT TUE MAY 26 2015
.SYNOPSIS...COOLER THAN NORMAL CONDITIONS WILL CONTINUE THROUGH
WEDNESDAY ALONG WITH WIDESPREAD CLOUDS. WARMER CONDITIONS ARE
EXPECTED DURING THE SECOND HALF OF THE WEEK...ESPECIALLY FOR
INLAND AREAS. HOWEVER...COASTAL AREAS WILL SEE ONLY LIMITED
WARMING AS AN ONSHORE FLOW REMAINS IN PLACE.
&&
.DISCUSSION...AS OF 3:00 AM TUESDAY...BROKEN RECORD FORECAST THIS
MORNING AS OVERNIGHT SATELLITE ALONG WITH SURFACE OBS INDICATE
WIDESPREAD CLOUDS THROUGH VIRTUALLY ALL OF OUR AREA. FORT ORD
PROFILER ALSO SHOWS LITTLE CHANGE FROM YESTERDAY AND IS AROUND
3000 FEET. WITH A MODERATE WESTERLY FLOW AT THE SURFACE DO NOT SEE
ANY REASON WE WILL DEVIATE MUCH FROM CONDITIONS ON MONDAY. IN
FACT...24 HOUR TEMPERATURE CHANGE RIGHT NOW HAS VIRTUALLY ALL
SPOTS WITHIN A DEGREE. WILL LIKELY SEE CLOUDS AT MANY COASTAL
LOCATIONS HANGING THROUGH THE ENTIRE DAY. HIGHS WILL RANGE FROM
THE MID 50S TO MID 60S AT THE COAST TO MID 60S TO MID 70S FOR MOST
INLAND SPOTS.
FOR TOMORROW A FEW DEGREES OF WARMER IS FORECAST...ESPECIALLY
INLAND...AS A RIDGE OF HIGH PRESSURE STARTS TO BUILD INTO OUR AREA
ALONG WITH SLIGHTLY WARMER TEMPERATURES ALOFT. HOWEVER...A NEARLY
PERSISTENT WESTERLY FLOW AT THE SURFACE COMBINED WITH SST VALUES
IN THE LOWER TO MID 50S WILL KEEP COASTAL SPOTS COOL. EVEN WITH
THE SLIGHT WARMING...ALL PLACES SHOULD STILL BE COOLER THAN
NORMAL. GUIDANCE IS SUGGESTING FEWER CLOUDS BY TOMORROW AFTERNOON
WITH SOME SUNSHINE DOWN TO THE COAST. AFTER MULTIPLE GREY
DAYS...THAT WOULD BE A WELCOME CHANGE FOR MANY PEOPLE.
THE RIDGE WILL CONTINUE TO BUILD TOWARD OUR AREA FOR THURSDAY
THROUGH SATURDAY WHILE 850 MB TEMPS ALSO INCREASE. THIS WILL LEAD
TO A MORE COMPRESSED MARINE LAYER PLUS MUCH WARMER INLAND TEMPS.
STILL NO SIGNS OF AN OFFSHORE WIND EVENT SO COASTAL SPOTS WILL SEE
MUCH LESS WARMING. BY FRIDAY WE WILL LIKELY SEE HIGHS AT THE COAST
MOSTLY IN THE 60S WITH 80S TO LOWER 90S INLAND. IN OTHER WORDS..A
MORE TYPICAL TEMPERATURE GRADIENT FOR THIS TIME OF YEAR.
TEMPERATURES WILL COOL A BIT GOING INTO NEXT WEEK AS AN UPPER
LEVEL LOW MOVES INTO NORTHERN CALIFORNIA. ALL ASSOCIATED RAINFALL
SHOULD BE WELL TO THE NORTH SO THE ONLY EXPECTED IMPACT WILL BE
COOLER TEMPERATURES...ESPECIALLY FOR INLAND SPOTS.
THE FLOW IS FORECAST TO BE PROGRESSIVE ENOUGH TO KICK THE LOW TO
THE EAST WHILE THE RIDGE STARTS TO BUILD BACK IN. LONGER RANGE
GUIDANCE FOR NEXT WEEK DOES SHOW WARMER THAN NORMAL TEMPS RETURNING
TO OUR AREA.
&&
.AVIATION...AS OF 4:45 AM PDT TUESDAY...FOR 12Z TAFS. STRATUS
INTRUSION INLAND ONCE AGAIN THIS MORNING WITH WIDESPREAD MVFR AND
LOCAL IFR CIGS OBSERVED. BOTH RUC AND WRF SHORT TERM GUIDANCE
LEANING TOWARDS EARLIER MIXING OUT OF MARINE DECK THIS MORNING
VERSUS PREVIOUS MORNINGS... WITH SCT POSBL BTWN 18-20Z THIS MORN
AT MANY LOCATIONS. LIGHT TO MODERATE ONSHORE FLOW THROUGH LATE
MORNING AND AFTERNOON WITH A FEW GUSTS UP TO 20 KT POSBL. DRIZZLE
MAY LEAD TO WET RUNWAYS AT COASTAL AIRPORTS THIS MORNING.
VICINITY OF KSFO... MVFR CIGS THROUGH 18 TO 20Z WITH VFR/SCT THIS
AFTERNOON EXPECTED PER LATEST SHORT TERM GUIDANCE. MVFR CIGS
RETURN 03-04Z WED. ONSHORE FLOW AOA 15 KT. SPOTTY DRIZZLE.
KSFO BRIDGE APPROACH...SIMILAR TO TERMINAL...EXCEPT CLEARING FROM
THE SOUTH A BIT EARLIER ON TUESDAY.
MONTEREY BAY AREA TERMINALS... MVFR CIGS WITH BRIEF IFR CIGS AND
SPOTTY DRIZZLE POSBL THIS MORNING. VFR CIGS WITH FEW TO SCT CLOUDS
LATER THIS AFTERNOON.
&&
.MARINE...AS OF 3:00 AM PDT TUESDAY...HIGH PRESSURE OVER THE EXTREME
EASTERN PACIFIC IS LEADING TO PREDOMINATELY GENTLE SEAS AND LIGHT
WINDS. WINDS VEER TOWARDS THE NORTHWEST AND INCREASE FROM MIDWEEK
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: BELL
AVIATION: BLIER
MARINE: DRP
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
307 AM PDT TUE MAY 26 2015
.SYNOPSIS...A WARMING TREND WILL OCCUR OVER CENTRAL CALIFORNIA
THROUGH THE END OF THE WEEK...WITH TEMPERATURES BECOMING ABOVE
NORMAL. OTHERWISE...THE REGION WILL REMAIN DRY...EXCEPT OVER THE
SOUTHERN SIERRA NEVADA WHERE AFTERNOON SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE THROUGH THURSDAY.
&&
.DISCUSSION...AMPLIFIED OFFSHORE UPPER RIDGE THAT HAS BEEN SLOWLY
PUSHING INLAND INTO CA IS PROVIDING OUR AREA WITH A NOTICABLE
WARMING TREND AS DAYTIME TEMPERATURES ON MEMORIAL DAY WERE CLOSE
TO SEASONAL NORMALS FOR LATE MAY ACROSS OUR AREA. MEANWHILE...A
WEAK SYSTEM DROPPING THROUGH THE GREAT BASIN OVERNIGHT HAS
PROVIDED FOR INCREASED ONSHORE P-GRADS RESULTING IN SOME LOCALLY
GUSTY WINDS ACROSS THE WEST SIDE OF THE SAN JOAQUIN VALLEY. WITH
GRADIENTS NOW DECREASING...WINDS WILL DECREASE TOWARD MORNING AND
WE THEREFORE DO NOT ANTICIPATE THE ISSUANCE OF ANY WIND HIGHLIGHTS
THIS MORNING...ALTHOUGH LOCAL GUSTS TO NEAR 35 MPH WILL BE
POSSIBLE ALONG THE WEST SIDE OF THE SAN JOAQUIN VALLEY FOR A FEW
MORE HOURS.
06Z WRF INDICATING A DRY NORTHWEST FLOW WILL PREVAIL TODAY OVER
CENTRAL CA KEEPING MOST OF OUR AREA DRY UNDER MAINLY CLEAR SKIES.
THE HRRR IS INDICATING ISOLATED SHOWERS THIS AFTERNOON OVER THE
HIGHER ELEVATIONS OF THE SOUTHERN SIERRA NEVADA AND THE WRF IS
INDICATING CAPES AND LI/S WILL BE SUFFICIENT FOR THUNDERSTORMS
NEAR THE CREST SO SO WILL CONTINUE TO MENTION A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS FOR THE HIGHER ELEVATIONS OF THE
SOUTHERN SIERRA NEVADA FOR THIS AFTERNOON AND EVENING.
IR IMAGERY IS INDICATING AN UPPER LOW CENTER NEAR 31N/132W
WHICH MAY SPREAD SOME HIGH CLOUDS INTO OUR AREA TONIGHT AND
WEDNESDAY AS IT TRACKS EAST OVER NORTHERN BAJA. OTHERWISE THIS
FEATURE WILL HAVE LITTLE IMPACT FOR OUR AREA. THE OFFSHORE RIDGE
IS PROGGED TO PUSH FURTHER INLAND ON WEDNESDAY AND THURSDAY
RESULTING IN RISES IN HEIGHTS AND DIURNAL THICKNESSES OVER OUR
AREA AND SUBSEQUENTLY DAYTIME TEMPERATURES WILL RISE TO ABOVE
NORMAL LEVELS. WRF PROGGED CAPES AND INSTABILITY ARE EXPECTED TO
DECREASE EACH DAY RESULTING IN LESS POTENTIAL FOR DIURNAL
CONVECTION OVER THE HIGHER SIERRA WEDNESDAY AND THURSDAY.
THE MEDIUM RANGE MODELS AND THEIR ENSEMBLE MEMBERS ARE IN FAIRLY
GOOD AGREEMENT WITH THE UPPER RIDGE AXIS MOVING SLOWLY INLAND ON
FRIDAY AND SATURDAY RESULTING IN MUCH ABOVE NORMAL DAYTIME
TEMPERATURES ACROSS OUR AREA WITH SOME LOCATIONS IN THE SAN
JOAQUIN VALLEY AND KERN COUNTY DESERTS REACHING THE CENTURY MARK.
IN ADDITION...WARMING TEMPERATURES ALOFT WILL RESULT IN A
CAPPING INVERSION WHICH WILL SHUT OFF ANY POTENTIAL FOR DIURNAL
CONVECTION IN THE SOUTHERN SIERRA NEVADA BY THE END OF THE WEEK.
A LOW PRESSURE CENTER IS PROGGED TO PUSH INTO THE PAC NW BY NEXT
MONDAY. WHILE THE MOISTURE FROM THIS SYSTEM IS EXPECTED TO REMAIN
WELL TO THE NORTH OF OUR AREA...IT WILL BRING HEIGHT FALLS AND
INCREASED ONSHORE P-GRADS...RESULTING IN A COOLING TREND FOR OUR
AREA EARLY NEXT WEEK ALONG WITH PERIODS OF INCREASED WINDS.
&&
.AVIATION...LOCAL MOUNTAIN OBSCURING IFR CONDITIONS IN SHOWERS
AND ISOLATED THUNDERSTORMS POSSIBLE ACROSS THE SIERRA NEVADA AFTER
18Z TUESDAY AND CONTINUING THROUGH 06Z WEDNESDAY. OTHERWISE...VFR
CONDITIONS WILL PREVAIL DURING THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS HIGH.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 05-26 103:1974 66:1946 68:2014 40:1953
KFAT 05-27 104:1974 55:1971 69:1896 46:1998
KFAT 05-28 107:1984 58:1953 69:2009 45:1927
KBFL 05-26 107:1951 68:1998 72:1979 40:1918
KBFL 05-27 106:1974 66:1971 75:1974 42:1917
KBFL 05-28 107:1973 67:1953 72:2009 43:1906
&&
.HNX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...DS
AVN/FW...DCH
SYNOPSIS...DS
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
948 AM MDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 946 AM MDT TUE MAY 26 2015
UPDATE TO ADJUST SKY COVER OVER THE PLAINS AND POPS. 12Z NAM IS
SHOWING FAIRLY WIDESPREAD PRECIP THIS EVE OVER THE PLAINS.
COVERAGE IS LIKELY OVERDONE BUT IT HAS SUPPORT FROM OTHER MODELS
INCLUDING THE LATEST HRRR. WILL KEEP 20-30 PERCENT POPS OVER THE
PLAINS THIS EVE...SPREADING EWD WITH TIME. ROSE
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM MDT TUE MAY 26 2015
CURRENTLY...H5 RAP ANALYSIS INDICATES THE UPPER SHORTWAVE RIDGE WAS
MOVING INTO THE 4 CORNERS REGION EARLY THIS MORNING...AND AS THE
UPPER LOW WAS SLOWLY PROGRESSING ACROSS NE AND THE
DAKOTAS...ACTIVITY ACROSS THE CWA HAS COME TO AN END. THERE ARE SOME
MID AND HIGH LEVEL CLOUDS LINGERING...AND TEMPS HAVE DROPPED INTO
THE UPPER 30S AND 40S FOR MOST LOCATIONS.
TODAY AND TONIGHT...THE UPPER RIDGE WILL SLIDE ACROSS COLORADO OVER
THE NEXT 24 HRS...ALLOWING FOR WARMER TEMPS AND A BIT LESS
CONVECTIVE ACTIVITY. HOWEVER...HI RES MODELS STILL SHOW CONVECTION
FIRING OVER THE HIGHER TERRAIN BY MIDDAY...INCREASING IN COVERAGE
THROUGH MID-AFTERNOON...THEN TRACKING EAST ACROSS THE PLAINS THROUGH
THE EVENING. LATEST SPC GUIDANCE SHOWS THE AREA UNDER GENERAL
THUNDER...SO ALTHOUGH THERE IS ALWAYS THE CHANCE OF A MARGINALLY
SEVERE STORM THIS AFTN AND EVE...POTENTIAL IS LESS TODAY THAN IT HAS
BEEN THE PAST FEW DAYS. MAIN THREATS OF ANY STORMS TODAY WILL BE
LTG...GUSTY WINDS TO 45 MPH...AND HAIL UP TO 1/2 INCH IN DIAMETER.
LOOK FOR MAX TEMPS TODAY CLIMBING INTO THE MID 60S TO MID 70S FOR
MOST LOCATIONS...AND IN THE 40S AND 50S FOR THE MTS. MOORE
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
...PRECIPITATION CHANCES RAMPING UP AGAIN FOR THURSDAY AND
FRIDAY...
WESTERN U.S. UPPER TROF TRANSLATES EASTWARD ON WEDNESDAY WITH SRN
STREAM ENERGY MOVING INTO DESERT SOUTHWEST WHILE NRN STREAM CLOSED
LOW SETTLES OVER ID/NW WY. MOISTURE INCREASES AGAIN AHEAD OF THE
SRN STREAM TROF WED AFTERNOON WITH SCATTERED THUNDERSTORMS
DEVELOPING OVER THE MOUNTAINS BY AFTERNOON. MEANWHILE...LEE TROF
WILL MIX OUT THE DRY LINE EASTWARD INTO THE SE PLAINS. GFS IS MOST
AGGRESSIVE WITH MIXING OUT THE LOW LEVEL MOISTURE ACROSS THE SE
PLAINS...WITH MOST AREAS IN THE 30S TO LOWER 40S BY LATE
AFTERNOON. NAM12 KEEPS LOW LEVEL FLOW MORE SOUTHEASTERLY ACROSS
THE EASTERN MOST COUNTIES WHICH KEEPS SFC DEW POINTS IN THE MID TO UPPER
50S AND CAPE VALUES AROUND 2000+J/KG NEAR THE CO/KS BORDER. GIVEN
THE TROFFING STILL BACK TO OUR WEST...LEANED MORE TOWARDS THE NAM
SOLN. WITH DEEP LAYER SHEARS RUNNING AROUND 40 KTS ACROSS THE FAR
EASTERN COUNTIES...THERE COULD BE ONE OR TWO SEVERE THUNDERSTORMS
THIS DAY...AND AREA IS OUTLOOKED WITH A SLIGHT RISK.
FOCUS FOR THUNDERSTORMS SHIFTS EASTWARD ACROSS THE PLAINS
WEDNESDAY EVENING WITH SOME POTENTIAL FOR CONVECTION TO HANG ON
PAST MIDNIGHT ACROSS THE FAR EASTERN COUNTIES AS LOW LEVEL JET
STRENGTHENS THEN SHIFTS EASTWARD.
THURSDAY AND FRIDAY LOOKS LIKE ANOTHER WET PERIOD AS UPPER TROF
SLOWLY SHIFTS EASTWARD ACROSS THE AREA. WHILE BRUNT OF THE UPPER
LEVEL ENERGY PASSES TO THE NORTH OF THE AREA...SOUTHERN STREAM
TROF WILL BE EJECTING SHORTWAVE ENERGY ACROSS CO THROUGH THE
PERIOD. PRECIPITABLE WATERS INCREASE FOR BOTH DAYS...AND WITH
DIFFUSE DRY LINE MIXING EASTWARD ACROSS THE EASTERN PLAINS DURING
THE AFTERNOON THIS MAY BE THE FOCUS FOR STRONGER THUNDERSTORMS
DURING THE AFTERNOON AND EVENING HOURS. MOISTURE WILL BE
SUFFICIENT TO RAISE THE RISK OF HEAVY RAINFALL FOR ALL OF THE
FORECAST AREA...AND THERE WILL BE THE POTENTIAL FOR FLASH
FLOODING...ESPECIALLY FOR THE SOUTHEAST MOUNTAINS AND PLAINS WHERE
ANTECEDENT SOIL MOISTURE IS ALREADY HIGH. ALTHOUGH MODELS DIFFER
WITH THE PLACEMENT OF THE HIGHER DEW POINTS TO THE EAST OF THE DRY
LINE...DEW POINTS IN THE MID 50S SHOULD YIELD CAPE VALUES OF
AROUND 2000 J/KG ACROSS THE EASTERN MOST COUNTIES THURS AFTERNOON.
SHEAR LOOKS A LITTLE WEAKER...PROBABLY DUE TO MARGINAL FLOW
ALOFT...BUT CERTAINLY ENOUGH CAPE TO WARRANT AN ISOLATED SEVERE
THREAT FOR PORTIONS OF THE SE PLAINS AGAIN THURSDAY AFTERNOON. LOW
LEVEL JET CRANKS UP ACROSS THE SE PLAINS THURS EVENING WITH
POTENTIAL FOR THUNDERSTORMS TO PERSIST PAST MIDNIGHT ACROSS THE
PLAINS AS A FRONT DROPS SOUTHWARD THOUGH THE REGION. PIKES PEAK
REGION COULD BE ANOTHER FOCAL POINT FOR FLASH FLOOD CONCERNS
THURSDAY AFTERNOON AND EVENING...THOUGH THIS WILL DEPEND ON THE
POSITION AND TIMING OF THIS FRONT. AS THE UPPER TROF SHIFTS
SLOWLY EASTWARD INTO THE NRN/CEN PLAINS FRIDAY/FRI NIGHT...A
DEEPER PUSH OF THE FRONT MOVES THROUGH AND BOTH THE GFS AND ECMWF
LOOK WET AGAIN FOR FRIDAY FOR MOST OF THE DISTRICT...BUT
PARTICULARLY ACROSS THE SE MTS AND PLAINS. FLASH FLOOD THREAT MAY
BE HIGHEST THIS DAY...ESPECIALLY FOR AREAS WHICH GET HIT ON
THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES WITH THE FRONT
ON FRIDAY...SO THERE IS STILL SOME UNCERTAINTY...BUT CONCEPTUALLY
THE RISK FOR FLASH FLOODING WILL BE ELEVATED AGAIN FOR THURSDAY
AND FRIDAY.
SATURDAY LOOKS COOL AND POTENTIALLY CAPPED FOR THE SOUTHEAST
PLAINS THOUGH UPSLOPE FLOW BEHIND THE FRONT SHOULD TRIGGER ANOTHER
ROUND OF SCATTERED THUNDERSTORMS FOR THE SE MTS AND ADJACENT I-25
CORRIDOR. THE MAIN THREAT WILL BE HEAVY RAINFALL AND THE
POTENTIAL FOR LOCALIZED FLASH FLOODING. THERE COULD BE SOME
POCKETS OF SUFFICIENT CAPE ALONG THE EASTERN SLOPES OF THE SE MTS
FOR SOME STRONG TO MARGINALLY SEVERE THUNDERSTORMS...BUT FOR NOW
DEEP LAYER SHEARS DO NOT LOOK TERRIBLY IMPRESSIVE. MAIN THREAT
LOOKS LIKE HEAVY RAIN AND POTENTIALLY FOR MARGINALLY SEVERE HAIL.
A DRYING AND WARMING TREND SETS IN FOR SUNDAY THROUGH EARLY NEXT
WEEK AS ANOTHER SHORT WAVE RIDGE MOVES OVER THE REGION. ANOTHER
TROF ENTERS THE WEST COAST SUNDAY NIGHT/MON...BUT TRACK APPEARS TO
STAY FARTHER OFF TO THE NORTHWEST THIS TIME...WHICH PUTS CO UNDER
RELATIVELY DRY SOUTHWEST FLOW ALOFT THROUGH TUESDAY. THUS GRIDS
WILL CARRY A GENERAL WARMING AND DRYING TREND. -KT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 333 AM MDT TUE MAY 26 2015
GENERALLY VFR CONDITIONS ACROSS THE REGION...INCLUDING THE THREE
MAIN TAF SITES OF KCOS...KPUB AND KALS OVER THE NEXT 24 HRS.
AFTN/EVE CONVECTION BETWEEN 18Z AND 04Z MAY PRODUCE INTERMITTENT
MVFR CONDITIONS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ROSE
SHORT TERM...MOORE
LONG TERM...KT
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
802 AM MDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 759 AM MDT TUE MAY 26 2015
WAVE MOVING ACROSS UTAH AT A DECENT CLOP THIS MORNING. ALREADY
SEEING A FEW NEW SHOWERS DEVELOPING ACROSS PORTIONS OF EASTERN
UTAH AND LATEST HRRR RUN SHOWS ACTIVITY INCREASING IN COVERAGE
FAIRLY QUICKLY BY MIDDAY. HAVE BUMPED POPS UP ACROSS MUCH OF THE
FORECAST AREA THROUGH THIS AFTERNOON. SHOULD SEE A FEW STRONGER
CELLS TODAY WITH HAIL AND HEAVY RAIN EXPECTED.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
A SHORTWAVE RIDGE WILL START THE DAY AS THE CLOSED LOW OVER THE
PACNW VERY SLOWLY STARTS TO DROP TO THE SOUTHEAST. SIMILAR
ATMOSPHERIC CONDITIONS REMAIN IN PLACE THAT HAVE BEEN FOR THE
LAST SEVERAL DAYS...PLENTY OF MOISTURE...DAYTIME HEATING AND
MODEST INSTABILITY. POTENTIAL VORTICITY FIELDS ALSO INDICATING A
WEAK UPPER LEVEL TROUGH WILL MOVE OVER THE AREA WHICH...WITH ALL
THE ABOVE...WILL CAUSE SHOWERS AND STORMS TO FIRE. CONVECTION WILL
BEGIN AROUND NOONTIME WHEN THE FIRST VORT MAX MOVES OVERHEAD FROM
WEST TO EAST THOUGH WIDESPREAD THUNDERSTORMS AND SHOWERS LOOK TO
REACH A MAXIMUM FROM 3PM ONWARDS AS THAT TROUGH APPROACHES FROM
THE WEST. SOME BRIEF HEAVY RAIN...GUSTY WINDS...AND SMALL HAIL
WILL REMAIN THE BIGGEST THREATS. MODELS KEEP PRECIP GOING THROUGH
MIDNIGHT SO FORECAST WILL FOLLOW SUIT THOUGH COVERAGE WILL
DROP...AS IT ALWAYS DOES...AFTER SUNSET. A FEW LINGERING SHOWERS
WILL LIKELY PERSIST AFTER MIDNIGHT.
BY WEDNESDAY...THE CLOSED LOW WILL ONLY HAVE MADE IT AS FAR AS NRN
ID SO EXPECT ANOTHER UNSETTLED DAY OF SHOWERS AND STORMS THOUGH
MODELS HINTING AT SOMEWHAT LESS COVERAGE. ASIDE FROM THAT...THE ONLY
REALLY BIG DIFFERENCE WILL BE TEMPERATURES THAT WILL BE GETTING
CLOSE TO NORMAL THANKS TO CYCLONIC FLOW AROUND THE AREA OF LOW
PRESSURE USHERING IN WARMER AIR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
THE BEGINNING OF JUNE MAY ACTUALLY FEEL LIKE JUNE...BUT THAT IS
STILL A FEW DAYS AWAY AS THE UNSETTLED PATTERN CONTINUES THROUGH
FRIDAY. PROGRESSIVE PATTERN AT A "SNAILS PACE" PREVAILS FOR MUCH
OF THE WEEK...PACIFIC NORTHWEST TROUGH NEEDS ABOUT 2-3 DAYS TO
REACH THE CENTRAL ROCKIES. BEFORE REACHING WYOMING...PACIFIC
NORTHWEST TROUGH SENDS PIECES OF PACIFIC ENERGY STREAMING ACROSS
THE INTERMOUNTAIN WEST INTO COLORADO. THIS HELPS FUEL DIURNAL
CONVECTION ON THURSDAY...AND CONTINUES INTO FRIDAY AS THE UPPER
LOW TRACKS ACROSS SRN WYOMING.
THE DRYING TREND BEGINS SATURDAY AS THE UPPER LOW MOVES DOWNSTREAM.
DRIER DOES NOT NECESSARILY MEAN DRY AS CONVECTIVE POTENTIAL EXISTS
EACH AFTERNOON INTO MONDAY. HOWEVER DESERT SOUTHWEST RIDGING
EXPANDS INTO COLORADO BY NEXT WEEK...RESULTING IN LESS CONVECTIVE
ACTIVITY WITH EACH PASSING DAY. BY NEXT MONDAY...ANY AFTERNOON
SHOWERS/STORMS MAY BE RELEGATED TO THE COLORADO SPINE.
TEMPERATURES BEGIN THEIR SUMMER ASCENT WITH DESERT VALLEYS
REACHING THE MID 80S TO LOWER 90S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 530 AM MDT TUE MAY 26 2015
LOCAL BR MAY EXIST ALONG RIVER/VALLEY BOTTOMS THROUGH 15Z THIS
MORNING (BRIEFLY OBSERVED AT KRIL EARLIER)...BUT ANY FOG WILL
DISSIPATE FAST AS MID LEVEL CLOUDS SPREAD FROM THE WEST.
AFTER 18Z...SCATTERED -SHRA/-TSRA WITH LOCALIZED TSRAGS WILL OCCUR
WITH THUNDERSTORMS IN THE VICINITY OF ALL TAF SITES. CHANCE OF
SHOWERS/STORMS EXIST UNTIL 03Z THIS EVENING...THEN THE SHOWERS
WILL DISSIPATE TONIGHT. PASSING -SHRA/-TSRA WILL BE LOWERING CIGS
TO BELOW ILS BREAKPOINS FOR MOUNTAINS SKI COUNTRY TAF SITES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...TGR
LONG TERM...PF
AVIATION...PF
AREA FORECAST DISCUSSION
NWS PUEBLO CO
425 AM MDT TUE MAY 26 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM MDT TUE MAY 26 2015
CURRENTLY...H5 RAP ANALYSIS INDICATES THE UPPER SHORTWAVE RIDGE WAS
MOVING INTO THE 4 CORNERS REGION EARLY THIS MORNING...AND AS THE
UPPER LOW WAS SLOWLY PROGRESSING ACROSS NE AND THE
DAKOTAS...ACTIVITY ACROSS THE CWA HAS COME TO AN END. THERE ARE SOME
MID AND HIGH LEVEL CLOUDS LINGERING...AND TEMPS HAVE DROPPED INTO
THE UPPER 30S AND 40S FOR MOST LOCATIONS.
TODAY AND TONIGHT...THE UPPER RIDGE WILL SLIDE ACROSS COLORADO OVER
THE NEXT 24 HRS...ALLOWING FOR WARMER TEMPS AND A BIT LESS
CONVECTIVE ACTIVITY. HOWEVER...HI RES MODELS STILL SHOW CONVECTION
FIRING OVER THE HIGHER TERRAIN BY MIDDAY...INCREASING IN COVERAGE
THROUGH MID-AFTERNOON...THEN TRACKING EAST ACROSS THE PLAINS THROUGH
THE EVENING. LATEST SPC GUIDANCE SHOWS THE AREA UNDER GENERAL
THUNDER...SO ALTHOUGH THERE IS ALWAYS THE CHANCE OF A MARGINALLY
SEVERE STORM THIS AFTN AND EVE...POTENTIAL IS LESS TODAY THAN IT HAS
BEEN THE PAST FEW DAYS. MAIN THREATS OF ANY STORMS TODAY WILL BE
LTG...GUSTY WINDS TO 45 MPH...AND HAIL UP TO 1/2 INCH IN DIAMETER.
LOOK FOR MAX TEMPS TODAY CLIMBING INTO THE MID 60S TO MID 70S FOR
MOST LOCATIONS...AND IN THE 40S AND 50S FOR THE MTS. MOORE
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
...PRECIPITATION CHANCES RAMPING UP AGAIN FOR THURSDAY AND
FRIDAY...
WESTERN U.S. UPPER TROF TRANSLATES EASTWARD ON WEDNESDAY WITH SRN
STREAM ENERGY MOVING INTO DESERT SOUTHWEST WHILE NRN STREAM CLOSED
LOW SETTLES OVER ID/NW WY. MOISTURE INCREASES AGAIN AHEAD OF THE
SRN STREAM TROF WED AFTERNOON WITH SCATTERED THUNDERSTORMS
DEVELOPING OVER THE MOUNTAINS BY AFTERNOON. MEANWHILE...LEE TROF
WILL MIX OUT THE DRY LINE EASTWARD INTO THE SE PLAINS. GFS IS MOST
AGGRESSIVE WITH MIXING OUT THE LOW LEVEL MOISTURE ACROSS THE SE
PLAINS...WITH MOST AREAS IN THE 30S TO LOWER 40S BY LATE
AFTERNOON. NAM12 KEEPS LOW LEVEL FLOW MORE SOUTHEASTERLY ACROSS
THE EASTERN MOST COUNTIES WHICH KEEPS SFC DEW POINTS IN THE MID TO UPPER
50S AND CAPE VALUES AROUND 2000+J/KG NEAR THE CO/KS BORDER. GIVEN
THE TROFFING STILL BACK TO OUR WEST...LEANED MORE TOWARDS THE NAM
SOLN. WITH DEEP LAYER SHEARS RUNNING AROUND 40 KTS ACROSS THE FAR
EASTERN COUNTIES...THERE COULD BE ONE OR TWO SEVERE THUNDERSTORMS
THIS DAY...AND AREA IS OUTLOOKED WITH A SLIGHT RISK.
FOCUS FOR THUNDERSTORMS SHIFTS EASTWARD ACROSS THE PLAINS
WEDNESDAY EVENING WITH SOME POTENTIAL FOR CONVECTION TO HANG ON
PAST MIDNIGHT ACROSS THE FAR EASTERN COUNTIES AS LOW LEVEL JET
STRENGTHENS THEN SHIFTS EASTWARD.
THURSDAY AND FRIDAY LOOKS LIKE ANOTHER WET PERIOD AS UPPER TROF
SLOWLY SHIFTS EASTWARD ACROSS THE AREA. WHILE BRUNT OF THE UPPER
LEVEL ENERGY PASSES TO THE NORTH OF THE AREA...SOUTHERN STREAM
TROF WILL BE EJECTING SHORTWAVE ENERGY ACROSS CO THROUGH THE
PERIOD. PRECIPITABLE WATERS INCREASE FOR BOTH DAYS...AND WITH
DIFFUSE DRY LINE MIXING EASTWARD ACROSS THE EASTERN PLAINS DURING
THE AFTERNOON THIS MAY BE THE FOCUS FOR STRONGER THUNDERSTORMS
DURING THE AFTERNOON AND EVENING HOURS. MOISTURE WILL BE
SUFFICIENT TO RAISE THE RISK OF HEAVY RAINFALL FOR ALL OF THE
FORECAST AREA...AND THERE WILL BE THE POTENTIAL FOR FLASH
FLOODING...ESPECIALLY FOR THE SOUTHEAST MOUNTAINS AND PLAINS WHERE
ANTECEDENT SOIL MOISTURE IS ALREADY HIGH. ALTHOUGH MODELS DIFFER
WITH THE PLACEMENT OF THE HIGHER DEW POINTS TO THE EAST OF THE DRY
LINE...DEW POINTS IN THE MID 50S SHOULD YIELD CAPE VALUES OF
AROUND 2000 J/KG ACROSS THE EASTERN MOST COUNTIES THURS AFTERNOON.
SHEAR LOOKS A LITTLE WEAKER...PROBABLY DUE TO MARGINAL FLOW
ALOFT...BUT CERTAINLY ENOUGH CAPE TO WARRANT AN ISOLATED SEVERE
THREAT FOR PORTIONS OF THE SE PLAINS AGAIN THURSDAY AFTERNOON. LOW
LEVEL JET CRANKS UP ACROSS THE SE PLAINS THURS EVENING WITH
POTENTIAL FOR THUNDERSTORMS TO PERSIST PAST MIDNIGHT ACROSS THE
PLAINS AS A FRONT DROPS SOUTHWARD THOUGH THE REGION. PIKES PEAK
REGION COULD BE ANOTHER FOCAL POINT FOR FLASH FLOOD CONCERNS
THURSDAY AFTERNOON AND EVENING...THOUGH THIS WILL DEPEND ON THE
POSITION AND TIMING OF THIS FRONT. AS THE UPPER TROF SHIFTS
SLOWLY EASTWARD INTO THE NRN/CEN PLAINS FRIDAY/FRI NIGHT...A
DEEPER PUSH OF THE FRONT MOVES THROUGH AND BOTH THE GFS AND ECMWF
LOOK WET AGAIN FOR FRIDAY FOR MOST OF THE DISTRICT...BUT
PARTICULARLY ACROSS THE SE MTS AND PLAINS. FLASH FLOOD THREAT MAY
BE HIGHEST THIS DAY...ESPECIALLY FOR AREAS WHICH GET HIT ON
THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES WITH THE FRONT
ON FRIDAY...SO THERE IS STILL SOME UNCERTAINTY...BUT CONCEPTUALLY
THE RISK FOR FLASH FLOODING WILL BE ELEVATED AGAIN FOR THURSDAY
AND FRIDAY.
SATURDAY LOOKS COOL AND POTENTIALLY CAPPED FOR THE SOUTHEAST
PLAINS THOUGH UPSLOPE FLOW BEHIND THE FRONT SHOULD TRIGGER ANOTHER
ROUND OF SCATTERED THUNDERSTORMS FOR THE SE MTS AND ADJACENT I-25
CORRIDOR. THE MAIN THREAT WILL BE HEAVY RAINFALL AND THE
POTENTIAL FOR LOCALIZED FLASH FLOODING. THERE COULD BE SOME
POCKETS OF SUFFICIENT CAPE ALONG THE EASTERN SLOPES OF THE SE MTS
FOR SOME STRONG TO MARGINALLY SEVERE THUNDERSTORMS...BUT FOR NOW
DEEP LAYER SHEARS DO NOT LOOK TERRIBLY IMPRESSIVE. MAIN THREAT
LOOKS LIKE HEAVY RAIN AND POTENTIALLY FOR MARGINALLY SEVERE HAIL.
A DRYING AND WARMING TREND SETS IN FOR SUNDAY THROUGH EARLY NEXT
WEEK AS ANOTHER SHORT WAVE RIDGE MOVES OVER THE REGION. ANOTHER
TROF ENTERS THE WEST COAST SUNDAY NIGHT/MON...BUT TRACK APPEARS TO
STAY FARTHER OFF TO THE NORTHWEST THIS TIME...WHICH PUTS CO UNDER
RELATIVELY DRY SOUTHWEST FLOW ALOFT THROUGH TUESDAY. THUS GRIDS
WILL CARRY A GENERAL WARMING AND DRYING TREND. -KT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 333 AM MDT TUE MAY 26 2015
GENERALLY VFR CONDITIONS ACROSS THE REGION...INCLUDING THE THREE
MAIN TAF SITES OF KCOS...KPUB AND KALS OVER THE NEXT 24 HRS.
AFTN/EVE CONVECTION BETWEEN 18Z AND 04Z MAY PRODUCE INTERMITTENT
MVFR CONDITIONS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MOORE
LONG TERM...KT
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS ALBANY NY
655 AM EDT TUE MAY 26 2015
.SYNOPSIS...
WARM AND HUMID WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY
DURING THE AFTERNOON INTO THE EARLY EVENING THROUGH MID WEEK. SOME
STORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY WILL BE MORE HUMID THAN MONDAY. ONLY SOME MINOR ADJUSTMENTS
WEER MADE THIS MORNING.
THE REGION IS IN A WARM AND HUMID AIRMASS WITH RIDGING ALONG THE
EASTERN SEABOARD. A SHORT WAVE TROUGH WILL MOVE INTO THE WESTERN
GREAT LAKES TODAY WITH THE RIDGE OVER THE NORTHEAST HOLDING
STEADY. GUIDANCE INCLUDING THE MESOSCALE HRRR INDICATE DIURNALLY
DRIVEN CONVECTION SHOULD INITIATE ACROSS THE CENTRAL AND SOUTHERN
PORTION OF THE FORECAST AREA THIS AFTERNOON. WITH PRECIPITABLE
WATER VALUES RISING TO 1.5+ INCHES STORMS WILL BE CAPABLE OF
PRODUCING HEAVY DOWNPOURS.
TODAY WILL BE MORE HUMID THAN MONDAY WITH DEW POINTS IN THE MAINLY
IN THE UPPER 50S TO LOWER 60S. IT WILL BE VERY WARM/HOT WITH HIGHS
IN THE 80S...WITH MID/UPPER 80S UP THE HUDSON VALLEY. ACROSS THE
HIGHER TERRAIN OF THE WESTERN ADIRONDACKS...EASTERN CATSKILLS AND
SOUTHERN GREENS HIGHS SHOULD GET INTO THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
BETTER AND MORE WIDESPREAD CHANCES FOR CONVECTION EXPECTED
WEDNESDAY. THE SHORT WAVE TROUGH WILL MOVE ACROSS THE GREAT LAKES
REGION AND HEIGHTS WILL FALL SOME ACROSS THE NORTHEAST. HOWEVER
LARGE SCALE FORCING WILL REMAIN TO OUR NORTH AS THE RIGHT-REAR
QUADRANT OF THE UPPER LEVEL JET STREAK WILL BE LOCATED OVER
EASTERN CANADA AND MOVING TO THE NORTHEAST. ACROSS THE REGION
WE WILL HAVE DEW POINTS IN THE 60S AND MODEST SOUTHWESTERLY DEEP
LAYER SHEAR SO STRONG STORMS WITH GUSTY WINDS ARE POSSIBLE. THE
STORM PREDICTION CENTER CONTINUES TO KEEP OUR AREA UNDER MARGINAL
RISK FOR SEVERE WEATHER...HOWEVER DOES NOTE THAT IF GREATER
INSTABILITY IS EXPECTED THEN AN UPGRADE TO A SLIGHT RISK MAY BE
NEEDED. CONTINUE TO HAVE MENTION OF STRONG STORMS POSSIBLE FOR
WEDNESDAY IN OUR HAZARDOUS WEATHER OUTLOOK AND ADDED GUSTY WINDS.
HIGH TEMPERATURES SHOULD BE A COUPLE/FEW DEGREES LOWER WEDNESDAY
THAN THURSDAY DUE TO MORE CLOUD COVER AND THE CONVECTION...MID
70S TO MID 80S.
THE SHORT WAVE TROUGH WILL CONTINUE TO PRESS EASTWARD INTO THE
RIDGE WEDNESDAY NIGHT AND THURSDAY SHEARING OUT WITH TIME. ALONG
WITH TROUGH A WEAK COLD FRONTAL BOUNDARY WILL MOVE INTO AND ACROSS
THE REGION THROUGH THURSDAY NIGHT. CHANCES FOR CONVECTION WILL
PERSIST UNTIL THE SHORT WAVE MOVES OFF TO THE EAST AND BOUNDARY
SHIFTS THROUGH BUT DECREASE IN TIME AS THE FEATURES WEAKEN. IT
WILL NOT BE AS HOT OR HUMID THURSDAY HOWEVER ABOVE NORMAL
TEMPERATURES WILL CONTINUE...HIGHS LOWER 70S TO LOWER 80S.
WITH PRECIPITABLE WATER VALUES OF 1.5+ INCHES STORMS WILL BE
CAPABLE OF PRODUCING HEAVY DOWNPOURS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE EXTENDED FORECAST OPENS WITH HIGH PRESSURE BRIEFLY BUILDING
IN OVER ERN NY AND NEW ENGLAND IN THE WAKE OF A WEAK COLD FRONTAL
PASSAGE. THE GFS/ECMWF/CAN GGEM HAVE TRENDED DRIER FOR THIS DAY.
THE FRONTAL BOUNDARY MAY STALL CLOSE ENOUGH TO THE SRN NEW ENGLAND
AND NJ COAST FOR SOME ISOLD-SCT SHOWERS AND THUNDERSTORMS
ESPECIALLY SOUTH OF THE INTERSTATE 90 CORRIDOR. A SLIGHT TO LOW
CHC THREAT WAS KEPT IN FOR THE AFTERNOON TIME FRAME FOR THE FCST
AREA WITH LOW CHANCE POPS SOUTH OF THE CAPITAL REGION. H850 TEMPS
WILL STILL BE IN THE +13C TO +15C RANGE WITH MEAN UPPER RIDING
OVER THE REGION. EXPECT HIGHS IN THE LOWER TO M80S IN THE
VALLEYS...AND M70S TO NEAR 80F OVER THE HILLS AND MTNS. ANY SHOWER
OR THUNDERSTORMS ACTIVITY SHOULD WANE WITH THE LOSS OF THE DIURNAL
HEATING. LOWS WILL BE IN THE 60-65F RANGE IN THE LOWER
ELEVATIONS...AND M50S TO 60F OVER THE HIGHER TERRAIN.
SAT-SUN...A PROGRESSIVE UPPER LEVEL TROUGH WILL BE MOVING ACROSS
CNTRL CANADA...THE UPPER MIDWEST...AND THE GREAT LAKES REGION. BROAD
SW FLOW ALOFT ASSOCIATED WITH THE HIGH AMPLITUDE RIDGE OVER THE EAST
COAST WILL KEEP THE HUMID AIR MASS AROUND FOR THE FIRST HALF OF THE
WEEKEND. THE COLD FRONT WILL BE APPROACHING ON SATURDAY WITH AN
UNSTABLE AIR MASS AHEAD OF IT...ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS IS POSSIBLE. SOME OF THE THUNDERSTORMS COULD BE
STRONG DEPENDING ON THE EXACT AMOUNT OF INSTABILITY AVAILABLE. THE
LATEST GFS HAS SFC DEWPTS WELL INTO THE 60S WITH SBCAPES OF 1000-
2000 J/KG. PWATS INCREASE BACK TO 1.33-1.75 INCHES OVER THE FCST
AREA. SOME HEAVY DOWNPOURS WILL BE LIKELY WITH ANY CONVECTION. WE
EXPECT THE SCT SHOWERS AND THUNDERSTORM TO CONTINUE INTO THE
OVERNIGHT PERIOD AHEAD OF THE FRONT. HIGHS ON SATURDAY WILL BE IN
THE MID AND U80S OVER THE VALLEY AREAS...AND M70S TO L80S IN THE
MTNS. MUCH COOLER TEMPS ARE EXPECTED ON SUNDAY WITH THE FRONTAL
BOUNDARY STALLING NEAR THE REGION. OCCASIONAL SHOWERS AND SOME
ISOLD THUNDERSTORMS MAY LINGER ON THE 2ND HALF OF THE WEEKEND NOW.
HIGHS WILL BE MAINLY IN THE 60S TO L70S OVER THE FCST AREA.
SUN NIGHT TO MONDAY...THE MEDIUM RANGE GUIDANCE DIVERGES ON WHERE
THE FRONT GOES TO START NEXT WEEK. THE ECMWF PUSHES THE FRONT SOUTH
OF THE FCST AREA WITH A 1032 HPA SFC ANTICYCLONE RIDGING IN FROM SRN
QUEBEC. COOLER AND DRIER WEATHER WOULD PREVAIL. THE WPC GUIDANCE
IS STARTING TO LEAN TOWARDS THE ECMWF SCENARIO WITH THE SFC RIDGE
WINNING OUT...AND THE FRONT STALLING NEAR DC AND THE MID ATLANTIC
REGION. THE GFS HAS A SOAKER FOR THE START OF THE WORK WEEK WITH A
WAVE MOVING ALONG THE FRONT...AND A STRONG LOW-LEVEL BAROCLINIC ZONE
BTWN THE WAVE AND SFC HIGH. OVERALL...WE KEPT A LOW CHC OF SHOWERS
IN FOR MOST OF THE AREA SUNDAY NIGHT...AND THEN WENT LOW CHC SOUTH
OF THE CAPITAWARM TEMPERATURES AND INCREASINGLY HUMID CONDITIONS ARE
FORECAST FOR THIS WEEK WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...
ESPECIALLY MID WEEK.
RH VALUES TONIGHT RECOVER BETWEEN 70 AND 90 PERCENT TONIGHT...THEN
EXPECTED TO RANGE BETWEEN 40 AND 60 PERCENT TUESDAY AFTERNOON WITH
VALUES BETWEEN 50 AND 70 PERCENT WEDNESDAY AFTERNOON.
THE BETTER CHANCES FOR THUNDERSTORMS WILL BE DURING THE AFTERNOON
INTO EARLY EVENING HOURS.L REGION ON MONDAY...AND SLIGHT CHC TO THE
NORTH AND WEST. THIS FCST WOULD NEED FINE TUNING IF THE GFS IS
RIGHT. TEMPS WILL BE RUNNING SLIGHTLY BELOW NORMAL TO OPEN THE WEEK.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
ERN NY AND WRN NEW ENGLAND WILL BE IN A WARM SECTOR WITH HIGH
PRESSURE OVER THE WESTERN ATLANTIC OCEAN TODAY INTO TOMORROW. SOME
POP UP ISOLD SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE LATE THIS
AFTERNOON INTO TONIGHT.
MID AND HIGH LEVEL CLOUDS CONTINUE THIS MORNING FOR
KGFL/KALB/KPSF/KPOU WITH VFR CONDITIONS. THE CLOUDS WILL THIN LATE
THIS MORNING WITH MAINLY SOME HIGH CLOUDS AROUND WITH SCT-BKN
CUMULUS FOR THE PM. SOME POP-UP SHOWERS OR THUNDERSTORMS MAY
DEVELOP BY THE MID TO LATE PM IN THE HUMID AIR MASS. VCSH GROUPS
AND CIGS BKN050-060 WERE USED FOR THE TERMINALS.
THE SHOWERS/ISOLD THUNDERSTORMS WILL DIMINISH EARLY THIS EVENING.
THE INCREASED MOISTURE IN THE BOUNDARY LAYER AND ANY LOCATIONS THAT
MAY GET WET...MAY ALLOW FOR SOME PATCHY FOG OR LOW STRATUS TO FORM.
THE BEST CHC FOR AT LEAST MVFR CONDITIONS WILL BE AT KGFL AND KPSF.
CONFIDENCE WAS NOT HIGH ENOUGH TO PLACE PROB30 OR TEMPO GROUPS IN
FOR THUNDERSTORMS THIS AFTERNOON.
THE WINDS WILL BE FROM SOUTH AT 5-12 KTS THIS MORNING WITH SOME
GUSTS AROUND 20 KTS AT KALB/KPSF. THE WINDS WILL CONTINUE FROM THE
S TO SW AT 10-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KALB/KPSF IN
THE AFTERNOON. EXPECT THE WINDS TO DECREASE TO LESS THAN 10 KTS
TONIGHT.
OUTLOOK...
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA. THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE
OF SHRA. FRIDAY TO FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT
CHANCE OF SHRA...TSRA. SATURDAY: MODERATE OPERATIONAL IMPACT.
CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
WARM AND HUMID WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY
DURING THE AFTERNOON INTO THE EARLY EVENING.
MINIMUM RH VALUES THIS AFTERNOON WILL BE IN THE LOWER 40S TO LOWER
50S...WITH MINIMUMS WEDNESDAY AND THURSDAY AFTERNOONS IN THE 50S.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS EXPECTED THIS WEEK...HOWEVER
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS.
THE U.S. DROUGHT MONITOR HAS MUCH OF EASTERN NEW YORK AND WESTERN
NEW ENGLAND IN THE D1 CATEGORY...WHICH IS CONSIDERED MODERATE
DROUGHT AT THIS TIME.
WARM AND HUMID WITH CHANCES FOR SHOWERS AND THUNDERSTORMS...MAINLY
DURING THE AFTERNOON INTO THE EARLY EVENING. THE BETTER AND MORE
WIDESPREAD CHANCES ARE EXPECTED WEDNESDAY AFTERNOON INT0 THE EVENING.
PRECIPITABLE WATER VALUES OF 1.5+ INCHES ARE EXPECTED SO STORMS WILL
BE CAPABLE OF PRODUCING HEAVY DOWNPOURS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MIAMI FL
914 AM EDT TUE MAY 26 2015
.UPDATE...
ISOLATED SHOWERS WILL CONTINUE TO MOVE ONSHORE ALONG THE EAST
COAST THROUGH THE MORNING HOURS. THE LATEST HRRR SHOWING THE
COVERAGE WILL SLOWLY TRANSITION TO THE INTERIOR AND GULF COAST
FROM LATE MORNING THROUGH EARLY AFTERNOON. WHILE MOST WILL LIKELY
REMAIN AS SHOWERS, THERE IS A POSSIBILITY A FEW COULD DEVELOP
INTO A THUNDERSTORM, MAINLY NEAR THE GULF COAST. OTHERWISE, TODAY
LOOKS TO BE FAIRLY QUIET WEATHER WISE. ALSO, WITH THE WEAK SHOWERS
ALONG THE ATLANTIC COAST, THERE WILL BE A SLIGHT POSSIBILITY OF A
BRIEF WATERSPOUT. HOWEVER, ANY SPOUTS THAT DO FORM ARE EXPECTED
TO BE WEAK TODAY.
&&
.PREV DISCUSSION... /ISSUED 743 AM EDT TUE MAY 26 2015/
AVIATION...
DRIER LOW/MID LEVEL AIR WILL MOVE INTO THE REGION LATE THIS
MORNING THROUGH THE AFTERNOON HOURS. THIS SHOULD LEAD TO LOWER
CHANCES OF RAIN ACROSS THE REGION AFTER THE MORNING. EASTERLY FLOW
10-15 KNOTS WITH HIGHER GUSTS WILL PREVAIL THROUGH THE DAY...WITH
SLIGHTLY LOWER SPEEDS OVERNIGHT. SCATTERED SHOWERS AND STORMS ARE
POSSIBLE NEAR KAPF AFTER 18Z. MAINLY VFR CONDITIONS WILL
PREVAIL...BUT BRIEF MVFR CIGS AROUND 2.5KFT ARE POSSIBLE.
PREV DISCUSSION... /ISSUED 334 AM EDT TUE MAY 26 2015/
.HIGH RISK OF RIP CURRENTS EAST COAST BEACHES THROUGH EARLY
THURSDAY MORNING...
SHORT TERM...
STRONG HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC WATERS
TODAY INTO WEDNESDAY...AS A TROUGH OF LOW PRESSURE REMAINS OVER
THE CENTRAL UNITED STATES. THIS WILL ALLOW FOR THE BREEZY EASTERLY
WIND FLOW TO REMAIN OVER SOUTH FLORIDA...AND ALLOW FOR THE VERY
DRY AIR OVER THE WESTERN ATLANTIC WATERS TO BUILD INTO SOUTH
FLORIDA STARTING THIS AFTERNOON INTO WEDNESDAY.
THE SHORT RANGE MODELS ARE FORECASTING THE PWAT VALUES TO FALL
DOWN TO AROUND 1 INCH BY WEDNESDAY WHICH WILL BE CLOSE THE THE
MINIMUM PWAT VALUES FOR THIS TIME OF YEAR WHICH ARE IN THE 0.85
TO 0.95 INCH RANGE. THIS MEANS THAT THE ISOLATED SHOWERS THAT BEEN
GOING ON EARLY THIS MORNING OVER THE THE EAST COAST METRO AREAS
AND THE ADJACENT COASTAL WATERS SHOULD COME TO AND END BY THIS
AFTERNOON. REST OF SOUTH FLORIDA SHOULD ALSO REMAIN DRY
TODAY...EXCEPT FOR A FEW SHOWERS AND POSSIBILITY OF A THUNDERSTORM
OVER THE WEST COAST METRO AREAS THIS AFTERNOON WHERE THE EAST
COAST SEA BREEZE MEETS THE WEST COAST SEA BREEZE. THE WEATHER WILL
THEN REMAIN DRY TONIGHT INTO WEDNESDAY OVER MOST OF SOUTH
FLORIDA...EXCEPT FOR THE WEST COAST METRO AREAS WHERE A SHOWER
COULD DEVELOP IN THE AFTERNOON HOURS.
NAPLES COULD GET UP TO NEAR THE RECORD HIGH TODAY WHICH IS 93
DEGREES SET BACK IN 1989. THEREFORE...NEAR RECORD HIGHS WILL BE
MENTION IN THE FORECAST FOR THE NAPLES AREA TODAY.
THE STRONG HIGH WILL START TO BREAK DOWN LATE THIS WEEK OVER THE
WESTERN ATLANTIC WATERS...AS THE TROUGH OF LOW PRESSURE REMAINS
OVER CENTRAL UNITED STATES. THIS WILL ALLOW FOR THE BREEZY
EASTERLY WIND FLOW TO RELAX OVER SOUTH FLORIDA LATE THIS
WEEK...AND ALLOW FOR SOME MOISTURE TO WORK BACK INTO SOUTH
FLORIDA. THEREFORE...THURSDAY SHOULD BE ANOTHER MOSTLY DRY DAY
OVER SOUTH FLORIDA BEFORE SOME SHOWERS AND THUNDERSTORMS RETURN TO
THE AREA ON FRIDAY WITH THE BEST COVERAGE OVER THE INTERIOR AND
WEST COAST METRO AREAS.
LONG TERM...
THE HIGH WILL CONTINUE TO WEAKEN OVER THE WESTERN ATLANTIC WATERS
THIS WEEKEND...AS THE TROUGH OF LOW PRESSURE STARTS TO MOVE EAST
INTO THE TENNESSEE VALLEY REGION. THIS WILL KEEP THE EASTERLY
WIND FLOW OVER SOUTH FLORIDA, BUT ALLOW FOR MORE DEEPER TROPICAL
MOISTURE TO WORK INTO THE AREA. THEREFORE...SOUTH FLORIDA WILL SEE
MORE SCATTERED SHOWERS AND THUNDERSTORMS THIS WEEKEND WITH THE
BEST COVERAGE OVER THE WESTERN AREAS.
MARINE...
THE WINDS WILL BE EASTERLY THIS WEEK INTO THIS WEEKEND...AS THE
SPEEDS DECREASE FROM BREEZY CONDITIONS TODAY DOWN TO LESS THAN 15
KNOTS BY LATE THIS WEEK INTO THIS WEEKEND. THIS WILL KEEP THE HIGH
RISK OF RIP CURRENTS GOING ALONG THE EAST COAST BEACHES OF SOUTH
FLORIDA TODAY INTO AT LEAST WEDNESDAY NIGHT. THEREFORE...THE HIGH
RISK OF RIP CURRENTS HAVE BEEN EXTENDED UNTIL EARLY THURSDAY
MORNING FOR THE EAST COAST BEACHES OF SOUTH FLORIDA. THE SCEC WILL
ALSO CONTINUE FOR THE GULF...ATLANTIC...AND BISCAYNE BAY WATERS
TODAY INTO TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 76 89 76 / 20 10 10 10
FORT LAUDERDALE 88 78 88 78 / 20 10 10 10
MIAMI 89 77 89 77 / 20 10 10 10
NAPLES 93 73 92 71 / 30 20 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH LATE WEDNESDAY NIGHT FOR FLZ168-
172-173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...13/SI
LONG TERM....54/BNB
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1050 AM CDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 1038 AM CDT TUE MAY 26 2015
MADE A FEW UPDATES TO POPS/WEATHER AND HOURLY TEMPS FOR TODAY
BASED ON TRENDS OF CURRENT CONVECTION MOVING THROUGH CENTRAL IL
LATE THIS MORNING INTO EAST CENTRAL IL BY THE NOON HOUR. A GENERAL
WEAKENING TREND HAS BEEN NOTED THE PAST HOUR, SO ONLY A BRIEF
HEAVY DOWNPOUR IS ANTICIPATED WITH THE LINE OF SHOWERS-ISOLATED
THUNDERSTORMS.
A VERY BRIEF PERIOD OF PARTIAL CLEARING IS ANTICIPATED AFTER THE
SHOWERS MOVE THROUGH, WHICH MAY HELP TO SLIGHTLY INCREASE THE
INSTABILITY IN CENTRAL AND EASTERN IL THIS AFTERNOON. HOWEVER,
SATELLITE IS SHOWING THAT CUMULUS WILL MOST LIKELY RAPIDLY FILL
IN. THE HRRR, NAM12 AND RAP ALL SEEM TO HAVE A FAIRLY GOOD HANDLE
ON THE WEAKENING TREND OF THE LINE OF CONVECTION, WITH SCATTERED
SHOWERS AND THUNDERSTORMS REDEVELOPING THIS AFTERNOON. A SHORTWAVE
TROUGH MOVING NORTHEAST FROM THE OZARKS WILL PROVIDE UPPER LEVEL
SUPPORT TO SOUTHEAST AND EAST CENTRAL IL, BUT INSTABILITY WILL BE
MARGINAL AT BEST. THUS, STRONG/SEVERE STORMS SHOULD BE QUITE
LIMITED IN COVERAGE, IF THEY DEVELOP AT ALL.
&&
.SHORT TERM...(TODAY)
ISSUED AT 343 AM CDT TUE MAY 26 2015
LOW CLOUDS HAVE BEEN ADVECTING INTO THE AREA AND WILL REMAIN OVER
THE AREA THIS MORNING. LOWER CLOUDS INDICATING LOTS OF LOW LEVEL
MOISTURE BEING ADVECTED INTO THE AREA AHEAD OF THE WEATHER SYSTEM
THAT STILL IS WEST OF THE CWA. RADAR AND SATELLITE LOOPS SHOW
SEVERAL MCVS WEST OF THE AREA WITH SOME SHOWERS MOVING NORTH THROUGH
SOUTHEASTERN MO. MODELS CONTINUE TO INDICATE PCPN REDEVELOPING
TODAY. CLOUDS WILL LIMIT THE DEGREE OF INSTABILITY BUT STILL
EXPECTING ENOUGH FOR THUNDERSTORMS, JUST NOT ENOUGH FOR ANYTHING
SEVERE, WHICH SHOULD BE EAST AND SOUTHEAST OF THE AREA WHERE LESS
CLOUDS WILL BE. CLOUD COVER WILL ALSO TEMPER WARM UP AS WELL SO ONLY
EXPECTING UPPER 70S FOR HIGHS WHICH IS MUCH LESS THAN PAST TWO DAYS.
POPS WILL BE A GRADUAL INCREASE TODAY REACHING LIKELY LATER THIS
MORNING AND THEN MOVING NORTH AND EAST THIS AFTERNOON, BECOMING
CHANCE CATEGORY BY LATE AFTERNOON AS THE PCPN MOVES EAST OF THE
AREA. SOUTHERLY WINDS WILL BE A TAD GUSTY AGAIN, JUST NOT AS MUCH AS
YESTERDAY.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 343 AM CDT TUE MAY 26 2015
UNTIL THE UPPER WAVE PULLS INTO THE GREAT LAKES REGION, LINGERING
POPS WILL REMAIN OVER THE FA FOR THIS EVENING. BETTER CHANCES WILL
REMAIN TO THE EAST OVERNIGHT. REMAINS OF THE FRONT WILL STALL OUT
ALONG THE OHIO RIVER VALLEY AND PROVIDE A BIT OF FOCUS FOR ANOTHER
PIECE OF ENERGY EJECTING OUT OF THE SOUTHWEST. MODELS DIFFERING
WITH THE NORTHERLY EXTENT OF THE PRECIP, BUT LAST FEW RUNS BRINGING
IN SOME PRECIPITATION FOR WEDNESDAY IN THE SOUTHEAST. NAM IS A
LITTLE MORE WIDESPREAD, BUT CONCENTRATING THE POPS TO THE SOUTH AND
EAST FOR NOW. TIMING ISSUES REMAIN IN PLACE FOR THIS SYNOPTIC RUN
FOR THE NEXT SYSTEM QUICK ON THE HEELS AS THE DEEP WAVE OVER THE SW
STARTS TO MOVE OUT INTO THE PLAINS. CONVECTION AND PRECIP STARTS TO
SPREAD OVER THE EASTERN HALF OF THE COUNTRY IN THE MODELS WITH WEAK
SOUTHWESTERLY FLOW ALOFT SHIFTING TO WEAK FLOW OVERALL. WARM AND
MUGGY CONDITIONS CONTINUE IN A MORE SUMMERLIKE AIRMASS THROUGHOUT
THE WEEK...BUT THAT NEXT SYSTEM WILL BRING A COLD FRONT INTO THE
REGION FOR THE FIRST HALF OF THE WEEKEND TO FOCUS THE RAIN, WITH A
COOLER AIRMASS BEHIND IT DROPPING THE TEMPS FOR THE WEEKEND OUT OF
THE 80S FOR A COUPLE DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 708 AM CDT TUE MAY 26 2015
LOW STRATUS HAS OVERSPREAD ALL TAF SITES THIS MORNING. THIS LOW
STRATUS LOOKS TO REMAIN OVER ALL SITES UNTIL SOMETIME THIS
AFTERNOON AFTER A NARROW BAND OF SHOWERS MOVES THROUGH THE AREA.
SPI IS THE ONLY ONE AT MVFR STATUS RIGHT NOW. ALL OTHER TAF SITES
ARE MVFR. BY THIS AFTERNOON ALL SITES SHOULD BE MVFR WITH HIGHER
CIGS AROUND 2.5KFT. SHOWERS WILL BE POSSIBLE THIS MORNING AS RADAR
LOOPS SHOWS. THEN HAS THE DAY HEATS UP THUNDERSTORMS WILL BE
POSSIBLE. WILL GO WITH VCTS FOR NOW GIVEN UNCERTAINTY OF LOCATION
OF ANY THUNDERSTORMS. THESE SHOULD END SOMETIME EARLY THIS
EVENING. SKIES SHOULD THEN BE VFR AS THE AREA SHOULD BE WELL IN
THE WARM SECTOR. THERE COULD BE MORE PCPN OVERNIGHT TONIGHT...BUT
LOTS OF UNCERTAINTY THERE SO WILL NOT INCLUDE AT THIS TIME. WINDS
WILL BECOME SOUTHERLY WITH SOME GUSTINESS THIS AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1028 AM CDT TUE MAY 26 2015
.UPDATE...
1007 AM CDT
A SFC LOW IS OVER IOWA AND ITS WARM/STATIONARY FRONT IS WELL TO
OUR NORTH OVER CENTRAL WI. ITS COLD FRONT STRETCHES FROM THE LOW
THROUGH CENTRAL KANSAS. AN AREA OF MAINLY RAIN AND A FEW
THUNDERSTORMS IS SLOWLY SPREADING NNE ACROSS NORTH CENTRAL IL. SO
FAR THE SHOWERS HAVE BEEN BEHAVING ACROSS MY CWA...BUT A FEW CELLS
TO THE WEST HAVE SHOWN SIGNS OF ROTATION.
LIKING THE LATEST RAP GUIDANCE WHICH KEEPS CAPE VALUES ON THE LOW
SIDE WITH ONLY A FEW HUNDREDS J/KG OF CAPE TO WORK WITH. THIS IS
ASSUMING SKIES STAY OVERCAST...AND THINKING WE WILL BE OVERCAST
TODAY. THAT BEING SAID...ANY LOCATIONS THAT SEE SUNSHINE COULD
DEVELOP ENOUGH CAPE TO SUPPORT TALLER CELLS AND POSSIBLY SEVERE
WEATHER. IN GENERAL THINKING DAMAGING WINDS AND AN ISOLATED
TORNADO ARE THE MAIN THREATS...BUT STRONGER STORMS WITH HIGHER
CAPE VALUES COULD SUPPORT HAIL. RADAR IMAGERY IS SHOWING GRAVITY
WAVE TAGS MOVING ALONG THE LINE OF STORMS AND WHEN THE TAGS
INTERSECT THE LINE...STORMS BEGIN TO SPIN. THEREFORE THE TORNADO
THREAT IS NOT ZERO.
THIS FIRST BATCH OF PRECIP WILL PUSH EAST THROUGH THE EARLY AFTN
HOURS AND EXPECTING ADDITIONAL SCATTERED TO NUMEROUS THUNDERSTORMS
DEVELOPMENT BEHIND THE LINE OVER NORTH CENTRAL IL. THE SECOND
WAVE SHIFTS EAST THROUGH THE EARLY EVENING HOURS. PWAT VALUES ARE
1.2-1.5 INCHES SO HEAVY DOWNPOURS ARE PSBL.
JEE
&&
.SHORT TERM...
319 AM CDT
THROUGH TUESDAY NIGHT...
FOR THE REMAINDER OF THE OVERNIGHT HOURS...CONDITIONS WILL REMAIN
QUIET ACROSS THE CWA AS A SERIES OF SHORT WAVES CONTINUE TO TRACK
NORTH AROUND THE TOP OF A PERSISTENT UPPER LEVEL RIDGE WHICH EXTENDS
FROM THE SERN CONUS THROUGH THE UPPER MISSISSIPPI VALLEY. THIS
UPPER RIDGE HAS BEEN THE FEATURE WHICH HAS CONTROLLED THE PATH OF
THE SERIES OF SHORTWAVES LIFTING OUT OF THE SOUTHERN PLAINS...AND
WILL CONTINUE TO DO SO THROUGH THE DAY TODAY. SLY...MODERATELY
STRONG...WINDS WILL PERSIST THROUGH THE NIGHT...AND MUCH OF THE DAY
ALLOWING FOR SFC DEWPOINTS TO REMAIN CONSISTENT OR POSSIBLE INCH A
LITTLE HIGHER.
MAIN CONCERN FOR THE MORNING HOURS WILL BE THE TRACK OF A STRONG
SHORT WAVE AND ASSOCIATED SFC LOW LIFTING NORTHWARD THROUGH THE
MIDDLE MISSISSIPPI VALLEY. THIS FEATURE WILL PREDOMINANTLY IMPACT
ERN IOWA AND WRN IL BY ARND DAYBREAK. THROUGH THE MORNING...THE
COMBINATION OF ISENTROPIC LIFT IN THE WARM SECTOR OF THE
SYSTEM...ALL OF IL AND INTO NWRN IN...WILL LEAD TO SOME
DESTABILIZATION ACROSS THE REGION. A SFC TROUGH...AS WELL INDICATED
BY THE LATEST HIGH RES GUIDANCE...WITH LIFT THROUGH NRN IL/IN
THROUGH THE DAY...COINCIDENT WITH A STRONG SSWLY LOW LEVEL JET OF 45-
50 KT...WITH PROVIDE THE POTENTIAL FOR SHOWERS AND STRONG TO SEVERE
THUNDERSTORMS ACROSS THE CWA. BASED ON WIND PROFILES AND MID LEVEL
DRYING...THE PRIMARY CONCERN WITH REGARD TO SEVERE WEATHER WILL BE
STRONG WIND GUSTS. HOWEVER...SOME OF THE HIGH RES SFC WIND GUIDANCE
SUGGEST SOME SLIGHT BACKING OF SFC WINDS FROM 180-190 DEGREES TO 160-
170 DEGREES...WHILE WINDS ALOFT REMAIN SWLY. THIS SLIGHT BACKING OF
THE SFC WINDS COULD PROVIDE ENOUGH DIRECTIONAL SHEAR THROUGH THE
LOWER LEVELS TO BRING AN ISOLD TORNADO THREAT. LOCALLY HEAVY
RAINFALL WILL ALSO BE CONCERNED WITH PWATS REACHING 1.75 INCHES
LATER THIS MORNING. HOWEVER...FLOODING WILL LIKELY NOT BE A
SIGNIFICANT CONCERN AS THE SWLY WINDS RIGHT OFF THE DECK WILL RANGE
FROM ARND 45 KT ABOVE THE BOUNDARY LAYER TO ARND 90KT AT UPPER
LEVELS WHICH SHOULD ALLOW ANY OF THE STRONGER STORMS THAT DO DEVELOP
TO MOVE QUICKLY.
BY EARLY AFTERNOON...THE MAIN SHORT WAVE WILL LIFT INTO WISCONSIN
WHILE A SFC TROUGH TRACKS EAST ACROSS THE AREA. THIS WILL LEAD TO
WINDS AT THE SFC VEERING TO SWLY...SETTING UP A UNIDIRECTIONAL WIND
PROFILE...EFFECTIVELY MINIMIZING THE SEVERE WEATHER THREAT TO THE
REGION. BY LATE AFTERNOON AND INTO THE EVENING THE MODELS ARE
ADVERTISING THAT A DRY SLOW SHOULD NOSE INTO NRN IL...EFFECTIVELY
CUTTING OFF THE PCPN AREA INTO 2 SEPARATE AREA...ONE OVER WISCONSIN
AND ERN IOWA AND ANOTHER MORE FOCUSED OVER INDIANA. THE NWRN
INDIANA COUNTIES WILL STILL HAVE A CHANCE FOR SOME SHOWERS AND
THUNDERSTORMS INTO THE EVENING...WHILE PCPN CHANCES OVER NRN IL
BEGIN TO WANE. MUCH OF THE MODEL GUIDANCE ALSO INDICATED THAT THE
SHORTWAVE SHOULD SLOW IT`S PROGRESSION THROUGH WISCONSIN AS IT
APPROACHES THE APEX OF THE UPPER RIDGE. AN ASSOCIATED SFC
TROUGH/COLD FRONT EXTENDING SOUTHWEST FROM THE SFC LOW WILL LINGER
OVER ERN IOWA IN THE EARLY EVENING BEFORE STEADILY PUSHING ACROSS
NRN IL AND INTO NWRN IN OVERNIGHT. THROUGH THE NIGHT...THE
STRONGEST UPPER LEVEL FORCING WILL BE WELL NORTH OF THE CWA...SO ANY
LINGERING CHANCES FOR PCPN OVERNIGHT WILL BE LOW AND LIKELY CONFINED
TO THE NRN TIER COUNTIES OF IL...ALONG THE WI BORDER.
KREIN
&&
.LONG TERM...
229 AM CDT
WEDNESDAY THROUGH MONDAY...
WEDNESDAY THROUGH THURSDAY...
OPEN 500MB WAVE WILL BE LIFTING NORTHEAST ACROSS THE UPPER MIDWEST
INTO ONTARIO AND EVENTUALLY QUEBEC...WITH HEIGHTS SLOWLY INCREASING
WED AFTN. SFC FEATURES REMAIN DISORGANIZED WED...WITH A BOUNDARY
SLOWLY SHIFTING EAST. OPER GUIDANCE DIFFERS ON HOW QUICKLY PRECIP
WILL DEPART THE REGION. ENSEMBLE DATA SUGGESTS HOLDING ONTO CHC TO
SLIGHT CHC POPS MAINLY FOR THE CENTRAL/EASTERN CWFA WED/WED EVE.
ALTHOUGH WITH SOME HINT OF SFC HEIGHTS NUDGING UP...IT IS POSSIBLE
THAT SOME DRY AIR COULD FILTER IN AND KICK PRECIP EAST BY MIDDAY AND
ALLOW FOR A MAINLY DRY WED. SFC WINDS WILL BE TURNING SOUTHWEST TO
WEST...KEEPING AN OFFSHORE FLOW FOR LOCATIONS CLOSE TO LAKE
MICHIGAN. TEMPS SHOULD YET AGAIN TOUCH UPR 70S TO ARND 80 WED...IF
CLOUDS AND PRECIP CAN PUSH EAST BY MIDDAY...SOME CLEARING WOULD
ALLOW SFC TEMPS TO PUSH A COUPLE DEGREES WARMER INTO THE LOW 80S IN
SOME LOCATIONS. LATE IN THE EVENING THE GRADIENT SLACKENS
FURTHER...AND COULD ALLOW A LATE DAY ONSHORE FLOW TO DEVELOP FOR
AREAS ADJACENT TO LAKE MICHIGAN.
MID-LVL FLOW BEGINS TO FLATTEN AS A WEAK SFC RIDGE BECOMES ORIENTED
FROM WESTERN QUEBEC SOUTH THROUGH THE EASTERN OHIO RIVER VALLEY.
THIS WILL GENERALLY ALLOW A SOUTHERLY FLOW...ALTHOUGH THE GRADIENT
IS NOT VERY STRONG. THIS SHOULD SET THE STAGE FOR A LAKE
BREEZE/ONSHORE FLOW TO DEVELOP THUR. TIMING COULD END UP BEING
SLIGHTLY EARLIER GIVEN THE LIGHT SFC GRADIENT. GUIDANCE HAS BEEN
CONSISTENT IN HOLDING PRECIP WEST/SOUTH OF THE FORECAST AREA
THUR...AS A RESULT OF THE WEAK SFC RIDGING. SO ONE MORE MILD DAY
WITH HIGHS WARMING BACK INTO THE UPR 70S/LOW 80S...HOWEVER AS
PREVIOUSLY NOTED...A LAKE BREEZE IS LIKELY TO DEVELOP. THIS WILL
BLEED THE MUCH COOLER MARINE AIR WEST ACROSS NORTHEAST IL AND
DOWNTOWN CHICAGO. IF THE TIMING IS EARLIER IN THE DAY THUR...TEMPS
MAY NOT WARM BEYOND THE LOW/MID 60S ALONG THE CHICAGO LAKEFRONT.
FLOW THEN TURNS SOUTHERLY THUR NIGHT WITH THE MORE PROGRESSIVE FLOW
IN THE MID-LVLS PUSHING THE RIDGING EAST. A RETURN FLOW MOISTURE
WILL CONTINUE TO BE FOCUSED ACROSS THE CENTRAL CONUS THUR EVE...WITH
A SLOW MOVING FRONTAL BOUNDARY NUDGING EAST THUR NIGHT TOWARDS
WESTERN IL. THIS FRONTAL BOUNDARY WILL BECOME ENERGIZED AS A ROBUST
500MB VORT MAX BREAKS SOUTH FROM CENTRAL CANADA LATE THUR NIGHT.
THIS SHOULD ALLOW FOR AN ATMOSPHERIC RIVER TO DEVELOP FROM THE
SOUTHERN PLAINS STRETCHING NORTH THROUGH THE MID-MISSOURI VALLEY
INTO THE WESTERN GREAT LAKES EARLY FRI MORNING.
FRIDAY THROUGH EARLY NEXT WEEK...
ENSEMBLES CONTINUE TO PROG A ROBUST TROUGH SLIDING SOUTH FROM
CENTRAL CANADA FRI. THIS COUPLED WITH DOWNSTREAM MID-LVL RIDGING
ACROSS THE SOUTHEAST CONUS WILL STRENGTHEN THE FRONTAL BOUNDARY
THAT WILL BE ORIENTED FROM THE SOUTHERN PLAINS STRETCHING
NORTHEAST THROUGH THE GREAT LAKES REGION INTO WESTERN QUEBEC.
THIS SETUP IS IDEAL FOR THE DEVELOPMENT OF AN ATMOSPHERIC RIVER WITH
ABUNDANT LOW LEVEL MOISTURE AND EFFICIENT PRECIP PRODUCING
CONVECTION.
OPER GUIDANCE HAS BEEN RELATIVELY CONSISTENT WITH BRINGING A SERIES
OF WAVES ALONG THE SLOW MOVING FRONTAL BOUNDARY FRI AFTN/EVE...THEN
THE BOUNDARY SHOULD SLIDE EAST WITH WINDS QUICKLY VEERING
NORTH/NORTHEAST FOR SAT AND USHERING IN MUCH COOLER AIR TO THE
REGION.
CURRENT INDICATIONS ARE THAT HIGHS SAT MAY STRUGGLE TO WARM BEYOND
THE UPR 50S ACROSS NORTHEAST IL/NORTHWEST IN...WITH ONLY LOW 60S
ELSEWHERE. STRONG SFC RIDGE WILL REMAIN NORTH OF THE REGION...SO THE
PRIOR FRONTAL BOUNDARY MAY BECOME QUASI-STATIONARY FOR THE WEEKEND
ALONG THE OHIO VALLEY AND CONTINUE TO FEED PRECIP CHANCES TO THE
SOUTHERN CWFA.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* MVFR CEILINGS CONTINUE THIS MORNING.
* PERIODS OF -SHRA WITH PERIODIC TSRA THIS AFTERNOON.
* SOUTH TO SOUTH-SOUTHWEST WINDS INCREASING THROUGH THE MORNING TO
GUST OVER 20KT
KREIN/MM
//DISCUSSION...UPDATED 12Z...
A MID LEVEL DISTURBANCE MOVING FROM THE SOUTHERN PLAINS TO NRN IL
BY THIS AFTERNOON MAY BRING ANOTHER ROUND OF SHOWERS WITH SCT
THUNDERSTORMS TO THE REGION. UPPER LEVEL FORCING FROM THE MID
LEVEL DISTURBANCE AND AN UPPER LEVEL JET STREAM WILL ENHANCE THE
LIKELIHOOD FOR PCPN AND THE CHANCE FOR TSRA...WITH THE MOST
LIKELY CHANCE FOR ACTIVITY FROM LATE MORNING THROUGH EARLY
EVENING. SOME UNCERTAINTY REMAINS IN PINNING DOWN THE EXACT
PERIOD FOR THE TSRA...SO WILL MAINTAIN THE GOING TEMPO FOR LATE
MORNING THROUGH EARLY AFTERNOON. HOWEVER...THE PCPN TIMING COULD
BE SHIFTED OR EXPANDED IN TIME.
LOW LEVEL MOISTURE STREAMING NORTHWARD AHEAD OF LOW PRESSURE OVER
THE MID MISSISSIPPI VALLEY HAS BROUGHT A LOW MVFR STRATUS DECK
ACROSS THE REGION. SOME SITES ARE REPORTING CIGS DROPPING INTO IFR
RANGE...SO WILL INCLUDE THE POSSIBILITY IN A TEMPO GROUP THROUGH
LATE MORNING. DAYTIME WARMING SHOULD ALLOW FOR INCREASE DEEP LAYER
MIXING WHICH SHOULD SCATTER OUT THE STRATUS DECK.
WINDS WILL BE GENERALLY SOUTHERLY TODAY...THOUGH DIRECTION MAY BE
A BIT VARIABLE AROUND CONVECTIVE ACTIVITY. SOME GUSTINESS IS
LIKELY TO BEGIN BY LATE MORNING...WITH THE LATEST GUIDANCE
SUGGESTING THAT WINDS COULD STRENGTHEN AND BECOME EVEN MORE GUSTY
TONIGHT WITH WINDS VEERING SWLY AS SURFACE LOW PRESSURE MOVES
NORTHEAST ACROSS SOUTHERN WISCONSIN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN WIND TRENDS TODAY. MEDIUM IN WIND TRENDS
TONIGHT.
* HIGH CONFIDENCE IN MVFR CIGS THIS MORNING.
* HIGH CONFIDENCE IN SHOWERS AND MEDIUM CONFIDENCE OF A PERIOD OF
TSRA. LOW CONFIDENCE IN SPECIFIC TSRA TIMING AND IMPACT ON THE
TERMINALS WITH MULTIPLE ROUNDS POSSIBLE BETWEEN 18Z AND 02Z.
KREIN/MM
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WX NIL/VFR. SOUTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA AT NIGHT. SOUTHEAST WINDS.
FRIDAY...TSRA/SHRA LIKELY THROUGH THE DAY AND NIGHT. MVFR
POSSIBLE. SOUTHWEST WINDS.
SATURDAY...SHRA LIKELY WITH A CHANCE OF TSRA DURING THE DAY.
NORTHEAST WINDS.
SUNDAY...CHANCE OF SHRA. EAST WINDS. MVFR POSSIBLE.
MONDAY...CHANCE OF SHRA. SOUTHEAST WINDS. MVFR POSSIBLE.
KREIN
&&
.MARINE...
229 AM CDT
WARM MOIST AIR CONTINUES TO FEED NORTH ACROSS THE LAKE
TODAY...WHICH MAY HELP TO FURTHER ENHANCE ANY AREAS OF FOG THAT
HAVE ALREADY DEVELOPED. IT IS POSSIBLE PATCHY DENSE FOG MAY
DEVELOP...ALTHOUGH WINDS MAY BE JUST STRONG ENOUGH TO LIMIT THE
COVERAGE AND INTENSITY OF THE FOG. A SURFACE LOW PRESSURE SYSTEM
WILL BE LIFTING NORTH ACROSS EASTERN IOWA INTO CENTRAL WISCONSIN
THIS EVENING. THE GRADIENT WILL TIGHTEN ACROSS THE
CENTRAL/SOUTHERN PORTIONS OF THE LAKE...WHICH WITH WARMER
NEARSHORE WATERS EXPECT SOME SLIGHTLY BETTER MIXING TO OCCUR.
FURTHER OUT ACROSS THE OPEN WATERS THE WATER REMAINS COLD AND
EXPECT THE STABILITY TO MAKE IT DIFFICULT TO MIX TO THE SFC THE
HIGHER GUSTS. HIGH PRESSURE THEN ARRIVES LATE WEDNESDAY WITH LIGHT
WINDS DEVELOPING. THEN HIGH PRESSURE SHIFTS EAST THURSDAY
NIGHT...WITH SOUTHERLY WINDS DEVELOPING AGAIN FRIDAY. A FRONTAL
BOUNDARY WILL APPROACH LAKE MICHIGAN LATE FRIDAY NIGHT THEN
STEADILY SLIDE SOUTH ALONG THE LAKE. THIS WILL ALLOW WINDS TO
QUICKLY VEER FROM SOUTH TO NORTH/NORTHEAST SATURDAY. ALONG WITH
THIS QUICK WIND SHIFT WILL BE COOLER AIR SLIDING SOUTH OVER THE
LAKE. WAVES SHOULD EASILY BUILD SATURDAY FOR THE CENTRAL/SOUTHERN
PORTIONS OF THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1044 AM EDT TUE MAY 26 2015
.SYNOPSIS...
ISSUED AT 358 AM EDT TUE MAY 26 2015
AN UPPER LEVEL DISTURBANCE WILL LIFT NORTHEAST TODAY...AND WILL
BRING A GOOD CHANCE FOR THUNDERSTORMS TO THE AREA THIS AFTERNOON.
MORE STORMS ARE POSSIBLE WEDNESDAY AFTERNOON FOLLOWED BY DRY
CONDITIONS THURSDAY THROUGH THURSDAY NIGHT. TEMPERATURES WILL BE
ABOVE NORMAL FOR THIS TIME OF YEAR WITH HIGHS WARMING INTO THE MID
80S BY FRIDAY. THERE IS A GOOD CHANCE FOR RAIN THIS WEEKEND WITH
COOLER TEMPERATURES.
&&
.UPDATE...
ISSUED AT 1044 AM EDT TUE MAY 26 2015
A FEW MINOR UPDATES TO THE GOING FORECAST FOR THIS AFTERNOON AND
EVENING. MORNING WATER VAPOR SHOWS DECENT SHORTWAVE SHEARING
NORTHEAST AS EXPECTED. LINE OF CONVECTION MOVING THROUGH ILLINOIS IS
ASSOCIATED WITH TRAILING CONVERGENT BOUNDARY. VAST MAJORITY OF
LATEST GUIDANCE SHOWS MOST OF OUR CWA GETTING AT LEAST A HUNDREDTH
OF PRECIP SO BUMPED POPS INTO LIKELY CATEGORY. SEVERE WEATHER THREAT
REMAINS MORE NEBULOUS GIVEN ABUNDANT PREFRONTAL CLOUDS...LACKLUSTER
FORCING...AND MIDLEVEL LAPSE RATES BELOW 6 C/KM. THAT BEING SAID...
12Z NAM...RAP...AND HRRR ALL SHOW POCKETS OF MLCAPE VALUES AROUND
1000 J/KG THIS AFTERNOON. 0-6KM BULK SHEAR VECTORS ARE AROUND 30 KTS
WITH 0-3KM VALUES AROUND 25 KTS. NOT REALLY SUPPORTIVE OF A
WIDESPREAD/ORGANIZED SEVERE WEATHER THREAT BUT A FEW CLUSTERS OF
STORMS COULD BECOME SEVERE. THIS IS ESPECIALLY TRUE IN OUR SOUTHEAST
HALF GIVEN MUCH LESS CLOUD COVER...THOUGH WOULDN`T RULE OUT THE
NORTHWEST DUE TO BETTER FORCING AND SHEAR. DAMAGING STRAIGHT LINE
WINDS WILL DEFINITELY BE THE MAIN CONCERN GIVEN STRONG LOW LEVEL
FLOW...THOUGH AN ISOLATED TORNADO CANT BE RULED OUT DUE TO DECENT
0-1KM SHEAR VALUES AND RELATIVELY LOW LCLS. HAIL THREAT IS
NEGLIGIBLE. EXPECT STORMS TO MOVE INTO OUR WESTERN AREAS SHORTLY
AFTER NOON AND CONTINUE THROUGH THE EARLY EVENING HOURS. WILL
CONTINUE TO MONITOR SATELLITE AND SURFACE OBSERVATIONAL TRENDS FOR
ANY EVIDENCE OF ENHANCED SURFACE HEATING/MOISTURE POOLING THROUGH
MIDDAY AS THIS LINE APPROACHES. AGAIN...SEVERE RISK IS STILL
CONDITIONAL AT THIS POINT BUT CERTAINLY BEARS WATCHING AS THE DAY
WEARS ON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT TUE MAY 26 2015
CONVECTIVELY ENHANCED SRN STREAM SW OVR NE OK WILL DAMPEN NEWD
THROUGH ERN IA TDA. HWVR UNLIKE YDA UPR JET STREAK ALIGNED A BIT
FURTHER EWD W/A MORE ROBUST HGT FALLS OVERSPREADING CWA THIS AFTN.
UPSTREAM CLD EVOLUTION SUGGESTS POCKETS OF INSOLATION WILL DVLP
THROUGH MORNING W/AT LEAST A FVRBL YET LIMITED SFC BASED
DESTABILIZATION RESPONSE RESULTING. EWD EXTENT OF MORE SIG SYNOPTIC
SCALE FORCING MUCH IN DOUBT HWVR POTENTIAL EXISTS FOR UPSCALE
ORGANIZATION ORGANIZATION TO CONVN ESP SHLD BTR THAN XPCD
INSTABILITY DVLP.
REGARDLESS OF OUTCOME...FOLLOWING DRYSLOT AND INCREASING MID LVL
SUBSIDENCE QUICK TO FOLLOW THIS EVENING AND OTHER THAN A LINGERING
SHOWER GENERALLY EAST HAVE DROPPED POPS AFT 06Z.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM EDT TUE MAY 26 2015
THERE ARE LOTS OF CHALLENGES THIS LONG TERM PERIOD AS THE LONG WAVE
TROF BECOMES REESTABLISHED OVER THE WESTERN CONUS AFTER EJECTING A
COUPLE OF SHORT WAVE TROFS ACROSS THE CENTRAL CONUS. AHEAD OF THESE
SYSTEMS...PLENTY OF MOISTURE WILL BE AVAILABLE FOR SHOWERS AND
STORMS...ALBEIT RELATIVELY STABLE MID LEVEL LAPSE RATES WILL TEND TO
LIMIT CONVECTION. ALSO...SOME UPSTREAM CONVECTION WILL TEND TO
INTERCEPT MOISTURE FLUX AND LIMIT VERY DEEP MOISTURE TRANSPORT
NORTH. OVERALL...THE AIRMASS OVER THE CENTRAL THIRD OF THE CONUS HAS
HAD ASTOUNDING PRECIPITATION EFFICIENCY...WITH OKLAHOMA CITY
APPROACHING 20 INCHES OF RAIN SO FAR THIS MONTH...WELL ABOVE THE
RECORD RAINFALL FOR ANY MONTH IN THIS CITY. WITH SO MUCH RECENT RAIN
UPSTREAM... THERE WILL LIKELY BE RECYCLING OF MOISTURE AS REFLECTED
IN RESEARCH AS WHAT HAPPENED IN THE 1993 FLOODS. KEPT THESE FACTORS
IN MIND WITH THIS PORTION OF THE FORECAST. MADE ONLY MINOR
ADJUSTMENTS TO THE TIMING AND PLACEMENT OF SHOWER AND STORMS
WEDNESDAY AS THE FAR SOUTHEAST PORTION OF AN EJECTING UPPER LEVEL
TROF SHOULD BE SE SUFFICIENT TO GENERATE SOME STORMS...ESPECIALLY
WITH DAYTIME HEATING. FOR THIS WEEKEND...A SLOW MOVING SOUTHERN
STREAM SYSTEM WILL ATTEMPT TO MERGE WITH A NORTHERN STREAM TROF OVER
THE UPPER GREAT LAKES REGION. STILL SOME UNCERTAINTY ON HOW THIS
WILL PLAY OUT...BUT FOR NOW...RAIN CHANCES AT LEAST AT SOME POINT
LOOK REAL FAVORABLE AS THE UPPER LEVEL TROF INTERACTS WITH THE
SURFACE BOUNDARY. AS FOR TEMPERATURES...KEPT TEMPERATURES WARM
WEDNESDAY THROUGH FRIDAY...WITH HIGHS FRIDAY WELL INTO THE 80S AS
SUPPORTED BY THE GFS MEX FOR THE PAST SEVERAL DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 646 AM EDT TUE MAY 26 2015
INCREASING LL MSTR FLUX AHD OF EJECTING UPSTREAM SW TROUGH OVR
ERN KS RESULTING IN RAPIDLY EWD EXPANDING MVFR CIGS. HWVR
W/SUNRISE XPC RAPID MIXING WILL ENSUE AS CIG HGTS SETTLE OUT INTO
LOW BOUND VFR CU/SC. DECAYED ARC OF EARLIER SHRA/TSRA ACRS ERN
MO/WRN IL MARK THE LEADING EDGE OF HGT FALLS ASSOCD/W UPSTREAM SW
AND AS THAT SYS EJECTS RAPIDLY NEWD INTO WRN WI LT THIS AFTN WILL
SERVE AS THE PRIMARY FOCUSING MECHANISM FOR CONVN DVLPMNT INVOF THE
TERMINALS TWD 18Z. DEGREE OF CONV VIGOR MUCH UNCERTAIN PENDING
EVOLUTION OF WARM SECTOR CLD CVR. SFC BASED DESTABILIZATION XPCD
TO BE REMAIN LIMITED W/BTR CHCS FOR UPSCALE ORGANIZATION ACRS NW
OH WHERE MORE UNSTABLE CONDS MAY DVLP. OUTSIDE GRADIENT WIND GUSTS
AOA 25KTS THIS AFTN...REGARDLESS BRIEF PD OF GUSTY SFC WINDS ARE PSBL
W/CONVN ESP INVOF KFWA TWD MID AFTN COINCIDENT W/CORE OF 45KT LLJ
OVERHEAD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...AGD
SYNOPSIS...SKIPPER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
641 AM CDT Tue May 26 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 258 AM CDT TUE MAY 26 2015
Precipitation persists over much of the area, though becoming
steadily more scattered in nature and generally rather low rates.
Appears more vigorous convection in western locations is long
upper trough axis, with whole upper system good northeast progress
through eastern Kansas with warming cloud tops.
Have a hard time ruling out precip for much of today and tonight.
Short-range models seem a bit too fast with main deformation
precip`s exit this morning, with latest HRRR runs similar in
isolated to scattered convection making its way southeast around
the low into northern areas in the late morning to early
afternoon. Still seeing best lower-level forcing in southern areas
late today into tonight were somewhat better convergence exists.
There is also decent larger-scale model similarity in another wave
rotating (perhaps taking shape in western Nebraska early this
morning) passing through over this same period, although heights
are still rising. Moisture through the column not up to recent
levels, but dewpoints into the lower 60s still support some
instability developing in peak heating. Fairly unidirectional and
modest wind speeds keep severe storm concerns low.
.LONG TERM...(Wednesday through Monday)
Issued at 258 AM CDT TUE MAY 26 2015
Surface high pressure moves into the Central Plains on Wednesday,
with the frontal boundary slowing over southern Kansas under
generally west southwest upper flow. Think more stable surface air
plus mid level ridging will keep northern areas dry on Wednesday
but could see some rumbles south depending on how far south the
front progresses. Next in a series of shortwave trofs moves over
eastern Kansas overnight into Thursday morning, and draws rain
chances back over our area. Have continued chances into Thursday,
although features driving rain chances are more mesoscale in
nature and timing will likely need adjustment.
Better model agreement on a slightly larger scale shortwave
feature lifting out of the southwest US and across eastern Kansas
for Friday, and will keep higher rain chances as a result. Front
slides southeast across the area through early Saturday morning,
cooling things down and bringing decreasing rain chances through
Sunday from northwest to southeast. If pattern persists, may be
able to end chances sooner. High temperatures Wednesday through
Friday are forecast in the upper 70s near 80, falling into the 60s
for the weekend behind the front, with lows in the 60s then
falling to the 50s late week.
&&
.AVIATION...(For the 12Z TAFs through 12Z Wednesday Morning)
Issued at 640 AM CDT TUE MAY 26 2015
VFR conditions anticipated. Brief IFR deck has exited and radars
showing increasing precip trends, so went with a SHRA mention but
no limitations anticipated out of this last band. Still too low
confidence in any additional precip mention beyond 14Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...65
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
612 AM CDT Tue May 26 2015
.DISCUSSION...
Issued at 455 AM CDT TUE MAY 26 2015
Today - Wednesday:
Vorticity max which lifted out of West TX yesterday and helped
generate the MCC that roared through east TX has attempted to merge
with the NE/KS upper trough. Hard to say if this process has been
successful. Operational models appear to wash out the vorticity max
currently over east central KS while allowing a separate h7
vorticity max to rotate east through the NE/KS upper trough and
across northern MO this afternoon.
Near term portion of forecast is tied to radar trends which shows a
fairly expansive region of tropical type showers with a few
thunderstorms. The entire region of rain is starting to lift
northeast. Have followed the trend of the HRRR and gone with
categorical PoPs for much of northern and west central MO this
morning. Think we`ll see scattered afternoon convection over
northern MO in response to the above mentioned h7 vorticity max
spinning through that area. A weak cold front/convergent zone is
expected to drift south through the CWA tonight and will provide
additional lift for scattered convection.
Also watching area of loosely organized convection coming out of NM
and into the TX Panhandle. Can see some rotation in water vapor
imagery. NAM and SREF seem to have best handle of this feature and
they both lift it northeast today. Am expecting to see scattered
convection reform with this feature and likely affect at least the
far southern counties this evening/overnight. So have upped PoPs
this region.
Wednesday should be relatively quiet with low chance PoPs tied to
weak convergence with whatever is left of the weak cold front.
Thursday - Weekend:
Very unsettled pattern as upper flow backs to the southwest and a
series of weak embedded disturbances lift northeast through the
Central Plains. Eventually a broad upper trough will shift east out
of the Central Rockies over the weekend and enhance precipitation
chances for at least Saturday. Deep moisture from the Gulf of Mexico
will once again flow northward and gradually result in a tropical
environment by Thursday night. Medium range models have been hitting
the PoPs hard with only minor run-to-run changes. See no reason to
deviate from likely PoPs during this period. Due to recent heavy
rains leaving sub-soil saturated will need to be watchful for
flooding issues as progged soundings once again are suggestive of
warm-rain processes.
Have some concern that the model PoPs are too low as both the
GFS/ECMWF still have the upper trough just passing through MO. Think
the model blended PoPs have not picked up on this. Sunday is looking
a bit chilly since we`ll be under an extensive cloud shield with
scattered convection.
Monday:
Finally should see the start of drying out as the upper trough
should have passed east of the region with subsidence overspreading
the region.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 608 AM CDT TUE MAY 26 2015
Large area of tropical type rain will gradually lift northeast and
out of northwest and west central MO by mid-morning and northern MO
by noon hour. However, scattered afternoon showers and isolated
thunderstorms look like they;ll reform across northern MO. Otherwise,
despite the rain ceilings have remained generally VFR. Should see
clouds scatter from the southwest this afternoon.
Additional area of showers and storms are expected to spread into
west central MO late this evening as a system lifts out of the TX
Panhandle.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH until 10 AM CDT this morning FOR KSZ102.
MO...FLASH FLOOD WATCH until 10 AM CDT this morning FOR MOZ001>005-
011-012.
&&
$$
DISCUSSION...MJ
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
303 AM PDT MON MAY 25 2015
.SYNOPSIS...A TROUGH ALOFT COMBINED WITH ENOUGH MOISTURE AND
INSTABILITY WILL HELP TO SPARK OFF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS TODAY THROUGH THURSDAY ACROSS THE SOUTHERN
GREAT BASIN ESPECIALLY OVER THE HIGHER ELEVATIONS. OTHERWISE EXPECT
DRY CONDITIONS WITH A WARMING TREND THROUGH THE END OF THE WEEK. THE
WARMEST WEATHER OF THE YEAR SO FAR IS EXPECTED THIS WEEKEND.
&&
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT.
THE CONVECTIVE COMPLEX THAT GOT GOING YESTERDAY EVENING ACROSS SOUTH-
CENTRAL NEVADA HAS PUSHED TOWARD THE UTAH BORDER EARLY THIS MORNING
IN A SOMEWHAT DECAYED STATE. MOST OF THE MAIN COMPLEX WAS NOW JUST
AN AREA OF LIGHT TO MODERATE RAIN, HOWEVER, WE HAVE SEEN SOME CELLS
DEVELOP ON THE SOUTHERN FLANK OF THE MAIN AREA OF PRECIPITATION
ACROSS NORTHERN MOHAVE COUNTY IN THE LAST HOUR. BASED ON THE HRRR,
THIS ACTIVITY IS ALL SLATED TO MOVE EAST AND SHOULD EXIT THE AREA BY
LATER THIS MORNING. HOWEVER, A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS WAS LEFT IN THE FORECAST FOR LINCOLN COUNTY AND ADDED
TO THE FORECAST FOR NORTHERN MOHAVE COUNTY TO ACCOUNT FOR THIS.
WHATEVER CLOUDS ARE AROUND FROM THIS SHOULD CLEAR OUT AS WELL BY
LATER THIS MORNING.
WE REMAIN IN A BROAD TROUGH IN THE MID AND UPPER LEVELS OF THE
ATMOSPHERE ACROSS THE SOUTHWEST. TWO FEATURES ARE OF NOTE THIS
MORNING. ONE IS THE MAIN JET STREAM WHICH IS PASSING BY TO OUR
SOUTH. THIS WILL PUSH A BAND OF HIGHER LEVEL MOISTURE ACROSS THE
SOUTHERN THIRD OF THE AREA TODAY INTO TONIGHT RESULTING IN HIGH
CLOUDS. SOME OF THE CLOUDS COULD ENHANCE OFF THE COASTAL RANGES OF
SOCAL BY LATER TODAY INTO TONIGHT AND THUS SKY COVER HERE MAY BE
UNDERDONE. THE SECOND FEATURE TO WATCH CAN BE SEEN ON WATER VAPOR
IMAGERY DIGGING SOUTH ACROSS NORCAL AND NORTHWESTERN NEVADA THIS
MORNING. THIS NEXT PIECE OF ENERGY WILL WORK SOUTH AND EAST ACROSS
THE SOUTHERN HALF OF NEVADA TODAY AND ONCE AGAIN WITH THE MOISTURE
(MAINLY MID-LEVEL) AND INSTABILITY IN PLACE HELP TO SPARK OFF
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON ACROSS THE
SOUTHERN GREAT BASIN ESPECIALLY OVER THE HIGHER ELEVATIONS. SIMILAR
TO YESTERDAY, ACTIVITY SHOULD PUSH WEST TO EAST ACROSS THE AREA.
INSPECTING THE HRRR AND LOCAL 4KM HIGH RESOLUTION ARW AND NMM
MODELS, THERE APPEARS TO BE TWO MAIN AREAS THAT WILL NEED TO BE
WATCHED THIS AFTERNOON. THE FIRST IS NORTHERN LINCOLN COUNTY AND THE
SECOND WILL BE ACROSS ESMERALDA COUNTY AS WELL AS THE WHITE
MOUNTAINS, NORTHERN OWENS VALLEY AND EASTERN SLOPES OF THE SOUTHERN
SIERRA NEVADA. POPS WERE RAISED SLIGHTLY FOR THE LATTER. THE MAIN
THREATS IN AND NEAR THUNDERSTORMS TODAY WILL BE GUSTY AND ERRATIC
WINDS TO 45 MPH, SMALL HAIL, LIGHTNING AND DOWNPOURS THAT COULD
PRODUCE LOCALIZED FLOODING. SHOWERS AND THUNDERSTORMS SHOULD
DECREASE THIS EVENING WITH THE LOSS OF HEATING. DESPITE THE TROUGH
OVERHEAD TEMPS WILL BE ON THE RISE TODAY WITH HIGHS RETURNING BACK
CLOSER TO NORMAL. THIS WILL SNAP THE SUB-90 STREAK IN LAS VEGAS THAT
HAS BEEN AROUND SINCE MAY 4TH. WITH TEMPS RISING, SNOW LEVELS WILL
BE AROUND 11000 FEET TODAY BUT ANY HEAVIER SHOWERS OVER THE HIGHEST
MOUNTAINS COULD AGAIN DROP A FEW INCHES OF SNOW. HIKERS AND OUTDOOR
ENTHUSIASTS IN THE SOUTHERN SIERRA NEVADA AND WHITE MOUNTAINS SHOULD
AGAIN BE ALERT FOR POTENTIAL WINTRY CONDITIONS ON AREA TRAILS AND
CAMPGROUNDS HIGHER UP.
A MID/UPPER LEVEL LOW WILL PUSH EAST ACROSS BAJA CALIFORNIA TONIGHT
AND HELP TO PUSH ANY CIRRUS ACROSS THE SOUTHERN HALF OF OUR AREA OFF
TO THE EAST ON WEDNESDAY, HOWEVER, SOME THICKER HIGH LEVEL CLOUDS
MAY START THE DAY OFF IN MOHAVE COUNTY. A BROAD MID/UPPER LEVEL
TROUGH WILL REMAIN ACROSS THE AREA FOR WEDNESDAY AND WITH ENERGY
RIPPLING THROUGH THE BASE OF THE TROUGH AND ENOUGH MOISTURE AS WELL
AS INSTABILITY REMAINING IN PLACE ONCE AGAIN RESULT IN SHOWERS AND
THUNDERSTORMS POPPING UP WITH THE HEATING OF THE DAY ACROSS THE
SOUTHERN GREAT BASIN. ONCE AGAIN EXPECT MAINLY AFTERNOON AND EVENING
ACTIVITY MAINLY OVER THE HIGHER ELEVATIONS. TEMPS WILL RISE A FEW
MORE DEGREES AS THE ATMOSPHERE CONTINUES TO WARM FURTHER. THIS
SHOULD PUSH HIGHS BACK CLOSER TO NORMAL AND I SIDED WITH THE WARMER
MAV (GFS) NUMBERS FOR HIGHS.
THE PESKY TROUGH ALOFT WILL FINALLY ALLOW FOR A FULL-FLEDGED FEEL OF
SPRING (MORE LIKE SUMMER DEPENDING ON YOUR TASTE AND HOW THIS SPRING
HAS BEEN) BY THURSDAY AS A RIDGE ALOFT STARTS TO TRANSITION IN. IF
YOU HAVE BEEN HOLDING OFF USING ON THE AIR CONDITIONER MUCH, GET
READY TO CRANK IT AS HIGHS SOAR TO ABOVE NORMAL READINGS FOR A
CHANGE. A WEAK RIPPLE IN THE FLOW AND LINGERING MOISTURE AND
INSTABILITY COULD STILL SET OFF A FEW SHOWERS AND THUNDERSTORMS IN
THE AFTERNOON AND EVENING OVER THE SOUTHERN GREAT BASIN, HOWEVER,
ACTIVITY SHOULD BE LESS IN AREAL COVERAGE COMPARED TO TUESDAY AND
WEDNESDAY. ONCE AGAIN ANY SHOWERS AND THUNDERSTORMS SHOULD END IN
THE EVENING WITH THE LOSS OF HEATING.
.LONG TERM...FRIDAY THROUGH TUESDAY.
THE STORY OF THE LONG TERM PERIOD WILL BE AFTERNOON HIGHS PUSHING
THE CENTURY MARK ACROSS MOST DESERT LOCALES THROUGH THE BEGINNING OF
NEXT WEEK...AS A SHORTWAVE RIDGE TRAVERSES OVER THE AREA THIS
WEEKEND. MINOR DIFFERENCES CONTINUE TO EXIST WITH OPERATIONAL
GUIDANCE REGARDING THE OVERALL AMPLITUDE OF THE AFOREMENTIONED
RIDGE. HOWEVER ALL BASE AND DERIVED GUIDANCE CONTINUES TO
CONSISTENTLY INDICATE HIGH TEMPERATURES AT LEAST WITHIN A FEW
DEGREES OF EACH OTHER FROM MODEL TO MODEL OVER THE WEEKEND...FURTHER
INCREASING CONFIDENCE OF THE FIRST 100 DEGREE DAY OF 2015 FOR MANY
DESERT LOCALES...INCLUDING LAS VEGAS. BOTH THE OPERATIONAL GFS/ECMWF
INDICATE A FAIRLY VIGOROUS TROUGH IMPINGING ON THE GREAT BASIN LATE
SUNDAY INTO MONDAY...WHICH WILL INCREASE SOUTHERLY/SOUTHWESTERLY
FLOW ACROSS MUCH OF THE CWA IN THIS TIMEFRAME. THIS WILL PROMOTE
GOOD MIXING...ESPECIALLY ON SUNDAY AFTERNOON...WHICH WILL BUMP UP
HIGH TEMPERATURES A FEW DEGREES FROM FRIDAY AND SATURDAY LIKELY
MAKING THIS THE HOTTEST DAY OF THE YEAR THUS FAR. TEMPERATURES WILL
COOL A FEW DEGREES MONDAY AND TUESDAY IN RESPONSE TO THE PASSING
TROUGH...BUT WILL REMAIN ABOVE SEASONAL NORMALS.
&&
.AVIATION...FOR MCCARRAN...WINDS SHOULD TURN SOUTHEAST LATE THIS
MORNING BETWEEN 120 AND 160 DEGREES TRUE DIRECTION THEN SHIFT MORE
TO THE SOUTH BETWEEN 170 AND 220 DEGREES AROUND 21Z TODAY AND
INCREASE TO 10-14 KTS WITH GUSTS TO AROUND 20 KTS. WINDS SHOULD
SLOWLY DECREASE THIS EVENING BETWEEN 05Z AND 07Z WEDNESDAY. A FEW
CLOUDS AOA 12K FEET THIS AFTERNOON WITH SCT-BKN CLOUDS AOA 25K FEET
LATER TONIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...MAINLY DIURNAL WIND DIRECTIONS THROUGH TONIGHT AT 12
KTS OR LESS. A FEW CLOUDS AOA 12K FEET TODAY WITH SCT-BKN CLOUDS AOA
25K FEET TONIGHT SOUTH OF KIYK-KDRA-KSGU LINE. NORTH OF THIS LINE
THERE WILL BE A POSSIBILITY OF SHRA/TSRA AROUND AGAIN MAINLY AFTER
20Z TODAY THROUGH 06Z OR SO WEDNESDAY. GUSTY AND ERRATIC
WINDS...MVFR OR LOWER VSBY IN HEAVIER SHRA AND CIGS TO 5K-8K FEET
ARE POSSIBLE. LOCAL MOUNTAIN OBSCURATIONS ARE ALSO POSSIBLE.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...STACHELSKI
LONG TERM...PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
522 AM MDT TUE MAY 26 2015
.AVIATION...
12Z TAF CYCLE
VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS. LESS COVERAGE
OF -TSRA/-SHRA TODAY AS COMPARED TO YESTERDAY. FAVORED AREAS WILL
BE ACROSS THE NORTHERN AND WESTERN MTNS...BUT VIRGA AND GUSTY
WINDS WILL BE MOST COMMON. HRRR SUGGESTS KFMN MAY BE IMPACTED
LATE THIS AFTN AS WELL...SO HAVE ADDED A VCSH TO THE TAF.
34
&&
.PREV DISCUSSION...320 AM MDT TUE MAY 26 2015...
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL MOVE OVER THE LAND OF ENCHANTMENT
TODAY...LIMITING SHOWER AND STORM COVERAGE WHILE ALLOWING TEMPERATURES
TO WARM A FEW DEGREES. SHOWERS AND STORMS WILL INCREASE IN NUMBER AND
AREAL COVERAGE THURSDAY AS LOW LEVEL MOISTURE BECOME MORE PLENTIFUL.
THIS WETTER AND MORE ACTIVE PERIOD WILL PERSIST THROUGH SUNDAY WITH
SHOWERS AND STORMS FAVORING THE CENTRAL AND EAST. HIGHS WILL CONTINUE
TO RANGE FROM NEAR TO BELOW AVERAGE FOR THE SEASON.
&&
.DISCUSSION...
SHOWERS AND STORMS ARE STILL EXPECTED TO BE AT A MINIMUM TODAY
THROUGH WEDNESDAY BEFORE INCREASING THURSDAY AND INTO THE WEEKEND.
A SHORT WAVE VISIBLE ON SATELLITE IMAGERY WILL BRUSH NRN NM...AND
HIGHEST GUIDANCE POPS FOR TODAY ARE AIMED AT THE NRN BORDER OF THE
STATE AS WELL AS SOME OF THE HIGHER TERRAIN OF THE WEST. STEERING FLOW
WOULD TAKE CELLS OFF THE MOUNTAINS AND TO THE EAST...A FEW MAY
SURVIVE LONG ENOUGH TO REACH THE NE PLAINS/PECOS VALLEY BY THIS EVENING
AND SUCCEEDING SHIFTS MAY NEED TO REEVALUATE JUST HOW FAR EAST AS
CURRENT POPS TAPER OFF RAPIDLY FARTHER EAST INTO THE PLAINS.
OTHERWISE...GUIDANCE WARMS UP TEMPERATURES CONSIDERABLY TODAY AND EVEN
MORESO WEDNESDAY.
THE SURGE OF MOISTURE WEDNESDAY NIGHT INTO THURSDAY REMAINS CONSISTENT
INTO THE EASTERN PLAINS ALTHOUGH SOME OF THE GUIDANCE POPS HAVE BACKED
OFF FOR THE EAST CENTRAL/SOUTHEAST. THE BIGGER EVENT NOW MAY BE THE
FRIDAY INTO SUNDAY PERIOD AS A FRONT PUSHES INTO THE PLAINS AND
WESTWARD TO THE CONTDVD. HIGH TEMPERATURES WHICH WARM UP TO NEAR
NORMAL WEDNESDAY IN THE EAST DIVE TO 10-15 DEGREES BELOW AVERAGE BY
SATURDAY. GUIDANCE STILL SEEMS TO WANT TO WARM UP A BIT TOO MUCH
THURSDAY AND STAYED BELOW IT FOR THE FORECAST HIGHS THAT DAY.
THE TROPICAL SYSTEM DEPICTED NEXT WEEK IS STILL THERE...BUT WHAT
IMPACT IT MIGHT HAVE ON NM WEATHER IS IN DOUBT.
&&
.FIRE WEATHER...
YESTERDAYS UPPER LEVEL WAVE HAS SHIFTED EASTWARD AND A WEAK WIND
SHIFT WILL SLIDE INTO NORTHEAST NM BEHIND IT THIS MORNING.
OTHERWISE...ZONAL FLOW WILL BE THE RULE TODAY. WITHOUT ANY
APPRECIABLE UPPER LEVEL FORCING...SHOWERS AND THUNDERSTORMS WILL BE
FOCUSED OVER THE NORTHERN MTNS THANKS TO OROGRAPHIC LIFT PLUS ENOUGH
RESIDUAL MOISTURE. A FEW STORMS MAY ALSO DEVELOP ACROSS NE NM BEHIND
THE FRONT...BUT OVERALL...SHOWER AND TSTM ACTIVITY WILL BE LESS
TODAY. WITH LESS CLOUD COVER AND PRECIPITATION...TEMPERATURES WILL
TREND UPWARD...ESPECIALLY ACROSS THE WEST. CORRESPONDINGLY...
HUMIDITIES WILL TREND DOWNWARD...ESPECIALLY FOR WESTERN NM...BUT
WILL STAY ABOVE 20 PERCENT FOR MOST AREAS.
SOUTHWESTERLY FLOW ON WEDNESDAY AHEAD OF THE NEXT SYSTEM WILL HELP
TEMPS TO WARM UP FURTHER. WEDNESDAY SHOULD BE THE WARMEST DAY OF THE
WEEK WITH MOST AREAS WITHIN 3 DEGREES OF NORMAL FOR LATE MAY. COULD
BE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS OVER THE NORTHERN
MTNS...BUT GENERALLY NOT MUCH CONVECTION EXPECTED FOR THE DAYTIME
PERIOD. HUMIDITIES WILL FALL BELOW 15 PERCENT ACROSS MUCH OF CENTRAL
AND WESTERN NM DURING THE AFTERNOON...WITH PERHAPS A FEW HOURS OF
SINGLE DIGIT HUMIDITIES ACROSS THE LOWER RIO GRANDE VALLEY. WINDS
LOOK TO BE TOO LIGHT TO SUPPORT CRITICAL CONDITIONS...THOUGH HAINES
VALUES OF 6 WILL BE PRESENT.
WEDNESDAY NIGHT...GULF MOISTURE WILL BE DRAWN BACK INTO THE EASTERN
PLAINS AND WITH THE NEXT UPPER LEVEL TROUGH AXIS APPROACHING THE
NM/AZ BORDER...EXPECT STORMS TO DEVELOP ACROSS THE EAST CENTRAL
PLAINS. AS THE TROUGH AXIS CROSSES NM ON THURSDAY...MORE CONVECTION
IS EXPECTED FROM THE CENTRAL MTN CHAIN EASTWARD. MEANWHILE...DRIER
CONDITIONS WILL PERSIST FROM THE RIO GRANDE VALLEY WESTWARD...WITH
HUMIDITIES FALLING BELOW 15 PERCENT AGAIN. LIGHT WINDS WILL PRECLUDE
CRITICAL CONDITIONS...BUT HAINES VALUES OF 6 WILL PERSIST.
ANOTHER BACK DOOR COLD FRONT WILL ENTER THE NORTHEAST PLAINS
FRIDAY...AND CONTINUE TO SLIDE SOUTHWARD THRU THE PLAINS FRIDAY
NIGHT...INCREASING PRECIP CHANCES ACROSS THE PLAINS ONCE AGAIN. THE
FRONT MAY SQUEAK THRU THE CENTRAL MTN CHAIN FRI NIGHT/EARLY SAT
MORNING. ON SATURDAY...STORMS SHOULD DEVELOP ALONG THE EAST SLOPES
OF THE CENTRAL MTN CHAIN...AND OUTFLOW BOUNDARIES SHOULD HELP PUSH
WHAT IS LEFT OF THE FRONTAL BOUNDARY WESTWARD TO AT LEAST THE
CONTINENTAL DIVIDE. THIS MAY MEAN A MORE ACTIVE SUNDAY IS IN STORE
FOR WESTERN NM.
GOOD TO EXCELLENT VENTILATION WILL PREVAIL THROUGH THE WEEKEND.
EXCEPTIONS WOULD BE ACROSS FAR NE NM FRIDAY...SATURDAY ALONG THE
EAST SLOPES OF THE CENTRAL MTN CHAIN...AND SUNDAY ACROSS THE NE
QUARTER OF THE STATE WHERE POOR TO FAIR VENTILATION IS EXPECTED.
34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1032 AM EDT TUE MAY 26 2015
.SYNOPSIS...AN UPPER LEVEL RIDGE OVER THE REGION WILL SLOWLY SHIFT
OFFSHORE THROUGH MID-WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...
THE LATEST UPPER-AIR ANALYSIS SHOWED THE WEST PART OF RIDGING
SURFACE AND ALOFT OVER THE CAROLINAS...AND THE LATEST SATELLITE
WATER VAPOR IMAGES SHOWS AMPLE MID-LEVEL DRY AIR ALONG THE CAROLINA
COAST. DURING THE MORNING...THE SPC MESOANALYSIS HAS SHOWN A GRADUAL
INCREASE IN PRECIPITABLE WATER VALUES OVER AND EAST OF THE COASTAL
PLAIN...IN CONCERT WITH THE RAP WHICH FORECASTS OVERALL PRECIPITABLE
WATER VALUES OF AROUND 1.5 INCHES OVER CENTRAL NORTH CAROLINA BY
00Z. WHILE FORECAST SOUNDINGS ARE FAIRLY STABLE...THE RAP DOES
FORECAST AFTERNOON MLCAPE IN THE LOWEST 3KM TO 500J/KG OR LESS.
850MB LIFT IS GREATEST TOWARD KFAY AND KCTZ EARLY THIS AFTERNOON...
WHERE THE LATEST REGIONAL RADAR IMAGES SHOW ISOLATED TO SCATTERED
SHOWERS NEAR AND JUST NORTH OF KILM. THE HRRR WRF GUIDANCE IS DOING
WELL WITH THIS MODEST CONVECTION...AND DESPITE ONLY MODEST
INSTABILITY...IN THE MOISTURE ADVECTION THE HRRR WRF DOES SHOW
MOSTLY ISOLATED SHOWERS SLOWLY MOVING NORTH ACROSS THE KFAY AND KCTZ
AREAS TO NEAR KRDU AND KRWI BY LATE IN THE DAY. FARTHER WEST...RAP
SOUNDINGS SHOW DECENT CIN THROUGH MUCH OF THE DAY...AND ANY ISOLATED
SHOWER OR STORM MAY HOLD OFF AS WELL UNTIL VERY LATE IN THE DAY
GIVEN THE WEAK LIFT AND LIMITED FORCING. HIGH TEMPERATURES IN THE
MID TO UPPER 80S WITH A FEW WIND GUSTS IN THE TEENS KNOTS WITH
MIXING DURING THE DAY...925MB AND 850MB WINDS TO 15KT.
CONVECTION SHOULD BE LARGELY DIURNALLY DRIVEN...BUT WILL KEEP A
SLIGHT CHANCE ACROSS THE WESTERN PIEDMONT OVERNIGHT WHERE THE
POTENTIAL FOR GLANCING SHOT DPVA ATTENDANT TO UPPER DISTURBANCES IS
HIGHEST. LOWS IN THE MID TO UPPER 60S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 300 AM TUESDAY...
MODELS GENERALLY AGREE THAT THE MID/UPPER LEVEL RIDGE MAY WEAKEN A
BIT WHILE DRIFTING EVER SO SLIGHTLY EASTWARD OVER THE WESTERN
ATLANTIC. FACTORS CONTRIBUTING TO RAIN CHANCES TODAY(DAYTIME HEATING
AND RESULTANT DESTABILIZATION...POTENTIAL FOR SHORTWAVE DISTURBANCES
ALOFT...AND SEABREEZE BOUNDARY) WILL ESSENTIALLY GOVERN RAIN CHANCES
AGAIN ON WEDNESDAY...BUT PERHAPS WITH MORE EQUITABLE RAIN CHANCES
EASTWARD INTO CENTRAL PIEDMONT.
HIGHER RAIN CHANCES AND CLOUD COVER MAY KNOCK A DEGREE OR TWO OFF OF
DAYTIME HIGHS. HIGHS IN THE LOWER/80S NORTHWEST TO MID/UPPER 80S
SOUTHEAST. LOWS IN THE MID/UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 320 AM TUESDAY...
STRONG UPPER LEVEL RIDGING ALONG THE SOUTHEAST COAST SHOWS SOME
SIGNS OF WEAKENING BY THURSDAY BUT IS STILL STRONG ENOUGH TO DEFLECT
THE SHORTWAVE CURRENTLY OVER THE CENTRAL PLAINS NORTH TOWARD THE
GREAT LAKES AND KEEP THE ASSOCIATED FRONTAL ZONE TO OUR NORTHWEST.
THOUGH FORCING OVER CENTRAL NC WILL BE WEAK ON THURSDAY...A WEAK
REMNANT SHEAR AXIS AMIDST PW OVER 1.5 INCHES AND 600 TO 1200 J/KG OF
MLCAPE...HIGHEST OVER THE WESTERN PIEDMONT...SHOULD LEAD TO
INCREASED...THOUGH STILL SCATTERED COVERAGE OF AFTERNOON
SHOWERS/STORMS. SHEAR WILL BE WEAK WITH THE UPPER TROUGH AND
STRONGEST WESTERLIES WELL WEST OF THE MOUNTAINS...SO SEVERE STORMS
WILL BE LIMITED.
THE UPPER RIDGE THEN LOOKS TO BUILD BACK SLIGHTLY FRIDAY INTO THE
WEEKEND WITH A LITTLE DRIER AIR ACTUALLY FORECAST TO FILTER IN FROM
THE EAST ON FRIDAY. THUS EXPECT MAINLY ISOLATED SHOWERS AND STORMS
FRIDAY AND SATURDAY AS THE AIRMASS SLOWLY RE-MOISTENS THROUGH THE
WEEKEND. ANOTHER SHORTWAVE AND COLD FRONT ARE FORECAST TO MOVE INTO
THE MIDWEST STATES EARLY NEXT WEEK...AND WHILE IT IS UNCERTAIN
WHETHER THAT FRONT WILL MAKE IT ALL THE WAY INTO NC AS WELL...THE
CHANCES OF CONVECTION WILL INCREASE FROM NORTH TO SOUTH SUNDAY
THROUGH TUESDAY.
THICKNESSES ARE PROJECTED TO BE NEARLY UNCHANGED THROUGH THE
PERIOD...WITH HIGHS MOSTLY IN THE MID TO UPPER 80S NEARLY
EVERYDAY...WITH SOME AREAS IN THE SOUTH REACHING 90 ON SATURDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AS OF 1030 AM TUESDAY...
SUB-VFR CEILINGS ACROSS THE WESTERN PIEDMONT LIFTED EARLY THIS
MORNING...AND MVFR CEILINGS TOWARD KFAY SHOULD SLOWLY LIFT TO VFR BY
EARLY AFTERNOON. THE BEST CHANCE FOR CONVECTION RELATIVE TO THE REST
OF CENTRAL NORTH CAROLINA SHOULD BE NEAR KFAY THIS AFTERNOON...WITH
ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE LATE IN THE DAY TOWARD
THE TRIAD...AND EVEN APPROACHING KRDU AND KRWI. FOR A POINT
FORECAST...HOWEVER...THIS PROBABILITY APPEARS TOO LOW TO MENTION IN
THE TERMINAL FORECAST AT THIS TIME.
WIDESPREAD MVFR/IFR CEILINGS EXPECTED EACH MORNING THROUGH THE
REMAINDER OF THE WORK WEEK AS SLY FLOW CONTINUES TO INCREASE OR
MAINTAIN LOW LEVEL MOISTURE OVER CENTRAL NC. THERE WILL BE A BETTER
CHANCE FOR AFTERNOON CONVECTION BOTH WEDNESDAY AND THURSDAY WITH THE
GREATEST CHANCES ON WEDNESDAY OVER THE PIEDMONT...AND AREAWIDE
THURSDAY.
THE HIGH PRESSURE SYSTEM WILL BEGIN TO BUILD BACK INTO THE CAROLINAS
FRIDAY INTO SATURDAY. THIS WILL BEGIN TO LIMIT THE CHANCES FOR
AFTERNOON CONVECTION ON FRIDAY AND MORE SO SATURDAY. THERE WILL
CONTINUE TO BE DECENT THREAT FOR EARLY MORNING MVFR/IFR CEILING AND
FOG FRIDAY AND SATURDAY MORNINGS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF/CBL
SHORT TERM...CBL
LONG TERM...BLS
AVIATION...CBL/WSS/DJF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
956 AM CDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 952 AM CDT TUE MAY 26 2015
GIVEN TRENDS IN THE 11-13 HRRR ITERATIONS...AND 00 UTC WRF-
ARW/NMM...ALL OF WHICH PERFORMED WELL YESTERDAY...INCREASED POPS
ALONG AND EAST OF THE MISSOURI RIVER FOR THIS AFTERNOON AND EARLY
EVENING WITH SLIGHTLY HIGHER DEWPOINTS IN PLACE AND A TAD STRONGER
OVERALL FORCING. ACROSS THE WEST...CLOSER TO THE SURFACE RIDGE
AXIS...TRENDED POPS DOWN...WHICH IS IN AGREEMENT WITH THE 06 AND
INCOMING 12 UTC GLOBAL SUITES.
UPDATE
ISSUED AT 635 AM CDT TUE MAY 26 2015
ONLY UPDATE WAS TO EXPAND FOG WORDING SOUTHWEST. WILL ALSO ISSUE A
SPECIAL WEATHER STATEMENT FOR THIS AREA WITH WEB CAMS INDICATING
SOME AREAS OF DENSE FOG. AT THIS TIME DOES NOT APPEAR WIDESPREAD
ENOUGH FOR A DENSE FOG ADVISORY WITH VISIBILITIES FLUCTUATING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM CDT TUE MAY 26 2015
A NICE DAY WITH TEMPERATURES IN THE 70S AND 80S IS ON TAP FOR
WESTERN AND CENTRAL NORTH DAKOTA.
SOME ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AS DIURNAL
HEATING PROVIDES SOME INSTABILITY AND DIFFERENTIAL DIVERGENCE
PROVIDES ENOUGH LIFT ENHANCEMENT. THE 00 UTC WRFS AND THE LATEST
RAP RUN SHOWS ISOLATED CONVECTION DEVELOPING MAINLY OVER CENTRAL
NORTH DAKOTA THIS AFTERNOON AND DIEING OUT AROUND SUNSET.
HOWEVER...DUE TO THE BROAD AREA OF INSTABILITY AND DIVERGENCE
ALOFT...AND LOW CONFIDENCE IN ANY ONE PARTICULAR MODEL...WENT
AHEAD AND PUT IN POSSIBLE ISOLATED THUNDERSTORMS ACROSS ALL
WESTERN AND CENTRAL NORTH DAKOTA.
LATE TONIGHT A COLD FRONT WILL ENTER NORTHERN NORTH DAKOTA. SOME
ISOLATED SHOWERS ARE POSSIBLE EARLY TOMORROW MORNING NORTH. LEE
CYCLOGENESIS WILL ALSO OCCUR LATE TONIGHT INTO TOMORROW. A SURFACE
LOW IS PROGGED TO ENTER THE WESTERN DAKOTAS BY TOMORROW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 403 AM CDT TUE MAY 26 2015
TWO ACTIVE PERIODS...WITH A DRY AND COOL COUPLE OF DAYS IN THE
MIDDLE...WILL HIGHLIGHT THE LONG TERM PERIOD.
UPPER LEVEL LOW/SHORT WAVE TROUGH OVER THE PACIFIC NORTHWEST WILL
EJECT LEAD WAVES ACROSS THE DAKOTAS EACH BRINGING CHANCES FOR
PRECIPITATION WEDNESDAY-THURSDAY. BEST CHANCE FOR WIDESPREAD
RAINFALL AND SCATTERED THUNDERSTORMS LOOKS TO BE THE WEDNESDAY
AFTERNOON-EVENING PERIOD WHEN ONE OF THE MORE DEFINED S/WV
IMPULSES MOVES EAST ACROSS NORTH DAKOTA ALONG WITH AN AREA OF SFC
LOW PRESSURE. PARENT UPPER LOW IS PROJECTED TO REMAIN OFF TO OUR
SOUTH AS IT MOVES EAST INTO THE CENTRAL PLAINS TOWARDS THE END OF
THE WEEK. A STABLE AIRMASS ASSOCIATED WITH SURFACE HIGH PRESSURE
WILL DEVELOP FROM NORTH TO SOUTH LATE THURSDAY NIGHT INTO FRIDAY
ACROSS THE NORTHERN PLAINS...AND REMAINS IN PLACE THROUGH
SATURDAY. HIGHS FRI-SAT COMFORTABLE AT 55-65.
ROBUST RETURN FLOW SUNDAY INTO EARLY NEXT WEEK AS HIGH PRESSURE
MOVES OFF TO OUR EAST. STRONG MOISTURE ADVECTION ALONG WITH
HIGH TEMPERATURES WARMING INTO THE 70S TO LOWER 80S WILL RESULT
IN INCREASING INSTABILITY MONDAY INTO TUESDAY. 12Z GFS/EC PROJECT
ANYWHERE FROM 1500-3500 J/KG OF MUCAPE. BECOMES MORE INTERESTING
TUESDAY-WEDNESDAY WHEN FLOW ALOFT TRANSITIONS TO SOUTHWESTERLY.
LOTS OF UNCERTAINTY YET BUT SOMETHING WORTH KEEPING AN EYE ON OVER
THE NEXT SEVERAL DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 952 AM CDT TUE MAY 26 2015
VFR CONDITIONS EXPECTED AREA WIDE FOR TODAY OUTSIDE OF SCATTERED
SHOWERS AND THUNDERSTORMS THAT ARE EXPECTED TO DEVELOP THIS
AFTERNOON AND INTO THE EVENING...MAINLY ACROSS CENTRAL NORTH
DAKOTA. KMOT AND KJMS ARE THE MOST LIKELY TERMINALS TO BE
IMPACTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1045 AM EDT TUE MAY 26 2015
.SYNOPSIS...
WARM AND HUMID AIR WILL REMAIN IN PLACE OVER THE MIDDLE OHIO VALLEY
THROUGH THE REST OF THE WEEK. AS UPPER LEVEL DISTURBANCES MOVE
THROUGH THE AREA...THERE WILL BE OCCASIONAL CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND WEDNESDAY...AND THEN AGAIN OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SKIES ARE CLEARING ACROSS THE REGION WHICH WILL ALLOW FOR A WINDOW
OF HEATING AND DESTABILIZATION. HOWEVER POOR MID LEVEL LAPSE
RATES AS SEEN ON THE 12Z SOUNDING SHOULD BE A LIMITING FACTOR IN
HOW MUCH INSTABILITY DEVELOPS. STILL SOME QUESTION OF CONVECTIVE
TIMING ALTHOUGH RECENT RUNS OF THE HRRR AND RAP ARE IN AGREEMENT
IN DEVELOPING STORMS MOVING INTO THE WESTERN AND SOUTHERN PARTS OF
THE FORECAST AREA AROUND OR SHORTLY AFTER 18Z AND THEN TRACKING
ACROSS THE REGION THROUGH THE AFTERNOON AND EARLY EVENING. THIS IS
BROADLY IN AGREEMENT WITH THE NSSL WRF SOLUTION. IT DOES APPEAR
THAT ADDITIONAL SCATTERED CONVECTION MAY CONTINUE AFTER 00Z WITH
THE BETTER CHANCE SEEMINGLY IN THE SOUTHEAST COUNTIES ALTHOUGH
THIS MORE FAVORABLE LOCATION MAY DIFFER DEPENDING ON HOW EARLIER
STORMS EVOLVE.
FORECAST INSTABILITY AND SHEAR SEEM ON THE MARGINAL SIDE AND THE
JUXTAPOSITION OF THESE TWO FACTORS DOES NOT APPEAR PARTICULARLY
IN SYNC. NONETHELESS CANNOT RULE OUT A FEW SEVERE STORMS THIS
AFTERNOON AND EARLY EVENING WITH DAMAGING STRAIGHT LINE WINDS THE
MAIN THREAT.
MAIN UPDATE WAS ADJUSTING TIMING OF POPS AND BUMPING UP WINDS
SLIGHTLY.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ON WEDNESDAY...AN UPPER TROUGH WILL BE MOVING EAST INTO THE GREAT
LAKES REGION. INITIALLY FAIRLY WELL-DEFINED OVER THE UPPER
MISSISSIPPI VALLEY (AND HELPING TO DRIVE THE MORE ACTIVE WEATHER
ON TUESDAY)...THIS TROUGH WILL BE WASHING OUT AS IT PROGRESSES
AHEAD. STILL...IT WILL LEAVE THE MIDDLE OHIO VALLEY IN A FAVORABLE
AREA OF LIFT...THOUGH SURFACE FEATURES WILL BE LACKING AND THUS
FORCING MAY NOT BE PARTICULARLY WELL FOCUSED. WHILE SHEAR WILL
CONTINUE TO BE MODEST...INSTABILITY SHOULD ACTUALLY INCREASE
SLIGHTLY FROM TUESDAY...WITH MLCAPE VALUES PERHAPS APPROACHING
2000 J/KG IN THE SOUTHWESTERN SECTIONS OF THE CWA (AND UP TO 1500
J/KG ELSEWHERE). THUS...AMONG THE SCATTERED THUNDERSTORMS THAT
DEVELOP...A FEW STRONG TO POSSIBLY SEVERE STORMS MAY OCCUR.
AS THE AFOREMENTIONED TROUGH CONTINUES TO WEAKEN AND MOVE
EAST...THE ILN FORECAST AREA WILL END UP IN A REGIME OF BUILDING
RIDGING ALOFT...AND A WEAK/NEBULOUS AREA OF HIGH PRESSURE AT THE
SURFACE. BY THURSDAY...THIS WILL BEGIN TO LIMIT THE CHANCES FOR
CONVECTION...WITH DIURNAL DEVELOPMENT ONLY APPEARING TO BE A
POSSIBILITY IN THE SOUTHERN HALF OF THE FORECAST AREA. FRIDAY WILL
LIKELY BEGIN DRY AS WELL...THOUGH THE FLOW WILL BE SWITCHING BACK
TO THE SOUTH IN THE SECOND HALF OF THE DAY...LEAVING A POSSIBILITY
FOR SOME DEVELOPMENT (ESPECIALLY FOR THE SOUTHWESTERN HALF OF THE
FORECAST AREA) BY LATE AFTERNOON AND EVENING. TO NOTE...THE GFS
HAS BEEN A LITTLE MORE AGGRESSIVE THAN OTHER MODELS WITH THE
SOUTHWARD PUSH OF THE AREA OF HIGH PRESSURE INTO THE OHIO
VALLEY...AND WOULD SUPPORT AN EVEN DRIER FORECAST FOR THURSDAY AND
THE FIRST HALF OF FRIDAY.
TEMPERATURES AND DEWPOINTS ARE EXPECTED TO CHANGE VERY LITTLE OVER
THE COURSE OF THE WEEK. A VERY SLIGHTLY DRIER AIR MASS WILL BE
SETTLING IN ON THURSDAY AND INTO FRIDAY...WHICH MAY ALLOW SOME
SLIGHTLY COOLER MIN TEMPS ON FRIDAY MORNING. OTHERWISE...MIN TEMPS
WILL LIKELY NOT DROP BELOW THE MID 60S. MAX TEMPS SHOULD REMAIN
AROUND 80 DEGREES...BUT CONVECTION AND CLOUDS (OR A LACK THEREOF)
COULD HAVE AN IMPACT IN EITHER DIRECTION...ESPECIALLY TODAY
(TUESDAY) AND WEDNESDAY. FRIDAY MAY BE THE WARMEST DAY OF THE
WEEK...WITH DRY AND SUNNY CONDITIONS TO BEGIN THE DAY...WITH WARM
ADVECTION KICKING IN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MID/UPPER LEVEL FLOW WILL BECOME MORE AMPLIFIED THROUGH THE
WEEKEND AS SHORT WAVE ENERGY MOVES OUT OF THE ROCKIES AND INTO THE
CENTRAL PLAINS. THIS WILL EVENTUALLY LEAD TO A FRONTAL BOUNDARY
PUSHING DOWN TOWARD AND POSSIBLY THROUGH OUR FA THROUGH EARLY NEXT
WEEK. HOWEVER...THERE REMAINS QUITE A BIT OF DIFFERENCE BETWEEN
THE ECMWF/GFS/CMC WITH HOW FAST AND HOW FAR SOUTH TO PUSH THE
FRONT AND WHETHER OR NOT TO STALL IT OUT ACROSS OUR AREA TOWARD
THE END OF THE PERIOD. THIS WILL LEAD TO THE POTENTIAL FOR A
FAIRLY WET/MORE ACTIVE PERIOD THROUGH THE END OF THE LONG TERM BUT
DUE TO THE TIMING UNCERTAINTIES...WILL JUST KEEP POPS IN THE HIGH
CHANCE CATEGORY.
FRIDAY WILL BE SEASONABLY WARM WITH HIGHS IN THE MID 80S. MORE
SEASONABLE TEMPERATURES WILL THEN BEGIN TO PUSH DOWN FROM THE NORTH
OVER THE WEEKEND...BUT THEY WILL ULTIMATELY BE DICTATED BY THE
PLACEMENT/TIMING OF THE FRONTAL BOUNDARY. FOR THAT REASON...HAVE
GENERALLY GONE WITH A MODEL BLEND FOR TEMPERATURES SATURDAY THROUGH
MONDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
OUR REGION WILL BE UNDERNEATH A MOIST SOUTHWEST FLOW ALOFT. MORNING
DAYTIME HEATING WILL RESULT IN CUMULUS DEVELOPMENT WITH WINDS
PICKING UP FROM THE SOUTH. BY THE AFTERNOON HOURS...A DISTURBANCE
WILL ROTATE NORTHEAST INTO THE WESTERN GREAT LAKES. A TRAILING
TAIL/INFLECTION IN THE MID LEVELS WILL TEAM UP WITH A POTENTIAL
LOW LEVEL CONVERGENT AXIS TO BRING THE LIKELIHOOD OF SHOWERS AND
THUNDERSTORMS. THERE CONTINUES TO BE SOME TIMING AND EVOLUTION
ISSUES WITH THE HIGH RESOLUTION MODELS. HAVE PICKED A 3 HOUR TEMPO
WINDOW WHEN THE BEST CHANCE FOR THUNDERSTORMS SHOULD BE AT EACH
TAF SITE LATE THIS AFTERNOON INTO THIS EVENING. WITH THE MOIST
AIRMASS IN PLACE...MVFR CONDITIONS WILL BE LIKELY WITH STORMS WITH
LOCAL POCKETS OF IFR CONDITIONS (MOST LIKELY VISIBILITIES) DUE TO
HEAVY RAINFALL IN THE STRONGEST CORES.
FOR TONIGHT...DISTURBANCE AND ITS TAIL/INFLECTION WILL PUSH OFF TO
THE NORTHEAST THROUGH THE REMAINDER OF OUR REGION. WITH THE LOSS
OF DAYTIME HEATING...WE SHOULD SEE A GRADUAL DECREASE IN
THUNDERSTORM ACTIVITY...WITH JUST A FEW SHOWERS LINGERING IN THE
MOIST FLOW LATE TONIGHT. MODELS SUGGEST THAT MVFR/IFR CEILINGS
(DUE TO POTENTIAL STRATUS) MAY DEVELOP IN THE 06Z TO 12Z. HAVE
ADDED MVFR CEILINGS TO THE TAF SITES FOR NOW.
.OUTLOOK...MVFR/IFR CEILINGS POSSIBLE WEDNESDAY MORNING. THUNDERSTORMS
POSSIBLE WEDNESDAY AFTERNOON AND EVENING...AND AGAIN SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
854 AM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE AT THE SFC AND ALOFT WILL REMAIN JUST OFF THE EAST
COAST THROUGH THE END OF THE WEEK. A COLD FRONT WILL LIKELY PUSH
ACROSS THE REGION NEXT WEEKEND...THEN STALL JUST SOUTH OF THE
STATE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DEEP SOUTH-SOUTHWESTERLY FLOW ON WESTERN PERIPHERY OF THE
DOMINANT COAST RIDGE WILL TRANSPORT GULF OF MEX MOISTURE
NORTHWARD INTO CENTRAL PA EARLY THIS MORNING. SAT-DERIVED PWATS NR
1.7 INCHES ACROSS NORTHERN/WESTERN PA AT 09Z. REGIONAL RADAR AT
1230Z SHOWING ISOLATED-SCATTERED SHRA DEVELOPING IN THIS MOIST
AIR MASS IN ADVANCE OF A MID LVL VORT MAX LIFTING NE OUT OF
SOUTHERN OHIO. BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL
CARRY CHC OF SHRA ACROSS THE NW MTNS THIS MORNING. FOR AREAS
SOUTH AND EAST OF KJST/KUNV/KIPT...THE REST OF THE LATE MORNING
HRS SHOULD REMAIN DRY.
AFTER THE PASSAGE OF THE SHORTWAVE LATER THIS MORNING...LG SCALE
FORCING BECOMES QUITE VERY WEAK. HOWEVER...HEATING OF MOIST AIR
MASS WITH PWATS 2-3SD ABV CLIMO SHOULD YIELD SCT DIURNALLY-DRIVEN
SHRA/TSRA THIS AFTN WITH LATEST NAM AND SREF MEAN SFC-CAPES MAXING
OUT AROUND 1000 J/KG. THE BEST CHC FOR CONVECTION WILL LIKELY BE
ACROSS THE CENTRAL MTNS AND MIDDLE SUSQ VALLEY...WHERE 50 PCT POPS
PAINTED. EARLY CLOUDS/SHOWERS ACROSS THE NW SHOULD RESULT IN LESS
INSTABILITY AND A DIMINISHED CHC OF CONVECTION UP THERE. ACROSS
SOUTHEAST PA...WARMER TEMPS ALOFT SHOULD HELP SUPPRESS CONVECTION
OVR THE LOWER SUSQ VALLEY.
MEAN SREF/GEFS CAPES TOP OUT NR OR SLIGHTLY LESS THAN 1000 J/KG
THIS AFTN AND SHEAR NOT PARTICULARLY STRONG. THUS...SPC OUTLOOK
KEEPS THE MRGL RISK WEST OF OUR CWA.
EARLY AM IR LOOP SUGGESTS AREAS SOUTH OF I-80 WILL DAWN MSUNNY
TODAY. HOWEVER...A GOOD DEAL OF CU SHOULD DEVELOP BY MIDDAY BASED
ON MDL SOUNDINGS. TEMPS ARE LIKELY TO BE A BIT COOLER THAN MONDAY
DUE TO MORE CLOUDS...WITH MAXES FROM THE U70S OVR THE ALLEGHENY
PLATEAU...TO THE M80S ACROSS THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
DIURNALLY-DRIVEN CONVECTION SHOULD DIE OFF AFTER SUNSET THIS
EVENING. THE REST OF THE NIGHT WILL LIKELY FEATURE WARM AND
TRANQUIL CONDS. HIGH PWAT AIR MASS WILL RESULT IN MID SUMMER MIN
TEMPS...WITH LOWS IN THE M/U60S MOST PLACES.
A POTENT SHORTWAVE LIFTING THRU THE GRT LKS WILL INTRODUCE A
BETTER CHC OF SHRA/TSRA ON WEDNESDAY. MDL TIMING OF THIS FEATURE
SUGGESTS SHOWERS COULD ARRIVE EARLY IN THE DAY ACROSS THE W
COUNTIES...WITH A GREATER RISK OF PM TSRA ACROSS EASTERN PA. GEFS
MEAN CAPES PEAK ARND 1200 J/KG ACROSS THE SE COUNTIES WED AFTN.
HOWEVER...MID LVL WINDS AND ASSOC DEEP LYR SHEAR NOT PARTICULARLY
STRONG IN MDL DATA...SO SVR WX THREAT JUST MRGL. MCLDY SKIES WILL
HOLD TEMPS DOWN A BIT...BUT CONSALL STILL SUGGESTS HIGH TEMPS BTWN
THE M70S-L80S...SEVERAL DEG ABV NORMAL FOR LATE MAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRES AT SFC AND ALOFT JUST OFF THE EAST COAST SHOULD KEEP
WARM/HUMID AIR OVR CENTRAL PA THRU THE END OF THE WEEK. PASSAGE
OF MID LVL SHORTWAVE ON THURSDAY SHOULD SUPPORT ADDITIONAL SCT
SHRA/TSRA THURSDAY. BY FRIDAY...BULK OF MED RANGE GUIDANCE IMPLIES
DRIER WX /ESP NORTHERN PA/...AS LOWER PWAT AIR MASS WORKS INTO
CENTRAL PA IN ASSOC WITH HIGH PRES WORKING ACROSS S ONTARIO INTO N
NEW ENG.
A COLD FRONT WILL LIKELY BRING AN END TO THE SUMMERLIKE
WARMTH/HUMIDITY BY NEXT WEEKEND. A FAIR AMT OF AGREEMENT AMONG
MED RANGE GUIDANCE THAT A PERIOD OF RAINY WX COULD FOLLOW LATE
SUNDAY/MONDAY AS WAVE OF LOW PRES RIDES EASTWARD ALONG STALLED
FRONTAL BNDRY SOUTH OF PA.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
ISOLATED SHOWER ACTIVITY HAS DEVELOPED ALONG A SW TO NE LINE FROM
NEAR KJST TO NORTH OF KIPT. ACTIVITY IS LIGHT AND SHOULD NOT
CAUSE A DIRECT IMPACT. HOWEVER...MOISTURE FROM THE SHOWERS WILL
LEAD TO LOWERED CIGS OVER THE NEXT COUPLE OF HOURS ACROSS THAT
REGION.
VFR SHOULD CONTINUE AT MOST SITES OVER THE NEXT 24 HOURS. HIGHEST
CONFIDENCE IN BRIEF 1-3HR PERIOD OF 3-6SM VISIBILITY RESTRICTIONS
IN BR/HZ IS AT MDT/LNS AROUND DAYBREAK TUESDAY. GIVEN RELATIVELY
LOW PROBABILITY/EXPECTED COVERAGE...DECIDED NOT TO EXPLICITLY
MENTION TSTMS IN TERMINALS AT THIS TIME. LATER ISSUANCES SHOULD
INTRODUCE A VCTS FM GROUP WITH EITHER THE 06 OR 12Z ISSUANCE.
A SUMMER-TIME PATTERN WILL PERSIST THROUGH THE WEEK WITH REPLAY OF
PATCHY MORNING FOG GIVING WAY TO VFR AND AFTN ISOLD-SCT TSTMS. A
MORE DEFINED TSTM RISK SHOULD ARRIVE BY NEXT WEEKEND AS A COLD
FRONT PRESSES SEWD FROM THE GREAT LAKES.
OUTLOOK...
TUE-FRI...PATCHY A.M. MVFR FOG/BR. ISOLD-SCT P.M. TSTMS.
SAT-SUN...PATCHY A.M. MVFR FOG/BR. SCT-NMRS P.M TSTMS W/COLD
FROPA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LAMBERT
NEAR TERM...FITZGERALD/LAMBERT
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...GARTNER/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
616 AM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE AT THE SFC AND ALOFT WILL REMAIN JUST OFF THE EAST
COAST THROUGH THE END OF THE WEEK. A COLD FRONT WILL LIKELY PUSH
ACROSS THE REGION NEXT WEEKEND...THEN STALL JUST SOUTH OF THE
STATE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DEEP SOUTHERLY FLOW ON WESTERN PERIPHERY OF E COAST RIDGE IS
TRANSPORTING GULF OF MEX MOISTURE NORTHWARD INTO WESTERN EARLY
THIS MORNING. SAT-DERIVED PWATS NR 1.7 INCHES ACROSS
NORTHERN/WESTERN PA AT 09Z. REGIONAL RADAR AT 09Z SHOWING SCT
SHRA DEVELOPING IN THIS MOIST AIR MASS IN ADVANCE OF A MID LVL
VORT MAX LIFTING NE OUT OF SOUTHERN OHIO. BASED ON RADAR TRENDS
AND LATEST HRRR OUTPUT...WILL CARRY CHC OF SHRA ACROSS THE NW
MTNS EARLY THIS MORNING. FOR AREAS SOUTH AND EAST OF
KJST/KUNV/KIPT...THE AM HRS SHOULD REMAIN DRY.
AFTER PASSAGE OF SHORTWAVE LATER THIS MORNING...LG SCALE FORCING
BECOMES VERY WEAK. HOWEVER...HEATING OF MOIST AIR MASS WITH PWATS
2-3SD ABV CLIMO SHOULD YIELD SCT DIURNALLY-DRIVEN SHRA/TSRA THIS
AFTN. BEST CHC WILL LIKELY BE ACROSS THE CENTRAL MTNS AND MIDDLE
SUSQ VALLEY...WHERE 50 PCT POPS PAINTED. EARLY CLOUDS/SHOWERS
ACROSS THE NW SHOULD RESULT IN LESS INSTABILITY AND A DIMINISHED
CHC OF CONVECTION UP THERE. ACROSS SOUTHEAST PA...WARMER TEMPS
ALOFT SHOULD HELP SUPPRESS CONVECTION OVR THE LOWER SUSQ VALLEY.
MEAN SREF/GEFS CAPES TOP OUT NR OR SLIGHTLY LESS THAN 1000 J/KG
THIS AFTN AND SHEAR NOT PARTICULARLY STRONG. THUS...SPC OUTLOOK
KEEPS THE MRGL RISK WEST OF OUR CWA.
EARLY AM IR LOOP SUGGESTS AREAS SOUTH OF I-80 WILL DAWN MSUNNY
TODAY. HOWEVER...A GOOD DEAL OF CU SHOULD DEVELOP BY MIDDAY BASED
ON MDL SOUNDINGS. TEMPS ARE LIKELY TO BE A BIT COOLER THAN MONDAY
DUE TO MORE CLOUDS...WITH MAXES FROM THE U70S OVR THE ALLEGHENY
PLATEAU...TO THE M80S ACROSS THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
DIURNALLY-DRIVEN CONVECTION SHOULD DIE OFF AFTER SUNSET THIS
EVENING. THE REST OF THE NIGHT WILL LIKELY FEATURE WARM AND
TRANQUIL CONDS. HIGH PWAT AIR MASS WILL RESULT IN MID SUMMER MIN
TEMPS WITH LOWS IN THE M/U60S MOST PLACES.
A POTENT SHORTWAVE LIFTING THRU THE GRT LKS WILL INTRODUCE A
BETTER CHC OF SHRA/TSRA ON WEDNESDAY. MDL TIMING OF THIS FEATURE
SUGGESTS SHOWERS COULD ARRIVE EARLY IN THE DAY ACROSS THE W
COUNTIES...WITH A GREATER RISK OF PM TSRA ACROSS EASTERN PA. GEFS
MEAN CAPES PEAK ARND 1200 J/KG ACROSS THE SE COUNTIES WED AFTN.
HOWEVER...MID LVL WINDS AND ASSOC DEEP LYR SHEAR NOT PARTICULARLY
STRONG IN MDL DATA...SO SVR WX THREAT JUST MRGL. MCLDY SKIES WILL
HOLD TEMPS DOWN A BIT...BUT CONSALL STILL SUGGESTS HIGH TEMPS BTWN
THE M70S-L80S...SEVERAL DEG ABV NORMAL FOR LATE MAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRES AT SFC AND ALOFT JUST OFF THE EAST COAST SHOULD KEEP
WARM/HUMID AIR OVR CENTRAL PA THRU THE END OF THE WEEK. PASSAGE
OF MID LVL SHORTWAVE ON THURSDAY SHOULD SUPPORT ADDITIONAL SCT
SHRA/TSRA THURSDAY. BY FRIDAY...BULK OF MED RANGE GUIDANCE IMPLIES
DRIER WX /ESP NORTHERN PA/...AS LOWER PWAT AIR MASS WORKS INTO
CENTRAL PA IN ASSOC WITH HIGH PRES WORKING ACROSS S ONTARIO INTO N
NEW ENG.
A COLD FRONT WILL LIKELY BRING AN END TO THE SUMMERLIKE
WARMTH/HUMIDITY BY NEXT WEEKEND. HOWEVER...A FAIR AMT OF AGREEMENT
AMONG MED RANGE GUIDANCE THAT A PERIOD OF RAINY WX COULD FOLLOW
LATE SUNDAY/MONDAY AS WAVE OF LOW PRES RIDES EASTWARD ALONG
STALLED FRONTAL BNDRY SOUTH OF PA.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
ISOLATED SHOWER ACTIVITY HAS DEVELOPED ALONG A SW TO NE LINE FROM
NEAR KJST TO NORTH OF KIPT. ACTIVITY IS LIGHT AND SHOULD NOT
CAUSE A DIRECT IMPACT. HOWEVER...MOISTURE FROM THE SHOWERS WILL
LEAD TO LOWERED CIGS OVER THE NEXT COUPLE OF HOURS ACROSS THAT
REGION.
VFR SHOULD CONTINUE AT MOST SITES OVER THE NEXT 24 HOURS. HIGHEST
CONFIDENCE IN BRIEF 1-3HR PERIOD OF 3-6SM VISIBILITY RESTRICTIONS
IN BR/HZ IS AT MDT/LNS AROUND DAYBREAK TUESDAY. GIVEN RELATIVELY
LOW PROBABILITY/EXPECTED COVERAGE...DECIDED NOT TO EXPLICITLY
MENTION TSTMS IN TERMINALS AT THIS TIME. LATER ISSUANCES SHOULD
INTRODUCE A VCTS FM GROUP WITH EITHER THE 06 OR 12Z ISSUANCE.
A SUMMER-TIME PATTERN WILL PERSIST THROUGH THE WEEK WITH REPLAY OF
PATCHY MORNING FOG GIVING WAY TO VFR AND AFTN ISOLD-SCT TSTMS. A
MORE DEFINED TSTM RISK SHOULD ARRIVE BY NEXT WEEKEND AS A COLD
FRONT PRESSES SEWD FROM THE GREAT LAKES.
OUTLOOK...
TUE-FRI...PATCHY A.M. MVFR FOG/BR. ISOLD-SCT P.M. TSTMS.
SAT-SUN...PATCHY A.M. MVFR FOG/BR. SCT-NMRS P.M TSTMS W/COLD
FROPA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...GARTNER/STEINBUGL
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1042 AM CDT TUE MAY 26 2015
.UPDATE...
THE MAIN CHANGES MADE TO THE ONGOING FORECAST WERE TO DROP HIGH
TEMPERATURES ACROSS PARTS OF THE AREA DUE TO THE CLOUDS ALONG THE
I-35 CORRIDOR AND TO ADJUST POPS FOR TODAY. HIGH RESOLUTION MODELS
CONTINUE TO SUGGEST THAT WE WILL ONLY SEE A FEW ISOLATED
THUNDERSTORMS THIS AFTERNOON. THE HRRR AND TEXAS TECH WRF BOTH
PICK UP ON THE POSSIBILITY OF A SERRANIAS DEL BURRO SUPERCELL OR
TWO. BOTH MESOSCALE MODELS KEEP THESE STORMS OVER MEXICO...BUT
WITH A FAVORABLE ENVIRONMENT FOR STORMS ACROSS THE RIO GRANDE
PLAINS IT IS WORTH WATCHING. THE MORNING DEL RIO UPPER AIR
SOUNDING WAS UN-CAPPED WITH A GOOD AMOUNT OF SHEAR AND LARGE CAPE
NEAR 4000 J/KG. WHAT SHOULD KEEP ACTIVITY MORE ISOLATED TODAY IS
THAT THE MID AND UPPER LEVELS ARE FAIRLY DRY.
RIVER FLOODING IS STILL A MAJOR CONCERN ACROSS OUR ARE WITH
MODERATE OR MAJOR FLOODING ONGOING ALONG THE
COLORADO...FRIO...GUADALUPE...SAN MARCOS...AND NUECES RIVERS.
THERE ARE TWO SURVEY TEAMS CURRENTLY OUT SURVEYING DAMAGE REPORTS
FROM YESTERDAYS STORMS. ONE WENT OUT TO THE TEXAS HILL COUNTRY
WHILE THE OTHER WILL BE VISITING BASTROP COUNTY AND THE COASTAL
PLAINS COUNTIES. MORE INFORMATION WILL BE PROVIDED THIS AFTERNOON
ONCE THESE TEAMS RETURN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 86 73 87 72 86 / 20 20 20 20 30
AUSTIN BERGSTROM INTL AIRPORT 85 72 87 71 86 / 20 20 20 20 30
NEW BRAUNFELS MUNI AIRPORT 86 73 88 72 87 / 20 20 20 20 30
BURNET MUNI AIRPORT 85 69 86 70 84 / 20 20 20 20 30
DEL RIO INTL AIRPORT 89 74 89 74 86 / 30 20 20 20 40
GEORGETOWN MUNI AIRPORT 85 70 87 71 86 / 20 20 20 20 30
HONDO MUNI AIRPORT 86 73 88 73 86 / 30 20 20 20 40
SAN MARCOS MUNI AIRPORT 85 73 87 72 85 / 20 20 20 20 30
LA GRANGE - FAYETTE REGIONAL 86 74 88 73 87 / 20 20 20 20 40
SAN ANTONIO INTL AIRPORT 87 74 88 73 86 / 20 20 20 20 30
STINSON MUNI AIRPORT 87 74 88 73 87 / 20 20 20 20 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...26
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
128 PM MDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 124 PM MDT TUE MAY 26 2015
RADAR CONTINUES TO LIGHT UP THIS AFTERNOON WITH A FEW STRONGER
CELLS POPPING UP OVER THE HIGHER TERRAIN SOUTHWEST. OUTFLOW
BOUNDARIES EVIDENT IN 0.5 DEGREE SLICES WILL PROVIDE ADDITIONAL
FOCUS FOR NEW STORM DEVELOPMENT AS WE WORK THROUGH THIS AFTERNOON.
HAIL...HEAVY RAIN AND GUSTY OUTFLOW WINDS WILL BE THE PRIMARY
CONCERNS THROUGH EARLY THIS EVENING. HAVE MADE SOME ADJUSTMENTS TO
THE GRIDS TO FIT CURRENT AND EXPECTED TRENDS OVER THE NEXT FEW
HOURS.
UPDATE ISSUED AT 759 AM MDT TUE MAY 26 2015
WAVE MOVING ACROSS UTAH AT A DECENT CLIP THIS MORNING. ALREADY
SEEING A FEW NEW SHOWERS DEVELOPING ACROSS PORTIONS OF EASTERN
UTAH AND LATEST HRRR RUN SHOWS ACTIVITY INCREASING IN COVERAGE
FAIRLY QUICKLY BY MIDDAY. HAVE BUMPED POPS UP ACROSS MUCH OF THE
FORECAST AREA THROUGH THIS AFTERNOON. SHOULD SEE A FEW STRONGER
CELLS TODAY WITH HAIL AND HEAVY RAIN EXPECTED.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
A SHORTWAVE RIDGE WILL START THE DAY AS THE CLOSED LOW OVER THE
PACNW VERY SLOWLY STARTS TO DROP TO THE SOUTHEAST. SIMILAR
ATMOSPHERIC CONDITIONS REMAIN IN PLACE THAT HAVE BEEN FOR THE
LAST SEVERAL DAYS...PLENTY OF MOISTURE...DAYTIME HEATING AND
MODEST INSTABILITY. POTENTIAL VORTICITY FIELDS ALSO INDICATING A
WEAK UPPER LEVEL TROUGH WILL MOVE OVER THE AREA WHICH...WITH ALL
THE ABOVE...WILL CAUSE SHOWERS AND STORMS TO FIRE. CONVECTION WILL
BEGIN AROUND NOONTIME WHEN THE FIRST VORT MAX MOVES OVERHEAD FROM
WEST TO EAST THOUGH WIDESPREAD THUNDERSTORMS AND SHOWERS LOOK TO
REACH A MAXIMUM FROM 3PM ONWARDS AS THAT TROUGH APPROACHES FROM
THE WEST. SOME BRIEF HEAVY RAIN...GUSTY WINDS...AND SMALL HAIL
WILL REMAIN THE BIGGEST THREATS. MODELS KEEP PRECIP GOING THROUGH
MIDNIGHT SO FORECAST WILL FOLLOW SUIT THOUGH COVERAGE WILL
DROP...AS IT ALWAYS DOES...AFTER SUNSET. A FEW LINGERING SHOWERS
WILL LIKELY PERSIST AFTER MIDNIGHT.
BY WEDNESDAY...THE CLOSED LOW WILL ONLY HAVE MADE IT AS FAR AS NRN
ID SO EXPECT ANOTHER UNSETTLED DAY OF SHOWERS AND STORMS THOUGH
MODELS HINTING AT SOMEWHAT LESS COVERAGE. ASIDE FROM THAT...THE ONLY
REALLY BIG DIFFERENCE WILL BE TEMPERATURES THAT WILL BE GETTING
CLOSE TO NORMAL THANKS TO CYCLONIC FLOW AROUND THE AREA OF LOW
PRESSURE USHERING IN WARMER AIR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
THE BEGINNING OF JUNE MAY ACTUALLY FEEL LIKE JUNE...BUT THAT IS
STILL A FEW DAYS AWAY AS THE UNSETTLED PATTERN CONTINUES THROUGH
FRIDAY. PROGRESSIVE PATTERN AT A "SNAILS PACE" PREVAILS FOR MUCH
OF THE WEEK...PACIFIC NORTHWEST TROUGH NEEDS ABOUT 2-3 DAYS TO
REACH THE CENTRAL ROCKIES. BEFORE REACHING WYOMING...PACIFIC
NORTHWEST TROUGH SENDS PIECES OF PACIFIC ENERGY STREAMING ACROSS
THE INTERMOUNTAIN WEST INTO COLORADO. THIS HELPS FUEL DIURNAL
CONVECTION ON THURSDAY...AND CONTINUES INTO FRIDAY AS THE UPPER
LOW TRACKS ACROSS SRN WYOMING.
THE DRYING TREND BEGINS SATURDAY AS THE UPPER LOW MOVES DOWNSTREAM.
DRIER DOES NOT NECESSARILY MEAN DRY AS CONVECTIVE POTENTIAL EXISTS
EACH AFTERNOON INTO MONDAY. HOWEVER DESERT SOUTHWEST RIDGING
EXPANDS INTO COLORADO BY NEXT WEEK...RESULTING IN LESS CONVECTIVE
ACTIVITY WITH EACH PASSING DAY. BY NEXT MONDAY...ANY AFTERNOON
SHOWERS/STORMS MAY BE RELEGATED TO THE COLORADO SPINE.
TEMPERATURES BEGIN THEIR SUMMER ASCENT WITH DESERT VALLEYS
REACHING THE MID 80S TO LOWER 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1127 AM MDT TUE MAY 26 2015
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THIS
EVENING...WITH ACTIVITY BECOMING MORE ISOLATED IN NATURE AFTER
06Z. EXPECT ILS BREAKPOINTS TO BE MET OR EXCEEDED AT ALL SITES AS
SHOWERS MOVE THROUGH. OTHERWISE...VFR CONDITIONS WILL PERSIST.
GUSTY OUTFLOW WINDS TO 30KTS...HAIL AND HEAVY RAIN WILL ACCOMPANY
THE STRONGEST STORMS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...TGR
LONG TERM...PF
AVIATION...JDC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1142 AM MDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 946 AM MDT TUE MAY 26 2015
UPDATE TO ADJUST SKY COVER OVER THE PLAINS AND POPS. 12Z NAM IS
SHOWING FAIRLY WIDESPREAD PRECIP THIS EVE OVER THE PLAINS.
COVERAGE IS LIKELY OVERDONE BUT IT HAS SUPPORT FROM OTHER MODELS
INCLUDING THE LATEST HRRR. WILL KEEP 20-30 PERCENT POPS OVER THE
PLAINS THIS EVE...SPREADING EWD WITH TIME. ROSE
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM MDT TUE MAY 26 2015
CURRENTLY...H5 RAP ANALYSIS INDICATES THE UPPER SHORTWAVE RIDGE WAS
MOVING INTO THE 4 CORNERS REGION EARLY THIS MORNING...AND AS THE
UPPER LOW WAS SLOWLY PROGRESSING ACROSS NE AND THE
DAKOTAS...ACTIVITY ACROSS THE CWA HAS COME TO AN END. THERE ARE SOME
MID AND HIGH LEVEL CLOUDS LINGERING...AND TEMPS HAVE DROPPED INTO
THE UPPER 30S AND 40S FOR MOST LOCATIONS.
TODAY AND TONIGHT...THE UPPER RIDGE WILL SLIDE ACROSS COLORADO OVER
THE NEXT 24 HRS...ALLOWING FOR WARMER TEMPS AND A BIT LESS
CONVECTIVE ACTIVITY. HOWEVER...HI RES MODELS STILL SHOW CONVECTION
FIRING OVER THE HIGHER TERRAIN BY MIDDAY...INCREASING IN COVERAGE
THROUGH MID-AFTERNOON...THEN TRACKING EAST ACROSS THE PLAINS THROUGH
THE EVENING. LATEST SPC GUIDANCE SHOWS THE AREA UNDER GENERAL
THUNDER...SO ALTHOUGH THERE IS ALWAYS THE CHANCE OF A MARGINALLY
SEVERE STORM THIS AFTN AND EVE...POTENTIAL IS LESS TODAY THAN IT HAS
BEEN THE PAST FEW DAYS. MAIN THREATS OF ANY STORMS TODAY WILL BE
LTG...GUSTY WINDS TO 45 MPH...AND HAIL UP TO 1/2 INCH IN DIAMETER.
LOOK FOR MAX TEMPS TODAY CLIMBING INTO THE MID 60S TO MID 70S FOR
MOST LOCATIONS...AND IN THE 40S AND 50S FOR THE MTS. MOORE
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
...PRECIPITATION CHANCES RAMPING UP AGAIN FOR THURSDAY AND
FRIDAY...
WESTERN U.S. UPPER TROF TRANSLATES EASTWARD ON WEDNESDAY WITH SRN
STREAM ENERGY MOVING INTO DESERT SOUTHWEST WHILE NRN STREAM CLOSED
LOW SETTLES OVER ID/NW WY. MOISTURE INCREASES AGAIN AHEAD OF THE
SRN STREAM TROF WED AFTERNOON WITH SCATTERED THUNDERSTORMS
DEVELOPING OVER THE MOUNTAINS BY AFTERNOON. MEANWHILE...LEE TROF
WILL MIX OUT THE DRY LINE EASTWARD INTO THE SE PLAINS. GFS IS MOST
AGGRESSIVE WITH MIXING OUT THE LOW LEVEL MOISTURE ACROSS THE SE
PLAINS...WITH MOST AREAS IN THE 30S TO LOWER 40S BY LATE
AFTERNOON. NAM12 KEEPS LOW LEVEL FLOW MORE SOUTHEASTERLY ACROSS
THE EASTERN MOST COUNTIES WHICH KEEPS SFC DEW POINTS IN THE MID TO UPPER
50S AND CAPE VALUES AROUND 2000+J/KG NEAR THE CO/KS BORDER. GIVEN
THE TROFFING STILL BACK TO OUR WEST...LEANED MORE TOWARDS THE NAM
SOLN. WITH DEEP LAYER SHEARS RUNNING AROUND 40 KTS ACROSS THE FAR
EASTERN COUNTIES...THERE COULD BE ONE OR TWO SEVERE THUNDERSTORMS
THIS DAY...AND AREA IS OUTLOOKED WITH A SLIGHT RISK.
FOCUS FOR THUNDERSTORMS SHIFTS EASTWARD ACROSS THE PLAINS
WEDNESDAY EVENING WITH SOME POTENTIAL FOR CONVECTION TO HANG ON
PAST MIDNIGHT ACROSS THE FAR EASTERN COUNTIES AS LOW LEVEL JET
STRENGTHENS THEN SHIFTS EASTWARD.
THURSDAY AND FRIDAY LOOKS LIKE ANOTHER WET PERIOD AS UPPER TROF
SLOWLY SHIFTS EASTWARD ACROSS THE AREA. WHILE BRUNT OF THE UPPER
LEVEL ENERGY PASSES TO THE NORTH OF THE AREA...SOUTHERN STREAM
TROF WILL BE EJECTING SHORTWAVE ENERGY ACROSS CO THROUGH THE
PERIOD. PRECIPITABLE WATERS INCREASE FOR BOTH DAYS...AND WITH
DIFFUSE DRY LINE MIXING EASTWARD ACROSS THE EASTERN PLAINS DURING
THE AFTERNOON THIS MAY BE THE FOCUS FOR STRONGER THUNDERSTORMS
DURING THE AFTERNOON AND EVENING HOURS. MOISTURE WILL BE
SUFFICIENT TO RAISE THE RISK OF HEAVY RAINFALL FOR ALL OF THE
FORECAST AREA...AND THERE WILL BE THE POTENTIAL FOR FLASH
FLOODING...ESPECIALLY FOR THE SOUTHEAST MOUNTAINS AND PLAINS WHERE
ANTECEDENT SOIL MOISTURE IS ALREADY HIGH. ALTHOUGH MODELS DIFFER
WITH THE PLACEMENT OF THE HIGHER DEW POINTS TO THE EAST OF THE DRY
LINE...DEW POINTS IN THE MID 50S SHOULD YIELD CAPE VALUES OF
AROUND 2000 J/KG ACROSS THE EASTERN MOST COUNTIES THURS AFTERNOON.
SHEAR LOOKS A LITTLE WEAKER...PROBABLY DUE TO MARGINAL FLOW
ALOFT...BUT CERTAINLY ENOUGH CAPE TO WARRANT AN ISOLATED SEVERE
THREAT FOR PORTIONS OF THE SE PLAINS AGAIN THURSDAY AFTERNOON. LOW
LEVEL JET CRANKS UP ACROSS THE SE PLAINS THURS EVENING WITH
POTENTIAL FOR THUNDERSTORMS TO PERSIST PAST MIDNIGHT ACROSS THE
PLAINS AS A FRONT DROPS SOUTHWARD THOUGH THE REGION. PIKES PEAK
REGION COULD BE ANOTHER FOCAL POINT FOR FLASH FLOOD CONCERNS
THURSDAY AFTERNOON AND EVENING...THOUGH THIS WILL DEPEND ON THE
POSITION AND TIMING OF THIS FRONT. AS THE UPPER TROF SHIFTS
SLOWLY EASTWARD INTO THE NRN/CEN PLAINS FRIDAY/FRI NIGHT...A
DEEPER PUSH OF THE FRONT MOVES THROUGH AND BOTH THE GFS AND ECMWF
LOOK WET AGAIN FOR FRIDAY FOR MOST OF THE DISTRICT...BUT
PARTICULARLY ACROSS THE SE MTS AND PLAINS. FLASH FLOOD THREAT MAY
BE HIGHEST THIS DAY...ESPECIALLY FOR AREAS WHICH GET HIT ON
THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES WITH THE FRONT
ON FRIDAY...SO THERE IS STILL SOME UNCERTAINTY...BUT CONCEPTUALLY
THE RISK FOR FLASH FLOODING WILL BE ELEVATED AGAIN FOR THURSDAY
AND FRIDAY.
SATURDAY LOOKS COOL AND POTENTIALLY CAPPED FOR THE SOUTHEAST
PLAINS THOUGH UPSLOPE FLOW BEHIND THE FRONT SHOULD TRIGGER ANOTHER
ROUND OF SCATTERED THUNDERSTORMS FOR THE SE MTS AND ADJACENT I-25
CORRIDOR. THE MAIN THREAT WILL BE HEAVY RAINFALL AND THE
POTENTIAL FOR LOCALIZED FLASH FLOODING. THERE COULD BE SOME
POCKETS OF SUFFICIENT CAPE ALONG THE EASTERN SLOPES OF THE SE MTS
FOR SOME STRONG TO MARGINALLY SEVERE THUNDERSTORMS...BUT FOR NOW
DEEP LAYER SHEARS DO NOT LOOK TERRIBLY IMPRESSIVE. MAIN THREAT
LOOKS LIKE HEAVY RAIN AND POTENTIALLY FOR MARGINALLY SEVERE HAIL.
A DRYING AND WARMING TREND SETS IN FOR SUNDAY THROUGH EARLY NEXT
WEEK AS ANOTHER SHORT WAVE RIDGE MOVES OVER THE REGION. ANOTHER
TROF ENTERS THE WEST COAST SUNDAY NIGHT/MON...BUT TRACK APPEARS TO
STAY FARTHER OFF TO THE NORTHWEST THIS TIME...WHICH PUTS CO UNDER
RELATIVELY DRY SOUTHWEST FLOW ALOFT THROUGH TUESDAY. THUS GRIDS
WILL CARRY A GENERAL WARMING AND DRYING TREND. -KT
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1138 AM MDT TUE MAY 26 2015
MAIN AVN CONCERN WILL BE TS POTENTIAL...PARTICULARLY AT KCOS
LATE THIS AFTERNOON AND EVE. COULD SEE BRIEF MVFR-IFR CONDITIONS
ALONG WITH HEAVY RAINFALL AND POSSIBLY SOME SMALL HAIL. THREAT
WILL BE HIGHEST FROM 22Z-03Z THIS EVE. SOME MODEL FORECASTS ARE
INDICATING TWO ROUNDS OF CONVECTION...ONE THIS AFTERNOON AND
ANOTHER LATER THIS EVENING...POSSIBLY LINGERING PAST 06Z. WINDS
WILL CONTINUE TO BE LIGHT EXCEPT VCTS. SIMILAR PICTURE
TOMORROW...ALTHOUGH STORMS COULD EB A BIT STRONGER
TOMORROW...ESPECIALLY E OF I-25. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ROSE
SHORT TERM...MOORE
LONG TERM...KT
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1129 AM MDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 759 AM MDT TUE MAY 26 2015
WAVE MOVING ACROSS UTAH AT A DECENT CLOP THIS MORNING. ALREADY
SEEING A FEW NEW SHOWERS DEVELOPING ACROSS PORTIONS OF EASTERN
UTAH AND LATEST HRRR RUN SHOWS ACTIVITY INCREASING IN COVERAGE
FAIRLY QUICKLY BY MIDDAY. HAVE BUMPED POPS UP ACROSS MUCH OF THE
FORECAST AREA THROUGH THIS AFTERNOON. SHOULD SEE A FEW STRONGER
CELLS TODAY WITH HAIL AND HEAVY RAIN EXPECTED.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
A SHORTWAVE RIDGE WILL START THE DAY AS THE CLOSED LOW OVER THE
PACNW VERY SLOWLY STARTS TO DROP TO THE SOUTHEAST. SIMILAR
ATMOSPHERIC CONDITIONS REMAIN IN PLACE THAT HAVE BEEN FOR THE
LAST SEVERAL DAYS...PLENTY OF MOISTURE...DAYTIME HEATING AND
MODEST INSTABILITY. POTENTIAL VORTICITY FIELDS ALSO INDICATING A
WEAK UPPER LEVEL TROUGH WILL MOVE OVER THE AREA WHICH...WITH ALL
THE ABOVE...WILL CAUSE SHOWERS AND STORMS TO FIRE. CONVECTION WILL
BEGIN AROUND NOONTIME WHEN THE FIRST VORT MAX MOVES OVERHEAD FROM
WEST TO EAST THOUGH WIDESPREAD THUNDERSTORMS AND SHOWERS LOOK TO
REACH A MAXIMUM FROM 3PM ONWARDS AS THAT TROUGH APPROACHES FROM
THE WEST. SOME BRIEF HEAVY RAIN...GUSTY WINDS...AND SMALL HAIL
WILL REMAIN THE BIGGEST THREATS. MODELS KEEP PRECIP GOING THROUGH
MIDNIGHT SO FORECAST WILL FOLLOW SUIT THOUGH COVERAGE WILL
DROP...AS IT ALWAYS DOES...AFTER SUNSET. A FEW LINGERING SHOWERS
WILL LIKELY PERSIST AFTER MIDNIGHT.
BY WEDNESDAY...THE CLOSED LOW WILL ONLY HAVE MADE IT AS FAR AS NRN
ID SO EXPECT ANOTHER UNSETTLED DAY OF SHOWERS AND STORMS THOUGH
MODELS HINTING AT SOMEWHAT LESS COVERAGE. ASIDE FROM THAT...THE ONLY
REALLY BIG DIFFERENCE WILL BE TEMPERATURES THAT WILL BE GETTING
CLOSE TO NORMAL THANKS TO CYCLONIC FLOW AROUND THE AREA OF LOW
PRESSURE USHERING IN WARMER AIR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM MDT TUE MAY 26 2015
THE BEGINNING OF JUNE MAY ACTUALLY FEEL LIKE JUNE...BUT THAT IS
STILL A FEW DAYS AWAY AS THE UNSETTLED PATTERN CONTINUES THROUGH
FRIDAY. PROGRESSIVE PATTERN AT A "SNAILS PACE" PREVAILS FOR MUCH
OF THE WEEK...PACIFIC NORTHWEST TROUGH NEEDS ABOUT 2-3 DAYS TO
REACH THE CENTRAL ROCKIES. BEFORE REACHING WYOMING...PACIFIC
NORTHWEST TROUGH SENDS PIECES OF PACIFIC ENERGY STREAMING ACROSS
THE INTERMOUNTAIN WEST INTO COLORADO. THIS HELPS FUEL DIURNAL
CONVECTION ON THURSDAY...AND CONTINUES INTO FRIDAY AS THE UPPER
LOW TRACKS ACROSS SRN WYOMING.
THE DRYING TREND BEGINS SATURDAY AS THE UPPER LOW MOVES DOWNSTREAM.
DRIER DOES NOT NECESSARILY MEAN DRY AS CONVECTIVE POTENTIAL EXISTS
EACH AFTERNOON INTO MONDAY. HOWEVER DESERT SOUTHWEST RIDGING
EXPANDS INTO COLORADO BY NEXT WEEK...RESULTING IN LESS CONVECTIVE
ACTIVITY WITH EACH PASSING DAY. BY NEXT MONDAY...ANY AFTERNOON
SHOWERS/STORMS MAY BE RELEGATED TO THE COLORADO SPINE.
TEMPERATURES BEGIN THEIR SUMMER ASCENT WITH DESERT VALLEYS
REACHING THE MID 80S TO LOWER 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1127 AM MDT TUE MAY 26 2015
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THIS
EVENING...WITH ACTIVITY BECOMING MORE ISOLATED IN NATURE AFTER
06Z. EXPECT ILS BREAKPOINTS TO BE MET OR EXCEEDED AT ALL SITES AS
SHOWERS MOVE THROUGH. OTHERWISE...VFR CONDITIONS WILL PERSIST.
GUSTY OUTFLOW WINDS TO 30KTS...HAIL AND HEAVY RAIN WILL ACCOMPANY
THE STRONGEST STORMS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...TGR
LONG TERM...PF
AVIATION...JDC
AREA FORECAST DISCUSSION
NWS MIAMI FL
139 PM EDT TUE MAY 26 2015
.AVIATION...
ISOLATED SHOWERS REMAIN ACROSS THE ATLANTIC WATERS SOUTH OF KFXE.
THESE SHOWERS MAY AFFECT THE EAST COAST TAF SITES FROM KFLL
SOUTHWARD OVER THE NEXT COUPLE HOURS. SCATTERED SHOWERS AND A FEW
STORMS ARE POSSIBLE NEAR KAPF THIS AFTERNOON. EAST WINDS 15-20
KNOTS WILL CONTINUE THIS AFTERNOON...DIMINISHING TO 10-15 KNOTS
TONIGHT AND THROUGH THE END OF THE TAF PERIOD. DRIER AIR WILL MOVE
INTO THE REGION TONIGHT...WITH MAINLY DRY CONDITIONS EXPECTED
OVERNIGHT AND THROUGH THE END OF THE TAF PERIOD. BRIEF MVFR
CONDITIONS ARE POSSIBLE IN AND AROUND SHOWERS.
&&
.PREV DISCUSSION... /ISSUED 914 AM EDT TUE MAY 26 2015/
UPDATE...
ISOLATED SHOWERS WILL CONTINUE TO MOVE ONSHORE ALONG THE EAST
COAST THROUGH THE MORNING HOURS. THE LATEST HRRR SHOWING THE
COVERAGE WILL SLOWLY TRANSITION TO THE INTERIOR AND GULF COAST
FROM LATE MORNING THROUGH EARLY AFTERNOON. WHILE MOST WILL LIKELY
REMAIN AS SHOWERS, THERE IS A POSSIBILITY A FEW COULD DEVELOP
INTO A THUNDERSTORM, MAINLY NEAR THE GULF COAST. OTHERWISE, TODAY
LOOKS TO BE FAIRLY QUIET WEATHER WISE. ALSO, WITH THE WEAK SHOWERS
ALONG THE ATLANTIC COAST, THERE WILL BE A SLIGHT POSSIBILITY OF A
BRIEF WATERSPOUT. HOWEVER, ANY SPOUTS THAT DO FORM ARE EXPECTED
TO BE WEAK TODAY.
PREV DISCUSSION... /ISSUED 743 AM EDT TUE MAY 26 2015/
AVIATION...
DRIER LOW/MID LEVEL AIR WILL MOVE INTO THE REGION LATE THIS
MORNING THROUGH THE AFTERNOON HOURS. THIS SHOULD LEAD TO LOWER
CHANCES OF RAIN ACROSS THE REGION AFTER THE MORNING. EASTERLY FLOW
10-15 KNOTS WITH HIGHER GUSTS WILL PREVAIL THROUGH THE DAY...WITH
SLIGHTLY LOWER SPEEDS OVERNIGHT. SCATTERED SHOWERS AND STORMS ARE
POSSIBLE NEAR KAPF AFTER 18Z. MAINLY VFR CONDITIONS WILL
PREVAIL...BUT BRIEF MVFR CIGS AROUND 2.5KFT ARE POSSIBLE.
PREV DISCUSSION... /ISSUED 334 AM EDT TUE MAY 26 2015/
HIGH RISK OF RIP CURRENTS EAST COAST BEACHES THROUGH EARLY
THURSDAY MORNING...
SHORT TERM...
STRONG HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC WATERS
TODAY INTO WEDNESDAY...AS A TROUGH OF LOW PRESSURE REMAINS OVER
THE CENTRAL UNITED STATES. THIS WILL ALLOW FOR THE BREEZY EASTERLY
WIND FLOW TO REMAIN OVER SOUTH FLORIDA...AND ALLOW FOR THE VERY
DRY AIR OVER THE WESTERN ATLANTIC WATERS TO BUILD INTO SOUTH
FLORIDA STARTING THIS AFTERNOON INTO WEDNESDAY.
THE SHORT RANGE MODELS ARE FORECASTING THE PWAT VALUES TO FALL
DOWN TO AROUND 1 INCH BY WEDNESDAY WHICH WILL BE CLOSE THE THE
MINIMUM PWAT VALUES FOR THIS TIME OF YEAR WHICH ARE IN THE 0.85
TO 0.95 INCH RANGE. THIS MEANS THAT THE ISOLATED SHOWERS THAT BEEN
GOING ON EARLY THIS MORNING OVER THE THE EAST COAST METRO AREAS
AND THE ADJACENT COASTAL WATERS SHOULD COME TO AND END BY THIS
AFTERNOON. REST OF SOUTH FLORIDA SHOULD ALSO REMAIN DRY
TODAY...EXCEPT FOR A FEW SHOWERS AND POSSIBILITY OF A THUNDERSTORM
OVER THE WEST COAST METRO AREAS THIS AFTERNOON WHERE THE EAST
COAST SEA BREEZE MEETS THE WEST COAST SEA BREEZE. THE WEATHER WILL
THEN REMAIN DRY TONIGHT INTO WEDNESDAY OVER MOST OF SOUTH
FLORIDA...EXCEPT FOR THE WEST COAST METRO AREAS WHERE A SHOWER
COULD DEVELOP IN THE AFTERNOON HOURS.
NAPLES COULD GET UP TO NEAR THE RECORD HIGH TODAY WHICH IS 93
DEGREES SET BACK IN 1989. THEREFORE...NEAR RECORD HIGHS WILL BE
MENTION IN THE FORECAST FOR THE NAPLES AREA TODAY.
THE STRONG HIGH WILL START TO BREAK DOWN LATE THIS WEEK OVER THE
WESTERN ATLANTIC WATERS...AS THE TROUGH OF LOW PRESSURE REMAINS
OVER CENTRAL UNITED STATES. THIS WILL ALLOW FOR THE BREEZY
EASTERLY WIND FLOW TO RELAX OVER SOUTH FLORIDA LATE THIS
WEEK...AND ALLOW FOR SOME MOISTURE TO WORK BACK INTO SOUTH
FLORIDA. THEREFORE...THURSDAY SHOULD BE ANOTHER MOSTLY DRY DAY
OVER SOUTH FLORIDA BEFORE SOME SHOWERS AND THUNDERSTORMS RETURN TO
THE AREA ON FRIDAY WITH THE BEST COVERAGE OVER THE INTERIOR AND
WEST COAST METRO AREAS.
LONG TERM...
THE HIGH WILL CONTINUE TO WEAKEN OVER THE WESTERN ATLANTIC WATERS
THIS WEEKEND...AS THE TROUGH OF LOW PRESSURE STARTS TO MOVE EAST
INTO THE TENNESSEE VALLEY REGION. THIS WILL KEEP THE EASTERLY
WIND FLOW OVER SOUTH FLORIDA, BUT ALLOW FOR MORE DEEPER TROPICAL
MOISTURE TO WORK INTO THE AREA. THEREFORE...SOUTH FLORIDA WILL SEE
MORE SCATTERED SHOWERS AND THUNDERSTORMS THIS WEEKEND WITH THE
BEST COVERAGE OVER THE WESTERN AREAS.
MARINE...
THE WINDS WILL BE EASTERLY THIS WEEK INTO THIS WEEKEND...AS THE
SPEEDS DECREASE FROM BREEZY CONDITIONS TODAY DOWN TO LESS THAN 15
KNOTS BY LATE THIS WEEK INTO THIS WEEKEND. THIS WILL KEEP THE HIGH
RISK OF RIP CURRENTS GOING ALONG THE EAST COAST BEACHES OF SOUTH
FLORIDA TODAY INTO AT LEAST WEDNESDAY NIGHT. THEREFORE...THE HIGH
RISK OF RIP CURRENTS HAVE BEEN EXTENDED UNTIL EARLY THURSDAY
MORNING FOR THE EAST COAST BEACHES OF SOUTH FLORIDA. THE SCEC WILL
ALSO CONTINUE FOR THE GULF...ATLANTIC...AND BISCAYNE BAY WATERS
TODAY INTO TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 89 76 88 / 10 10 10 10
FORT LAUDERDALE 78 88 78 87 / 10 10 10 10
MIAMI 77 89 77 88 / 10 10 10 10
NAPLES 73 92 71 91 / 20 20 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH LATE WEDNESDAY NIGHT FOR FLZ168-
172-173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...13/SI
LONG TERM....13/SI
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
603 PM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A LINE OF SHOWERS/TSTMS STRETCHING FROM EASTERN GEORGIA INTO
NORTHERN FLORIDA CONTINUES TO MOVE SLOWLY EAST. BOTH THE RAP AND
H3R SHOW THIS ACTIVITY STRENGTHENING AFTER SUNSET AS IT INTERSECTS
THE SEA BREEZE LURKING ACROSS FAR INTERIOR SOUTHEAST GEORGIA. THIS
SCENARIO SEEMS PLAUSIBLE GIVEN CURRENT RADAR AND MESOSCALE TRENDS.
THE GRIDDED AND TEXT FORECASTS HAVE BEEN UPDATED TO INCREASE POPS
UP TO 40 PERCENT ACROSS THE FAR SOUTHWESTERN AREAS.
INSTABILITY PARAMETERS ARE RATHER ELEVATED WITH SBCAPES IN
EXCESS OF 2500 J/KG WITH DCAPES NEARING 1200 J/K. AN ISOLATED
STRONG TO SEVERE TSTM CAN NOT BE RULED OUT GIVEN THE LEVEL OF DCAPE
IN PLACE. DAMAGING WINDS, CLOUD TO GROUND LIGHTNING AND LOCALLY
HEAVY RAINFALL WILL BE THE PRIMARY HAZARDS. GIVEN THE WEAK SHEAR
IN PLACE, WELL- ORGANIZED SEVERE TSTMS APPEAR UNLIKELY ATTM,
ALTHOUGH MESOSCALE BOUNDARY INTERACTIONS COULD SUPPORT SHORT-TERM
CONVECTIVE CONGLOMERATIONS.
PATCHY FOG WILL BE POSSIBLE AGAIN INLAND LATE TONIGHT TOWARDS SUNRISE
WHERE TEMPERATURES ARE EXPECTED TO MEET/EXCEED CROSSOVER TEMPS AND
WHERE MORE SIGNIFICANT RAINFALL WILL HAVE FALLEN. TEMPERATURES
OVERNIGHT WILL BE QUITE MILD...WITH LOWS IN THE UPPER 60S/LOW
70S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...PART OF THE DEEP LAYERED MEAN ANTI-CYCLONE CENTERED OFF
THE SE COAST WILL GET NUDGED A BIT FURTHER INTO THE ATLANTIC IN
RESPONSE TO WEAK IMPULSES THAT IMPINGE ON THE WESTERN PERIPHERY OF
THIS LARGE SCALE FEATURE. UNDERNEATH AT THE SURFACE WE STILL FIND
SPRAWLING ATLANTIC HIGH PRESSURE ALIGNED ACROSS THE FORECAST
ZONES...BUT IN RESPONSE TO THE PERTURBATIONS ALOFT AND A SLIGHTLY
WEAKER RIDGE THERE IS ALSO A SUBTLE LEE SIDE TROUGH THAT IS ABLE TO
DEVELOP. OVERALL THERE IS STILL ENOUGH OF A CAP TO LIMIT HOW MUCH
CONVECTION IS ABLE TO DEVELOP...ESPECIALLY ACROSS OUR EASTERN
SECTIONS. BUT FURTHER INLAND THE MOISTURE PROFILES ARE A LITTLE
BETTER AND THE SUBSIDENCE IS LESS PRONOUNCED. WE HAVE OPTED FOR
SLIGHT CHANCE-CHANCE POPS MAINLY NEAR AND INLAND FROM I-95 FOR THE
LATE MORNING/AFTERNOON PERIOD WHERE WE FIND THE HIGHEST THETA-E AIR.
THE LACK OF SHEAR AND ONLY MODEST THERMODYNAMICS AT BEST WILL
SUPPORT LITTLE IF ANY RISK OF STRONG/SEVERE STORMS. WITHIN A SUB-
TROPICAL MARITIME AIR MASS OUR MAX TEMPS WILL PEAK IN THE MID-UPPER
80S AWAY FROM THE IMMEDIATE COAST. CONVECTION FAR INLAND WILL FADE
WITHIN THE NOCTURNAL STABILIZING INFLUENCES WEDNESDAY EVENING. WE/LL
MAINTAIN A WEATHER WATCH FOR POSSIBLE FOG NW TIER WHERE RAINS
OCCURRED EARLIER IN CONJUNCTION WITH LIGHT UPSLOPE FLOW. A LARGE
RANGE OF TEMPS FROM LOWER 60S NORMALLY COOL SPOTS TO 68-72 ON THE
BARRIER ISLANDS.
THURSDAY THROUGH FRIDAY...THE DEEP RIDGING GETS SHUNTED BACK A BIT
FURTHER WEST IN RESPONSE TO A DEEP CYCLONE AND IT/S ASSOCIATED
SURFACE WAVE CENTERED FAR EAST/NE OF THE BAHAMAS. INCREASING
SUBSIDENCE...THE LACK OF FORCING AND DIMINISHING MOISTURE SUGGESTS
THAT DIURNAL RAIN CHANCES WILL ONLY BE 20-30 PERCENT FAR INLAND
THURSDAY AND NO MORE THAN 10 PERCENT FRIDAY. VERY LITTLE
FLUCTUATIONS IN MAX/MIN TEMPS FROM RECENT DAYS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A BROAD UPPER RIDGE WILL EXIST FRIDAY NIGHT THROUGH SUNDAY BEFORE AN
UPPER TROUGH BEGINS TO PUSH INTO THE EASTERN UNITED STATES EARLY
NEXT WEEK. ALTHOUGH WEAK CAPPING WILL EXIST FOR THE BRUNT OF THE
PERIOD...ONSHORE MOISTURE FLUX WITH HIGH TEMPS IN THE UPPER 80S TO
NEAR 90 AND A DAILY SEA BREEZE WILL SUPPORT ISOLATED SHOWERS AND
TSTMS. A MORE PROMINENT UPPER TROUGH APPROACHING ON TUESDAY SHOULD
SUPPORT BETTER COVERAGE OF SHOWERS AND TSTMS.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
VFR IS EXPECTED TO PREVAIL THROUGH MUCH OF THE 18Z TAF CYCLE.
MODEL SOUNDINGS HINT THAT BRIEF PERIODS OF MVFR CIGS MAY DEVELOP
LATE TONIGHT...THUS HAVE TRENDED THAT DIRECTION IN THE TAF. SOME
LIGHT FOG MAY DEVELOP AS WELL...HOWEVER BETTER CHANCES WILL REMAIN
INLAND FROM THE TERMINALS SO KEPT OUT MENTION FOR NOW. ANY
LINGERING LOW CIGS WILL LIFT SHORTLY AFTER SUNRISE.
EXTENDED AVIATION OUTLOOK...MAINLY VFR THROUGH THE PERIOD.
&&
.MARINE...
TONIGHT...MARINE CONDITIONS WILL BE RATHER BENIGN TONIGHT AS
SURFACE HIGH PRESSURE REMAINS EAST OF THE WATERS. SOUTHEAST
ONSHORE FLOW OF 10-15 KT WILL DECREASE TO 5-10 KT LATE. SEAS WILL
BE 2-3 FT...EXCEPT IN THE OUTER GA WATERS WHERE 3-4 FT IS
EXPECTED.
WEDNESDAY THROUGH FRIDAY...A RATHER FLAT BUT ENORMOUS SUB-TROPICAL
RIDGE WILL MAINTAIN IT/S HOLD ACROSS THE COASTAL WATERS...GENERATING
A CONTINUOUS ONSHORE FLOW THROUGH THE PERIOD. EVEN WITH MINOR SEA
BREEZE INFLUENCES WINDS WILL HOLD UNDER 10 OR 15 KT. SEAS WILL BE A
MIX OF WIND-DRIVEN WAVES AND EVENTUALLY MORE SWELL ENERGY ARRIVING
DUE TO THE PERSISTENT EAST-SE FLOW. COMBINED SEAS WILL HOLD AT LESS
THAN OR EQUAL TO 3 OR 4 FT.
SATURDAY THROUGH MONDAY...SPRAWLING ATLANTIC HIGH PRESSURE WILL
CONTINUE TO CONTROL CONDITIONS LOCALLY AS IT LIES OVERHEAD INTO
EARLY NEXT WEEK. ONSHORE TRAJECTORIES WON/T OBTAIN ANYTHING MORE
THAN 10 OR 15 KT...AND WHILE SWELL ENERGY WILL BECOME MORE THE
DOMINANT FEATURE...SEAS ARE STILL MAINLY 4 FT OR LESS.
RIP CURRENTS...MARGINAL SWELLS AND ELEVATED ONSHORE WINDS WILL
CONTINUE TODAY SO WE MAINTAIN A MODERATE RISK ACROSS CHARLESTON
COUNTY BEACHES FOR THE REST OF THE DAYTIME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
515 PM CDT TUE MAY 26 2015
.SHORT TERM...
253 PM CDT
THROUGH WEDNESDAY...
A SURFACE LOW IS OVER NORTHEAST IA AND SW WI WITH A VORT MAX OVER
IOWA. THE LOWS COLD FRONT REMAINS A BIT FURTHER BACK OVER CENTRAL IA
AND EASTERN KS. THE LOW WILL DEEPEN SLIGHTLY AS IT MOVES OVER
CENTRAL WI AND ITS COLD FRONT SWINGS THROUGH WEDNESDAY. THE MAIN
CONCERN RIGHT NOW IS HOW MUCH CONVECTION WILL DEVELOP THIS
AFTERNOON. THE LATEST RAP ANALYSIS SUGGESTS A RIBBON OF 1000 J/KG
OF CAPE IS OVER I-39...BUT THINKING THAT CAPE IN REALITY IS AROUND
500 J/KG DUE TO LIMITED HEATING. CAPE VALUES COULD RISE TO AROUND
1000 J/KG AS THERE ARE A FEW BREAKS IN THE CLOUDS...BUT THINKING IN
GENERAL THE BREAKS ARE MOVING TOO QUICKLY AND TOO FEW AND FAR BTWN
TO AMOUNT TO MUCH. SHEAR VALUES REMAIN VERY FAVORABLE FOR ORGANIZED
STORMS WITH VALUES AROUND 35-40 KT.
THEREFORE EXPECTING SCATTERED SHOWER/TS DEVELOPMENT THIS AFTN IN THE
WAKE OF THE LINE OF SHOWERS THAT IS SHIFTING EAST ACROSS INDIANA
RIGHT NOW. A SECOND SKINNY LINE OF CONVECTION LIES FROM DIXON IL TO
JERSEYVILLE IL WITH A FEW ADDITIONAL CELLS OUT AHEAD OF IT. DUE TO
LIMITED CAPE AS DISCUSSED ABOVE...THE STRONGER CELLS MAY PRODUCE
DAMAGING WINDS. WINDS HAVE VEERED TO THE SW AND HELICITY IS MUCH
LOWER SO NOT AS CONCERNED ABOUT ISOLATED TORNADOES AS I WAS THIS
MORNING. PWAT VALUES REMAIN VERY IMPRESSIVE AT 1.4-1.7 INCHES SO
ANY OF THE NEW SHOWERS WILL BE CAPABLE OF ADDITIONAL HEAVY DOWNPOURS.
THE AREA OF SCATTERED SHOWERS AND STORMS SHIFTS EAST OF THE CWA THIS
EVENING...BUT WE ARE NOT DONE YET. ANOTHER ROUND OF SHOWERS AND
PERHAPS OF THUNDERSTORMS MAY FORM THIS EVENING AS THE VORT MAX
APPROACHES. THINKING THE COVERAGE WILL BE BEST ALONG AND WEST OF
GARY INDIANA TO PAXTON IL LINE. HAVE LOW CONFIDENCE IN COVERAGE AND
TIMING OF THIS ROUND OF SHOWERS...BUT NOT EXPECTING MUCH THUNDER AND
NO SEVERE WEATHER. DEWPOINTS REMAIN IN THE 60S TONIGHT SO THINKING
WE WILL NOT COOL MUCH...SO KEPT LOWS IN THE LOW TO MID 60S.
THE PATTERN REMAINS MESSY TOMORROW BUT NOT AS ACTIVE. A PAIR OF
VORT STREAMERS AND THE LOWS COLD FRONT ROTATE THROUGH AND SHOWERS
AND STORMS MAY FORM ALONG THEM. THE FIRST IS ASSOCIATED WITH THE
UPPER LEVEL LOW SHIFTING NE INTO ONTARIO TOMORROW. SHOWERS AND
STORMS WITH THIS VORT STREAMER WOULD CLIP THE NORTHERN CWA...NORTH
OF I-88. PRECIP MAY SINK SOUTH ACROSS DUPAGE AND COOK COUNTIES IN
THE AFTN...BUT HAVE LOW CONFIDENCE IN HOW FAR SOUTH THE PRECIP WILL
GET.
CLOUD COVER SHIFTS EAST THROUGH THE AFTERNOON WITH AREAS WEST OF I-
55 BECOMING MOSTLY SUNNY BY MID AFTN. DID NOT MAKE TOO MANY CHANGES
TO HIGH TEMPS TOMORROW AS CLOUD COVER WILL PLAY A ROLE. HAVE TEMPS
IN THE UPPER 70S TO LOW 80S. A LAKE BREEZE IS POSSIBLE LATE IN THE
AFTN AND EVENING SO EXPECTING LAKE COOLING ESPECIALLY AT WAUKEGAN.
JEE
&&
.LONG TERM...
330 PM CDT
WEDNESDAY NIGHT THROUGH TUESDAY...
LOCAL AREA WILL START OUT FIRMLY UNDER MID/UPPER RIDGING ON
WEDNESDAY NIGHT AND THURSDAY...RESULTING IN A DRY AND WARM PERIOD
AS 925 MB TEMPS CLIMB FROM THE UPPER TEENS CELSISUS BY EARLY
THURSDAY TO THE LOWER 20S CELSISUS EARLY THURSDAY EVENING. INLAND
TEMPERATURES WILL WARM TO THE LOWER-MID 80S ON THURSDAY...BUT
DESPITE SOUTHERLY SURFACE FLOW...GRADIENT WILL BE WEAK ENOUGH TO
ENABLE A LAKE BREEZE TO DEVELOP AND PUSH INLAND FAIRLY EARLY. THIS
WILL KEEP LAKESHORE TEMPS (ESPECIALLY IL SHORE) IN THE UPPER 60S.
CHANGES WILL START TO TAKE PLACE THURSDAY NIGHT WITH UPPER RIDGE
AXIS GETTING SHUNTED EAST AND ALLOWS SHORTWAVE ENERGY TO LIFT
EAST-NORTHEAST ACROSS THE AREA AFTER MIDNIGHT INTO FRIDAY ALONG
WITH STRENGTHENING AND VEERING LOW LEVEL JET. HAVE FOCUSED MID
CHANCE POPS INTO NORTHWEST CWA LATE THURSDAY NIGHT AND THEN SPREAD
LIKELY POPS FOR MUCH OF THE CWA FRIDAY MORNING AND EARLY
AFTERNOON. IT APPEARS THAT BETTER MOISTURE CONVERGENCE AND UPPER
FORCING WILL LIFT NORTH AND REFOCUS INTO NORTHWEST CWA FRIDAY
AFTERNOON AND TAILORED POPS AS SUCH...BUT THEN A STRONGER WAVE
WILL MOVE ACROSS THE AREA SATURDAY NIGHT. CONFIDENCE IS A BIT
LOWER IN HIGH TEMPS FRIDAY DUE TO UNCERTAINTY OVER IMPACT OF
CLOUDS/PRECIP...BUT VERY MILD START TO DAY AND WARM AIRMASS IN
PLACE SHOULD STILL SUPPORT HIGHS INTO THE LOWER-MID 80S...WARMEST
IN SOUTHEAST HALF OF CWA. THE WARM TEMPS...DEWPOINTS WELL INTO THE
60S AND MODEST MIDLEVEL LAPSE RATES WILL YIELD MODEST CAPE
VALUES...SO CANNOT RULE OUT AN ISOLATED SEVERE THREAT FOR DAMAGING
WINDS INTO FRIDAY EVENING. COULD BE SOME WET MICROBURSTS WITH PWAT
VALUES IN 1.5 TO 1.75 INCH RANGE.
A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA FRIDAY
NIGHT...RESULTING IN MUCH COOLER WEATHER FOR THE LAST WEEKEND OF
MAY. HIGHS ON THE LAKEFRONT ARE LIKELY TO STAY IN THE 50S ON BOTH
SATURDAY AND SUNDAY...WITH ONLY 60S AND 70S INLAND ON SATURDAY AND
60S ON SUNDAY. WILL NEED TO WATCH FOR A WAVE OF SURFACE LOW
PRESSURE FORMING SOUTH OF THE AREA ON SATURDAY...SO KEPT HIGHER
CONSENSUS POPS FOR NOW SATURDAY MORNING...BUT IF TRENDS ON MUCH OF
GUIDANCE CONTINUE MAY BE ABLE TO LOWER POPS SATURDAY THROUGH
MONDAY WITH EXPANSIVE COOL HIGH PRESSURE OVER THE GREAT LAKES.
TEMPERATURES WILL THEN WARM BACK TO NEAR NORMAL FOR EARLY JUNE BY
TUESDAY WITH SOUTHERLY FLOW ON BACK SIDE OF HIGH TO EAST...THOUGH
ONSHORE FLOW LOOKS TO CONTINUE FOR AT LEAST A PORTION OF THE
LAKEFRONT.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* ISOLATED MVFR THIS AFTERNOON.
* RAIN SHOWERS POSSIBLY DROPPING TO MVFR THIS AFTERNOON.
* SOUTH TO SOUTHWEST WINDS...GUSTING TO MID/UPPER 20KTS.
* MVFR IN FOG AND LOW CLOUDS WEDNESDAY MORNING.
MM/RODRIGUEZ
//DISCUSSION...UPDATED 20Z...
LINE OF SHOWERS HAS DECREASED VSBYS TO 1 MILE UPSTREAM EARLY THIS
AFTERNOON. AS THE LINE PROGRESSES NORTHEASTWARD...COULD SEE SOME
STRONGER POCKETS OF RAIN AND TALLER EMBEDDED CELLS PRODUCE
ISOLATED LIGHTNING. LOW CHANCE/CONFIDENCE OF ANY OF THESE CELLS
HITTING THE TERMINALS...SO KEPT VCTS IN THE TAFS THROUGH 19Z.
LOOKING TOWARD WEDNESDAY MORNING...LOW LEVEL MOISTURE AND A WEAK
INVERSION WILL ALLOW A CHANCE FOR MVFR FOG AND CIGS TO WORK INTO
THE TERMINALS. THE AFTERNOON WILL FEATURE A SCATTERED TO POSSIBLY
BROKEN DECK AT 025. INTO THE EVENING...EXPECT OVERCAST CONDITIONS
WITH LIGHT RAIN POSSIBLE. THERE IS A CHANCE FOR THE LAKE BREEZE TO
WORK INTO ORD NEAR OR JUST AFTER 00Z WEDNESDAY EVENING.
MM
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM HIGH CONFIDENCE WITH TEMPO MVFR THIS AFTERNOON.
* HIGH CONFIDENCE WITH RAIN TRENDS THIS AFTERNOON.
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
* LOW-MEDIUM CONFIDENCE IN FOG AND MVFR CONDITIONS WEDNESDAY
MORNING.
MM/RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WX NIL/VFR. SOUTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA AT NIGHT. SOUTHEAST WINDS.
FRIDAY...TSRA/SHRA LIKELY THROUGH THE DAY AND NIGHT. MVFR
POSSIBLE. SOUTHWEST WINDS.
SATURDAY...SHRA LIKELY WITH A CHANCE OF TSRA DURING THE DAY.
NORTHEAST WINDS.
SUNDAY...CHANCE OF SHRA. EAST WINDS. MVFR POSSIBLE.
MONDAY...CHANCE OF SHRA. SOUTHEAST WINDS. MVFR POSSIBLE.
KREIN
&&
.MARINE...
417 PM CDT
WINDS REMAIN GUSTY THIS AFTERNOON AND DECIDED TO ISSUE A SMALL
CRAFT ADVISORY FOR STRONG WINDS INTO THIS EVENING. THE SOUTH WINDS
BECOME SOUTHWEST THIS EVENING. LOW PRESSURE MOVES OVER QUEBEC
TOMORROW AFTERNOON AND COLD FRONT TRAILING FROM THE LOW SWINGS
THROUGH. WINDS WEAKEN WEDNESDAY AFTERNOON AND A LAKE BREEZE IS
EXPECTED LATE WEDNESDAY AFTERNOON.
MODEST SOUTHERLY FLOW IS EXPECTED ON THURSDAY...WITH LAKE BREEZE
INFLUENCES IN THE SOUTHERN PORTION OF THE LAKE...THEN A PERIOD OF
SLIGHTLY STRONGER SOUTHERLY FLOW ON FRIDAY AHEAD OF A STRONG COLD
FRONT...THOUGH WARM AIRMASS WILL LIMIT MIXING. WILL LIKELY NEED TO
ADD AREAS OF FOG OVER THE LAKE. THE STRONG COLD FRONT WILL SWEEP
ACROSS THE LAKE FRIDAY NIGHT INTO SATURDAY...BRINGING NORTHERLY
WINDS TO 30 KT. WILL NEED TO WATCH FOR A PERIOD OF NORTHERLY GALES
SHOWN ON SOME MODEL GUIDANCE. WILL NEED A SMALL CRAFT ADVISORY
SATURDAY MORNING THROUGH SUNDAY MORNING UNTIL WAVES SUBSIDE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
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
417 PM CDT TUE MAY 26 2015
.SHORT TERM...
253 PM CDT
THROUGH WEDNESDAY...
A SURFACE LOW IS OVER NORTHEAST IA AND SW WI WITH A VORT MAX OVER
IOWA. THE LOWS COLD FRONT REMAINS A BIT FURTHER BACK OVER CENTRAL IA
AND EASTERN KS. THE LOW WILL DEEPEN SLIGHTLY AS IT MOVES OVER
CENTRAL WI AND ITS COLD FRONT SWINGS THROUGH WEDNESDAY. THE MAIN
CONCERN RIGHT NOW IS HOW MUCH CONVECTION WILL DEVELOP THIS
AFTERNOON. THE LATEST RAP ANALYSIS SUGGESTS A RIBBON OF 1000 J/KG
OF CAPE IS OVER I-39...BUT THINKING THAT CAPE IN REALITY IS AROUND
500 J/KG DUE TO LIMITED HEATING. CAPE VALUES COULD RISE TO AROUND
1000 J/KG AS THERE ARE A FEW BREAKS IN THE CLOUDS...BUT THINKING IN
GENERAL THE BREAKS ARE MOVING TOO QUICKLY AND TOO FEW AND FAR BTWN
TO AMOUNT TO MUCH. SHEAR VALUES REMAIN VERY FAVORABLE FOR ORGANIZED
STORMS WITH VALUES AROUND 35-40 KT.
THEREFORE EXPECTING SCATTERED SHOWER/TS DEVELOPMENT THIS AFTN IN THE
WAKE OF THE LINE OF SHOWERS THAT IS SHIFTING EAST ACROSS INDIANA
RIGHT NOW. A SECOND SKINNY LINE OF CONVECTION LIES FROM DIXON IL TO
JERSEYVILLE IL WITH A FEW ADDITIONAL CELLS OUT AHEAD OF IT. DUE TO
LIMITED CAPE AS DISCUSSED ABOVE...THE STRONGER CELLS MAY PRODUCE
DAMAGING WINDS. WINDS HAVE VEERED TO THE SW AND HELICITY IS MUCH
LOWER SO NOT AS CONCERNED ABOUT ISOLATED TORNADOES AS I WAS THIS
MORNING. PWAT VALUES REMAIN VERY IMPRESSIVE AT 1.4-1.7 INCHES SO
ANY OF THE NEW SHOWERS WILL BE CAPABLE OF ADDITIONAL HEAVY DOWNPOURS.
THE AREA OF SCATTERED SHOWERS AND STORMS SHIFTS EAST OF THE CWA THIS
EVENING...BUT WE ARE NOT DONE YET. ANOTHER ROUND OF SHOWERS AND
PERHAPS OF THUNDERSTORMS MAY FORM THIS EVENING AS THE VORT MAX
APPROACHES. THINKING THE COVERAGE WILL BE BEST ALONG AND WEST OF
GARY INDIANA TO PAXTON IL LINE. HAVE LOW CONFIDENCE IN COVERAGE AND
TIMING OF THIS ROUND OF SHOWERS...BUT NOT EXPECTING MUCH THUNDER AND
NO SEVERE WEATHER. DEWPOINTS REMAIN IN THE 60S TONIGHT SO THINKING
WE WILL NOT COOL MUCH...SO KEPT LOWS IN THE LOW TO MID 60S.
THE PATTERN REMAINS MESSY TOMORROW BUT NOT AS ACTIVE. A PAIR OF
VORT STREAMERS AND THE LOWS COLD FRONT ROTATE THROUGH AND SHOWERS
AND STORMS MAY FORM ALONG THEM. THE FIRST IS ASSOCIATED WITH THE
UPPER LEVEL LOW SHIFTING NE INTO ONTARIO TOMORROW. SHOWERS AND
STORMS WITH THIS VORT STREAMER WOULD CLIP THE NORTHERN CWA...NORTH
OF I-88. PRECIP MAY SINK SOUTH ACROSS DUPAGE AND COOK COUNTIES IN
THE AFTN...BUT HAVE LOW CONFIDENCE IN HOW FAR SOUTH THE PRECIP WILL
GET.
CLOUD COVER SHIFTS EAST THROUGH THE AFTERNOON WITH AREAS WEST OF I-
55 BECOMING MOSTLY SUNNY BY MID AFTN. DID NOT MAKE TOO MANY CHANGES
TO HIGH TEMPS TOMORROW AS CLOUD COVER WILL PLAY A ROLE. HAVE TEMPS
IN THE UPPER 70S TO LOW 80S. A LAKE BREEZE IS POSSIBLE LATE IN THE
AFTN AND EVENING SO EXPECTING LAKE COOLING ESPECIALLY AT WAUKEGAN.
JEE
&&
.LONG TERM...
330 PM CDT
WEDNESDAY NIGHT THROUGH TUESDAY...
LOCAL AREA WILL START OUT FIRMLY UNDER MID/UPPER RIDGING ON
WEDNESDAY NIGHT AND THURSDAY...RESULTING IN A DRY AND WARM PERIOD
AS 925 MB TEMPS CLIMB FROM THE UPPER TEENS CELSISUS BY EARLY
THURSDAY TO THE LOWER 20S CELSISUS EARLY THURSDAY EVENING. INLAND
TEMPERATURES WILL WARM TO THE LOWER-MID 80S ON THURSDAY...BUT
DESPITE SOUTHERLY SURFACE FLOW...GRADIENT WILL BE WEAK ENOUGH TO
ENABLE A LAKE BREEZE TO DEVELOP AND PUSH INLAND FAIRLY EARLY. THIS
WILL KEEP LAKESHORE TEMPS (ESPECIALLY IL SHORE) IN THE UPPER 60S.
CHANGES WILL START TO TAKE PLACE THURSDAY NIGHT WITH UPPER RIDGE
AXIS GETTING SHUNTED EAST AND ALLOWS SHORTWAVE ENERGY TO LIFT
EAST-NORTHEAST ACROSS THE AREA AFTER MIDNIGHT INTO FRIDAY ALONG
WITH STRENGTHENING AND VEERING LOW LEVEL JET. HAVE FOCUSED MID
CHANCE POPS INTO NORTHWEST CWA LATE THURSDAY NIGHT AND THEN SPREAD
LIKELY POPS FOR MUCH OF THE CWA FRIDAY MORNING AND EARLY
AFTERNOON. IT APPEARS THAT BETTER MOISTURE CONVERGENCE AND UPPER
FORCING WILL LIFT NORTH AND REFOCUS INTO NORTHWEST CWA FRIDAY
AFTERNOON AND TAILORED POPS AS SUCH...BUT THEN A STRONGER WAVE
WILL MOVE ACROSS THE AREA SATURDAY NIGHT. CONFIDENCE IS A BIT
LOWER IN HIGH TEMPS FRIDAY DUE TO UNCERTAINTY OVER IMPACT OF
CLOUDS/PRECIP...BUT VERY MILD START TO DAY AND WARM AIRMASS IN
PLACE SHOULD STILL SUPPORT HIGHS INTO THE LOWER-MID 80S...WARMEST
IN SOUTHEAST HALF OF CWA. THE WARM TEMPS...DEWPOINTS WELL INTO THE
60S AND MODEST MIDLEVEL LAPSE RATES WILL YIELD MODEST CAPE
VALUES...SO CANNOT RULE OUT AN ISOLATED SEVERE THREAT FOR DAMAGING
WINDS INTO FRIDAY EVENING. COULD BE SOME WET MICROBURSTS WITH PWAT
VALUES IN 1.5 TO 1.75 INCH RANGE.
A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA FRIDAY
NIGHT...RESULTING IN MUCH COOLER WEATHER FOR THE LAST WEEKEND OF
MAY. HIGHS ON THE LAKEFRONT ARE LIKELY TO STAY IN THE 50S ON BOTH
SATURDAY AND SUNDAY...WITH ONLY 60S AND 70S INLAND ON SATURDAY AND
60S ON SUNDAY. WILL NEED TO WATCH FOR A WAVE OF SURFACE LOW
PRESSURE FORMING SOUTH OF THE AREA ON SATURDAY...SO KEPT HIGHER
CONSENSUS POPS FOR NOW SATURDAY MORNING...BUT IF TRENDS ON MUCH OF
GUIDANCE CONTINUE MAY BE ABLE TO LOWER POPS SATURDAY THROUGH
MONDAY WITH EXPANSIVE COOL HIGH PRESSURE OVER THE GREAT LAKES.
TEMPERATURES WILL THEN WARM BACK TO NEAR NORMAL FOR EARLY JUNE BY
TUESDAY WITH SOUTHERLY FLOW ON BACK SIDE OF HIGH TO EAST...THOUGH
ONSHORE FLOW LOOKS TO CONTINUE FOR AT LEAST A PORTION OF THE
LAKEFRONT.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ISOLATED MVFR THIS AFTERNOON
* RAIN SHOWERS POSSIBLY DROPPING TO MVFR
* SOUTH WINDS VARYING FROM SOUTH-SOUTHWEST THIS EVENING.
* MVFR IN FOG AND LOW CLOUDS WEDNESDAY MORNING.
MM
//DISCUSSION...UPDATED 20Z...
LINE OF SHOWERS HAS DECREASED VSBYS TO 1 MILE UPSTREAM EARLY THIS
AFTERNOON. AS THE LINE PROGRESSES NORTHEASTWARD...COULD SEE SOME
STRONGER POCKETS OF RAIN AND TALLER EMBEDDED CELLS PRODUCE
ISOLATED LIGHTNING. LOW CHANCE/CONFIDENCE OF ANY OF THESE CELLS
HITTING THE TERMINALS...SO KEPT VCTS IN THE TAFS THROUGH 19Z.
LOOKING TOWARD WEDNESDAY MORNING...LOW LEVEL MOISTURE AND A WEAK
INVERSION WILL ALLOW A CHANCE FOR MVFR FOG AND CIGS TO WORK INTO
THE TERMINALS. THE AFTERNOON WILL FEATURE A SCATTERED TO POSSIBLY
BROKEN DECK AT 025. INTO THE EVENING...EXPECT OVERCAST CONDITIONS
WITH LIGHT RAIN POSSIBLE. THERE IS A CHANCE FOR THE LAKE BREEZE TO
WORK INTO ORD NEAR OR JUST AFTER 00Z WEDNESDAY EVENING.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN TEMPO MVFR THIS AFTERNOON.
* HIGH CONFIDENCE IN RAIN TIMING THIS AFTERNOON. LOW CONFIDENCE ON
THUNDER CHANCES.
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION WITH HIGH CONFIDENCE
IN WIND SPEED.
* LOW-MEDIUM CONFIDENCE IN FOG AND MVFR CONDITIONS WEDNESDAY
MORNING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WX NIL/VFR. SOUTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA AT NIGHT. SOUTHEAST WINDS.
FRIDAY...TSRA/SHRA LIKELY THROUGH THE DAY AND NIGHT. MVFR
POSSIBLE. SOUTHWEST WINDS.
SATURDAY...SHRA LIKELY WITH A CHANCE OF TSRA DURING THE DAY.
NORTHEAST WINDS.
SUNDAY...CHANCE OF SHRA. EAST WINDS. MVFR POSSIBLE.
MONDAY...CHANCE OF SHRA. SOUTHEAST WINDS. MVFR POSSIBLE.
KREIN
&&
.MARINE...
417 PM CDT
WINDS REMAIN GUSTY THIS AFTERNOON AND DECIDED TO ISSUE A SMALL
CRAFT ADVISORY FOR STRONG WINDS INTO THIS EVENING. THE SOUTH WINDS
BECOME SOUTHWEST THIS EVENING. LOW PRESSURE MOVES OVER QUEBEC
TOMORROW AFTERNOON AND COLD FRONT TRAILING FROM THE LOW SWINGS
THROUGH. WINDS WEAKEN WEDNESDAY AFTERNOON AND A LAKE BREEZE IS
EXPECTED LATE WEDNESDAY AFTERNOON.
MODEST SOUTHERLY FLOW IS EXPECTED ON THURSDAY...WITH LAKE BREEZE
INFLUENCES IN THE SOUTHERN PORTION OF THE LAKE...THEN A PERIOD OF
SLIGHTLY STRONGER SOUTHERLY FLOW ON FRIDAY AHEAD OF A STRONG COLD
FRONT...THOUGH WARM AIRMASS WILL LIMIT MIXING. WILL LIKELY NEED TO
ADD AREAS OF FOG OVER THE LAKE. THE STRONG COLD FRONT WILL SWEEP
ACROSS THE LAKE FRIDAY NIGHT INTO SATURDAY...BRINGING NORTHERLY
WINDS TO 30 KT. WILL NEED TO WATCH FOR A PERIOD OF NORTHERLY GALES
SHOWN ON SOME MODEL GUIDANCE. WILL NEED A SMALL CRAFT ADVISORY
SATURDAY MORNING THROUGH SUNDAY MORNING UNTIL WAVES SUBSIDE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
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
332 PM CDT TUE MAY 26 2015
.SHORT TERM...
253 PM CDT
THROUGH WEDNESDAY...
A SURFACE LOW IS OVER NORTHEAST IA AND SW WI WITH A VORT MAX OVER
IOWA. THE LOWS COLD FRONT REMAINS A BIT FURTHER BACK OVER CENTRAL IA
AND EASTERN KS. THE LOW WILL DEEPEN SLIGHTLY AS IT MOVES OVER
CENTRAL WI AND ITS COLD FRONT SWINGS THROUGH WEDNESDAY. THE MAIN
CONCERN RIGHT NOW IS HOW MUCH CONVECTION WILL DEVELOP THIS
AFTERNOON. THE LATEST RAP ANALYSIS SUGGESTS A RIBBON OF 1000 J/KG
OF CAPE IS OVER I-39...BUT THINKING THAT CAPE IN REALITY IS AROUND
500 J/KG DUE TO LIMITED HEATING. CAPE VALUES COULD RISE TO AROUND
1000 J/KG AS THERE ARE A FEW BREAKS IN THE CLOUDS...BUT THINKING IN
GENERAL THE BREAKS ARE MOVING TOO QUICKLY AND TOO FEW AND FAR BTWN
TO AMOUNT TO MUCH. SHEAR VALUES REMAIN VERY FAVORABLE FOR ORGANIZED
STORMS WITH VALUES AROUND 35-40 KT.
THEREFORE EXPECTING SCATTERED SHOWER/TS DEVELOPMENT THIS AFTN IN THE
WAKE OF THE LINE OF SHOWERS THAT IS SHIFTING EAST ACROSS INDIANA
RIGHT NOW. A SECOND SKINNY LINE OF CONVECTION LIES FROM DIXON IL TO
JERSEYVILLE IL WITH A FEW ADDITIONAL CELLS OUT AHEAD OF IT. DUE TO
LIMITED CAPE AS DISCUSSED ABOVE...THE STRONGER CELLS MAY PRODUCE
DAMAGING WINDS. WINDS HAVE VEERED TO THE SW AND HELICITY IS MUCH
LOWER SO NOT AS CONCERNED ABOUT ISOLATED TORNADOES AS I WAS THIS
MORNING. PWAT VALUES REMAIN VERY IMPRESSIVE AT 1.4-1.7 INCHES SO
ANY OF THE NEW SHOWERS WILL BE CAPABLE OF ADDITIONAL HEAVY DOWNPOURS.
THE AREA OF SCATTERED SHOWERS AND STORMS SHIFTS EAST OF THE CWA THIS
EVENING...BUT WE ARE NOT DONE YET. ANOTHER ROUND OF SHOWERS AND
PERHAPS OF THUNDERSTORMS MAY FORM THIS EVENING AS THE VORT MAX
APPROACHES. THINKING THE COVERAGE WILL BE BEST ALONG AND WEST OF
GARY INDIANA TO PAXTON IL LINE. HAVE LOW CONFIDENCE IN COVERAGE AND
TIMING OF THIS ROUND OF SHOWERS...BUT NOT EXPECTING MUCH THUNDER AND
NO SEVERE WEATHER. DEWPOINTS REMAIN IN THE 60S TONIGHT SO THINKING
WE WILL NOT COOL MUCH...SO KEPT LOWS IN THE LOW TO MID 60S.
THE PATTERN REMAINS MESSY TOMORROW BUT NOT AS ACTIVE. A PAIR OF
VORT STREAMERS AND THE LOWS COLD FRONT ROTATE THROUGH AND SHOWERS
AND STORMS MAY FORM ALONG THEM. THE FIRST IS ASSOCIATED WITH THE
UPPER LEVEL LOW SHIFTING NE INTO ONTARIO TOMORROW. SHOWERS AND
STORMS WITH THIS VORT STREAMER WOULD CLIP THE NORTHERN CWA...NORTH
OF I-88. PRECIP MAY SINK SOUTH ACROSS DUPAGE AND COOK COUNTIES IN
THE AFTN...BUT HAVE LOW CONFIDENCE IN HOW FAR SOUTH THE PRECIP WILL
GET.
CLOUD COVER SHIFTS EAST THROUGH THE AFTERNOON WITH AREAS WEST OF I-
55 BECOMING MOSTLY SUNNY BY MID AFTN. DID NOT MAKE TOO MANY CHANGES
TO HIGH TEMPS TOMORROW AS CLOUD COVER WILL PLAY A ROLE. HAVE TEMPS
IN THE UPPER 70S TO LOW 80S. A LAKE BREEZE IS POSSIBLE LATE IN THE
AFTN AND EVENING SO EXPECTING LAKE COOLING ESPECIALLY AT WAUKEGAN.
JEE
&&
.LONG TERM...
330 PM CDT
WEDNESDAY NIGHT THROUGH TUESDAY...
LOCAL AREA WILL START OUT FIRMLY UNDER MID/UPPER RIDGING ON
WEDNESDAY NIGHT AND THURSDAY...RESULTING IN A DRY AND WARM PERIOD
AS 925 MB TEMPS CLIMB FROM THE UPPER TEENS CELSISUS BY EARLY
THURSDAY TO THE LOWER 20S CELSISUS EARLY THURSDAY EVENING. INLAND
TEMPERATURES WILL WARM TO THE LOWER-MID 80S ON THURSDAY...BUT
DESPITE SOUTHERLY SURFACE FLOW...GRADIENT WILL BE WEAK ENOUGH TO
ENABLE A LAKE BREEZE TO DEVELOP AND PUSH INLAND FAIRLY EARLY. THIS
WILL KEEP LAKESHORE TEMPS (ESPECIALLY IL SHORE) IN THE UPPER 60S.
CHANGES WILL START TO TAKE PLACE THURSDAY NIGHT WITH UPPER RIDGE
AXIS GETTING SHUNTED EAST AND ALLOWS SHORTWAVE ENERGY TO LIFT
EAST-NORTHEAST ACROSS THE AREA AFTER MIDNIGHT INTO FRIDAY ALONG
WITH STRENGTHENING AND VEERING LOW LEVEL JET. HAVE FOCUSED MID
CHANCE POPS INTO NORTHWEST CWA LATE THURSDAY NIGHT AND THEN SPREAD
LIKELY POPS FOR MUCH OF THE CWA FRIDAY MORNING AND EARLY
AFTERNOON. IT APPEARS THAT BETTER MOISTURE CONVERGENCE AND UPPER
FORCING WILL LIFT NORTH AND REFOCUS INTO NORTHWEST CWA FRIDAY
AFTERNOON AND TAILORED POPS AS SUCH...BUT THEN A STRONGER WAVE
WILL MOVE ACROSS THE AREA SATURDAY NIGHT. CONFIDENCE IS A BIT
LOWER IN HIGH TEMPS FRIDAY DUE TO UNCERTAINTY OVER IMPACT OF
CLOUDS/PRECIP...BUT VERY MILD START TO DAY AND WARM AIRMASS IN
PLACE SHOULD STILL SUPPORT HIGHS INTO THE LOWER-MID 80S...WARMEST
IN SOUTHEAST HALF OF CWA. THE WARM TEMPS...DEWPOINTS WELL INTO THE
60S AND MODEST MIDLEVEL LAPSE RATES WILL YIELD MODEST CAPE
VALUES...SO CANNOT RULE OUT AN ISOLATED SEVERE THREAT FOR DAMAGING
WINDS INTO FRIDAY EVENING. COULD BE SOME WET MICROBURSTS WITH PWAT
VALUES IN 1.5 TO 1.75 INCH RANGE.
A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA FRIDAY
NIGHT...RESULTING IN MUCH COOLER WEATHER FOR THE LAST WEEKEND OF
MAY. HIGHS ON THE LAKEFRONT ARE LIKELY TO STAY IN THE 50S ON BOTH
SATURDAY AND SUNDAY...WITH ONLY 60S AND 70S INLAND ON SATURDAY AND
60S ON SUNDAY. WILL NEED TO WATCH FOR A WAVE OF SURFACE LOW
PRESSURE FORMING SOUTH OF THE AREA ON SATURDAY...SO KEPT HIGHER
CONSENSUS POPS FOR NOW SATURDAY MORNING...BUT IF TRENDS ON MUCH OF
GUIDANCE CONTINUE MAY BE ABLE TO LOWER POPS SATURDAY THROUGH
MONDAY WITH EXPANSIVE COOL HIGH PRESSURE OVER THE GREAT LAKES.
TEMPERATURES WILL THEN WARM BACK TO NEAR NORMAL FOR EARLY JUNE BY
TUESDAY WITH SOUTHERLY FLOW ON BACK SIDE OF HIGH TO EAST...THOUGH
ONSHORE FLOW LOOKS TO CONTINUE FOR AT LEAST A PORTION OF THE
LAKEFRONT.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ISOLATED MVFR THIS AFTERNOON
* RAIN SHOWERS POSSIBLY DROPPING TO MVFR
* SOUTH WINDS VARYING FROM SOUTH-SOUTHWEST THIS EVENING.
* MVFR IN FOG AND LOW CLOUDS WEDNESDAY MORNING.
MM
//DISCUSSION...UPDATED 20Z...
LINE OF SHOWERS HAS DECREASED VSBYS TO 1 MILE UPSTREAM EARLY THIS
AFTERNOON. AS THE LINE PROGRESSES NORTHEASTWARD...COULD SEE SOME
STRONGER POCKETS OF RAIN AND TALLER EMBEDDED CELLS PRODUCE
ISOLATED LIGHTNING. LOW CHANCE/CONFIDENCE OF ANY OF THESE CELLS
HITTING THE TERMINALS...SO KEPT VCTS IN THE TAFS THROUGH 19Z.
LOOKING TOWARD WEDNESDAY MORNING...LOW LEVEL MOISTURE AND A WEAK
INVERSION WILL ALLOW A CHANCE FOR MVFR FOG AND CIGS TO WORK INTO
THE TERMINALS. THE AFTERNOON WILL FEATURE A SCATTERED TO POSSIBLY
BROKEN DECK AT 025. INTO THE EVENING...EXPECT OVERCAST CONDITIONS
WITH LIGHT RAIN POSSIBLE. THERE IS A CHANCE FOR THE LAKE BREEZE TO
WORK INTO ORD NEAR OR JUST AFTER 00Z WEDNESDAY EVENING.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN TEMPO MVFR THIS AFTERNOON.
* HIGH CONFIDENCE IN RAIN TIMING THIS AFTERNOON. LOW CONFIDENCE ON
THUNDER CHANCES.
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION WITH HIGH CONFIDENCE
IN WIND SPEED.
* LOW-MEDIUM CONFIDENCE IN FOG AND MVFR CONDITIONS WEDNESDAY
MORNING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WX NIL/VFR. SOUTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA AT NIGHT. SOUTHEAST WINDS.
FRIDAY...TSRA/SHRA LIKELY THROUGH THE DAY AND NIGHT. MVFR
POSSIBLE. SOUTHWEST WINDS.
SATURDAY...SHRA LIKELY WITH A CHANCE OF TSRA DURING THE DAY.
NORTHEAST WINDS.
SUNDAY...CHANCE OF SHRA. EAST WINDS. MVFR POSSIBLE.
MONDAY...CHANCE OF SHRA. SOUTHEAST WINDS. MVFR POSSIBLE.
KREIN
&&
.MARINE...
229 AM CDT
WARM MOIST AIR CONTINUES TO FEED NORTH ACROSS THE LAKE
TODAY...WHICH MAY HELP TO FURTHER ENHANCE ANY AREAS OF FOG THAT
HAVE ALREADY DEVELOPED. IT IS POSSIBLE PATCHY DENSE FOG MAY
DEVELOP...ALTHOUGH WINDS MAY BE JUST STRONG ENOUGH TO LIMIT THE
COVERAGE AND INTENSITY OF THE FOG. A SURFACE LOW PRESSURE SYSTEM
WILL BE LIFTING NORTH ACROSS EASTERN IOWA INTO CENTRAL WISCONSIN
THIS EVENING. THE GRADIENT WILL TIGHTEN ACROSS THE
CENTRAL/SOUTHERN PORTIONS OF THE LAKE...WHICH WITH WARMER
NEARSHORE WATERS EXPECT SOME SLIGHTLY BETTER MIXING TO OCCUR.
FURTHER OUT ACROSS THE OPEN WATERS THE WATER REMAINS COLD AND
EXPECT THE STABILITY TO MAKE IT DIFFICULT TO MIX TO THE SFC THE
HIGHER GUSTS. HIGH PRESSURE THEN ARRIVES LATE WEDNESDAY WITH LIGHT
WINDS DEVELOPING. THEN HIGH PRESSURE SHIFTS EAST THURSDAY
NIGHT...WITH SOUTHERLY WINDS DEVELOPING AGAIN FRIDAY. A FRONTAL
BOUNDARY WILL APPROACH LAKE MICHIGAN LATE FRIDAY NIGHT THEN
STEADILY SLIDE SOUTH ALONG THE LAKE. THIS WILL ALLOW WINDS TO
QUICKLY VEER FROM SOUTH TO NORTH/NORTHEAST SATURDAY. ALONG WITH
THIS QUICK WIND SHIFT WILL BE COOLER AIR SLIDING SOUTH OVER THE
LAKE. WAVES SHOULD EASILY BUILD SATURDAY FOR THE CENTRAL/SOUTHERN
PORTIONS OF THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
300 PM CDT TUE MAY 26 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 300 PM CDT TUE MAY 26 2015
2 PM SURFACE MAP SHOWED LOW PRESSURE CENTERED JUST NORTHWEST OF
DUBUQUE. INITIAL BAND OF CONVECTIVE SHOWERS/ISOLATED THUNDERSTORMS
WHICH MOVED THROUGH THE FORECAST AREA EARLIER HAS ADVANCED NORTHEAST
ACROSS THE INDIANA BORDER...WITH A SECONDARY AXIS OF LIGHT SHOWERS
MOVING EAST AHEAD OF AN UPPER DISTURBANCE CROSSING THE MISSISSIPPI
RIVER.
HRRR AND OTHER HIGH-RESOLUTION MODEL GUIDANCE HAS BEEN DOING A
REASONABLE JOB WITH THE ACTIVITY TODAY...AND WAS GENERALLY FOLLOWED
FOR THE RAIN TRENDS TONIGHT. HAVE MADE SOME ADJUSTMENTS WITH GOING
MAINLY ISOLATED SHOWERS/STORMS THIS EVENING EXCEPT WEST OF I-55...
WHERE LOW CHANCE POP`S WERE KEPT AS A WAVE/TROUGH ADVANCES EAST
ACROSS NORTHERN MISSOURI. HAVE LINGERED THESE 30% CHANCES OVERNIGHT
FROM ABOUT DECATUR WESTWARD. SHOULD SEE SKIES BECOME PARTLY CLOUDY
ACROSS THE SOUTHERN CWA THIS EVENING...BEFORE SOME INCREASE IS NOTED
AGAIN AHEAD OF THE INCOMING WAVE.
&&
.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 300 PM CDT TUE MAY 26 2015
AN UNSETTLED WEATHER PATTERN LOOKS TO CONTINUE THROUGH MONDAY ACROSS
CENTRAL AND SOUTHEAST IL ALONG WITH WARM AND RATHER HUMID SUMMERLIKE
CONDITIONS THE REST OF THE WEEK. A COLD FRONT MOVING SE THROUGH
CENTRAL AND SOUTHEAST IL DURING SATURDAY WILL BRING COOLER
TEMPERATURES DURING THIS WEEKEND ESPECIALLY ON SUNDAY.
UPPER LEVEL TROF OVER THE UPPER MIDWEST MOVES INTO MI ON WED WHILE
PUSHING A WEAK FRONT SE INTO THE IL RIVER VALLEY WED AFTERNOON. ALSO
HAVE A SHORT WAVE EJECTING NE FROM THE SOUTHERN PLAINS INTO SE IL
AND CENTRAL INDIANA BY 18Z/WED. INCREASE INSTABLITY ON WED WITH
CAPES OF 1000-2000 J/KG AND HIGHEST SOUTH OF I-72 TO RETURN CHANCES
OF SHOWERS AND THUNDERSTORMS WITH LOWER CHANCES NW OF IL RIVER AND
HIGHER CHANCES IN SOUTHEAST IL. SPC HAS MARGINAL RISK OF SEVERE WED
AFTERNOON SE OF A SHELYVILLE TO PARIS LINE. CONVECTION CHANCES WILL
LINGER SOUTH OF I-72 WED NIGHT MAINLY WED EVENING. THEN ISOLATED
CHANCES OF CONVECTION SHIFT INTO SOUTHERN AND SW AREAS ON THU AS
WEAK HIGH PRESSURE DRIFTS ACROSS THE GREAT LAKES AND MORE STABLE AIR
OVER NE CWA FROM I-74 NE WHERE IT SHOULD BE DRY. NAM MODEL IS STILL
RATHER UNSTABLE THU SW OF I-74 BUT THINK IT MAY BE OVERDOING THIS AS
STRONGER INSTABLITY CLOSER MO AND THE OHIO RIVER VALLEY ON THU PLUS
HAVE UPPER LEVEL RIDGE BUILDING OVER THE EASTERN STATES THU.
WARM FRONT LIFTS NORTH ACROSS CENTRAL IL THU NIGHT AND IN BREEZY SSW
FLOW ON FRIDAY WITH CHANCES OF SHOWERS AND THUNDERSTORM HIGHEST OVER
IL RIVER VALLEY (LIKELY CHANCES WEST OF IL RIVER ON FRIDAY) AND
LOWEST NEAR WABASH RIVER. WARM HIGHS IN THE LOWER 80S WED AND MID
80S THU AND FRI AND A FEW AREAS COULD REACH UPPER 80S WITH ENOUGH
SUNSHINE ESPECIALLY NEAR WABASH RIVER WHERE RAIN CHANCES ARE LOWER.
HAVE LIKELY CHANCES OF SHOWERS AND THUNDERSTORMS FRI NIGHT AND SAT
WITH COLD FRONT PUSHING SE THROUGH CENTRAL IL DURING SATURDAY. HIGHS
SAT TO CONTRAST FROM LOWER 70S NW OF IL RIVER TO LOW 80S IN
SOUTHEAST IL. CONTINUE LIKELY CHANCES OF SHOWERS AND THUNDERSTORMS
SAT NIGHT IN SOUTHEAST IL ESPECIALLY SAT EVENING WHILE LOWERED POPS
TO LOW CHANCE NW OVER IL RIVER VALLEY BEHIND COLD FRONT. AREAS NW OF
IL RIVER NOW APPEAR DRY ON SUNDAY WHILE CHANCE OF SHOWERS AND
THUNDERSTORMS LINGERS FROM I-72 SOUTH CLOSER TO FRONTAL BOUNDARY
PUSHING SE OF OHIO RIVER OVER KY/TN. SUNDAY APPEARS TO BE COOLEST
DAY WITH HIGHS IN UPPER 60S CENTRAL IL AND LOWER 70S SE IL.
EXTENDED MODELS LIKE GFS AND ECMWF CONTINUE TO SHOW A WEAK CUTOFF
UPPER LEVEL LOW EJECTING INTO MO BY MON AND TO CONTINUE CHANCES OF
SHOWERS AND ISOLATED THUNDERSTORMS MONDAY AND TUESDAY. HIGHS IN THE
LOW TO MID 70S MONDAY AND MID TO UPPER 70S TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1240 PM CDT TUE MAY 26 2015
PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED AT
TIMES THE NEXT 12-15 HOURS, BETWEEN 18Z AND 08Z, ACROSS CENTRAL
AND EASTERN IL.
THE LATEST HRRR REFLECTIVITY FORECAST HAD A PRETTY GOOD HANDLE ON
THE LOW TOPPED CONVECTION THAT HAS FIRED UP IN THE MS RIVER VALLEY
AROUND THE NOON HOUR. THIS IS EXPECTED TO MOVE INTO CENTRAL IL
FROM 19-21Z AND THEN EASTERN IL FROM 21-23Z. GENERALLY VFR
CONDITIONS ARE ANTICIPATED, BUT WOULD ANTICIPATE MVFR FOR A VERY
SHORT PERIOD OF TIME DURING ANY HEAVY DOWNPOURS.
AFTER A BRIEF BREAK IN CONVECTION EARLY THIS EVENING, THE MAIN
COLD FRONT IS EXPECTED TO MOVE TOWARD CENTRAL IL JUST AFTER
SUNSET. THIS WILL RESULT IN MORE SCATTERED SHOWERS. DECIDED NOT TO
INCLUDE ANY MENTION OF THUNDER AT THIS POINT SINCE INSTABILITY IS
EXPECTED TO BE QUITE LIMITED. AFTER THE FRONTAL PASSAGE THE WIND
IS EXPECTED TO GRADUALLY SHIFT FROM SW TO WSW. THIS WILL ALSO BE
ACCOMPANIED BY VFR CEILINGS/STRATOCUMULUS CLOUDS WRAPPING AROUND
THE LOW LEVEL CYCLONIC FLOW THROUGH MUCH OF WEDNESDAY MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEELHART
LONG TERM...07
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
259 PM CDT TUE MAY 26 2015
.SHORT TERM...
253 PM CDT
THROUGH WEDNESDAY...
A SURFACE LOW IS OVER NORTHEAST IA AND SW WI WITH A VORT MAX OVER
IOWA. THE LOWS COLD FRONT REMAINS A BIT FURTHER BACK OVER CENTRAL IA
AND EASTERN KS. THE LOW WILL DEEPEN SLIGHTLY AS IT MOVES OVER
CENTRAL WI AND ITS COLD FRONT SWINGS THROUGH WEDNESDAY. THE MAIN
CONCERN RIGHT NOW IS HOW MUCH CONVECTION WILL DEVELOP THIS
AFTERNOON. THE LATEST RAP ANALYSIS SUGGESTS A RIBBON OF 1000 J/KG
OF CAPE IS OVER I-39...BUT THINKING THAT CAPE IN REALITY IS AROUND
500 J/KG DUE TO LIMITED HEATING. CAPE VALUES COULD RISE TO AROUND
1000 J/KG AS THERE ARE A FEW BREAKS IN THE CLOUDS...BUT THINKING IN
GENERAL THE BREAKS ARE MOVING TOO QUICKLY AND TOO FEW AND FAR BTWN
TO AMOUNT TO MUCH. SHEAR VALUES REMAIN VERY FAVORABLE FOR ORGANIZED
STORMS WITH VALUES AROUND 35-40 KT.
THEREFORE EXPECTING SCATTERED SHOWER/TS DEVELOPMENT THIS AFTN IN THE
WAKE OF THE LINE OF SHOWERS THAT IS SHIFTING EAST ACROSS INDIANA
RIGHT NOW. A SECOND SKINNY LINE OF CONVECTION LIES FROM DIXON IL TO
JERSEYVILLE IL WITH A FEW ADDITIONAL CELLS OUT AHEAD OF IT. DUE TO
LIMITED CAPE AS DISCUSSED ABOVE...THE STRONGER CELLS MAY PRODUCE
DAMAGING WINDS. WINDS HAVE VEERED TO THE SW AND HELICITY IS MUCH
LOWER SO NOT AS CONCERNED ABOUT ISOLATED TORNADOES AS I WAS THIS
MORNING. PWAT VALUES REMAIN VERY IMPRESSIVE AT 1.4-1.7 INCHES SO
ANY OF THE NEW SHOWERS WILL BE CAPABLE OF ADDITIONAL HEAVY DOWNPOURS.
THE AREA OF SCATTERED SHOWERS AND STORMS SHIFTS EAST OF THE CWA THIS
EVENING...BUT WE ARE NOT DONE YET. ANOTHER ROUND OF SHOWERS AND
PERHAPS OF THUNDERSTORMS MAY FORM THIS EVENING AS THE VORT MAX
APPROACHES. THINKING THE COVERAGE WILL BE BEST ALONG AND WEST OF
GARY INDIANA TO PAXTON IL LINE. HAVE LOW CONFIDENCE IN COVERAGE AND
TIMING OF THIS ROUND OF SHOWERS...BUT NOT EXPECTING MUCH THUNDER AND
NO SEVERE WEATHER. DEWPOINTS REMAIN IN THE 60S TONIGHT SO THINKING
WE WILL NOT COOL MUCH...SO KEPT LOWS IN THE LOW TO MID 60S.
THE PATTERN REMAINS MESSY TOMORROW BUT NOT AS ACTIVE. A PAIR OF
VORT STREAMERS AND THE LOWS COLD FRONT ROTATE THROUGH AND SHOWERS
AND STORMS MAY FORM ALONG THEM. THE FIRST IS ASSOCIATED WITH THE
UPPER LEVEL LOW SHIFTING NE INTO ONTARIO TOMORROW. SHOWERS AND
STORMS WITH THIS VORT STREAMER WOULD CLIP THE NORTHERN CWA...NORTH
OF I-88. PRECIP MAY SINK SOUTH ACROSS DUPAGE AND COOK COUNTIES IN
THE AFTN...BUT HAVE LOW CONFIDENCE IN HOW FAR SOUTH THE PRECIP WILL
GET.
CLOUD COVER SHIFTS EAST THROUGH THE AFTERNOON WITH AREAS WEST OF I-
55 BECOMING MOSTLY SUNNY BY MID AFTN. DID NOT MAKE TOO MANY CHANGES
TO HIGH TEMPS TOMORROW AS CLOUD COVER WILL PLAY A ROLE. HAVE TEMPS
IN THE UPPER 70S TO LOW 80S. A LAKE BREEZE IS POSSIBLE LATE IN THE
AFTN AND EVENING SO EXPECTING LAKE COOLING ESPECIALLY AT WAUKEGAN.
JEE
&&
.LONG TERM...
229 AM CDT
WEDNESDAY THROUGH MONDAY...
WEDNESDAY THROUGH THURSDAY...
OPEN 500MB WAVE WILL BE LIFTING NORTHEAST ACROSS THE UPPER MIDWEST
INTO ONTARIO AND EVENTUALLY QUEBEC...WITH HEIGHTS SLOWLY INCREASING
WED AFTN. SFC FEATURES REMAIN DISORGANIZED WED...WITH A BOUNDARY
SLOWLY SHIFTING EAST. OPER GUIDANCE DIFFERS ON HOW QUICKLY PRECIP
WILL DEPART THE REGION. ENSEMBLE DATA SUGGESTS HOLDING ONTO CHC TO
SLIGHT CHC POPS MAINLY FOR THE CENTRAL/EASTERN CWFA WED/WED EVE.
ALTHOUGH WITH SOME HINT OF SFC HEIGHTS NUDGING UP...IT IS POSSIBLE
THAT SOME DRY AIR COULD FILTER IN AND KICK PRECIP EAST BY MIDDAY AND
ALLOW FOR A MAINLY DRY WED. SFC WINDS WILL BE TURNING SOUTHWEST TO
WEST...KEEPING AN OFFSHORE FLOW FOR LOCATIONS CLOSE TO LAKE
MICHIGAN. TEMPS SHOULD YET AGAIN TOUCH UPR 70S TO ARND 80 WED...IF
CLOUDS AND PRECIP CAN PUSH EAST BY MIDDAY...SOME CLEARING WOULD
ALLOW SFC TEMPS TO PUSH A COUPLE DEGREES WARMER INTO THE LOW 80S IN
SOME LOCATIONS. LATE IN THE EVENING THE GRADIENT SLACKENS
FURTHER...AND COULD ALLOW A LATE DAY ONSHORE FLOW TO DEVELOP FOR
AREAS ADJACENT TO LAKE MICHIGAN.
MID-LVL FLOW BEGINS TO FLATTEN AS A WEAK SFC RIDGE BECOMES ORIENTED
FROM WESTERN QUEBEC SOUTH THROUGH THE EASTERN OHIO RIVER VALLEY.
THIS WILL GENERALLY ALLOW A SOUTHERLY FLOW...ALTHOUGH THE GRADIENT
IS NOT VERY STRONG. THIS SHOULD SET THE STAGE FOR A LAKE
BREEZE/ONSHORE FLOW TO DEVELOP THUR. TIMING COULD END UP BEING
SLIGHTLY EARLIER GIVEN THE LIGHT SFC GRADIENT. GUIDANCE HAS BEEN
CONSISTENT IN HOLDING PRECIP WEST/SOUTH OF THE FORECAST AREA
THUR...AS A RESULT OF THE WEAK SFC RIDGING. SO ONE MORE MILD DAY
WITH HIGHS WARMING BACK INTO THE UPR 70S/LOW 80S...HOWEVER AS
PREVIOUSLY NOTED...A LAKE BREEZE IS LIKELY TO DEVELOP. THIS WILL
BLEED THE MUCH COOLER MARINE AIR WEST ACROSS NORTHEAST IL AND
DOWNTOWN CHICAGO. IF THE TIMING IS EARLIER IN THE DAY THUR...TEMPS
MAY NOT WARM BEYOND THE LOW/MID 60S ALONG THE CHICAGO LAKEFRONT.
FLOW THEN TURNS SOUTHERLY THUR NIGHT WITH THE MORE PROGRESSIVE FLOW
IN THE MID-LVLS PUSHING THE RIDGING EAST. A RETURN FLOW MOISTURE
WILL CONTINUE TO BE FOCUSED ACROSS THE CENTRAL CONUS THUR EVE...WITH
A SLOW MOVING FRONTAL BOUNDARY NUDGING EAST THUR NIGHT TOWARDS
WESTERN IL. THIS FRONTAL BOUNDARY WILL BECOME ENERGIZED AS A ROBUST
500MB VORT MAX BREAKS SOUTH FROM CENTRAL CANADA LATE THUR NIGHT.
THIS SHOULD ALLOW FOR AN ATMOSPHERIC RIVER TO DEVELOP FROM THE
SOUTHERN PLAINS STRETCHING NORTH THROUGH THE MID-MISSOURI VALLEY
INTO THE WESTERN GREAT LAKES EARLY FRI MORNING.
FRIDAY THROUGH EARLY NEXT WEEK...
ENSEMBLES CONTINUE TO PROG A ROBUST TROUGH SLIDING SOUTH FROM
CENTRAL CANADA FRI. THIS COUPLED WITH DOWNSTREAM MID-LVL RIDGING
ACROSS THE SOUTHEAST CONUS WILL STRENGTHEN THE FRONTAL BOUNDARY
THAT WILL BE ORIENTED FROM THE SOUTHERN PLAINS STRETCHING
NORTHEAST THROUGH THE GREAT LAKES REGION INTO WESTERN QUEBEC.
THIS SETUP IS IDEAL FOR THE DEVELOPMENT OF AN ATMOSPHERIC RIVER WITH
ABUNDANT LOW LEVEL MOISTURE AND EFFICIENT PRECIP PRODUCING
CONVECTION.
OPER GUIDANCE HAS BEEN RELATIVELY CONSISTENT WITH BRINGING A SERIES
OF WAVES ALONG THE SLOW MOVING FRONTAL BOUNDARY FRI AFTN/EVE...THEN
THE BOUNDARY SHOULD SLIDE EAST WITH WINDS QUICKLY VEERING
NORTH/NORTHEAST FOR SAT AND USHERING IN MUCH COOLER AIR TO THE
REGION.
CURRENT INDICATIONS ARE THAT HIGHS SAT MAY STRUGGLE TO WARM BEYOND
THE UPR 50S ACROSS NORTHEAST IL/NORTHWEST IN...WITH ONLY LOW 60S
ELSEWHERE. STRONG SFC RIDGE WILL REMAIN NORTH OF THE REGION...SO THE
PRIOR FRONTAL BOUNDARY MAY BECOME QUASI-STATIONARY FOR THE WEEKEND
ALONG THE OHIO VALLEY AND CONTINUE TO FEED PRECIP CHANCES TO THE
SOUTHERN CWFA.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ISOLATED MVFR THIS AFTERNOON
* RAIN SHOWERS POSSIBLY DROPPING TO MVFR
* SOUTH WINDS VARYING FROM SOUTH-SOUTHWEST THIS EVENING.
* MVFR IN FOG AND LOW CLOUDS WEDNESDAY MORNING.
MM
//DISCUSSION...UPDATED 20Z...
LINE OF SHOWERS HAS DECREASED VSBYS TO 1 MILE UPSTREAM EARLY THIS
AFTERNOON. AS THE LINE PROGRESSES NORTHEASTWARD...COULD SEE SOME
STRONGER POCKETS OF RAIN AND TALLER EMBEDDED CELLS PRODUCE
ISOLATED LIGHTNING. LOW CHANCE/CONFIDENCE OF ANY OF THESE CELLS
HITTING THE TERMINALS...SO KEPT VCTS IN THE TAFS THROUGH 19Z.
LOOKING TOWARD WEDNESDAY MORNING...LOW LEVEL MOISTURE AND A WEAK
INVERSION WILL ALLOW A CHANCE FOR MVFR FOG AND CIGS TO WORK INTO
THE TERMINALS. THE AFTERNOON WILL FEATURE A SCATTERED TO POSSIBLY
BROKEN DECK AT 025. INTO THE EVENING...EXPECT OVERCAST CONDITIONS
WITH LIGHT RAIN POSSIBLE. THERE IS A CHANCE FOR THE LAKE BREEZE TO
WORK INTO ORD NEAR OR JUST AFTER 00Z WEDNESDAY EVENING.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN TEMPO MVFR THIS AFTERNOON.
* HIGH CONFIDENCE IN RAIN TIMING THIS AFTERNOON. LOW CONFIDENCE ON
THUNDER CHANCES.
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION WITH HIGH CONFIDENCE
IN WIND SPEED.
* LOW-MEDIUM CONFIDENCE IN FOG AND MVFR CONDITIONS WEDNESDAY
MORNING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WX NIL/VFR. SOUTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA AT NIGHT. SOUTHEAST WINDS.
FRIDAY...TSRA/SHRA LIKELY THROUGH THE DAY AND NIGHT. MVFR
POSSIBLE. SOUTHWEST WINDS.
SATURDAY...SHRA LIKELY WITH A CHANCE OF TSRA DURING THE DAY.
NORTHEAST WINDS.
SUNDAY...CHANCE OF SHRA. EAST WINDS. MVFR POSSIBLE.
MONDAY...CHANCE OF SHRA. SOUTHEAST WINDS. MVFR POSSIBLE.
KREIN
&&
.MARINE...
229 AM CDT
WARM MOIST AIR CONTINUES TO FEED NORTH ACROSS THE LAKE
TODAY...WHICH MAY HELP TO FURTHER ENHANCE ANY AREAS OF FOG THAT
HAVE ALREADY DEVELOPED. IT IS POSSIBLE PATCHY DENSE FOG MAY
DEVELOP...ALTHOUGH WINDS MAY BE JUST STRONG ENOUGH TO LIMIT THE
COVERAGE AND INTENSITY OF THE FOG. A SURFACE LOW PRESSURE SYSTEM
WILL BE LIFTING NORTH ACROSS EASTERN IOWA INTO CENTRAL WISCONSIN
THIS EVENING. THE GRADIENT WILL TIGHTEN ACROSS THE
CENTRAL/SOUTHERN PORTIONS OF THE LAKE...WHICH WITH WARMER
NEARSHORE WATERS EXPECT SOME SLIGHTLY BETTER MIXING TO OCCUR.
FURTHER OUT ACROSS THE OPEN WATERS THE WATER REMAINS COLD AND
EXPECT THE STABILITY TO MAKE IT DIFFICULT TO MIX TO THE SFC THE
HIGHER GUSTS. HIGH PRESSURE THEN ARRIVES LATE WEDNESDAY WITH LIGHT
WINDS DEVELOPING. THEN HIGH PRESSURE SHIFTS EAST THURSDAY
NIGHT...WITH SOUTHERLY WINDS DEVELOPING AGAIN FRIDAY. A FRONTAL
BOUNDARY WILL APPROACH LAKE MICHIGAN LATE FRIDAY NIGHT THEN
STEADILY SLIDE SOUTH ALONG THE LAKE. THIS WILL ALLOW WINDS TO
QUICKLY VEER FROM SOUTH TO NORTH/NORTHEAST SATURDAY. ALONG WITH
THIS QUICK WIND SHIFT WILL BE COOLER AIR SLIDING SOUTH OVER THE
LAKE. WAVES SHOULD EASILY BUILD SATURDAY FOR THE CENTRAL/SOUTHERN
PORTIONS OF THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
253 PM CDT TUE MAY 26 2015
.SHORT TERM...
253 PM CDT
THROUGH WEDNESDAY...
A SURFACE LOW IS OVER NORTHEAST IA AND SW WI WITH A VORT MAX OVER
IOWA. THE LOWS COLD FRONT REMAINS A BIT FURTHER BACK OVER CENTRAL IA
AND EASTERN KS. THE LOW WILL DEEPEN SLIGHTLY AS IT MOVES OVER
CENTRAL WI AND ITS COLD FRONT SWINGS THROUGH WEDNESDAY. THE MAIN
CONCERN RIGHT NOW IS HOW MUCH CONVECTION WILL DEVELOP THIS
AFTERNOON. THE LATEST RAP ANALYSIS SUGGESTS A RIBBON OF 1000 J/KG
OF CAPE IS OVER I-39...BUT THINKING THAT CAPE IN REALITY IS AROUND
500 J/KG DUE TO LIMITED HEATING. CAPE VALUES COULD RISE TO AROUND
1000 J/KG AS THERE ARE A FEW BREAKS IN THE CLOUDS...BUT THINKING IN
GENERAL THE BREAKS ARE MOVING TOO QUICKLY AND TOO FEW AND FAR BTWN
TO AMOUNT TO MUCH. SHEAR VALUES REMAIN VERY FAVORABLE FOR ORGANIZED
STORMS WITH VALUES AROUND 35-40 KT.
THEREFORE EXPECTING SCATTERED SHOWER/TS DEVELOPMENT THIS AFTN IN THE
WAKE OF THE LINE OF SHOWERS THAT IS SHIFTING EAST ACROSS INDIANA
RIGHT NOW. A SECOND SKINNY LINE OF CONVECTION LIES FROM DIXON IL TO
JERSEYVILLE IL WITH A FEW ADDITIONAL CELLS OUT AHEAD OF IT. DUE TO
LIMITED CAPE AS DISCUSSED ABOVE...THE STRONGER CELLS MAY PRODUCE
DAMAGING WINDS. WINDS HAVE VEERED TO THE SW AND HELICITY IS MUCH
LOWER SO NOT AS CONCERNED ABOUT ISOLATED TORNADOES AS I WAS THIS
MORNING. PWAT VALUES REMAIN VERY IMPRESSIVE AT 1.4-1.7 INCHES SO
ANY OF THE NEW SHOWERS WILL BE CAPABLE OF ADDITIONAL HEAVY DOWNPOURS.
THE AREA OF SCATTERED SHOWERS AND STORMS SHIFTS EAST OF THE CWA THIS
EVENING...BUT WE ARE NOT DONE YET. ANOTHER ROUND OF SHOWERS AND
PERHAPS OF THUNDERSTORMS MAY FORM THIS EVENING AS THE VORT MAX
APPROACHES. THINKING THE COVERAGE WILL BE BEST ALONG AND WEST OF
GARY INDIANA TO PAXTON IL LINE. HAVE LOW CONFIDENCE IN COVERAGE AND
TIMING OF THIS ROUND OF SHOWERS...BUT NOT EXPECTING MUCH THUNDER AND
NO SEVERE WEATHER. DEWPOINTS REMAIN IN THE 60S TONIGHT SO THINKING
WE WILL NOT COOL MUCH...SO KEPT LOWS IN THE LOW TO MID 60S.
THE PATTERN REMAINS MESSY TOMORROW BUT NOT AS ACTIVE. A PAIR OF
VORT STREAMERS AND THE LOWS COLD FRONT ROTATE THROUGH AND SHOWERS
AND STORMS MAY FORM ALONG THEM. THE FIRST IS ASSOCIATED WITH THE
UPPER LEVEL LOW SHIFTING NE INTO ONTARIO TOMORROW. SHOWERS AND
STORMS WITH THIS VORT STREAMER WOULD CLIP THE NORTHERN CWA...NORTH
OF I-88. PRECIP MAY SINK SOUTH ACROSS DUPAGE AND COOK COUNTIES IN
THE AFTN...BUT HAVE LOW CONFIDENCE IN HOW FAR SOUTH THE PRECIP WILL
GET.
CLOUD COVER SHIFTS EAST THROUGH THE AFTERNOON WITH AREAS WEST OF I-
55 BECOMING MOSTLY SUNNY BY MID AFTN. DID NOT MAKE TOO MANY CHANGES
TO HIGH TEMPS TOMORROW AS CLOUD COVER WILL PLAY A ROLE. HAVE TEMPS
IN THE UPPER 70S TO LOW 80S. A LAKE BREEZE IS POSSIBLE LATE IN THE
AFTN AND EVENING SO EXPECTING LAKE COOLING ESPECIALLY AT WAUKEGAN.
JEE
&&
.LONG TERM...
229 AM CDT
WEDNESDAY THROUGH MONDAY...
WEDNESDAY THROUGH THURSDAY...
OPEN 500MB WAVE WILL BE LIFTING NORTHEAST ACROSS THE UPPER MIDWEST
INTO ONTARIO AND EVENTUALLY QUEBEC...WITH HEIGHTS SLOWLY INCREASING
WED AFTN. SFC FEATURES REMAIN DISORGANIZED WED...WITH A BOUNDARY
SLOWLY SHIFTING EAST. OPER GUIDANCE DIFFERS ON HOW QUICKLY PRECIP
WILL DEPART THE REGION. ENSEMBLE DATA SUGGESTS HOLDING ONTO CHC TO
SLIGHT CHC POPS MAINLY FOR THE CENTRAL/EASTERN CWFA WED/WED EVE.
ALTHOUGH WITH SOME HINT OF SFC HEIGHTS NUDGING UP...IT IS POSSIBLE
THAT SOME DRY AIR COULD FILTER IN AND KICK PRECIP EAST BY MIDDAY AND
ALLOW FOR A MAINLY DRY WED. SFC WINDS WILL BE TURNING SOUTHWEST TO
WEST...KEEPING AN OFFSHORE FLOW FOR LOCATIONS CLOSE TO LAKE
MICHIGAN. TEMPS SHOULD YET AGAIN TOUCH UPR 70S TO ARND 80 WED...IF
CLOUDS AND PRECIP CAN PUSH EAST BY MIDDAY...SOME CLEARING WOULD
ALLOW SFC TEMPS TO PUSH A COUPLE DEGREES WARMER INTO THE LOW 80S IN
SOME LOCATIONS. LATE IN THE EVENING THE GRADIENT SLACKENS
FURTHER...AND COULD ALLOW A LATE DAY ONSHORE FLOW TO DEVELOP FOR
AREAS ADJACENT TO LAKE MICHIGAN.
MID-LVL FLOW BEGINS TO FLATTEN AS A WEAK SFC RIDGE BECOMES ORIENTED
FROM WESTERN QUEBEC SOUTH THROUGH THE EASTERN OHIO RIVER VALLEY.
THIS WILL GENERALLY ALLOW A SOUTHERLY FLOW...ALTHOUGH THE GRADIENT
IS NOT VERY STRONG. THIS SHOULD SET THE STAGE FOR A LAKE
BREEZE/ONSHORE FLOW TO DEVELOP THUR. TIMING COULD END UP BEING
SLIGHTLY EARLIER GIVEN THE LIGHT SFC GRADIENT. GUIDANCE HAS BEEN
CONSISTENT IN HOLDING PRECIP WEST/SOUTH OF THE FORECAST AREA
THUR...AS A RESULT OF THE WEAK SFC RIDGING. SO ONE MORE MILD DAY
WITH HIGHS WARMING BACK INTO THE UPR 70S/LOW 80S...HOWEVER AS
PREVIOUSLY NOTED...A LAKE BREEZE IS LIKELY TO DEVELOP. THIS WILL
BLEED THE MUCH COOLER MARINE AIR WEST ACROSS NORTHEAST IL AND
DOWNTOWN CHICAGO. IF THE TIMING IS EARLIER IN THE DAY THUR...TEMPS
MAY NOT WARM BEYOND THE LOW/MID 60S ALONG THE CHICAGO LAKEFRONT.
FLOW THEN TURNS SOUTHERLY THUR NIGHT WITH THE MORE PROGRESSIVE FLOW
IN THE MID-LVLS PUSHING THE RIDGING EAST. A RETURN FLOW MOISTURE
WILL CONTINUE TO BE FOCUSED ACROSS THE CENTRAL CONUS THUR EVE...WITH
A SLOW MOVING FRONTAL BOUNDARY NUDGING EAST THUR NIGHT TOWARDS
WESTERN IL. THIS FRONTAL BOUNDARY WILL BECOME ENERGIZED AS A ROBUST
500MB VORT MAX BREAKS SOUTH FROM CENTRAL CANADA LATE THUR NIGHT.
THIS SHOULD ALLOW FOR AN ATMOSPHERIC RIVER TO DEVELOP FROM THE
SOUTHERN PLAINS STRETCHING NORTH THROUGH THE MID-MISSOURI VALLEY
INTO THE WESTERN GREAT LAKES EARLY FRI MORNING.
FRIDAY THROUGH EARLY NEXT WEEK...
ENSEMBLES CONTINUE TO PROG A ROBUST TROUGH SLIDING SOUTH FROM
CENTRAL CANADA FRI. THIS COUPLED WITH DOWNSTREAM MID-LVL RIDGING
ACROSS THE SOUTHEAST CONUS WILL STRENGTHEN THE FRONTAL BOUNDARY
THAT WILL BE ORIENTED FROM THE SOUTHERN PLAINS STRETCHING
NORTHEAST THROUGH THE GREAT LAKES REGION INTO WESTERN QUEBEC.
THIS SETUP IS IDEAL FOR THE DEVELOPMENT OF AN ATMOSPHERIC RIVER WITH
ABUNDANT LOW LEVEL MOISTURE AND EFFICIENT PRECIP PRODUCING
CONVECTION.
OPER GUIDANCE HAS BEEN RELATIVELY CONSISTENT WITH BRINGING A SERIES
OF WAVES ALONG THE SLOW MOVING FRONTAL BOUNDARY FRI AFTN/EVE...THEN
THE BOUNDARY SHOULD SLIDE EAST WITH WINDS QUICKLY VEERING
NORTH/NORTHEAST FOR SAT AND USHERING IN MUCH COOLER AIR TO THE
REGION.
CURRENT INDICATIONS ARE THAT HIGHS SAT MAY STRUGGLE TO WARM BEYOND
THE UPR 50S ACROSS NORTHEAST IL/NORTHWEST IN...WITH ONLY LOW 60S
ELSEWHERE. STRONG SFC RIDGE WILL REMAIN NORTH OF THE REGION...SO THE
PRIOR FRONTAL BOUNDARY MAY BECOME QUASI-STATIONARY FOR THE WEEKEND
ALONG THE OHIO VALLEY AND CONTINUE TO FEED PRECIP CHANCES TO THE
SOUTHERN CWFA.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR THIS AFTERNOON
* RAIN WITH EMBEDDED THUNDER POSSIBLE
* SOUTH WINDS VARYING FROM SOUTHEAST EARLY TO SOUTHWEST THIS
EVENING.
* MVFR IN FOG AND LOW CLOUDS WEDNESDAY MORNING.
MM
//DISCUSSION...UPDATED 18Z...
LINE OF SHOWERS HAS DECREASED VSBYS TO 1 MILE UPSTREAM EARLY THIS
AFTERNOON. AS THE LINE PROGRESSES NORTHEASTWARD...COULD SEE SOME
STRONGER POCKETS OF RAIN AND TALLER EMBEDDED CELLS PRODUCE
ISOLATED LIGHTNING. LOW CHANCE/CONFIDENCE OF ANY OF THESE CELLS
HITTING THE TERMINALS...SO KEPT VCTS IN THE TAFS THROUGH 19Z.
LOOKING TOWARD WEDNESDAY MORNING...LOW LEVEL MOISTURE AND A WEAK
INVERSION WILL ALLOW A CHANCE FOR MVFR FOG AND CIGS TO WORK INTO
THE TERMINALS. THE AFTERNOON WILL FEATURE A SCATTERED TO POSSIBLY
BROKEN DECK AT 025. INTO THE EVENING...EXPECT OVERCAST CONDITIONS
WITH LIGHT RAIN POSSIBLE. THERE IS A CHANCE FOR THE LAKE BREEZE TO
WORK INTO ORD NEAR OR JUST AFTER 00Z WEDNESDAY EVENING.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE REMAINING MVFR THIS AFTERNOON.
* HIGH CONFIDENCE IN RAIN TIMING THIS AFTERNOON. LOW CONFIDENCE ON
THUNDER CHANCES.
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION WITH HIGH CONFIDENCE
IN WIND SPEED EXCEPT LOW CONFIDENCE IF THUNDERSTORMS OCCUR.
* LOW-MEDIUM CONFIDENCE IN FOG AND MVFR CONDITIONS WEDNESDAY
MORNING.
*
MM
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WX NIL/VFR. SOUTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA AT NIGHT. SOUTHEAST WINDS.
FRIDAY...TSRA/SHRA LIKELY THROUGH THE DAY AND NIGHT. MVFR
POSSIBLE. SOUTHWEST WINDS.
SATURDAY...SHRA LIKELY WITH A CHANCE OF TSRA DURING THE DAY.
NORTHEAST WINDS.
SUNDAY...CHANCE OF SHRA. EAST WINDS. MVFR POSSIBLE.
MONDAY...CHANCE OF SHRA. SOUTHEAST WINDS. MVFR POSSIBLE.
KREIN
&&
.MARINE...
229 AM CDT
WARM MOIST AIR CONTINUES TO FEED NORTH ACROSS THE LAKE
TODAY...WHICH MAY HELP TO FURTHER ENHANCE ANY AREAS OF FOG THAT
HAVE ALREADY DEVELOPED. IT IS POSSIBLE PATCHY DENSE FOG MAY
DEVELOP...ALTHOUGH WINDS MAY BE JUST STRONG ENOUGH TO LIMIT THE
COVERAGE AND INTENSITY OF THE FOG. A SURFACE LOW PRESSURE SYSTEM
WILL BE LIFTING NORTH ACROSS EASTERN IOWA INTO CENTRAL WISCONSIN
THIS EVENING. THE GRADIENT WILL TIGHTEN ACROSS THE
CENTRAL/SOUTHERN PORTIONS OF THE LAKE...WHICH WITH WARMER
NEARSHORE WATERS EXPECT SOME SLIGHTLY BETTER MIXING TO OCCUR.
FURTHER OUT ACROSS THE OPEN WATERS THE WATER REMAINS COLD AND
EXPECT THE STABILITY TO MAKE IT DIFFICULT TO MIX TO THE SFC THE
HIGHER GUSTS. HIGH PRESSURE THEN ARRIVES LATE WEDNESDAY WITH LIGHT
WINDS DEVELOPING. THEN HIGH PRESSURE SHIFTS EAST THURSDAY
NIGHT...WITH SOUTHERLY WINDS DEVELOPING AGAIN FRIDAY. A FRONTAL
BOUNDARY WILL APPROACH LAKE MICHIGAN LATE FRIDAY NIGHT THEN
STEADILY SLIDE SOUTH ALONG THE LAKE. THIS WILL ALLOW WINDS TO
QUICKLY VEER FROM SOUTH TO NORTH/NORTHEAST SATURDAY. ALONG WITH
THIS QUICK WIND SHIFT WILL BE COOLER AIR SLIDING SOUTH OVER THE
LAKE. WAVES SHOULD EASILY BUILD SATURDAY FOR THE CENTRAL/SOUTHERN
PORTIONS OF THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1240 PM CDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 1038 AM CDT TUE MAY 26 2015
MADE A FEW UPDATES TO POPS/WEATHER AND HOURLY TEMPS FOR TODAY
BASED ON TRENDS OF CURRENT CONVECTION MOVING THROUGH CENTRAL IL
LATE THIS MORNING INTO EAST CENTRAL IL BY THE NOON HOUR. A GENERAL
WEAKENING TREND HAS BEEN NOTED THE PAST HOUR, SO ONLY A BRIEF
HEAVY DOWNPOUR IS ANTICIPATED WITH THE LINE OF SHOWERS-ISOLATED
THUNDERSTORMS.
A VERY BRIEF PERIOD OF PARTIAL CLEARING IS ANTICIPATED AFTER THE
SHOWERS MOVE THROUGH, WHICH MAY HELP TO SLIGHTLY INCREASE THE
INSTABILITY IN CENTRAL AND EASTERN IL THIS AFTERNOON. HOWEVER,
SATELLITE IS SHOWING THAT CUMULUS WILL MOST LIKELY RAPIDLY FILL
IN. THE HRRR, NAM12 AND RAP ALL SEEM TO HAVE A FAIRLY GOOD HANDLE
ON THE WEAKENING TREND OF THE LINE OF CONVECTION, WITH SCATTERED
SHOWERS AND THUNDERSTORMS REDEVELOPING THIS AFTERNOON. A SHORTWAVE
TROUGH MOVING NORTHEAST FROM THE OZARKS WILL PROVIDE UPPER LEVEL
SUPPORT TO SOUTHEAST AND EAST CENTRAL IL, BUT INSTABILITY WILL BE
MARGINAL AT BEST. THUS, STRONG/SEVERE STORMS SHOULD BE QUITE
LIMITED IN COVERAGE, IF THEY DEVELOP AT ALL.
&&
.SHORT TERM...(TODAY)
ISSUED AT 343 AM CDT TUE MAY 26 2015
LOW CLOUDS HAVE BEEN ADVECTING INTO THE AREA AND WILL REMAIN OVER
THE AREA THIS MORNING. LOWER CLOUDS INDICATING LOTS OF LOW LEVEL
MOISTURE BEING ADVECTED INTO THE AREA AHEAD OF THE WEATHER SYSTEM
THAT STILL IS WEST OF THE CWA. RADAR AND SATELLITE LOOPS SHOW
SEVERAL MCVS WEST OF THE AREA WITH SOME SHOWERS MOVING NORTH THROUGH
SOUTHEASTERN MO. MODELS CONTINUE TO INDICATE PCPN REDEVELOPING
TODAY. CLOUDS WILL LIMIT THE DEGREE OF INSTABILITY BUT STILL
EXPECTING ENOUGH FOR THUNDERSTORMS, JUST NOT ENOUGH FOR ANYTHING
SEVERE, WHICH SHOULD BE EAST AND SOUTHEAST OF THE AREA WHERE LESS
CLOUDS WILL BE. CLOUD COVER WILL ALSO TEMPER WARM UP AS WELL SO ONLY
EXPECTING UPPER 70S FOR HIGHS WHICH IS MUCH LESS THAN PAST TWO DAYS.
POPS WILL BE A GRADUAL INCREASE TODAY REACHING LIKELY LATER THIS
MORNING AND THEN MOVING NORTH AND EAST THIS AFTERNOON, BECOMING
CHANCE CATEGORY BY LATE AFTERNOON AS THE PCPN MOVES EAST OF THE
AREA. SOUTHERLY WINDS WILL BE A TAD GUSTY AGAIN, JUST NOT AS MUCH AS
YESTERDAY.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 343 AM CDT TUE MAY 26 2015
UNTIL THE UPPER WAVE PULLS INTO THE GREAT LAKES REGION, LINGERING
POPS WILL REMAIN OVER THE FA FOR THIS EVENING. BETTER CHANCES WILL
REMAIN TO THE EAST OVERNIGHT. REMAINS OF THE FRONT WILL STALL OUT
ALONG THE OHIO RIVER VALLEY AND PROVIDE A BIT OF FOCUS FOR ANOTHER
PIECE OF ENERGY EJECTING OUT OF THE SOUTHWEST. MODELS DIFFERING
WITH THE NORTHERLY EXTENT OF THE PRECIP, BUT LAST FEW RUNS BRINGING
IN SOME PRECIPITATION FOR WEDNESDAY IN THE SOUTHEAST. NAM IS A
LITTLE MORE WIDESPREAD, BUT CONCENTRATING THE POPS TO THE SOUTH AND
EAST FOR NOW. TIMING ISSUES REMAIN IN PLACE FOR THIS SYNOPTIC RUN
FOR THE NEXT SYSTEM QUICK ON THE HEELS AS THE DEEP WAVE OVER THE SW
STARTS TO MOVE OUT INTO THE PLAINS. CONVECTION AND PRECIP STARTS TO
SPREAD OVER THE EASTERN HALF OF THE COUNTRY IN THE MODELS WITH WEAK
SOUTHWESTERLY FLOW ALOFT SHIFTING TO WEAK FLOW OVERALL. WARM AND
MUGGY CONDITIONS CONTINUE IN A MORE SUMMERLIKE AIRMASS THROUGHOUT
THE WEEK...BUT THAT NEXT SYSTEM WILL BRING A COLD FRONT INTO THE
REGION FOR THE FIRST HALF OF THE WEEKEND TO FOCUS THE RAIN, WITH A
COOLER AIRMASS BEHIND IT DROPPING THE TEMPS FOR THE WEEKEND OUT OF
THE 80S FOR A COUPLE DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1240 PM CDT TUE MAY 26 2015
PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED AT
TIMES THE NEXT 12-15 HOURS, BETWEEN 18Z AND 08Z, ACROSS CENTRAL
AND EASTERN IL.
THE LATEST HRRR REFLECTIVITY FORECAST HAD A PRETTY GOOD HANDLE ON
THE LOW TOPPED CONVECTION THAT HAS FIRED UP IN THE MS RIVER VALLEY
AROUND THE NOON HOUR. THIS IS EXPECTED TO MOVE INTO CENTRAL IL
FROM 19-21Z AND THEN EASTERN IL FROM 21-23Z. GENERALLY VFR
CONDITIONS ARE ANTICIPATED, BUT WOULD ANTICIPATE MVFR FOR A VERY
SHORT PERIOD OF TIME DURING ANY HEAVY DOWNPOURS.
AFTER A BRIEF BREAK IN CONVECTION EARLY THIS EVENING, THE MAIN
COLD FRONT IS EXPECTED TO MOVE TOWARD CENTRAL IL JUST AFTER
SUNSET. THIS WILL RESULT IN MORE SCATTERED SHOWERS. DECIDED NOT TO
INCLUDE ANY MENTION OF THUNDER AT THIS POINT SINCE INSTABILITY IS
EXPECTED TO BE QUITE LIMITED. AFTER THE FRONTAL PASSAGE THE WIND
IS EXPECTED TO GRADUALLY SHIFT FROM SW TO WSW. THIS WILL ALSO BE
ACCOMPANIED BY VFR CEILINGS/STRATOCUMULUS CLOUDS WRAPPING AROUND
THE LOW LEVEL CYCLONIC FLOW THROUGH MUCH OF WEDNESDAY MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1232 PM CDT TUE MAY 26 2015
.UPDATE...
1007 AM CDT
A SFC LOW IS OVER IOWA AND ITS WARM/STATIONARY FRONT IS WELL TO
OUR NORTH OVER CENTRAL WI. ITS COLD FRONT STRETCHES FROM THE LOW
THROUGH CENTRAL KANSAS. AN AREA OF MAINLY RAIN AND A FEW
THUNDERSTORMS IS SLOWLY SPREADING NNE ACROSS NORTH CENTRAL IL. SO
FAR THE SHOWERS HAVE BEEN BEHAVING ACROSS MY CWA...BUT A FEW CELLS
TO THE WEST HAVE SHOWN SIGNS OF ROTATION.
LIKING THE LATEST RAP GUIDANCE WHICH KEEPS CAPE VALUES ON THE LOW
SIDE WITH ONLY A FEW HUNDREDS J/KG OF CAPE TO WORK WITH. THIS IS
ASSUMING SKIES STAY OVERCAST...AND THINKING WE WILL BE OVERCAST
TODAY. THAT BEING SAID...ANY LOCATIONS THAT SEE SUNSHINE COULD
DEVELOP ENOUGH CAPE TO SUPPORT TALLER CELLS AND POSSIBLY SEVERE
WEATHER. IN GENERAL THINKING DAMAGING WINDS AND AN ISOLATED
TORNADO ARE THE MAIN THREATS...BUT STRONGER STORMS WITH HIGHER
CAPE VALUES COULD SUPPORT HAIL. RADAR IMAGERY IS SHOWING GRAVITY
WAVE TAGS MOVING ALONG THE LINE OF STORMS AND WHEN THE TAGS
INTERSECT THE LINE...STORMS BEGIN TO SPIN. THEREFORE THE TORNADO
THREAT IS NOT ZERO.
THIS FIRST BATCH OF PRECIP WILL PUSH EAST THROUGH THE EARLY AFTN
HOURS AND EXPECTING ADDITIONAL SCATTERED TO NUMEROUS THUNDERSTORMS
DEVELOPMENT BEHIND THE LINE OVER NORTH CENTRAL IL. THE SECOND
WAVE SHIFTS EAST THROUGH THE EARLY EVENING HOURS. PWAT VALUES ARE
1.2-1.5 INCHES SO HEAVY DOWNPOURS ARE PSBL.
JEE
&&
.SHORT TERM...
319 AM CDT
THROUGH TUESDAY NIGHT...
FOR THE REMAINDER OF THE OVERNIGHT HOURS...CONDITIONS WILL REMAIN
QUIET ACROSS THE CWA AS A SERIES OF SHORT WAVES CONTINUE TO TRACK
NORTH AROUND THE TOP OF A PERSISTENT UPPER LEVEL RIDGE WHICH EXTENDS
FROM THE SERN CONUS THROUGH THE UPPER MISSISSIPPI VALLEY. THIS
UPPER RIDGE HAS BEEN THE FEATURE WHICH HAS CONTROLLED THE PATH OF
THE SERIES OF SHORTWAVES LIFTING OUT OF THE SOUTHERN PLAINS...AND
WILL CONTINUE TO DO SO THROUGH THE DAY TODAY. SLY...MODERATELY
STRONG...WINDS WILL PERSIST THROUGH THE NIGHT...AND MUCH OF THE DAY
ALLOWING FOR SFC DEWPOINTS TO REMAIN CONSISTENT OR POSSIBLE INCH A
LITTLE HIGHER.
MAIN CONCERN FOR THE MORNING HOURS WILL BE THE TRACK OF A STRONG
SHORT WAVE AND ASSOCIATED SFC LOW LIFTING NORTHWARD THROUGH THE
MIDDLE MISSISSIPPI VALLEY. THIS FEATURE WILL PREDOMINANTLY IMPACT
ERN IOWA AND WRN IL BY ARND DAYBREAK. THROUGH THE MORNING...THE
COMBINATION OF ISENTROPIC LIFT IN THE WARM SECTOR OF THE
SYSTEM...ALL OF IL AND INTO NWRN IN...WILL LEAD TO SOME
DESTABILIZATION ACROSS THE REGION. A SFC TROUGH...AS WELL INDICATED
BY THE LATEST HIGH RES GUIDANCE...WITH LIFT THROUGH NRN IL/IN
THROUGH THE DAY...COINCIDENT WITH A STRONG SSWLY LOW LEVEL JET OF 45-
50 KT...WITH PROVIDE THE POTENTIAL FOR SHOWERS AND STRONG TO SEVERE
THUNDERSTORMS ACROSS THE CWA. BASED ON WIND PROFILES AND MID LEVEL
DRYING...THE PRIMARY CONCERN WITH REGARD TO SEVERE WEATHER WILL BE
STRONG WIND GUSTS. HOWEVER...SOME OF THE HIGH RES SFC WIND GUIDANCE
SUGGEST SOME SLIGHT BACKING OF SFC WINDS FROM 180-190 DEGREES TO 160-
170 DEGREES...WHILE WINDS ALOFT REMAIN SWLY. THIS SLIGHT BACKING OF
THE SFC WINDS COULD PROVIDE ENOUGH DIRECTIONAL SHEAR THROUGH THE
LOWER LEVELS TO BRING AN ISOLD TORNADO THREAT. LOCALLY HEAVY
RAINFALL WILL ALSO BE CONCERNED WITH PWATS REACHING 1.75 INCHES
LATER THIS MORNING. HOWEVER...FLOODING WILL LIKELY NOT BE A
SIGNIFICANT CONCERN AS THE SWLY WINDS RIGHT OFF THE DECK WILL RANGE
FROM ARND 45 KT ABOVE THE BOUNDARY LAYER TO ARND 90KT AT UPPER
LEVELS WHICH SHOULD ALLOW ANY OF THE STRONGER STORMS THAT DO DEVELOP
TO MOVE QUICKLY.
BY EARLY AFTERNOON...THE MAIN SHORT WAVE WILL LIFT INTO WISCONSIN
WHILE A SFC TROUGH TRACKS EAST ACROSS THE AREA. THIS WILL LEAD TO
WINDS AT THE SFC VEERING TO SWLY...SETTING UP A UNIDIRECTIONAL WIND
PROFILE...EFFECTIVELY MINIMIZING THE SEVERE WEATHER THREAT TO THE
REGION. BY LATE AFTERNOON AND INTO THE EVENING THE MODELS ARE
ADVERTISING THAT A DRY SLOW SHOULD NOSE INTO NRN IL...EFFECTIVELY
CUTTING OFF THE PCPN AREA INTO 2 SEPARATE AREA...ONE OVER WISCONSIN
AND ERN IOWA AND ANOTHER MORE FOCUSED OVER INDIANA. THE NWRN
INDIANA COUNTIES WILL STILL HAVE A CHANCE FOR SOME SHOWERS AND
THUNDERSTORMS INTO THE EVENING...WHILE PCPN CHANCES OVER NRN IL
BEGIN TO WANE. MUCH OF THE MODEL GUIDANCE ALSO INDICATED THAT THE
SHORTWAVE SHOULD SLOW IT`S PROGRESSION THROUGH WISCONSIN AS IT
APPROACHES THE APEX OF THE UPPER RIDGE. AN ASSOCIATED SFC
TROUGH/COLD FRONT EXTENDING SOUTHWEST FROM THE SFC LOW WILL LINGER
OVER ERN IOWA IN THE EARLY EVENING BEFORE STEADILY PUSHING ACROSS
NRN IL AND INTO NWRN IN OVERNIGHT. THROUGH THE NIGHT...THE
STRONGEST UPPER LEVEL FORCING WILL BE WELL NORTH OF THE CWA...SO ANY
LINGERING CHANCES FOR PCPN OVERNIGHT WILL BE LOW AND LIKELY CONFINED
TO THE NRN TIER COUNTIES OF IL...ALONG THE WI BORDER.
KREIN
&&
.LONG TERM...
229 AM CDT
WEDNESDAY THROUGH MONDAY...
WEDNESDAY THROUGH THURSDAY...
OPEN 500MB WAVE WILL BE LIFTING NORTHEAST ACROSS THE UPPER MIDWEST
INTO ONTARIO AND EVENTUALLY QUEBEC...WITH HEIGHTS SLOWLY INCREASING
WED AFTN. SFC FEATURES REMAIN DISORGANIZED WED...WITH A BOUNDARY
SLOWLY SHIFTING EAST. OPER GUIDANCE DIFFERS ON HOW QUICKLY PRECIP
WILL DEPART THE REGION. ENSEMBLE DATA SUGGESTS HOLDING ONTO CHC TO
SLIGHT CHC POPS MAINLY FOR THE CENTRAL/EASTERN CWFA WED/WED EVE.
ALTHOUGH WITH SOME HINT OF SFC HEIGHTS NUDGING UP...IT IS POSSIBLE
THAT SOME DRY AIR COULD FILTER IN AND KICK PRECIP EAST BY MIDDAY AND
ALLOW FOR A MAINLY DRY WED. SFC WINDS WILL BE TURNING SOUTHWEST TO
WEST...KEEPING AN OFFSHORE FLOW FOR LOCATIONS CLOSE TO LAKE
MICHIGAN. TEMPS SHOULD YET AGAIN TOUCH UPR 70S TO ARND 80 WED...IF
CLOUDS AND PRECIP CAN PUSH EAST BY MIDDAY...SOME CLEARING WOULD
ALLOW SFC TEMPS TO PUSH A COUPLE DEGREES WARMER INTO THE LOW 80S IN
SOME LOCATIONS. LATE IN THE EVENING THE GRADIENT SLACKENS
FURTHER...AND COULD ALLOW A LATE DAY ONSHORE FLOW TO DEVELOP FOR
AREAS ADJACENT TO LAKE MICHIGAN.
MID-LVL FLOW BEGINS TO FLATTEN AS A WEAK SFC RIDGE BECOMES ORIENTED
FROM WESTERN QUEBEC SOUTH THROUGH THE EASTERN OHIO RIVER VALLEY.
THIS WILL GENERALLY ALLOW A SOUTHERLY FLOW...ALTHOUGH THE GRADIENT
IS NOT VERY STRONG. THIS SHOULD SET THE STAGE FOR A LAKE
BREEZE/ONSHORE FLOW TO DEVELOP THUR. TIMING COULD END UP BEING
SLIGHTLY EARLIER GIVEN THE LIGHT SFC GRADIENT. GUIDANCE HAS BEEN
CONSISTENT IN HOLDING PRECIP WEST/SOUTH OF THE FORECAST AREA
THUR...AS A RESULT OF THE WEAK SFC RIDGING. SO ONE MORE MILD DAY
WITH HIGHS WARMING BACK INTO THE UPR 70S/LOW 80S...HOWEVER AS
PREVIOUSLY NOTED...A LAKE BREEZE IS LIKELY TO DEVELOP. THIS WILL
BLEED THE MUCH COOLER MARINE AIR WEST ACROSS NORTHEAST IL AND
DOWNTOWN CHICAGO. IF THE TIMING IS EARLIER IN THE DAY THUR...TEMPS
MAY NOT WARM BEYOND THE LOW/MID 60S ALONG THE CHICAGO LAKEFRONT.
FLOW THEN TURNS SOUTHERLY THUR NIGHT WITH THE MORE PROGRESSIVE FLOW
IN THE MID-LVLS PUSHING THE RIDGING EAST. A RETURN FLOW MOISTURE
WILL CONTINUE TO BE FOCUSED ACROSS THE CENTRAL CONUS THUR EVE...WITH
A SLOW MOVING FRONTAL BOUNDARY NUDGING EAST THUR NIGHT TOWARDS
WESTERN IL. THIS FRONTAL BOUNDARY WILL BECOME ENERGIZED AS A ROBUST
500MB VORT MAX BREAKS SOUTH FROM CENTRAL CANADA LATE THUR NIGHT.
THIS SHOULD ALLOW FOR AN ATMOSPHERIC RIVER TO DEVELOP FROM THE
SOUTHERN PLAINS STRETCHING NORTH THROUGH THE MID-MISSOURI VALLEY
INTO THE WESTERN GREAT LAKES EARLY FRI MORNING.
FRIDAY THROUGH EARLY NEXT WEEK...
ENSEMBLES CONTINUE TO PROG A ROBUST TROUGH SLIDING SOUTH FROM
CENTRAL CANADA FRI. THIS COUPLED WITH DOWNSTREAM MID-LVL RIDGING
ACROSS THE SOUTHEAST CONUS WILL STRENGTHEN THE FRONTAL BOUNDARY
THAT WILL BE ORIENTED FROM THE SOUTHERN PLAINS STRETCHING
NORTHEAST THROUGH THE GREAT LAKES REGION INTO WESTERN QUEBEC.
THIS SETUP IS IDEAL FOR THE DEVELOPMENT OF AN ATMOSPHERIC RIVER WITH
ABUNDANT LOW LEVEL MOISTURE AND EFFICIENT PRECIP PRODUCING
CONVECTION.
OPER GUIDANCE HAS BEEN RELATIVELY CONSISTENT WITH BRINGING A SERIES
OF WAVES ALONG THE SLOW MOVING FRONTAL BOUNDARY FRI AFTN/EVE...THEN
THE BOUNDARY SHOULD SLIDE EAST WITH WINDS QUICKLY VEERING
NORTH/NORTHEAST FOR SAT AND USHERING IN MUCH COOLER AIR TO THE
REGION.
CURRENT INDICATIONS ARE THAT HIGHS SAT MAY STRUGGLE TO WARM BEYOND
THE UPR 50S ACROSS NORTHEAST IL/NORTHWEST IN...WITH ONLY LOW 60S
ELSEWHERE. STRONG SFC RIDGE WILL REMAIN NORTH OF THE REGION...SO THE
PRIOR FRONTAL BOUNDARY MAY BECOME QUASI-STATIONARY FOR THE WEEKEND
ALONG THE OHIO VALLEY AND CONTINUE TO FEED PRECIP CHANCES TO THE
SOUTHERN CWFA.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR THIS AFTERNOON
* RAIN WITH EMBEDDED THUNDER POSSIBLE
* SOUTH WINDS VARYING FROM SOUTHEAST EARLY TO SOUTHWEST THIS
EVENING.
* MVFR IN FOG AND LOW CLOUDS WEDNESDAY MORNING.
MM
//DISCUSSION...UPDATED 18Z...
LINE OF SHOWERS HAS DECREASED VSBYS TO 1 MILE UPSTREAM EARLY THIS
AFTERNOON. AS THE LINE PROGRESSES NORTHEASTWARD...COULD SEE SOME
STRONGER POCKETS OF RAIN AND TALLER EMBEDDED CELLS PRODUCE
ISOLATED LIGHTNING. LOW CHANCE/CONFIDENCE OF ANY OF THESE CELLS
HITTING THE TERMINALS...SO KEPT VCTS IN THE TAFS THROUGH 19Z.
LOOKING TOWARD WEDNESDAY MORNING...LOW LEVEL MOISTURE AND A WEAK
INVERSION WILL ALLOW A CHANCE FOR MVFR FOG AND CIGS TO WORK INTO
THE TERMINALS. THE AFTERNOON WILL FEATURE A SCATTERED TO POSSIBLY
BROKEN DECK AT 025. INTO THE EVENING...EXPECT OVERCAST CONDITIONS
WITH LIGHT RAIN POSSIBLE. THERE IS A CHANCE FOR THE LAKE BREEZE TO
WORK INTO ORD NEAR OR JUST AFTER 00Z WEDNESDAY EVENING.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE REMAINING MVFR THIS AFTERNOON.
* HIGH CONFIDENCE IN RAIN TIMING THIS AFTERNOON. LOW CONFIDENCE ON
THUNDER CHANCES.
* MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION WITH HIGH CONFIDENCE
IN WIND SPEED EXCEPT LOW CONFIDENCE IF THUNDERSTORMS OCCUR.
* LOW-MEDIUM CONFIDENCE IN FOG AND MVFR CONDITIONS WEDNESDAY
MORNING.
*
MM
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WX NIL/VFR. SOUTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA AT NIGHT. SOUTHEAST WINDS.
FRIDAY...TSRA/SHRA LIKELY THROUGH THE DAY AND NIGHT. MVFR
POSSIBLE. SOUTHWEST WINDS.
SATURDAY...SHRA LIKELY WITH A CHANCE OF TSRA DURING THE DAY.
NORTHEAST WINDS.
SUNDAY...CHANCE OF SHRA. EAST WINDS. MVFR POSSIBLE.
MONDAY...CHANCE OF SHRA. SOUTHEAST WINDS. MVFR POSSIBLE.
KREIN
&&
.MARINE...
229 AM CDT
WARM MOIST AIR CONTINUES TO FEED NORTH ACROSS THE LAKE
TODAY...WHICH MAY HELP TO FURTHER ENHANCE ANY AREAS OF FOG THAT
HAVE ALREADY DEVELOPED. IT IS POSSIBLE PATCHY DENSE FOG MAY
DEVELOP...ALTHOUGH WINDS MAY BE JUST STRONG ENOUGH TO LIMIT THE
COVERAGE AND INTENSITY OF THE FOG. A SURFACE LOW PRESSURE SYSTEM
WILL BE LIFTING NORTH ACROSS EASTERN IOWA INTO CENTRAL WISCONSIN
THIS EVENING. THE GRADIENT WILL TIGHTEN ACROSS THE
CENTRAL/SOUTHERN PORTIONS OF THE LAKE...WHICH WITH WARMER
NEARSHORE WATERS EXPECT SOME SLIGHTLY BETTER MIXING TO OCCUR.
FURTHER OUT ACROSS THE OPEN WATERS THE WATER REMAINS COLD AND
EXPECT THE STABILITY TO MAKE IT DIFFICULT TO MIX TO THE SFC THE
HIGHER GUSTS. HIGH PRESSURE THEN ARRIVES LATE WEDNESDAY WITH LIGHT
WINDS DEVELOPING. THEN HIGH PRESSURE SHIFTS EAST THURSDAY
NIGHT...WITH SOUTHERLY WINDS DEVELOPING AGAIN FRIDAY. A FRONTAL
BOUNDARY WILL APPROACH LAKE MICHIGAN LATE FRIDAY NIGHT THEN
STEADILY SLIDE SOUTH ALONG THE LAKE. THIS WILL ALLOW WINDS TO
QUICKLY VEER FROM SOUTH TO NORTH/NORTHEAST SATURDAY. ALONG WITH
THIS QUICK WIND SHIFT WILL BE COOLER AIR SLIDING SOUTH OVER THE
LAKE. WAVES SHOULD EASILY BUILD SATURDAY FOR THE CENTRAL/SOUTHERN
PORTIONS OF THE LAKE.
BEACHLER
&&
.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
1110 AM CDT TUE MAY 26 2015
.UPDATE...
1007 AM CDT
A SFC LOW IS OVER IOWA AND ITS WARM/STATIONARY FRONT IS WELL TO
OUR NORTH OVER CENTRAL WI. ITS COLD FRONT STRETCHES FROM THE LOW
THROUGH CENTRAL KANSAS. AN AREA OF MAINLY RAIN AND A FEW
THUNDERSTORMS IS SLOWLY SPREADING NNE ACROSS NORTH CENTRAL IL. SO
FAR THE SHOWERS HAVE BEEN BEHAVING ACROSS MY CWA...BUT A FEW CELLS
TO THE WEST HAVE SHOWN SIGNS OF ROTATION.
LIKING THE LATEST RAP GUIDANCE WHICH KEEPS CAPE VALUES ON THE LOW
SIDE WITH ONLY A FEW HUNDREDS J/KG OF CAPE TO WORK WITH. THIS IS
ASSUMING SKIES STAY OVERCAST...AND THINKING WE WILL BE OVERCAST
TODAY. THAT BEING SAID...ANY LOCATIONS THAT SEE SUNSHINE COULD
DEVELOP ENOUGH CAPE TO SUPPORT TALLER CELLS AND POSSIBLY SEVERE
WEATHER. IN GENERAL THINKING DAMAGING WINDS AND AN ISOLATED
TORNADO ARE THE MAIN THREATS...BUT STRONGER STORMS WITH HIGHER
CAPE VALUES COULD SUPPORT HAIL. RADAR IMAGERY IS SHOWING GRAVITY
WAVE TAGS MOVING ALONG THE LINE OF STORMS AND WHEN THE TAGS
INTERSECT THE LINE...STORMS BEGIN TO SPIN. THEREFORE THE TORNADO
THREAT IS NOT ZERO.
THIS FIRST BATCH OF PRECIP WILL PUSH EAST THROUGH THE EARLY AFTN
HOURS AND EXPECTING ADDITIONAL SCATTERED TO NUMEROUS THUNDERSTORMS
DEVELOPMENT BEHIND THE LINE OVER NORTH CENTRAL IL. THE SECOND
WAVE SHIFTS EAST THROUGH THE EARLY EVENING HOURS. PWAT VALUES ARE
1.2-1.5 INCHES SO HEAVY DOWNPOURS ARE PSBL.
JEE
&&
.SHORT TERM...
319 AM CDT
THROUGH TUESDAY NIGHT...
FOR THE REMAINDER OF THE OVERNIGHT HOURS...CONDITIONS WILL REMAIN
QUIET ACROSS THE CWA AS A SERIES OF SHORT WAVES CONTINUE TO TRACK
NORTH AROUND THE TOP OF A PERSISTENT UPPER LEVEL RIDGE WHICH EXTENDS
FROM THE SERN CONUS THROUGH THE UPPER MISSISSIPPI VALLEY. THIS
UPPER RIDGE HAS BEEN THE FEATURE WHICH HAS CONTROLLED THE PATH OF
THE SERIES OF SHORTWAVES LIFTING OUT OF THE SOUTHERN PLAINS...AND
WILL CONTINUE TO DO SO THROUGH THE DAY TODAY. SLY...MODERATELY
STRONG...WINDS WILL PERSIST THROUGH THE NIGHT...AND MUCH OF THE DAY
ALLOWING FOR SFC DEWPOINTS TO REMAIN CONSISTENT OR POSSIBLE INCH A
LITTLE HIGHER.
MAIN CONCERN FOR THE MORNING HOURS WILL BE THE TRACK OF A STRONG
SHORT WAVE AND ASSOCIATED SFC LOW LIFTING NORTHWARD THROUGH THE
MIDDLE MISSISSIPPI VALLEY. THIS FEATURE WILL PREDOMINANTLY IMPACT
ERN IOWA AND WRN IL BY ARND DAYBREAK. THROUGH THE MORNING...THE
COMBINATION OF ISENTROPIC LIFT IN THE WARM SECTOR OF THE
SYSTEM...ALL OF IL AND INTO NWRN IN...WILL LEAD TO SOME
DESTABILIZATION ACROSS THE REGION. A SFC TROUGH...AS WELL INDICATED
BY THE LATEST HIGH RES GUIDANCE...WITH LIFT THROUGH NRN IL/IN
THROUGH THE DAY...COINCIDENT WITH A STRONG SSWLY LOW LEVEL JET OF 45-
50 KT...WITH PROVIDE THE POTENTIAL FOR SHOWERS AND STRONG TO SEVERE
THUNDERSTORMS ACROSS THE CWA. BASED ON WIND PROFILES AND MID LEVEL
DRYING...THE PRIMARY CONCERN WITH REGARD TO SEVERE WEATHER WILL BE
STRONG WIND GUSTS. HOWEVER...SOME OF THE HIGH RES SFC WIND GUIDANCE
SUGGEST SOME SLIGHT BACKING OF SFC WINDS FROM 180-190 DEGREES TO 160-
170 DEGREES...WHILE WINDS ALOFT REMAIN SWLY. THIS SLIGHT BACKING OF
THE SFC WINDS COULD PROVIDE ENOUGH DIRECTIONAL SHEAR THROUGH THE
LOWER LEVELS TO BRING AN ISOLD TORNADO THREAT. LOCALLY HEAVY
RAINFALL WILL ALSO BE CONCERNED WITH PWATS REACHING 1.75 INCHES
LATER THIS MORNING. HOWEVER...FLOODING WILL LIKELY NOT BE A
SIGNIFICANT CONCERN AS THE SWLY WINDS RIGHT OFF THE DECK WILL RANGE
FROM ARND 45 KT ABOVE THE BOUNDARY LAYER TO ARND 90KT AT UPPER
LEVELS WHICH SHOULD ALLOW ANY OF THE STRONGER STORMS THAT DO DEVELOP
TO MOVE QUICKLY.
BY EARLY AFTERNOON...THE MAIN SHORT WAVE WILL LIFT INTO WISCONSIN
WHILE A SFC TROUGH TRACKS EAST ACROSS THE AREA. THIS WILL LEAD TO
WINDS AT THE SFC VEERING TO SWLY...SETTING UP A UNIDIRECTIONAL WIND
PROFILE...EFFECTIVELY MINIMIZING THE SEVERE WEATHER THREAT TO THE
REGION. BY LATE AFTERNOON AND INTO THE EVENING THE MODELS ARE
ADVERTISING THAT A DRY SLOW SHOULD NOSE INTO NRN IL...EFFECTIVELY
CUTTING OFF THE PCPN AREA INTO 2 SEPARATE AREA...ONE OVER WISCONSIN
AND ERN IOWA AND ANOTHER MORE FOCUSED OVER INDIANA. THE NWRN
INDIANA COUNTIES WILL STILL HAVE A CHANCE FOR SOME SHOWERS AND
THUNDERSTORMS INTO THE EVENING...WHILE PCPN CHANCES OVER NRN IL
BEGIN TO WANE. MUCH OF THE MODEL GUIDANCE ALSO INDICATED THAT THE
SHORTWAVE SHOULD SLOW IT`S PROGRESSION THROUGH WISCONSIN AS IT
APPROACHES THE APEX OF THE UPPER RIDGE. AN ASSOCIATED SFC
TROUGH/COLD FRONT EXTENDING SOUTHWEST FROM THE SFC LOW WILL LINGER
OVER ERN IOWA IN THE EARLY EVENING BEFORE STEADILY PUSHING ACROSS
NRN IL AND INTO NWRN IN OVERNIGHT. THROUGH THE NIGHT...THE
STRONGEST UPPER LEVEL FORCING WILL BE WELL NORTH OF THE CWA...SO ANY
LINGERING CHANCES FOR PCPN OVERNIGHT WILL BE LOW AND LIKELY CONFINED
TO THE NRN TIER COUNTIES OF IL...ALONG THE WI BORDER.
KREIN
&&
.LONG TERM...
229 AM CDT
WEDNESDAY THROUGH MONDAY...
WEDNESDAY THROUGH THURSDAY...
OPEN 500MB WAVE WILL BE LIFTING NORTHEAST ACROSS THE UPPER MIDWEST
INTO ONTARIO AND EVENTUALLY QUEBEC...WITH HEIGHTS SLOWLY INCREASING
WED AFTN. SFC FEATURES REMAIN DISORGANIZED WED...WITH A BOUNDARY
SLOWLY SHIFTING EAST. OPER GUIDANCE DIFFERS ON HOW QUICKLY PRECIP
WILL DEPART THE REGION. ENSEMBLE DATA SUGGESTS HOLDING ONTO CHC TO
SLIGHT CHC POPS MAINLY FOR THE CENTRAL/EASTERN CWFA WED/WED EVE.
ALTHOUGH WITH SOME HINT OF SFC HEIGHTS NUDGING UP...IT IS POSSIBLE
THAT SOME DRY AIR COULD FILTER IN AND KICK PRECIP EAST BY MIDDAY AND
ALLOW FOR A MAINLY DRY WED. SFC WINDS WILL BE TURNING SOUTHWEST TO
WEST...KEEPING AN OFFSHORE FLOW FOR LOCATIONS CLOSE TO LAKE
MICHIGAN. TEMPS SHOULD YET AGAIN TOUCH UPR 70S TO ARND 80 WED...IF
CLOUDS AND PRECIP CAN PUSH EAST BY MIDDAY...SOME CLEARING WOULD
ALLOW SFC TEMPS TO PUSH A COUPLE DEGREES WARMER INTO THE LOW 80S IN
SOME LOCATIONS. LATE IN THE EVENING THE GRADIENT SLACKENS
FURTHER...AND COULD ALLOW A LATE DAY ONSHORE FLOW TO DEVELOP FOR
AREAS ADJACENT TO LAKE MICHIGAN.
MID-LVL FLOW BEGINS TO FLATTEN AS A WEAK SFC RIDGE BECOMES ORIENTED
FROM WESTERN QUEBEC SOUTH THROUGH THE EASTERN OHIO RIVER VALLEY.
THIS WILL GENERALLY ALLOW A SOUTHERLY FLOW...ALTHOUGH THE GRADIENT
IS NOT VERY STRONG. THIS SHOULD SET THE STAGE FOR A LAKE
BREEZE/ONSHORE FLOW TO DEVELOP THUR. TIMING COULD END UP BEING
SLIGHTLY EARLIER GIVEN THE LIGHT SFC GRADIENT. GUIDANCE HAS BEEN
CONSISTENT IN HOLDING PRECIP WEST/SOUTH OF THE FORECAST AREA
THUR...AS A RESULT OF THE WEAK SFC RIDGING. SO ONE MORE MILD DAY
WITH HIGHS WARMING BACK INTO THE UPR 70S/LOW 80S...HOWEVER AS
PREVIOUSLY NOTED...A LAKE BREEZE IS LIKELY TO DEVELOP. THIS WILL
BLEED THE MUCH COOLER MARINE AIR WEST ACROSS NORTHEAST IL AND
DOWNTOWN CHICAGO. IF THE TIMING IS EARLIER IN THE DAY THUR...TEMPS
MAY NOT WARM BEYOND THE LOW/MID 60S ALONG THE CHICAGO LAKEFRONT.
FLOW THEN TURNS SOUTHERLY THUR NIGHT WITH THE MORE PROGRESSIVE FLOW
IN THE MID-LVLS PUSHING THE RIDGING EAST. A RETURN FLOW MOISTURE
WILL CONTINUE TO BE FOCUSED ACROSS THE CENTRAL CONUS THUR EVE...WITH
A SLOW MOVING FRONTAL BOUNDARY NUDGING EAST THUR NIGHT TOWARDS
WESTERN IL. THIS FRONTAL BOUNDARY WILL BECOME ENERGIZED AS A ROBUST
500MB VORT MAX BREAKS SOUTH FROM CENTRAL CANADA LATE THUR NIGHT.
THIS SHOULD ALLOW FOR AN ATMOSPHERIC RIVER TO DEVELOP FROM THE
SOUTHERN PLAINS STRETCHING NORTH THROUGH THE MID-MISSOURI VALLEY
INTO THE WESTERN GREAT LAKES EARLY FRI MORNING.
FRIDAY THROUGH EARLY NEXT WEEK...
ENSEMBLES CONTINUE TO PROG A ROBUST TROUGH SLIDING SOUTH FROM
CENTRAL CANADA FRI. THIS COUPLED WITH DOWNSTREAM MID-LVL RIDGING
ACROSS THE SOUTHEAST CONUS WILL STRENGTHEN THE FRONTAL BOUNDARY
THAT WILL BE ORIENTED FROM THE SOUTHERN PLAINS STRETCHING
NORTHEAST THROUGH THE GREAT LAKES REGION INTO WESTERN QUEBEC.
THIS SETUP IS IDEAL FOR THE DEVELOPMENT OF AN ATMOSPHERIC RIVER WITH
ABUNDANT LOW LEVEL MOISTURE AND EFFICIENT PRECIP PRODUCING
CONVECTION.
OPER GUIDANCE HAS BEEN RELATIVELY CONSISTENT WITH BRINGING A SERIES
OF WAVES ALONG THE SLOW MOVING FRONTAL BOUNDARY FRI AFTN/EVE...THEN
THE BOUNDARY SHOULD SLIDE EAST WITH WINDS QUICKLY VEERING
NORTH/NORTHEAST FOR SAT AND USHERING IN MUCH COOLER AIR TO THE
REGION.
CURRENT INDICATIONS ARE THAT HIGHS SAT MAY STRUGGLE TO WARM BEYOND
THE UPR 50S ACROSS NORTHEAST IL/NORTHWEST IN...WITH ONLY LOW 60S
ELSEWHERE. STRONG SFC RIDGE WILL REMAIN NORTH OF THE REGION...SO THE
PRIOR FRONTAL BOUNDARY MAY BECOME QUASI-STATIONARY FOR THE WEEKEND
ALONG THE OHIO VALLEY AND CONTINUE TO FEED PRECIP CHANCES TO THE
SOUTHERN CWFA.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* MVFR CEILINGS CONTINUE INTO THIS AFTERNOON
* LINE OF RA APPROACHING TERMINALS WITH VCTS POSSIBLE
* SOUTH WINDS VARYING FROM SSE BECOMING SSW AFTER 23Z...GUSTING
OVER 20KT
MM
//DISCUSSION...UPDATED 16Z...
DECREASING CONFIDENCE IN ANY THUNDER REACHING THE TAF SITES THIS
AFTERNOON...SO DROPPED GROUP TO VCTS FOR A LIMITED TIME. HIGHER
CONFIDENCE IN LINE OF LIGHT TO MODERATE SHOWER ACTIVITY
APPROACHING FROM THE SOUTH-SOUTHWEST. VISIBLE SATELLITE SHOWS
CLEARING BEHIND THE LINE OF RAIN...WHICH WILL BE MONITORED FOR ANY
ADDITIONAL INSTABILITY DEVELOPING. AT THIS POINT...ONLY CONFIDENT
IN A CHANCE OF SHOWERS REDEVELOPING BEHIND THE LINE.
MM
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN MVFR CEILINGS.
* MEDIUM HIGH CONFIDENCE IN WIND SPEEDS AND MEDIUM IN WIND
DIRECTION.
* HIGH CONFIDENCE IN SHOWERS AND RAIN WITH MEDIUM CONFIDENCE IN
VCTS AND LOW CONFIDENCE IN ADDITIONAL TS DEVELOPMENT AFTER 21Z.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...WX NIL/VFR. SOUTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA AT NIGHT. SOUTHEAST WINDS.
FRIDAY...TSRA/SHRA LIKELY THROUGH THE DAY AND NIGHT. MVFR
POSSIBLE. SOUTHWEST WINDS.
SATURDAY...SHRA LIKELY WITH A CHANCE OF TSRA DURING THE DAY.
NORTHEAST WINDS.
SUNDAY...CHANCE OF SHRA. EAST WINDS. MVFR POSSIBLE.
MONDAY...CHANCE OF SHRA. SOUTHEAST WINDS. MVFR POSSIBLE.
KREIN
&&
.MARINE...
229 AM CDT
WARM MOIST AIR CONTINUES TO FEED NORTH ACROSS THE LAKE
TODAY...WHICH MAY HELP TO FURTHER ENHANCE ANY AREAS OF FOG THAT
HAVE ALREADY DEVELOPED. IT IS POSSIBLE PATCHY DENSE FOG MAY
DEVELOP...ALTHOUGH WINDS MAY BE JUST STRONG ENOUGH TO LIMIT THE
COVERAGE AND INTENSITY OF THE FOG. A SURFACE LOW PRESSURE SYSTEM
WILL BE LIFTING NORTH ACROSS EASTERN IOWA INTO CENTRAL WISCONSIN
THIS EVENING. THE GRADIENT WILL TIGHTEN ACROSS THE
CENTRAL/SOUTHERN PORTIONS OF THE LAKE...WHICH WITH WARMER
NEARSHORE WATERS EXPECT SOME SLIGHTLY BETTER MIXING TO OCCUR.
FURTHER OUT ACROSS THE OPEN WATERS THE WATER REMAINS COLD AND
EXPECT THE STABILITY TO MAKE IT DIFFICULT TO MIX TO THE SFC THE
HIGHER GUSTS. HIGH PRESSURE THEN ARRIVES LATE WEDNESDAY WITH LIGHT
WINDS DEVELOPING. THEN HIGH PRESSURE SHIFTS EAST THURSDAY
NIGHT...WITH SOUTHERLY WINDS DEVELOPING AGAIN FRIDAY. A FRONTAL
BOUNDARY WILL APPROACH LAKE MICHIGAN LATE FRIDAY NIGHT THEN
STEADILY SLIDE SOUTH ALONG THE LAKE. THIS WILL ALLOW WINDS TO
QUICKLY VEER FROM SOUTH TO NORTH/NORTHEAST SATURDAY. ALONG WITH
THIS QUICK WIND SHIFT WILL BE COOLER AIR SLIDING SOUTH OVER THE
LAKE. WAVES SHOULD EASILY BUILD SATURDAY FOR THE CENTRAL/SOUTHERN
PORTIONS OF THE LAKE.
BEACHLER
&&
.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 NORTHERN INDIANA
126 PM EDT TUE MAY 26 2015
.SYNOPSIS...
ISSUED AT 358 AM EDT TUE MAY 26 2015
AN UPPER LEVEL DISTURBANCE WILL LIFT NORTHEAST TODAY...AND WILL
BRING A GOOD CHANCE FOR THUNDERSTORMS TO THE AREA THIS AFTERNOON.
MORE STORMS ARE POSSIBLE WEDNESDAY AFTERNOON FOLLOWED BY DRY
CONDITIONS THURSDAY THROUGH THURSDAY NIGHT. TEMPERATURES WILL BE
ABOVE NORMAL FOR THIS TIME OF YEAR WITH HIGHS WARMING INTO THE MID
80S BY FRIDAY. THERE IS A GOOD CHANCE FOR RAIN THIS WEEKEND WITH
COOLER TEMPERATURES.
&&
.UPDATE...
ISSUED AT 1044 AM EDT TUE MAY 26 2015
A FEW MINOR UPDATES TO THE GOING FORECAST FOR THIS AFTERNOON AND
EVENING. MORNING WATER VAPOR SHOWS DECENT SHORTWAVE SHEARING
NORTHEAST AS EXPECTED. LINE OF CONVECTION MOVING THROUGH ILLINOIS IS
ASSOCIATED WITH TRAILING CONVERGENT BOUNDARY. VAST MAJORITY OF
LATEST GUIDANCE SHOWS MOST OF OUR CWA GETTING AT LEAST A HUNDREDTH
OF PRECIP SO BUMPED POPS INTO LIKELY CATEGORY. SEVERE WEATHER THREAT
REMAINS MORE NEBULOUS GIVEN ABUNDANT PREFRONTAL CLOUDS...LACKLUSTER
FORCING...AND MIDLEVEL LAPSE RATES BELOW 6 C/KM. THAT BEING SAID...
12Z NAM...RAP...AND HRRR ALL SHOW POCKETS OF MLCAPE VALUES AROUND
1000 J/KG THIS AFTERNOON. 0-6KM BULK SHEAR VECTORS ARE AROUND 30 KTS
WITH 0-3KM VALUES AROUND 25 KTS. NOT REALLY SUPPORTIVE OF A
WIDESPREAD/ORGANIZED SEVERE WEATHER THREAT BUT A FEW CLUSTERS OF
STORMS COULD BECOME SEVERE. THIS IS ESPECIALLY TRUE IN OUR SOUTHEAST
HALF GIVEN MUCH LESS CLOUD COVER...THOUGH WOULDN`T RULE OUT THE
NORTHWEST DUE TO BETTER FORCING AND SHEAR. DAMAGING STRAIGHT LINE
WINDS WILL DEFINITELY BE THE MAIN CONCERN GIVEN STRONG LOW LEVEL
FLOW...THOUGH AN ISOLATED TORNADO CANT BE RULED OUT DUE TO DECENT
0-1KM SHEAR VALUES AND RELATIVELY LOW LCLS. HAIL THREAT IS
NEGLIGIBLE. EXPECT STORMS TO MOVE INTO OUR WESTERN AREAS SHORTLY
AFTER NOON AND CONTINUE THROUGH THE EARLY EVENING HOURS. WILL
CONTINUE TO MONITOR SATELLITE AND SURFACE OBSERVATIONAL TRENDS FOR
ANY EVIDENCE OF ENHANCED SURFACE HEATING/MOISTURE POOLING THROUGH
MIDDAY AS THIS LINE APPROACHES. AGAIN...SEVERE RISK IS STILL
CONDITIONAL AT THIS POINT BUT CERTAINLY BEARS WATCHING AS THE DAY
WEARS ON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT TUE MAY 26 2015
CONVECTIVELY ENHANCED SRN STREAM SW OVR NE OK WILL DAMPEN NEWD
THROUGH ERN IA TDA. HWVR UNLIKE YDA UPR JET STREAK ALIGNED A BIT
FURTHER EWD W/A MORE ROBUST HGT FALLS OVERSPREADING CWA THIS AFTN.
UPSTREAM CLD EVOLUTION SUGGESTS POCKETS OF INSOLATION WILL DVLP
THROUGH MORNING W/AT LEAST A FVRBL YET LIMITED SFC BASED
DESTABILIZATION RESPONSE RESULTING. EWD EXTENT OF MORE SIG SYNOPTIC
SCALE FORCING MUCH IN DOUBT HWVR POTENTIAL EXISTS FOR UPSCALE
ORGANIZATION ORGANIZATION TO CONVN ESP SHLD BTR THAN XPCD
INSTABILITY DVLP.
REGARDLESS OF OUTCOME...FOLLOWING DRYSLOT AND INCREASING MID LVL
SUBSIDENCE QUICK TO FOLLOW THIS EVENING AND OTHER THAN A LINGERING
SHOWER GENERALLY EAST HAVE DROPPED POPS AFT 06Z.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM EDT TUE MAY 26 2015
THERE ARE LOTS OF CHALLENGES THIS LONG TERM PERIOD AS THE LONG WAVE
TROF BECOMES REESTABLISHED OVER THE WESTERN CONUS AFTER EJECTING A
COUPLE OF SHORT WAVE TROFS ACROSS THE CENTRAL CONUS. AHEAD OF THESE
SYSTEMS...PLENTY OF MOISTURE WILL BE AVAILABLE FOR SHOWERS AND
STORMS...ALBEIT RELATIVELY STABLE MID LEVEL LAPSE RATES WILL TEND TO
LIMIT CONVECTION. ALSO...SOME UPSTREAM CONVECTION WILL TEND TO
INTERCEPT MOISTURE FLUX AND LIMIT VERY DEEP MOISTURE TRANSPORT
NORTH. OVERALL...THE AIRMASS OVER THE CENTRAL THIRD OF THE CONUS HAS
HAD ASTOUNDING PRECIPITATION EFFICIENCY...WITH OKLAHOMA CITY
APPROACHING 20 INCHES OF RAIN SO FAR THIS MONTH...WELL ABOVE THE
RECORD RAINFALL FOR ANY MONTH IN THIS CITY. WITH SO MUCH RECENT RAIN
UPSTREAM... THERE WILL LIKELY BE RECYCLING OF MOISTURE AS REFLECTED
IN RESEARCH AS WHAT HAPPENED IN THE 1993 FLOODS. KEPT THESE FACTORS
IN MIND WITH THIS PORTION OF THE FORECAST. MADE ONLY MINOR
ADJUSTMENTS TO THE TIMING AND PLACEMENT OF SHOWER AND STORMS
WEDNESDAY AS THE FAR SOUTHEAST PORTION OF AN EJECTING UPPER LEVEL
TROF SHOULD BE SE SUFFICIENT TO GENERATE SOME STORMS...ESPECIALLY
WITH DAYTIME HEATING. FOR THIS WEEKEND...A SLOW MOVING SOUTHERN
STREAM SYSTEM WILL ATTEMPT TO MERGE WITH A NORTHERN STREAM TROF OVER
THE UPPER GREAT LAKES REGION. STILL SOME UNCERTAINTY ON HOW THIS
WILL PLAY OUT...BUT FOR NOW...RAIN CHANCES AT LEAST AT SOME POINT
LOOK REAL FAVORABLE AS THE UPPER LEVEL TROF INTERACTS WITH THE
SURFACE BOUNDARY. AS FOR TEMPERATURES...KEPT TEMPERATURES WARM
WEDNESDAY THROUGH FRIDAY...WITH HIGHS FRIDAY WELL INTO THE 80S AS
SUPPORTED BY THE GFS MEX FOR THE PAST SEVERAL DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 125 PM EDT TUE MAY 26 2015
FEW CHANGES TO THE GOING TAF FORECAST WITH AFTERNOON CONVECTION
THE MAIN CONCERN. LINE OF SHOWERS CURRENTLY PUSHING INTO WESTERN
INDIANA WITH SOME CONVECTION POPPING UP AHEAD OF IT WHERE MORNING
SUN HAS ALLOWED BETTER INSTABILITY TO BUILD. EXPECT THIS ACTIVITY
TO EXPAND AND STRENGTHEN THROUGH THE AFTERNOON AS IT INTERSECTS
MODERATELY UNSTABLE ENVIRONMENT OVER NORTHEAST INDIANA AND
NORTHWEST OHIO. A FEW STRONG TO SEVERE STORMS MAY BE POSSIBLE NEAR
KFWA WITH LOWER CHANCES AT KSBN. BEST CHANCES WILL BE IN THE
20-22Z TIMEFRAME. CONVECTION WILL EXIT THIS EVENING AND EXPECT
PREDOMINATELY VFR CONDITIONS OVERNIGHT. SLIGHT CHANCE FOR SOME
LOWER CIGS AGAIN TOMORROW MORNING BUT LATEST FORECAST SOUNDINGS
ARE MUCH DRIER AND MOS GUIDANCE IS NOT AS SUPPORTIVE SO WILL LEAVE
OUT MENTION FOR NOW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...AGD
SYNOPSIS...SKIPPER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
347 PM CDT TUE MAY 26 2015
...UPDATED FOR LONG TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1255 PM CDT TUE MAY 26 2015
TONIGHT:
THE MAIN CONCERN THIS EVENING IS THE SLIGHT CHANCE FOR
THUNDERSTORMS. HAVE BROAD BRUSHED SLIGHT POPS ACROSS THE REGION
AS FORCING IS WEAK AND UNCLEAR AT THIS TIME. HRRR AND THE 4 KM NAM
HAVE STORMS DEVELOPING LATE AFTERNOON INTO THE EVENING. THERE
COULD BE SOME LOW END SEVERE THUNDERSTORMS AS WELL WITH 500-1500
J/KG OF CAPE AND 30-40 KT OF BULK SHEAR. ACTIVITY WILL REMAIN
ISOLATED. PROBABLY THE MOST SEVERE STORMS WILL REMAIN SOUTH OF
THE FORECAST AREA. THREATS WOULD BE HAIL UP TO THE SIZE OF HALF
DOLLARS AND 60 MPH OUTFLOW WINDS. STORMS WILL BE FAIRLY HIGH BASED
AND LOW LEVEL SHEAR IS WEAK, SO NOT ANTICIPATING A TORNADO THREAT
AT THIS TIME FOR THIS EVENING. THE BEST AREAS FOR STORM ACTIVITY
WILL BE ACROSS THE NORTHWESTERN AND SOUTHEASTERN ZONES. OTHERWISE,
ACTIVITY WILL BE DIURNALLY BASED AND WILL WEAKEN AFTER SUNSET.
LOWS WILL BE IN THE 50S TO AROUND 60 ACROSS SOUTH-CENTRAL KANSAS.
TOMORROW:
MID TO UPPER LEVEL FLOW INCREASES TOMORROW. AT THE LOW LEVELS,
WARM AIR ADVECTION WILL CONTINUE. THERE IS SOME BUST POTENTIAL
WITH TEMPERATURES. SOME OF THE GUIDANCE KEEPS LINGERING
PRECIPITATION AND THUS COOLER HIGHS. STILL THINK THE WARM SECTOR
WILL SPREAD NORTHWARD ACROSS THE REGION WITH MANY LOCATIONS SEEING
WARM TEMPERATURES. CAPE IS FORECAST TO BE SIGNIFICANTLY HIGHER
TOMORROW WITH 2000-3000 J/KG. FORECAST SHEAR OF 45 KT WILL SUPPORT
SUPERCELLS. WILL HAVE TO WATCH OUT FOR TORNADO POTENTIAL AS SFC
WINDS BACK EAST-SOUTHEASTERLY. THERE IS ENOUGH LOW LEVEL
DIRECTIONAL AND SPEED SHEAR AS WELL. POPS WILL BE FAIRLY HIGH AT
THE END OF THE SHORT TERM PERIOD AND EXTENDING INTO THE LONG TERM.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 252 PM CDT TUE MAY 26 2015
A RATHER STORMY PATTERN WILL PERSIST THROUGH FRIDAY AS AN UPPER
LEVEL TROUGH OVER THE NORTHWESTERN UNITED STATES SLOWLY PROGRESSES
TOWARD WESTERN KANSAS. AHEAD OF THIS FEATURE, AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE, AND SEVERAL EPISODES OF THUNDERSTORMS ARE
LIKELY. IT IS VERY DIFFICULT TO TIME THESE THUNDERSTORM CLUSTERS; BUT
CLIMATOLOGY SAYS THAT LATE AFTERNOON THROUGH EARLY MORNING TIME
FRAME IS THE WETTEST FROM NOW ON THROUGH THE SUMMER, WITH 8 AM TO
3 PM TIME FRAME THE QUIETEST IN TERMS OF TOTAL RAINFALL AMOUNTS.
SOME OF THE STORMS DURING THIS PERIOD COULD BE SEVERE,
PARTICULARLY ON THURSDAY AS THE VERTICAL WIND SHEAR AND CAPE
VALUES WILL BE HIGHEST AT THAT TIME. AFTER THE UPPER LEVEL TROUGH
AXIS AND SURFACE COLD FRONT PASS FRIDAY NIGHT, THE LOWER LEVELS
WILL DRY OUT SOMEWHAT AND TEMPERATURES WILL COOL OFF INTO SATURDAY
AND SATURDAY NIGHT. HIGHS SATURDAY SHOULD ONLY REACH INTO THE
UPPER 60S, WITH LOWS NEAR 50 BY SUNDAY MORNING.
WEAK UPPER LEVEL RIDGING WILL DEVELOP OVER THE PLAINS BY LATE
SUNDAY INTO TUESDAY, ALONG WITH LEE TROUGHING, SOUTHERLY WINDS
AND A WARMING TREND. ALL OF THE RECENT RAIN DURING MAY AND
RESULTANT EVAPOTRANSPIRATION WILL LIMIT HOW WARM WE GET DURING THE
DAY. HIGHS OUGHT TO WARM INTO THE UPPER 70S TO LOWER 80S BY
MONDAY AND THEN MID TO UPPER 80S BY TUESDAY AND WEDNESDAY. A LARGE
UPPER LEVEL TROUGH WILL DEVELOP ACROSS THE WESTERN UNITED STATES
BY MID TO LATE NEXT WEEK WITH CONTINUED LEE TROUGHING, ALONG WITH
INCREASING CHANCES FOR THUNDERSTORMS, SOME OF WHICH COULD BE
SEVERE. IT IS TOO EARLY TOO TELL WHETHER THESE STORMS WILL BE AS
FAR SOUTH AS WESTERN KANSAS, BUT CLIMATOLOGY CERTAINLY FAVORS
THUNDERSTORMS ON THE CENTRAL HIGH PLAINS IN THIS TYPE OF PATTERN.
OVERNIGHT LOWS WILL ALSO INCREASE THROUGH THE PERIOD, ESPECIALLY
EAST OF THE 100TH MERIDIAN GIVEN THE RISING DEWPOINTS AND SOUTH
WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CDT TUE MAY 26 2015
AN UNCERTAIN FORECAST IN RESPECT TO CONVECTION THIS EVENING. LIFT
AND FORCING IS RATHER NEBULOUS AND THE MODELS ARE STRUGGLING WITH
CONVECTIVE PLACEMENT. SO, WILL LEAVE OUT CB/TS GROUPS FOR NOW.
COULD CHANGE LATER AS CONFIDENCE INCREASES AS WELL. ACTIVITY WILL
REMAIN ISOLATED, SO IMPACTS TO A SPECIFIC TERMINAL IS LOW OVERALL.
OTHERWISE, WINDS WILL BE WESTERLY TO NORTHWESTERLY 5-10 KT.
SOUTHERLY WINDS OF 5-10 KT ARE EXPECTED TOMORROW MORNING ALONG
WITH HIGH LEVEL CLOUDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 57 82 63 79 / 20 60 60 60
GCK 55 81 61 80 / 10 50 60 40
EHA 54 81 61 81 / 20 30 50 30
LBL 57 82 62 81 / 10 50 60 60
HYS 56 81 64 79 / 10 50 70 60
P28 60 82 65 79 / 20 50 60 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...FINCH
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1255 PM CDT TUE MAY 26 2015
...UPDATED SHORT TERM...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1255 PM CDT TUE MAY 26 2015
TONIGHT:
THE MAIN CONCERN THIS EVENING IS THE SLIGHT CHANCE FOR
THUNDERSTORMS. HAVE BROAD BRUSHED SLIGHT POPS ACROSS THE REGION
AS FORCING IS WEAK AND UNCLEAR AT THIS TIME. HRRR AND THE 4 KM NAM
HAVE STORMS DEVELOPING LATE AFTERNOON INTO THE EVENING. THERE
COULD BE SOME LOW END SEVERE THUNDERSTORMS AS WELL WITH 500-1500
J/KG OF CAPE AND 30-40 KT OF BULK SHEAR. ACTIVITY WILL REMAIN
ISOLATED. PROBABLY THE MOST SEVERE STORMS WILL REMAIN SOUTH OF
THE FORECAST AREA. THREATS WOULD BE HAIL UP TO THE SIZE OF HALF
DOLLARS AND 60 MPH OUTFLOW WINDS. STORMS WILL BE FAIRLY HIGH BASED
AND LOW LEVEL SHEAR IS WEAK, SO NOT ANTICIPATING A TORNADO THREAT
AT THIS TIME FOR THIS EVENING. THE BEST AREAS FOR STORM ACTIVITY
WILL BE ACROSS THE NORTHWESTERN AND SOUTHEASTERN ZONES. OTHERWISE,
ACTIVITY WILL BE DIURNALLY BASED AND WILL WEAKEN AFTER SUNSET.
LOWS WILL BE IN THE 50S TO AROUND 60 ACROSS SOUTH-CENTRAL KANSAS.
TOMORROW:
MID TO UPPER LEVEL FLOW INCREASES TOMORROW. AT THE LOW LEVELS,
WARM AIR ADVECTION WILL CONTINUE. THERE IS SOME BUST POTENTIAL
WITH TEMPERATURES. SOME OF THE GUIDANCE KEEPS LINGERING
PRECIPITATION AND THUS COOLER HIGHS. STILL THINK THE WARM SECTOR
WILL SPREAD NORTHWARD ACROSS THE REGION WITH MANY LOCATIONS SEEING
WARM TEMPERATURES. CAPE IS FORECAST TO BE SIGNIFICANTLY HIGHER
TOMORROW WITH 2000-3000 J/KG. FORECAST SHEAR OF 45 KT WILL SUPPORT
SUPERCELLS. WILL HAVE TO WATCH OUT FOR TORNADO POTENTIAL AS SFC
WINDS BACK EAST-SOUTHEASTERLY. THERE IS ENOUGH LOW LEVEL
DIRECTIONAL AND SPEED SHEAR AS WELL. POPS WILL BE FAIRLY HIGH AT
THE END OF THE SHORT TERM PERIOD AND EXTENDING INTO THE LONG TERM.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 228 AM CDT TUE MAY 26 2015
THE AREA WILL REMAIN CONVECTIVELY ACTIVE THROUGH THE END OF THE
WEEK. THE GFS AND NAM OUT TO 84 HOURS DOES HAVE DECENT
CONTINUITY/AGREEMENT WITH RESPECT TO THE TIMING OF POTENTIAL
CONVECTIVE EPISODES WHILE THE EC MAY BE ONLY SLIGHTLY LESS
AGGRESSIVE IN INDICATING PCPN. DAILY INSOLATION WILL BE A MAJOR
FACTOR IN SURFACE BASED STORMS DEVELOPING TO THE WEST OF THE CWA
AND FEEDING ON THE INSTABILITY INTO WESTERN KANSAS BOTH WEDNESDAY
NIGHT AND THURSDAY NIGHT, AND POSSIBLY EVEN FESTERING ACROSS THE
AREA VERY EARLY WEDNESDAY MORNING. WEDNESDAY DOES NOT APPEAR AS
LIKELY TO HAVE CONVECTION DEVELOP AS A LOW AMPLITUDE SHORTWAVE
RIDGE SHOULD PROVIDE SUBSIDENCE. AS FAR AS THE MOST WIDESPREAD
COVERAGE AND SEVERE POTENTIAL, WEDNESDAY NIGHT LOOKS THE MOST
FAVORABLE AT THIS TIME BASED ON THE NAM MESOSCALE FIELDS (BASIC
CAPE AND SHEAR COMBINATIONS). ADDITIONALLY THE ATMOSPHERE WILL
ONLY BECOME MORE MOIST FROM MIDWEEK INTO THE LATE WEEK AS THE
PRECIPITABLE WATER ONCE AGAIN INCREASES TO AROUND THE MIDWAY
POINT BETWEEN 1 AND 2 INCHES MUCH FARTHER WEST INTO THE HIGH
PLAINS. SO WEDNESDAY EVENING INTO THE OVERNIGHT COULD BE ANY AND
ALL MODES WITH LOCALIZED OR EVEN AREAS OF FLOODING AS WELL.
BEYOND THE MID WEEK TIMEFRAME...THE BASE OF THE MEAN TROUGH ENTERS
THE ROCKIES REGION LATE IN THE WEEK, PLACING THE HIGH PLAINS REGION
IN GENERAL IN A ZONE OF GOOD POSITIVE VORT ADVECTION. SOMETIME
AROUND FRIDAY, ANOTHER STRONG MID LEVEL WAVE SHOULD BE MOVING
THROUGH THE REGION, WHICH COULD TRIGGER SEVERE WEATHER IF AT THE
RIGHT TIME OF THE DAY, OR SUB SEVERE WITH HEAVY RAIN IF THE THE
CONDITIONAL INSTABILITY IS WEAK. THE REGION COMES UNDER A MEAN MID
LEVEL RIDGE BY EARLY NEXT WEEK, BUT EVEN THEN, THE GFS IS INDICATING
CENTRAL/SOUTHERN NOCTURNAL MCS POSSIBILITIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CDT TUE MAY 26 2015
AN UNCERTAIN FORECAST IN RESPECT TO CONVECTION THIS EVENING. LIFT
AND FORCING IS RATHER NEBULOUS AND THE MODELS ARE STRUGGLING WITH
CONVECTIVE PLACEMENT. SO, WILL LEAVE OUT CB/TS GROUPS FOR NOW.
COULD CHANGE LATER AS CONFIDENCE INCREASES AS WELL. ACTIVITY WILL
REMAIN ISOLATED, SO IMPACTS TO A SPECIFIC TERMINAL IS LOW OVERALL.
OTHERWISE, WINDS WILL BE WESTERLY TO NORTHWESTERLY 5-10 KT.
SOUTHERLY WINDS OF 5-10 KT ARE EXPECTED TOMORROW MORNING ALONG
WITH HIGH LEVEL CLOUDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 78 57 79 63 / 20 20 60 60
GCK 77 55 80 61 / 20 10 50 60
EHA 77 54 81 61 / 10 20 30 50
LBL 78 57 82 62 / 20 10 50 60
HYS 78 56 79 64 / 10 10 50 70
P28 80 60 80 65 / 20 20 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...RUSSELL
AVIATION...SUGDEN
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
1213 PM CDT Tue May 26 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 258 AM CDT TUE MAY 26 2015
Precipitation persists over much of the area, though becoming
steadily more scattered in nature and generally rather low rates.
Appears more vigorous convection in western locations is long
upper trough axis, with whole upper system good northeast progress
through eastern Kansas with warming cloud tops.
Have a hard time ruling out precip for much of today and tonight.
Short-range models seem a bit too fast with main deformation
precip`s exit this morning, with latest HRRR runs similar in
isolated to scattered convection making its way southeast around
the low into northern areas in the late morning to early
afternoon. Still seeing best lower-level forcing in southern areas
late today into tonight were somewhat better convergence exists.
There is also decent larger-scale model similarity in another wave
rotating (perhaps taking shape in western Nebraska early this
morning) passing through over this same period, although heights
are still rising. Moisture through the column not up to recent
levels, but dewpoints into the lower 60s still support some
instability developing in peak heating. Fairly unidirectional and
modest wind speeds keep severe storm concerns low.
.LONG TERM...(Wednesday through Monday)
Issued at 258 AM CDT TUE MAY 26 2015
Surface high pressure moves into the Central Plains on Wednesday,
with the frontal boundary slowing over southern Kansas under
generally west southwest upper flow. Think more stable surface air
plus mid level ridging will keep northern areas dry on Wednesday
but could see some rumbles south depending on how far south the
front progresses. Next in a series of shortwave trofs moves over
eastern Kansas overnight into Thursday morning, and draws rain
chances back over our area. Have continued chances into Thursday,
although features driving rain chances are more mesoscale in
nature and timing will likely need adjustment.
Better model agreement on a slightly larger scale shortwave
feature lifting out of the southwest US and across eastern Kansas
for Friday, and will keep higher rain chances as a result. Front
slides southeast across the area through early Saturday morning,
cooling things down and bringing decreasing rain chances through
Sunday from northwest to southeast. If pattern persists, may be
able to end chances sooner. High temperatures Wednesday through
Friday are forecast in the upper 70s near 80, falling into the 60s
for the weekend behind the front, with lows in the 60s then
falling to the 50s late week.
&&
.AVIATION...(For the 18Z TAFs through 18Z Wednesday Afternoon)
Issued at 1209 PM CDT TUE MAY 26 2015
Expect VFR conds to prevail through the period. Only issue may be
sct -shra or isolated tsra which is possible just about anywhere
through 06z given the unstable atmosphere and proximity of the
upper system and weak boundary. Simply don`t think coverage will
be sufficient to warrant any more than vcsh at this point.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...Omitt
AREA FORECAST DISCUSSION
NWS PADUCAH KY
246 PM CDT TUE MAY 26 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 246 PM CDT TUE MAY 26 2015
AS EXPECTED CONVECTION DEVELOPED ALONG THE EASTERN BORDER OF THE
FORECAST AREA AND QUICKLY LIFTED OFF TO THE NORTH/NORTHEAST AROUND
MIDDAY. SHOULD NOT SEE ANY OTHER CONVECTIVE DEVELOPMENT ACROSS
THE AREA LATE THIS AFTERNOON OR THIS EVENING...AS A COOLER...DRIER
AIRMASS CONTINUES TO ADVECT ACROSS THE REGION. SOUTHWEST WINDS ARE
BEGINNING TO LOSE STEAM OVER THE SOUTHERN HALF OF THE AREA...BUT
WILL LEAVE THE LAKE WIND ADVISORY IN INTACT TIL EXPIRATION.
THE HRRR TRIES TO BRING A CONVECTIVE COMPLEX EASTSOUTHEAST TOWARD
SOUTHEAST MISSOURI LATE TONIGHT...BUT WITH VEERED LOW-LEVEL FLOW
AND DRIER AIR IN PLACE...WOULD BE SURPRISED IF IT SURVIVED ALL THE
WAY TO OUR REGION.
THE MODELS CONTINUE TO DEVELOP DIURNAL CONVECTION MAINLY ACROSS
THE NORTHERN HALF OF THE AREA WEDNESDAY AFTERNOON...SO SEE NO
REASON TO DEVIATE FROM THE GOING FORECAST. MOST GUIDANCE DEVELOPS
THE CONVECTION SOUTHEASTWARD THROUGH WEST KENTUCKY INTO THE
EVENING...SO WILL HAVE CHANCE POPS WEDNESDAY NIGHT DOWN THERE WITH
LESSER/NO POPS IN THE NORTH.
GUIDANCE HAS CONSISTENTLY PUMPED UP AN UPPER-LEVEL RIDGE OVER THE
REGION ON THURSDAY. THIS AND A LACK OF ANY TANGIBLE SURFACE
BOUNDARY SHOULD MAKE IT DIFFICULT TO GET MUCH CONVECTION GOING. A
FEW ISOLATED SHOWERS OR STORMS CANNOT BE RULED OUT...SO WILL KEEP
THE LOW/SLIGHT CHANCES POPS GOING.
WITH THE DIURNAL NATURE OF ANY CONVECTION THURSDAY...FIGURE THAT
THURSDAY NIGHT WILL BE DRY. BUT...THE GFS DOES DEVELOP SOME
CONVECTION OVER SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS...AS
MINOR DISTURBANCES IN THE WEAK SOUTHWEST FLOW ALOFT STREAM OVER
THOSE AREAS. WILL KEEP A SLIGHT CHANCE IN THE FAR NORTHWEST/WEST
JUST TO BE SAFE. ELSEWHERE KEPT THURSDAY NIGHT DRY.
HIGH TEMPERATURES WILL BE WARMER WEDNESDAY AND THURSDAY
AFTERNOONS...WITH MIDDLE 80S FORECAST...AND UPPER 80S NOT OUT OF
THE QUESTION. NUDGED LOWS DOWN A BIT FROM THE PREVIOUS FORECAST EACH
NIGHT WITH THE DRIER AIRMASS EXPECTED TO LINGER AWHILE.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 246 PM CDT TUE MAY 26 2015
FOR THE EXTENDED PERIOD...WE WILL BE WATCHING HOW TWO UPPER LEVEL
SYSTEMS OUT WEST PHASE AS THEY EVENTUALLY TRY TO MERGE OVER THE
COUNTRYS MID SECTION. BY MIDWEEK...THE FIRST SYSTEM WILL BE A CLOSED
LOW OVER THE PACFIC NORTHWEST. THE OTHER SYSTEM WILL BE COMING
ONSHORE IN SOUTHERN CALIFORNIA/NORTHERN MEXICO. BY 12Z FRIDAY...THE
PACIFIC NORTHWEST SYSTEM WILL HAVE DIVED SOUTHEAST INTO THE NORTHERN
ROCKIES...WHILE THE SOUTHERN SYSTEM ENDS UP OVER OK/TX. THE UPPER
LEVEL SHORTWAVE OVER OK/TX WILL QUICKLY SCOOT NORTHEAST AND BECOME
ABSORBED IN THE NORTHERN STREAM. SO IT REALLY ENDS UP BYPASSING THE
AREA. SO AS FAR AS POPS ON FRIDAY...ANY CONVECTION WOULD BE MERELY
BASED ON AIR MASS TYPE POP UPS. HOWEVER...WILL HEDGE HIGHER ON POPS
IN OUR NORTHWESTERN COUNTIES DUE TO THE PASSAGE OF THE SHORTWAVE
JUST TO OUR WEST AND BETTER UPPER LEVEL FLOW.
MEANWHILE...WE WILL BE WATCHING THE PROGRESSION OF A FRONTAL
BOUNDARY...WHICH WILL BE DRAPED FROM THE UPPER GREAT LAKES THROUGH
THE CENTRAL PLAINS AND INTO WESTERN TEXAS AT THE START OF THE
PERIOD. THIS FRONT WILL SLOWLY APPROACH THE AREA FRIDAY...FRIDAY
NIGHT AND INTO SATURDAY. MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
THE PLACEMENT OF THE FRONT...AND HAVE ENTERING OUR REGION BY
SATURDAY AFTERNOON. THIS SHOULD PROVIDE A DECENT FOCUS FOR MORE
ORGANIZED CONVECTION.
EVEN THOUGH THE FRONT LOOKS TO SLIDE SOUTH OF THE AREA BY SATURDAY
NIGHT...THE AFOREMENTIONED UPPER TROUGH THAT WAS MAKING ITS WAY
THROUGH THE ROCKIES EARLIER...WILL BE PHASING WITH OTHER SUTBLE
WAVES IN THE SW FLOW ALOFT AND MOVE IN OUR DIRECTION. THIS WILL KEEP
PERIODIC CHANCES FOR CONVECTION IN OUR FORECAST FOR THE REST OF THE
WEEKEND AND INTO EARLY NEXT WEEK. A FEW MODEL RUNS ARE ADVERTISING A
CLOSED/CUT OFF LOW DEVELOPING SOMEWHERE IN OUR VICINITY. BUT I CAN
ALSO FORESEE MODELS SETTLING DOWN A BIT WITH THE BUSY UPPER FLOW
AND WE COULD END UP DRIER THAN WE HAVE FORECAST...ESPECIALLY FOR
EARLY NEXT WEEK (I.E. LIKE THE 12Z ECMWF IS INDICATING).
TEMPERATURES ON FRIDAY AND SATURDAY WILL BE IN THE 80S BUT THEN DROP
DOWN INTO THE UPPER 70S AS WE ROUND OUT THE WEEKEND AND INTO EARLY
NEXT WEEK...AS COOLER AIR FILTERS IN BEHIND THE FRONT.
&&
.AVIATION...
ISSUED AT 106 PM CDT TUE MAY 26 2015
OCCASIONAL MVFR CIGS THIS AFTERNOON BECOMING VFR AS SHOWERS EXIT
THE AREA...ESPECIALLY NEAR OWB. OTHERWISE VFR CIGS/VSBYS EXPECTED
THROUGH THE PERIOD. S WINDS AT 10 TO 15 KTS WITH GUSTS 20 TO 25
KTS TODAY...DECREASING THIS EVENING TO AROUND 5 KTS OVERNIGHT AND
INTO THE AM.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ075>078-
080>094.
MO...LAKE WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MOZ076-086-
087-100-107>112-114.
IN...LAKE WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR INZ081-082-
085>088.
KY...LAKE WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...CW
AVIATION...BP2|
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1245 PM CDT TUE MAY 26 2015
.AVIATION...
EXPECT VFR WEATHER TO BEGIN THE 26/18Z TAF ISSUE. CANNOT RULE OUT
CONVECTION TOTALLY THIS AFTERNOON...BUT COVERAGE SHOULD BE
ISOLATED AND SHOULD EASILY BE AVOIDED. EXPECT MVFR CIGS TO RETURN
AFTER 08Z TONIGHT ACROSS THE AREA. MIXING WILL ALLOW FOR THESE
CIGS TO LIFT TO VFR BY 27/16Z. /14/
&&
.PREV DISCUSSION... /ISSUED 1116 AM CDT TUE MAY 26 2015/
DISCUSSION...
HAVE UPDATED THE ZONES TO REMOVE THE HIGHER RAIN CHANCES OVER THE
SOUTHERN ZONES FOR THE REST OF THE MORNING AND SCALED BACK FOR THE
AFTERNOON WITH JUST THE MORE SOUTHERN WITH A LOWER CHANCE
CATEGORY. HRRR MODEL INDICATED DEVELOPMENT OVER PARTS OF DEEP
EAST TEXAS AND EAST ACROSS ADJACENT NORTHWEST AND NORTH CENTRAL
LOUISIANA DURING THE AFTERNOON. A SURFACE RIDGE OF HIGH PRESSURE
EXTENDED WEST INTO THE FORECAST AREA WITH A SOUTHWEST FLOW ALOFT
WITH A SERIES OF SMALLER SCALE DISTURBANCES MOVING THROUGH THE
FLOW AROUND A BROAD TROUGH ACROSS TEXAS. /06/
PREV DISCUSSION... /ISSUED 417 AM CDT TUE MAY 26 2015/
DISCUSSION...
AFTER WIDESPREAD SEVERE THUNDERSTORMS AFFECTED THE REGION DURING
THE AFTERNOON AND EVENING HOURS MONDAY...MUCH CALMER CONDITIONS
ARE EXPECTED IN THE SHORT TERM...WITH THE AIR MASS HAVING BEEN
STABILIZED AREAWIDE. THE MORNING IR SATELLITE IMAGERY CONTINUES TO
SHOW A WARMING OF THE CLOUD TOPS ACROSS THE REGION...WITH THE POST
SQUALL LINE RAINS DIMINISHING IN INTENSITY ATTM. WITH THE PRIMARY
SHORTWAVE RESPONSIBLE FOR THE MONDAY AFTERNOON/EVENING CONVECTION
HAVING ALREADY LIFTED TO THE NE OVER SE KS/NE OK /PER WATER VAPOR
IMAGERY/...THE THREAT FOR HEAVY RAINFALL IS ENDING...AND WILL BE
CANCELLING THE FLASH FLOOD WATCH FOR THE CWA WITH THE MORNING
FORECAST. THE GFS/HRRR HAVE INITIALIZED WELL THIS MORNING WITH
THE ONGOING CONVECTION...WITH IT CLEARING THE SRN/ERN SECTIONS OF
NCNTRL LA BETWEEN 12-15Z...AND THUS HAVE TAPERED POPS BACK FARTHER
W...EVEN DROPPING POPS THIS MORNING OVER MUCH OF SW AR/SE OK/NE
TX. STILL CAN/T RULE OUT ADDITIONAL SCT REDEVELOPMENT THIS
AFTERNOON MAINLY FROM LOWER TOLEDO BEND INTO NCNTRL LA...WITH
ISOLATED CONVECTION AT BEST POSSIBLE ELSEWHERE. TEMPS SHOULD AGAIN
CLIMB BACK TO NEAR CLIMO OVER MUCH OF THE REGION THIS AFTERNOON.
SW FLOW ALOFT WILL PERSIST OVER THE SRN PLAINS/LOWER MS VALLEY
TODAY AND TONIGHT...AS BROAD TROUGHING REMAINS OVER THE CNTRL AND
SRN PLAINS. THE SHORT TERM PROGS ARE KEYING ON ANOTHER SHORTWAVE
IN THIS FLOW TRAVERSING THE RED RIVER VALLEY THIS EVENING/OVERNIGHT...
WHICH MAY IGNITE SCT CONVECTION ALONG/JUST E OF THE W TX DRYLINE.
THUS...SCT CONVECTION MAY SHIFT E ALONG THE RED RIVER VALLEY
POSSIBLY AFFECTING SE OK/ADJACENT SW AR/EXTREME NE TX LATE
TONIGHT. HAVE MAINTAINED MID CHANCE POPS FOR THESE AREAS...AND
LOWERED POPS TO SLIGHT CHANCE FARTHER SE OVER DEEP E TX/SRN
SECTIONS OF NCNTRL LA FARTHER REMOVED FROM THIS SHORTWAVE.
MESOSCALE BNDRYS FROM THE OVERNIGHT CONVECTION MAY HELP INITIATE
REDEVELOPMENT FARTHER E OVER MUCH OF THE REGION WEDNESDAY...AS
DAYTIME HEATING CONTRIBUTES TO INCREASED INSTABILITY AS THE
SHORTWAVE TRAVERSES THE REGION. THIS CONVECTION SHOULD DIMINISH
TUESDAY EVENING WITH THE LOSS OF HEATING...WITH THE SHORT TERM
PROGS SUGGESTING THAT DIRTY RIDGING ALOFT WILL BUILD NE FROM E TX
INTO THE MID-MS VALLEY AHEAD OF UPPER TROUGHING THAT WILL DRIFT E
INTO THE ROCKIES.
THE GLOBAL MODELS SUGGEST THAT SCT CONVECTION WILL DEVELOP
BENEATH THIS DIRTY RIDGE WITH HEATING THURSDAY...BEFORE
DIMINISHING THURSDAY EVENING. HAVE MAINTAINED MID CHANCE POPS
AREAWIDE...WITH A MORE UNSETTLED PATTERN TAKING SHAPE FRIDAY
THROUGH THE UPCOMING WEEKEND AS THE UPPER TROUGH TO OUR W SETTLES
FARTHER S ACROSS THE SRN PLAINS. CONFIDENCE REMAINS LOW AS TO THE
EXTENT OF CONVECTION EACH DAY...ALTHOUGH FEEL THAT NE TX/SW AR/SE
OK MAY SEE THE CONVECTION INITIALLY...WITH THE CONVECTION POSSIBLY
SPREADING FARTHER ESE EACH AFTERNOON IN RESPONSE TO MESOSCALE
INTERACTIONS. THIS TROUGH MAY USHER A WEAK COOL FRONT S INTO THE
REGION BY SUNDAY...POSSIBLY WASHING OUT SOMEWHERE OVER E TX/N LA.
THUS...SCT CONVECTION WILL REMAIN POSSIBLE EACH DAY BEFORE THE
UPPER AIR PATTERN FINALLY TRIES TO CALM DOWN AS RIDGING ALOFT
BEGINS TO BUILD OVER MUCH OF THE PLAINS BY EARLY NEXT WEEK.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 71 86 70 86 / 30 40 20 40
MLU 70 86 70 86 / 20 40 30 40
DEQ 67 84 69 84 / 40 40 20 40
TXK 69 85 69 86 / 30 40 20 40
ELD 69 85 69 86 / 30 40 30 40
TYR 72 86 71 86 / 30 40 20 40
GGG 72 86 71 86 / 30 40 20 40
LFK 73 87 72 86 / 20 40 20 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1116 AM CDT TUE MAY 26 2015
.DISCUSSION...
HAVE UPDATED THE ZONES TO REMOVE THE HIGHER RAIN CHANCES OVER THE
SOUTHERN ZONES FOR THE REST OF THE MORNING AND SCALED BACK FOR THE
AFTERNOON WITH JUST THE MORE SOUTHERN WITH A LOWER CHANCE
CATEGORY. HRRR MODEL INDICATED DEVELOPMENT OVER PARTS OF DEEP
EAST TEXAS AND EAST ACROSS ADJACENT NORTHWEST AND NORTH CENTRAL
LOUISIANA DURING THE AFTERNOON. A SURFACE RIDGE OF HIGH PRESSURE
EXTENDED WEST INTO THE FORECAST AREA WITH A SOUTHWEST FLOW ALOFT
WITH A SERIES OF SMALLER SCALE DISTURBANCES MOVING THROUGH THE
FLOW AROUND A BROAD TROUGH ACROSS TEXAS. /06/
&&
.PREV DISCUSSION... /ISSUED 747 AM CDT TUE MAY 26 2015/
AVIATION...
IN THE WAKE OF A LATE NIGHT SQUALL LINE MOST SITES ARE MVFR/IFR.
SOME VFR HOLDING AND EXPECTING AREA WIDE BY 17-18Z. SFC WINDS
WILL BE S/SW AROUND 10 KTS WITH LOW LEVEL FLOW SW OF 20-40KTS
RIGHT OFF THE DECK...THEN SLACKING TO 10KTS BY 5KFT. GENERALLY SW
FLOW CONTINUES ON ASCENT INCREASING IN SPEED TO 50KTS BY
FL220...THEN SSW 60-80KTS ON UP. WE WILL KEEP MOSTLY DRY
TODAY...BUT ISOLD TSTMS WILL BE POSSIBLE WITH INCREASING COVERAGE
THIS WEEK...AND MAINLY MID TO LATE DAY.
PREV DISCUSSION... /ISSUED 417 AM CDT TUE MAY 26 2015/
DISCUSSION...
AFTER WIDESPREAD SEVERE THUNDERSTORMS AFFECTED THE REGION DURING
THE AFTERNOON AND EVENING HOURS MONDAY...MUCH CALMER CONDITIONS
ARE EXPECTED IN THE SHORT TERM...WITH THE AIR MASS HAVING BEEN
STABILIZED AREAWIDE. THE MORNING IR SATELLITE IMAGERY CONTINUES TO
SHOW A WARMING OF THE CLOUD TOPS ACROSS THE REGION...WITH THE POST
SQUALL LINE RAINS DIMINISHING IN INTENSITY ATTM. WITH THE PRIMARY
SHORTWAVE RESPONSIBLE FOR THE MONDAY AFTERNOON/EVENING CONVECTION
HAVING ALREADY LIFTED TO THE NE OVER SE KS/NE OK /PER WATER VAPOR
IMAGERY/...THE THREAT FOR HEAVY RAINFALL IS ENDING...AND WILL BE
CANCELLING THE FLASH FLOOD WATCH FOR THE CWA WITH THE MORNING
FORECAST. THE GFS/HRRR HAVE INITIALIZED WELL THIS MORNING WITH
THE ONGOING CONVECTION...WITH IT CLEARING THE SRN/ERN SECTIONS OF
NCNTRL LA BETWEEN 12-15Z...AND THUS HAVE TAPERED POPS BACK FARTHER
W...EVEN DROPPING POPS THIS MORNING OVER MUCH OF SW AR/SE OK/NE
TX. STILL CAN/T RULE OUT ADDITIONAL SCT REDEVELOPMENT THIS
AFTERNOON MAINLY FROM LOWER TOLEDO BEND INTO NCNTRL LA...WITH
ISOLATED CONVECTION AT BEST POSSIBLE ELSEWHERE. TEMPS SHOULD AGAIN
CLIMB BACK TO NEAR CLIMO OVER MUCH OF THE REGION THIS AFTERNOON.
SW FLOW ALOFT WILL PERSIST OVER THE SRN PLAINS/LOWER MS VALLEY
TODAY AND TONIGHT...AS BROAD TROUGHING REMAINS OVER THE CNTRL AND
SRN PLAINS. THE SHORT TERM PROGS ARE KEYING ON ANOTHER SHORTWAVE
IN THIS FLOW TRAVERSING THE RED RIVER VALLEY THIS EVENING/OVERNIGHT...
WHICH MAY IGNITE SCT CONVECTION ALONG/JUST E OF THE W TX DRYLINE.
THUS...SCT CONVECTION MAY SHIFT E ALONG THE RED RIVER VALLEY
POSSIBLY AFFECTING SE OK/ADJACENT SW AR/EXTREME NE TX LATE
TONIGHT. HAVE MAINTAINED MID CHANCE POPS FOR THESE AREAS...AND
LOWERED POPS TO SLIGHT CHANCE FARTHER SE OVER DEEP E TX/SRN
SECTIONS OF NCNTRL LA FARTHER REMOVED FROM THIS SHORTWAVE.
MESOSCALE BNDRYS FROM THE OVERNIGHT CONVECTION MAY HELP INITIATE
REDEVELOPMENT FARTHER E OVER MUCH OF THE REGION WEDNESDAY...AS
DAYTIME HEATING CONTRIBUTES TO INCREASED INSTABILITY AS THE
SHORTWAVE TRAVERSES THE REGION. THIS CONVECTION SHOULD DIMINISH
TUESDAY EVENING WITH THE LOSS OF HEATING...WITH THE SHORT TERM
PROGS SUGGESTING THAT DIRTY RIDGING ALOFT WILL BUILD NE FROM E TX
INTO THE MID-MS VALLEY AHEAD OF UPPER TROUGHING THAT WILL DRIFT E
INTO THE ROCKIES.
THE GLOBAL MODELS SUGGEST THAT SCT CONVECTION WILL DEVELOP
BENEATH THIS DIRTY RIDGE WITH HEATING THURSDAY...BEFORE
DIMINISHING THURSDAY EVENING. HAVE MAINTAINED MID CHANCE POPS
AREAWIDE...WITH A MORE UNSETTLED PATTERN TAKING SHAPE FRIDAY
THROUGH THE UPCOMING WEEKEND AS THE UPPER TROUGH TO OUR W SETTLES
FARTHER S ACROSS THE SRN PLAINS. CONFIDENCE REMAINS LOW AS TO THE
EXTENT OF CONVECTION EACH DAY...ALTHOUGH FEEL THAT NE TX/SW AR/SE
OK MAY SEE THE CONVECTION INITIALLY...WITH THE CONVECTION POSSIBLY
SPREADING FARTHER ESE EACH AFTERNOON IN RESPONSE TO MESOSCALE
INTERACTIONS. THIS TROUGH MAY USHER A WEAK COOL FRONT S INTO THE
REGION BY SUNDAY...POSSIBLY WASHING OUT SOMEWHERE OVER E TX/N LA.
THUS...SCT CONVECTION WILL REMAIN POSSIBLE EACH DAY BEFORE THE
UPPER AIR PATTERN FINALLY TRIES TO CALM DOWN AS RIDGING ALOFT
BEGINS TO BUILD OVER MUCH OF THE PLAINS BY EARLY NEXT WEEK.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 85 71 86 70 / 20 30 40 20
MLU 83 70 86 70 / 20 20 40 30
DEQ 84 67 84 69 / 20 40 40 20
TXK 84 69 85 69 / 20 30 40 20
ELD 84 69 85 69 / 20 30 40 30
TYR 85 72 86 71 / 20 30 40 20
GGG 85 72 86 71 / 20 30 40 20
LFK 87 73 87 72 / 30 20 40 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
06
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 PM EDT TUE MAY 26 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 420 PM EDT TUE MAY 26 2015
WV IMAGERY AND RAP ANALYSIS INDICATED WELL-DEFINED SHORTWAVE TROUGH
OVER NE IA LIFTING TO THE NE. A LARGE AREA OF SHOWERS ASSOCIATED
WITH THE SHRTWV WAS LIFTING FROM NRN WI THROUGH CNTRL UPPER MI. WITH
MLCAPE/MUCPE FROM NRN WI INTO UPPER MI ONLY AROUND 500 J/KG THE
STRONGER TSRA OVER NE WI HAVE DIMINISHED LEAVING ONLY EMBEDDED ISOLD
TSRA WITH THE SHRA. AT THE SFC(19Z)...LOW PRES WAS LOCATED OVER THE
SW CORNER OF WI WITH A TROUGH/WEAK FRONTAL BOUNDARY EXTENDING TO THE
NE INTO WRN UPPER MI.
TONIGHT...RADAR/SATELLITE TRENDS SUGGEST THAT THE SHOWERS WILL
CONTINUE TO SPREAD ACROSS THE CWA LATE THIS AFTERNOON INTO THIS
EVENING. WITH ONLY THE LIMITED INSTABILITY AVAILABLE...THE POTENTIAL
FOR STRONGER STORMS HAS DIMINISHED. HOWEVER...IF THERE IS SOME
CLEARING AND ADDITIONAL HEATING INTO THE SOUTH BEHIND INITIAL BATCH
OF SHOWERS...THE INSTABILITY MAY RECOVER ENOUGH FOR SOME ISOLATED
STRONGER STORMS NEAR THE VORT CENTER GIVEN THE SHEAR PROFILE (0-6KM
SHEAR OF 40-50 KNOTS). OTHERWISE...WITH ABUNDANT MOISTURE STREAMING
TOWARD THE AREA PUSHING PWAT VALUES TO NEAR 1.5 INCHES...LOCALLY
HEAVY RAIN MAY BE POSSIBLE WITH QPF AMOUNTS INTO THE 1-2 INCH
RANGE...ESPECIALLY OVER THE W HALF OF UPPER MI...IN LINE WITH THE
TRACK OF THE STRONGER MID LEVEL FGEN/DEFORMATION ASSOCIATED WITH THE
SHRTWV.
WEDNESDAY...THE LARGE SCALE SUPPORT FOR PCPN WILL DEPART TO THE NE
WITH THE SHORTWAVE. HOWEVER...WITH SOME CLEARING AND AFTERNOON
HEATING (TEMPS INTO THE MID 70S) MLCAPE VALUES INTO THE 500-1000
J/KG RANGE AND A WEAK SFC TROUGH LINGERING OVER THE AREA AND LAKE
BREEZE BOUNDARIES DEVELOPING...ISOLD/SCT SHRA/TSRA MAY REDEVELOP.
WITH RELATIVELY WEAK SHEAR...STRONG TSRA ARE NOT EXPECTED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 411 PM EDT TUE MAY 26 2015
WEDNESDAY NIGHT...THE FRONT WILL BE WELL PAST THE CWA BY WEDNESDAY
EVENING. THE UPPER LEVEL 500MB TROUGH AXIS WILL CONTINUE TO SHIFT TO
THE EAST OF THE U.P. AT THE SAME TIME...THE DEEPER MOISTURE AND
BETTER FORCING WILL SLIDE OUT OF THE AREA ALLOWING ANY LINGERING
SHOWERS OVER THE EAST HALF TO DIMINISH IN THE EVENING HOURS. THIS
BRIEF BREAK WILL BE FAIRLY SHORT LIVED WITH THE NEXT AREA OF LOW
PRESSURE SLIDING INTO THE NORTHERN PLAINS.
THURSDAY THROUGH FRIDAY NIGHT...DURING THE DAY THURSDAY...MUCH OF
THE AREA WILL SEE A CONTINUED BREAK FROM THE RAIN SHOWERS AS THE CWA
WILL CONTINUE TO BE BETWEEN SYSTEMS DURING THAT TIME...WITH THE COLD
FRONT TO THE EAST AND A LOW PRESSURE SYSTEM AND ASSOCIATED COLD
FRONT SLIDING INTO THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA.
MODELS ARE COMING INTO BETTER AGREEMENT WITH LOW PLACEMENT ALONG
WITH COLD FRONT TIMING THURSDAY NIGHT INTO FRIDAY...WITH THE COLD
FRONT MOVING THROUGH DURING PEAK HEATING. THE GFS IS STILL A BIT
MORE PROGRESSIVE WITH THE SYSTEM WHILE THE EC IS A LITTLE SLOWER AT
MOVING THE SYSTEM THROUGH. LATE THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON/EVENING LOOKS TO BE WET WITH SHOWERS AND THUNDERSTORMS
PUSHING INTO THE UPPER GREAT LAKES REGION. ALOFT...A 500 MB TROUGH
WILL PUSH ACROSS THE AREA AROUND THE SAME TIME FRAME...WHILE
LINGERING INTO THE OVERNIGHT HOURS FRIDAY NIGHT AS A RIDGE BEGINS TO
BUILD OVER THE WESTERN CONUS. AS THE FRONT IS EXPECTED TO MOVE IN
DURING PEAK HEATING...MUCAPE VALUES RANGE FROM 500-700 J/KG FROM THE
GFS TO AROUND 800-1100 J/KG FROM THE EC...MAINLY OVER THE INLAND
WEST. OVERALL INSTABILITY WILL BE LARGELY DEPENDENT UPON CLOUD COVER
OR BREAKS IN THE CLOUD COVER AHEAD OF THE SYSTEM. IF SKIES ARE
OVERCAST THROUGH THE DAY THE INSTABILITY WILL BE LOWER...HELPING TO
REDUCE THE SEVERE RISK. SHEAR VALUES ARE PROGGED TO BE AROUND 35 TO
40 KNOTS PERPENDICULAR TO THE FRONT. THE RISK AGAIN WILL BE
CONDITIONAL...DEPENDING LARGELY ON THE PRE-FRONTAL CLOUD COVER. THE
WARMER TEMPERATURES SLIDING ACROSS THE COLD WATERS OF THE GREAT
LAKES WILL ALSO ALLOW WIDESPREAD FOG TO FORM THURSDAY NIGHT INTO
FRIDAY...ESPECIALLY WHEN THE RAIN SHOWERS PUSH OVER THE LAKES.
TRAPPING MOISTURE UNDER A FAIRLY STRONG TEMPERATURE INVERSION AS
NOTED ON BUFKIT SOUNDINGS.
SATURDAY THROUGH THE REMAINING EXTENDED...NICE WEEKEND EXPECTED AS
DRY COOL CANADIAN HIGH PRESSURE IS EXPECTED TO SLIDE ACROSS THE
UPPER GREAT LAKES REGION IN THE WAKE OF THE LOW AND COLD FRONT.
THERE MAY BE A FEW SHOWERS LINGERING SHOWERS OVER THE FAR EAST
SATURDAY MORNING...BUT SHOULD END QUICKLY BY LATE MORNING OR EARLY
AFTERNOON. THE UPPER LEVEL 500MB TROUGH AXIS WILL SHIFT TO THE EAST
OF THE AREA BY SATURDAY EVENING AND OUT OF THE AREA BY SUNDAY. CALM
WINDS ASSOCIATED WITH THE SURFACE HIGH ALONG WITH VERY DRY AIR IN
PLACE WILL ALLOW TEMPERATURES TO DROP BELOW NORMAL...INTO THE 30S
FOR OVERNIGHT LOW TEMPERATURES AND HIGHS IN THE MID 50S TO LOW 60S.
FROST WILL LIKELY DEVELOP SATURDAY NIGHT INTO SUNDAY MORNING ACROSS
INLAND AREAS. THE NEXT AREA OF LOW PRESSURE IS PROGGED TO DEVELOP
OVER THE NORTHERN PLAINS MONDAY NIGHT AND SLOWLY SHIFT EASTWARD INTO
THE UPPER GREAT LAKES LATE TUESDAY. THERE ARE CONSIDERABLE
DIFFERENCES WITH TIMING AND PLACEMENT OF THIS SYSTEM SO CONFIDENCE
IN RAIN CHANCES IS LOW. CONSENSUS OF THE MODELS BROUGHT LIKELY POPS
IN BUT DECIDED TO ADJUST THEM BACK TO CHANCE POPS WITH THE
AFOREMENTIONED ISSUES IN MIND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 156 PM EDT TUE MAY 26 2015
A SHORTWAVE TROUGH APPROACHING FROM THE SSW WILL BRING SHRA TO THE
AREA BY MID AFTERNOON THAT WILL LINGER TONIGHT. SOME TSRA MAY BE
POSSIBLE IN CNTRL UPPER MI AFFECTING SAW AS WELL...BUT PROBABILIATY
IS TOO SMALL TO PUT INTO TAFS FOR NOW. IFR/LIFR CONDITIONS ARE
EXPECTED AGAIN BY LATE THIS EVENING AT ALL TERMINALS WITH SOME
UPSLOPE FLOW AND ABUNDANT LOW LEVEL MOISTURE REMAINING. ALTHOUGH VSBY
AT CMX MAY DROP BLO 1SM...THE RAIN WILL HELP LIMIT POTENTIAL FOR MORE
DENSE FOG AOB LANDING MINIMUMS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EDT TUE MAY 26 2015
WINDS ARE EXPECTED TO STAY AT OR BELOW 20 KNOTS FOR MOST OF THIS
FORECAST PERIOD WITH THE EXCEPTION OF FRI NIGHT INTO EARLY SATURDAY
WHERE THEY WILL BE UP TO 25 KNOTS ACROSS EASTERN LAKE SUPERIOR. FOG
WILL LINGER THROUGH WEDNESDAY MORNING AND MAY BE DENSE AT TIMES.
ADDITIONAL FOG IS EXPECTED TO DEVELOP THURSDAY NIGHT AND FRIDAY
AHEAD OF THE NEXT LOW AND ASSOCIATED COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS JACKSON MS
348 PM CDT TUE MAY 26 2015
.DISCUSSION...
ONLY ISOLATED LIGHT SHOWERS NOW LINGER ACROSS THE HIGHWAY 84/98
CORRIDOR THIS AFTERNOON. IT HAS BECOME A RATHER PLEASANT DAY ACROSS
THE REMAINDER OF THE CWA WITH THE BULK OF THE CLOUD COVER NOW HAVING
EXITED THE REGION. THIS ALL THANKS LARGELY TO SUBSIDENCE BEHIND THE
MCS THAT PUSHED ACROSS THE AREA THIS MORNING AND SOME RELATIVELY
DRIER AIR PUSHING INTO THE NORTHERN PORTION OF THE CWA. THERE IS
STILL SOME POTENTIAL FOR CONVECTION TO DEVELOP THIS EVENING OVER
SOUTHWESTERN PORTIONS OF THE CWA. THIS IS WHERE BETTER DEEP LAYER
MOISTURE STILL RESIDES AND THERE HAS BEEN GREATER OPPORTUNITY FOR
DESTABILIZATION THROUGH THE DAY. HOWEVER ANY ACTIVITY TONIGHT IS
EXPECTED TO JUST BE ISOLATED.
WEDNESDAY WE EXPECT TO SEE A RETURN TO GREATER CONVECTIVE COVERAGE
DURING THE DAY. THOUGH MORE RESPECTABLE FORCING WILL BE PULLING AWAY
FROM THE REGION...GUIDANCE IS SUGGESTING GOOD LAPSE RATES WILL BE
IN PLACE ACROSS THE AREA. DEEP LAYER SHEAR ISN`T EXPECTED TO BE
OVERLY IMPRESSIVE WITH 0-6 KM BULK SHEAR EXPECTED TO BE IN THE 20-25
KT RANGE...BUT THIS SHOULD STILL BE SUFFICIENT FOR A GOOD AMOUNT OF
THUNDERSTORMS. GIVEN THE STEEPER LAPSE RATES/GREATER INSTABILITY...
SOME OF THE STORMS COULD BE SEVERE...THUS WE ARE HIGHLIGHTING A
LIMITED RISK ACROSS THE ENTIRE CWA.
HEADING THROUGH THE END OF THE WEEK...MID/UPPER RIDGING WILL BUILD
ACROSS THE EASTERN PART OF THE COUNTRY BUT WE WILL REMAIN ON THE
RETURN FLOW SIDE OF THE SURFACE RIDGE. THIS WILL KEEP A RATHER MOIST
AIRMASS IN PLACE THROUGH MUCH OF THE PERIOD. THIS WILL ALLOW FOR
CONTINUED SCATTERED CONVECTION...WHICH WILL GENERALLY BE MORE
DIURNALLY DRIVEN. BY THE WEEKEND INTO EARLY NEXT WEEK...PERSISTENT
UPPER TROUGHING OVER THE WESTERN HALF OF THE COUNTRY WILL SHIFT
EASTWARD AND DEAMPLIFY. THIS WILL NUDGE A SURFACE FRONT TOWARD THE
AREA WHICH COULD PROVIDE ADDITIONAL FOCUS FOR PRECIP AT THE END OF
THE PERIOD. /DL/
&&
.AVIATION...VFR CONDITIONS HAVE RETURNED TO AREA THIS MORNING IN
WAKE OF OVERNIGHT MCS. MID/HIGH CLOUDS AND A FEW SHRA OVER EASTERN
SECTIONS GIVING WAY TO CLEARING FROM I-55 CORRIDOR WEST. EXPECT SOME
CU TO REDEVELOP IN LOW LEVEL MOISTURE THIS AFTERNOON...BUT
CONDITIONS SHOULD GENERALLY REMAIN VFR WITH ONLY LIMITED RISK FOR
ISOLATED SHRA REDEVELOPMENT. HRRR AND LATEST GFS IMPLY SOME SHRA/
TSRA REDEVELOPMENT UPSTREAM OVER E TX/LA LATER THIS AFTERNOON WITH
POTENTIAL FOR THIS ACTIVITY TO MOVE INTO SOUTHERN HALF OF AREA
TONIGHT. WILL HAVE TO MONITOR THIS...BUT GIVEN FACT THAT SUPPORT
LOOKS WEAK AND WILL BE MOVING IN AFTER SUNSET WILL NOT SHOW ANY
IMPACTS IN TAFS. SOME FOG APPEARS LIKELY AT LATE TONIGHT...
ESPECIALLY IN EAST CLOSER TO SURFACE RIDGE WITH LIGHT WINDS...SO
WILL CARRY AT LEAST MVFR VSBYS FOR A FEW HOURS AROUND SUNRISE.
/AEG/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 69 86 68 85 / 23 47 22 51
MERIDIAN 67 86 67 85 / 21 54 23 50
VICKSBURG 67 87 68 86 / 29 43 23 50
HATTIESBURG 69 86 68 86 / 32 58 28 58
NATCHEZ 68 86 69 85 / 34 49 25 58
GREENVILLE 69 86 69 86 / 20 39 23 42
GREENWOOD 68 85 68 85 / 20 43 23 45
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/AEG
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1121 AM CDT TUE MAY 26 2015
.UPDATE...SHOWER ACTIVITY ON THE BACK END OF THE MORNING CONVECTIVE
COMPLEX CONTINUES TO PUSH OUT OF THE AREA. MEANWHILE...CLEARING WAS
NOTED ON VISIBLE SATELLITE ALONG AND WEST OF I-55. TEMPS CONTINUE TO
BE COOLER THAN EARLIER ANTICIPATED...BUT SHOULD BEGIN TO RECOVER
WITH ADDITIONAL CLEARING. NEVERTHELESS...FORECAST HIGHS WERE BUMPED
DOWN A FEW DEGREES IN MOST AREAS. IT IS CONTINUING TO LOOK LIKE
REDEVELOPMENT WILL BE LESS LIKELY THROUGH MUCH OF THE DAY IN THE
SUBSIDENT REGIME BEHIND THE DEPARTING COMPLEX AS PWATS DROP TO NEAR
1 INCH ACROSS THE NORTHERN HALF OF THE AREA. REMOVED PRECIP WORDING
FOR THE AFTERNOON OVER THE NORTHERN HALF AND KEPT IN ONLY ISOLATED
POPS IN THE SOUTH. HRRR DOES HINT AT SOME REDEVELOPMENT ACROSS THE
SOUTH...BUT IT WOULD BE LATER ON INTO THE TONIGHT PERIOD. FORECAST
UPDATES HAVE BEEN SENT. /DL/
&&
.AVIATION...VFR CONDITIONS HAVE RETURNED TO AREA THIS MORNING IN
WAKE OF OVERNIGHT MCS. MID/HIGH CLOUDS AND A FEW SHRA OVER EASTERN
SECTIONS GIVING WAY TO CLEARING FROM I-55 CORRIDOR WEST. EXPECT SOME
CU TO REDEVELOP IN LOW LEVEL MOISTURE THIS AFTERNOON...BUT
CONDITIONS SHOULD GENERALLY REMAIN VFR WITH ONLY LIMITED RISK FOR
ISOLATED SHRA REDEVELOPMENT. HRRR AND LATEST GFS IMPLY SOME SHRA/
TSRA REDEVELOPMENT UPSTREAM OVER E TX/LA LATER THIS AFTERNOON WITH
POTENTIAL FOR THIS ACTIVITY TO MOVE INTO SOUTHERN HALF OF AREA
TONIGHT. WILL HAVE TO MONITOR THIS...BUT GIVEN FACT THAT SUPPORT
LOOKS WEAK AND WILL BE MOVING IN AFTER SUNSET WILL NOT SHOW ANY
IMPACTS IN TAFS. SOME FOG APPEARS LIKELY AT KHBG/KMEI LATE TONIGHT
CLOSER TO SURFACE RIDGE WITH LIGHT WINDS SO WILL CARRY AT LEAST MVFR
VSBYS FOR A FEW HOURS AROUND SUNRISE. /AEG/
&&
.DISCUSSION... /ISSUED AT 423 AM CDT TUE MAY 26 2015/
SHORT TERM...THROUGH WEDNESDAY NIGHT...
FOR TONIGHT THE HIRES MODELS DO NOT SHOW MUCH OF ANYTHING
GOING ON OUR AREA...BUT THEY SHOW AN MCS MOVING SOUTHEAST WEST OF
THE REGION...WHICH MAY SEND A WEAK BOUNDARY INTO THE REGION DURING
THE DAY WEDNESDAY. TAKING A CLOSER LOOK AT WEDNESDAY THERE WILL BE
SOME DEEP LAYER SHEAR OF AROUND 20 KNOTS. THERE MAY BE A POTENTIAL
FOR SOME STRONG TO SEVERE STORMS. MODELS SHOWS SOME 7C LAPSE RATES
WITH MIDLEVEL 500 MB TEMPS AROUND -11C...-6 SHOWALTER INDEX..VT NEAR
30 AND 20 KNOTS OF DEEP SHEAR. SURFACE BASED CAPE WILL BE AROUND
4000-5000 JUST WEST OF THE REGION DURING THE DAY. SO WITH THIS IN
MIND WILL PUT A LIMITED GRAPHIC FOR THE FAR WEST FOR WEDNESDAY.
/17/
LONG TERM...THURSDAY THROUGH TUESDAY...SLIGHTLY WARMER THAN NORMAL
TEMPERATURES WITH DAILY CHANCES FOR RAIN WILL CONTINUE THROUGH THE
LONG TERM. THE SURFACE RIDGE FROM THE WESTERN ATLANTIC ACROSS THE
GULF COAST STATES WILL REMAIN IN PLACE THURSDAY AND FRIDAY WITH WEAK
RIDGING ALOFT FROM THE WESTERN GULF ACROSS THE SOUTHEAST STATES.
THIS WILL RESULT IN MORE ISOLATED TO SCATTERED DIURNAL COVERAGE OF
CONVECTION TO END THE WORK WEEK. A CLOSED LOW OVER THE NORTHERN
ROCKIES THURSDAY WILL TRACK EAST TO THE CENTRAL PLAINS BY SATURDAY
AND HELP DEVELOP A SURFACE LOW THAT WILL MOVE TO THE MID MISSISSIPPI
RIVER VALLEY BY SATURDAY EVENING. AS HEIGHTS LOWER AND WAA INCREASES
AHEAD OF THE LOW PRESSURE SYSTEM RAIN CHANCES WILL INCREASE FROM THE
WEST OVER OUR CWA LATE SATURDAY INTO SUNDAY. THIS GFS RUN IS AGAIN A
LITTLE DEEPER WITH THE TROUGH AND STRONGER WITH THE ASSOCIATED
SURFACE LOW THAN THE ECMWF AND CMC. THE CLOSED LOW/UPPER LEVEL
TROUGH WILL SHIFT SLOWLY EAST THROUGH TUESDAY. THE GFS BRINGS THE
WEAK COLD FRONT INTO OUR CWA MONDAY MORNING BEFORE STALLING IT
ACROSS OUR SOUTHEAST AS THE CLOSED LOW MOVES NORTHEAST AWAY FROM THE
REGION. THE ECMWF IS SLOWER AND WETTER OVER OUR CWA THROUGH TUESDAY
WITH NO REAL FRONTAL BOUNDARY. CONSENSUS SUGGESTS DECENT POPS SUNDAY
AND MONDAY WITH COOLER AND DRIER WEATHER ON TUESDAY. NORMAL LOWS RUN
IN THE MID 60S AND NORMAL HIGHS RUN 85 TO 87F. DUE TO MOISTURE
LEVELS REMAINING HIGH THROUGH THE PERIOD OVERNIGHT LOWS WILL BE
ABOVE NORMAL. AFTERNOON HIGHS WILL TOP OUT CLOSE TO NORMAL THROUGH
THE PERIOD. /22/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/AEG/17/22
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
321 PM CDT Tue May 26 2015
.SHORT TERM...(This Evening through Wednesday Night)
Issued at 219 PM CDT TUE MAY 26 2015
Not much change to the overall forecast. Shortwave near the TX
Panhandle/western OK border will move east to the four state
KS/OK/MO/AR region by 12z. Increasing and veering low level flow
late tonight is expected to support a cluster of showers/tstms,
mainly for the sw or southern portion of the cwfa. HRRR is the
most bullish with other high resolution models not as aggressive,
but still have some signals for precip. Will need to watch rain
amounts in some of our more saturated areas of the western cwfa,
but not seeing anything that makes me overly concerned at this
point. Any hydro issues will likely be small scale/mesoscale.
Nocturnal precip should weaken as it moves east Wed morning, but
isolated-scattered diurnal development could occur late in the
day. However, overall shortwave ridging in the wake of the exiting
trough will probably suppress chances to some extent.
.LONG TERM...(Thursday through Tuesday)
Issued at 219 PM CDT TUE MAY 26 2015
A broad upper level trough will shift east into the Rockies Thu
with ripples in the sw flow aloft. Hard to pinpoint a period that
won`t have at least some chance of showers/tstms. A sw-ne oriented sfc
front is expected to move Fri night/Sat as what is left of the
shortwave approaches the region.
It looks like we may see at least a brief period of drier weather
later Sunday into Monday as a Midwestern sfc high noses south into
the region in the wake of the sfc front. There is at least general
agreement with medium range guidance in keeping a weak upper level
shear axis over the area by Tuesday but with only modest chances
for precip given drier air expected to be in place.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1238 PM CDT TUE MAY 26 2015
Ceilings will gradually improve from MVFR to VFR this afternoon at the
TAF sites as the stratus continues to erode. An area of
thunderstorms may develop in Eastern Kansas after 00z tonight and
begin to move into the TAF sites overnight however timing and
coverage is uncertain. MVFR conditions are then possible
overnight toward morning. Winds will remain around 10-15 kts
throughout the period.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...Burchfield
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1235 PM CDT Tue May 26 2015
.DISCUSSION...
Issued at 455 AM CDT TUE MAY 26 2015
Today - Wednesday:
Vorticity max which lifted out of West TX yesterday and helped
generate the MCC that roared through east TX has attempted to merge
with the NE/KS upper trough. Hard to say if this process has been
successful. Operational models appear to wash out the vorticity max
currently over east central KS while allowing a separate h7
vorticity max to rotate east through the NE/KS upper trough and
across northern MO this afternoon.
Near term portion of forecast is tied to radar trends which shows a
fairly expansive region of tropical type showers with a few
thunderstorms. The entire region of rain is starting to lift
northeast. Have followed the trend of the HRRR and gone with
categorical PoPs for much of northern and west central MO this
morning. Think we`ll see scattered afternoon convection over
northern MO in response to the above mentioned h7 vorticity max
spinning through that area. A weak cold front/convergent zone is
expected to drift south through the CWA tonight and will provide
additional lift for scattered convection.
Also watching area of loosely organized convection coming out of NM
and into the TX Panhandle. Can see some rotation in water vapor
imagery. NAM and SREF seem to have best handle of this feature and
they both lift it northeast today. Am expecting to see scattered
convection reform with this feature and likely affect at least the
far southern counties this evening/overnight. So have upped PoPs
this region.
Wednesday should be relatively quiet with low chance PoPs tied to
weak convergence with whatever is left of the weak cold front.
Thursday - Weekend:
Very unsettled pattern as upper flow backs to the southwest and a
series of weak embedded disturbances lift northeast through the
Central Plains. Eventually a broad upper trough will shift east out
of the Central Rockies over the weekend and enhance precipitation
chances for at least Saturday. Deep moisture from the Gulf of Mexico
will once again flow northward and gradually result in a tropical
environment by Thursday night. Medium range models have been hitting
the PoPs hard with only minor run-to-run changes. See no reason to
deviate from likely PoPs during this period. Due to recent heavy
rains leaving sub-soil saturated will need to be watchful for
flooding issues as progged soundings once again are suggestive of
warm-rain processes.
Have some concern that the model PoPs are too low as both the
GFS/ECMWF still have the upper trough just passing through MO. Think
the model blended PoPs have not picked up on this. Sunday is looking
a bit chilly since we`ll be under an extensive cloud shield with
scattered convection.
Monday:
Finally should see the start of drying out as the upper trough
should have passed east of the region with subsidence overspreading
the region.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1235 PM CDT TUE MAY 26 2015
Ceilings are lifting into VFR while things dry out behind this
morning`s precipitation. Scattered showers and a few storms will
likely redevelop over northern MO over the next few hours, but may
stay just north of the KC area. Could also see isolated to scattered
storms later this evening mainly to the east and southeast of KC
toward SZL and DMO.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
912 AM PDT MON MAY 25 2015
.SYNOPSIS...A TROUGH ALOFT COMBINED WITH ENOUGH MOISTURE AND
INSTABILITY WILL HELP TO SPARK OFF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS TODAY THROUGH THURSDAY ACROSS THE SOUTHERN
GREAT BASIN ESPECIALLY OVER THE HIGHER ELEVATIONS. OTHERWISE EXPECT
DRY CONDITIONS WITH A WARMING TREND THROUGH THE END OF THE WEEK. THE
WARMEST WEATHER OF THE YEAR SO FAR IS EXPECTED THIS WEEKEND.
&&
.UPDATE...MADE SOME MINOR MODIFICATIONS TO POP/SKY/WX/WIND THROUGH
THIS EVENING. THE SHOWERS THAT PERSISTED OVERNIGHT ACROSS THE
SOUTHERN GREAT BASIN ARE TAPERING OFF QUICKLY THIS MORNING. MODEST
INSTABILITY IS EXPECTED TO DEVELOP ONCE AGAIN THIS AFTERNOON ACROSS
THE SIERRA AND SOUTHERN GREAT BASIN AND WILL LIKELY LEAD TO ANOTHER
ROUND OF SHOWERS/ISOLATED THUNDERSTORMS TRIGGERED BY A SHORTWAVE
MOVING ACROSS CENTRAL NEVADA. I DID ADD IN A SLIGHT CHANCE OF PRECIP
OVER THE SPRING/SHEEP RANGES IN CLARK COUNTY AS MODELS DO HINT AT
THE POTENTIAL FOR SHOWERS THERE. ALSO TWEAKED WINDS TO BETTER MATCH
THE HRRR..SPECIFICALLY IN INCREASING SPEEDS AND KEEPING SOUTHEAST
WINDS GOING AT KLAS FOR A BIT LONGER.
&&
.AVIATION...FOR MCCARRAN...VFR CONDITIONS. SOUTHEAST WINDS ARE
EXPECTED TO INCREASE TO 8-14 KTS WITH GUSTS 15-20 KTS EARLY THIS
AFTERNOON. MODELS NOW INDICATED THAT A TURN TO SOUTH/SOUTHWEST WINDS
WILL BE A BIT LATER THAT PREVIOUSLY INDICATED. FOR THE MOMENT THE
BEST ESTIMATE AT THIS SWITCH IS 23-00Z THIS AFTERNOON. SPEEDS SHOULD
BEGIN TO DECREASE AFTER SUNSET. SIMILAR CONDITIONS ARE EXPECTED
WEDNESDAY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...MAINLY DIURNAL WIND DIRECTIONS THROUGH TONIGHT AT 15
KTS OR LESS. A FEW CLOUDS AOA 12K FEET TODAY WITH SCT-BKN CLOUDS AOA
25K FEET TONIGHT SOUTH OF KIYK-KDRA-KSGU LINE. NORTH OF THIS LINE
THERE WILL BE A POSSIBILITY OF SHRA/TSRA AROUND AGAIN MAINLY AFTER
20Z TODAY THROUGH 06Z OR SO WEDNESDAY. GUSTY AND ERRATIC
WINDS...MVFR OR LOWER VSBY IN HEAVIER SHRA AND CIGS TO 5K-8K FEET
ARE POSSIBLE. LOCAL MOUNTAIN OBSCURATIONS ARE ALSO POSSIBLE.
SIMILAR CONDITIONS ARE EXPECTED WEDNESDAY.
&&
.PREV DISCUSSION...
303 AM PDT MON MAY 25 2015
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT.
THE CONVECTIVE COMPLEX THAT GOT GOING YESTERDAY EVENING ACROSS SOUTH-
CENTRAL NEVADA HAS PUSHED TOWARD THE UTAH BORDER EARLY THIS MORNING
IN A SOMEWHAT DECAYED STATE. MOST OF THE MAIN COMPLEX WAS NOW JUST
AN AREA OF LIGHT TO MODERATE RAIN, HOWEVER, WE HAVE SEEN SOME CELLS
DEVELOP ON THE SOUTHERN FLANK OF THE MAIN AREA OF PRECIPITATION
ACROSS NORTHERN MOHAVE COUNTY IN THE LAST HOUR. BASED ON THE HRRR,
THIS ACTIVITY IS ALL SLATED TO MOVE EAST AND SHOULD EXIT THE AREA BY
LATER THIS MORNING. HOWEVER, A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS WAS LEFT IN THE FORECAST FOR LINCOLN COUNTY AND ADDED
TO THE FORECAST FOR NORTHERN MOHAVE COUNTY TO ACCOUNT FOR THIS.
WHATEVER CLOUDS ARE AROUND FROM THIS SHOULD CLEAR OUT AS WELL BY
LATER THIS MORNING.
WE REMAIN IN A BROAD TROUGH IN THE MID AND UPPER LEVELS OF THE
ATMOSPHERE ACROSS THE SOUTHWEST. TWO FEATURES ARE OF NOTE THIS
MORNING. ONE IS THE MAIN JET STREAM WHICH IS PASSING BY TO OUR
SOUTH. THIS WILL PUSH A BAND OF HIGHER LEVEL MOISTURE ACROSS THE
SOUTHERN THIRD OF THE AREA TODAY INTO TONIGHT RESULTING IN HIGH
CLOUDS. SOME OF THE CLOUDS COULD ENHANCE OFF THE COASTAL RANGES OF
SOCAL BY LATER TODAY INTO TONIGHT AND THUS SKY COVER HERE MAY BE
UNDERDONE. THE SECOND FEATURE TO WATCH CAN BE SEEN ON WATER VAPOR
IMAGERY DIGGING SOUTH ACROSS NORCAL AND NORTHWESTERN NEVADA THIS
MORNING. THIS NEXT PIECE OF ENERGY WILL WORK SOUTH AND EAST ACROSS
THE SOUTHERN HALF OF NEVADA TODAY AND ONCE AGAIN WITH THE MOISTURE
(MAINLY MID-LEVEL) AND INSTABILITY IN PLACE HELP TO SPARK OFF
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON ACROSS THE
SOUTHERN GREAT BASIN ESPECIALLY OVER THE HIGHER ELEVATIONS. SIMILAR
TO YESTERDAY, ACTIVITY SHOULD PUSH WEST TO EAST ACROSS THE AREA.
INSPECTING THE HRRR AND LOCAL 4KM HIGH RESOLUTION ARW AND NMM
MODELS, THERE APPEARS TO BE TWO MAIN AREAS THAT WILL NEED TO BE
WATCHED THIS AFTERNOON. THE FIRST IS NORTHERN LINCOLN COUNTY AND THE
SECOND WILL BE ACROSS ESMERALDA COUNTY AS WELL AS THE WHITE
MOUNTAINS, NORTHERN OWENS VALLEY AND EASTERN SLOPES OF THE SOUTHERN
SIERRA NEVADA. POPS WERE RAISED SLIGHTLY FOR THE LATTER. THE MAIN
THREATS IN AND NEAR THUNDERSTORMS TODAY WILL BE GUSTY AND ERRATIC
WINDS TO 45 MPH, SMALL HAIL, LIGHTNING AND DOWNPOURS THAT COULD
PRODUCE LOCALIZED FLOODING. SHOWERS AND THUNDERSTORMS SHOULD
DECREASE THIS EVENING WITH THE LOSS OF HEATING. DESPITE THE TROUGH
OVERHEAD TEMPS WILL BE ON THE RISE TODAY WITH HIGHS RETURNING BACK
CLOSER TO NORMAL. THIS WILL SNAP THE SUB-90 STREAK IN LAS VEGAS THAT
HAS BEEN AROUND SINCE MAY 4TH. WITH TEMPS RISING, SNOW LEVELS WILL
BE AROUND 11000 FEET TODAY BUT ANY HEAVIER SHOWERS OVER THE HIGHEST
MOUNTAINS COULD AGAIN DROP A FEW INCHES OF SNOW. HIKERS AND OUTDOOR
ENTHUSIASTS IN THE SOUTHERN SIERRA NEVADA AND WHITE MOUNTAINS SHOULD
AGAIN BE ALERT FOR POTENTIAL WINTRY CONDITIONS ON AREA TRAILS AND
CAMPGROUNDS HIGHER UP.
A MID/UPPER LEVEL LOW WILL PUSH EAST ACROSS BAJA CALIFORNIA TONIGHT
AND HELP TO PUSH ANY CIRRUS ACROSS THE SOUTHERN HALF OF OUR AREA OFF
TO THE EAST ON WEDNESDAY, HOWEVER, SOME THICKER HIGH LEVEL CLOUDS
MAY START THE DAY OFF IN MOHAVE COUNTY. A BROAD MID/UPPER LEVEL
TROUGH WILL REMAIN ACROSS THE AREA FOR WEDNESDAY AND WITH ENERGY
RIPPLING THROUGH THE BASE OF THE TROUGH AND ENOUGH MOISTURE AS WELL
AS INSTABILITY REMAINING IN PLACE ONCE AGAIN RESULT IN SHOWERS AND
THUNDERSTORMS POPPING UP WITH THE HEATING OF THE DAY ACROSS THE
SOUTHERN GREAT BASIN. ONCE AGAIN EXPECT MAINLY AFTERNOON AND EVENING
ACTIVITY MAINLY OVER THE HIGHER ELEVATIONS. TEMPS WILL RISE A FEW
MORE DEGREES AS THE ATMOSPHERE CONTINUES TO WARM FURTHER. THIS
SHOULD PUSH HIGHS BACK CLOSER TO NORMAL AND I SIDED WITH THE WARMER
MAV (GFS) NUMBERS FOR HIGHS.
THE PESKY TROUGH ALOFT WILL FINALLY ALLOW FOR A FULL-FLEDGED FEEL OF
SPRING (MORE LIKE SUMMER DEPENDING ON YOUR TASTE AND HOW THIS SPRING
HAS BEEN) BY THURSDAY AS A RIDGE ALOFT STARTS TO TRANSITION IN. IF
YOU HAVE BEEN HOLDING OFF USING ON THE AIR CONDITIONER MUCH, GET
READY TO CRANK IT AS HIGHS SOAR TO ABOVE NORMAL READINGS FOR A
CHANGE. A WEAK RIPPLE IN THE FLOW AND LINGERING MOISTURE AND
INSTABILITY COULD STILL SET OFF A FEW SHOWERS AND THUNDERSTORMS IN
THE AFTERNOON AND EVENING OVER THE SOUTHERN GREAT BASIN, HOWEVER,
ACTIVITY SHOULD BE LESS IN AREAL COVERAGE COMPARED TO TUESDAY AND
WEDNESDAY. ONCE AGAIN ANY SHOWERS AND THUNDERSTORMS SHOULD END IN
THE EVENING WITH THE LOSS OF HEATING.
.LONG TERM...FRIDAY THROUGH TUESDAY.
THE STORY OF THE LONG TERM PERIOD WILL BE AFTERNOON HIGHS PUSHING
THE CENTURY MARK ACROSS MOST DESERT LOCALES THROUGH THE BEGINNING OF
NEXT WEEK...AS A SHORTWAVE RIDGE TRAVERSES OVER THE AREA THIS
WEEKEND. MINOR DIFFERENCES CONTINUE TO EXIST WITH OPERATIONAL
GUIDANCE REGARDING THE OVERALL AMPLITUDE OF THE AFOREMENTIONED
RIDGE. HOWEVER ALL BASE AND DERIVED GUIDANCE CONTINUES TO
CONSISTENTLY INDICATE HIGH TEMPERATURES AT LEAST WITHIN A FEW
DEGREES OF EACH OTHER FROM MODEL TO MODEL OVER THE WEEKEND...FURTHER
INCREASING CONFIDENCE OF THE FIRST 100 DEGREE DAY OF 2015 FOR MANY
DESERT LOCALES...INCLUDING LAS VEGAS. BOTH THE OPERATIONAL GFS/ECMWF
INDICATE A FAIRLY VIGOROUS TROUGH IMPINGING ON THE GREAT BASIN LATE
SUNDAY INTO MONDAY...WHICH WILL INCREASE SOUTHERLY/SOUTHWESTERLY
FLOW ACROSS MUCH OF THE CWA IN THIS TIMEFRAME. THIS WILL PROMOTE
GOOD MIXING...ESPECIALLY ON SUNDAY AFTERNOON...WHICH WILL BUMP UP
HIGH TEMPERATURES A FEW DEGREES FROM FRIDAY AND SATURDAY LIKELY
MAKING THIS THE HOTTEST DAY OF THE YEAR THUS FAR. TEMPERATURES WILL
COOL A FEW DEGREES MONDAY AND TUESDAY IN RESPONSE TO THE PASSING
TROUGH...BUT WILL REMAIN ABOVE SEASONAL NORMALS.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...WOLCOTT
SHORT TERM........STACHELSKI
LONG TERM.........PULLIN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
307 PM EDT TUE MAY 26 2015
.SYNOPSIS...THE WESTERN EXTENT OF BROAD SURFACE HIGH PRESSURE...AND
A SEASONABLY MOIST AIR MASS...WILL PREVAIL OVER THE REGION FOR THE
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 PM TUESDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE WESTERN END OF HIGH PRESSURE
CONTINUING TO EXTEND OVER CENTRAL NORTH CAROLINA...WHILE WATER VAPOR
IMAGERY SHOWED WEAK MID-LEVEL VORTICITY AND AN INCREASE IN MID-LEVEL
MOISTURE OVER THE WESTERN CAROLINAS. PRECIPITABLE WATER VALUES HAD
INCREASED TOWARD INTERSTATE 95 AND EAST DURING THE DAY...SUCH THAT
THERE WERE FAIRLY UNIFORM VALUES AROUND 1.5 INCHES OVER CENTRAL
NORTH CAROLINA AS THE LATE AFTERNOON APPROACHED. SCATTERED
SHOWERS... AND ISOLATED THUNDER...OVER THE SOUTHERN COASTAL PLAIN
SHOULD GENERALLY DECREASE THIS EVENING AS GFS AND NAM BUFR SOUNDINGS
FORECAST LOW-LEVEL STABILITY INCREASING BY AROUND SUNSET. IN THE
MEANTIME...ISOLATED SHOWERS OR A VERY ISOLATED STORM MAY FIND THEIR
WAY ABOUT AS FAR NORTH AS U.S. 64 BASED ON A COMBINATION OF THE
LATEST RADAR TRENDS AND THE HRRR WRF. WHILE AN ISOLATED SHOWER VERY
LATE THIS AFTERNOON IS ALSO POSSIBLE OVER THE FAR WESTERN
PIEDMONT...SCATTERED SHOWERS MAY BE A BETTER POSSIBILITY OVER THE
WESTERN PIEDMONT AND TOWARD THE YADKIN RIVER LATER THIS EVENING WITH
THE APPROACH OF THE WEAK MID-LEVEL WAVE COINCIDENT WITH FORECAST
MOISTENING ON BUFR SOUNDINGS AND...AGAIN...HRRR WRF FORECASTS. 0-3KM
SHEAR ON THE SPC MESOANALYSIS...AND AS FORECAST BY THE NAM AND
GFS... IS LOW...SINGLE DIGITS KNOTS TO TEENS AT MOST...SO AS OF THIS
WRITING DO NOT EXPECT ANY STRONG...DEEP CONVECTION. THE GFS WOULD
SPREAD QPF FARTHER EAST THAN THE NAM AND THE HRRR WRF DEPICT...AND
BASED ON THE STABILITY EVEN ON THE KRDU...KFAY...AND KRWI GFS BUFR
SOUNDINGS OVERNIGHT...LEAN MORE TOWARD THE NAM AND RAP WHICH KEEP
MEASURABLE PRECIPITATION FARTHER WEST DURING THE OVERNIGHT HOURS.
AS ALSO NOTED IN THE AVIATION DISCUSSION BELOW...SREF MODEL
PROBABILITIES OF LOW CLOUDS ARE HIGH ESPECIALLY WEST OF INTERSTATE
95 OVERNIGHT. HOWEVER...THE STATISTICAL GUIDANCE IS NOT AS BULLISH
AND MODEL SOUNDINGS FROM THE GFS AND NAM DIFFER AS TO THE POTENTIAL
OF LOW CLOUDS LATE. SINCE LOW CLOUDS OCCURRED MAINLY TOWARD THE
YADKIN RIVER AND THE TRIAD EARLY THIS MORNING...THE OVERALL AIR MASS
HAS MOISTENED...AND 925MB WINDS SHOULD BE FAVORABLE OVERNIGHT WITH
VALUES OF 20 TO 30KT AS FORECAST BY THE GFS IN THE SOUTHWEST FLOW.
AS A RESULT...BELIEVE THERE WILL BE AREAS OF LOW CLOUDS LATE TONIGHT
CONTINUING INTO WEDNESDAY MORNING. OVERNIGHT LOWS 65 TO 70...SHY OF
ANY RECORD HIGH MINIMUM VALUES FOR MAY 27.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 305 PM TUESDAY...
INSTABILITY OVERALL INCREASES ACROSS CENTRAL NORTH CAROLINA
WEDNESDAY...WITH SURFACE-BASED CAPE RISING TO JUST OVER 1000J/KG
WHILE MLCAPE THROUGH THE LOWEST 3KM IS GENERALLY 500J/KG OR SO.
LIFTED INDICES ARE FORECAST TO BE SLIGHTLY LOWER COMPARED TO
TODAY... TO NEAR -5C WEDNESDAY AFTERNOON VERSUS ABOUT -3C.
ALOFT...THERE IS FORECAST WEAK AND BROAD DIFFLUENCE AND WEAK
CONVERGENCE AT 850MB...ALTHOUGH CERTAINLY THE NAM AND TO A LESSER
EXTENT THE GFS FORECAST MODEST LIFT OVER CENTRAL NORTH CAROLINA FOR
WEDNESDAY AFTERNOON. WINDS ALOFT ARE WEAK...AND ANY PIEDMONT TROUGH
SHOULD BE SOMEWHAT WEAK AS WELL...LEADING TO A DAY WHERE SCATTERED
MOSTLY DISORGANIZED SHOWERS AND THUNDERSTORMS SHOULD OCCUR AS THE
DAY PROGRESSES. ONCE AGAIN...0-3KM SHEAR IS LOW AND 850MB AND 925MB
WINDS ARE RELATIVELY LIGHT BY AFTERNOON...10 TO 20KT. HIGHS IN THE
80S.
OVERNIGHT...BUFR SOUNDINGS FROM BOTH THE NAM AND GFS SHOW INCREASING
STABILITY AS SURFACE HIGH PRESSURE IS FORECAST TO BUILD SOMEWHAT
BACK WEST. FOR THIS FORECAST WILL DIMINISH CHANCES EAST TO WEST AND
RETAIN A SLIGHT CHANCE OF SHOWERS IN THE OVERNIGHT HOURS ONLY TOWARD
THE YADKIN RIVER ESPECIALLY FOR FORECAST CONSISTENCY...BUT IF THE
NAM BUFR SOUNDINGS VERIFY IN PARTICULAR CENTRAL NORTH CAROLINA
SHOULD HAVE BELOW SLIGHT CHANCE POPS AFTER 06Z. LOWS IN THE MID TO
UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 210 PM TUESDAY...
THE REMNANT MOISTURE AND SHEAR AXIS FROM THE SYSTEM CURRENTLY OVER
THE MISS RIVER VALLEY WILL MOVE EAST AND BECOME CENTERED OVER
CENTRAL NC BY THURSDAY. WHILE THE BEST MID/UPR ENERGY WILL HAVE
LIFTED WELL TO OUR NORTH...THERE SHOULD BE ENOUGH MOISTURE AND
FORCING FOR AT LEAST SCATTERED AFTERNOON/EVENING SHOWERS/TSTMS.
INSTABILITY AND SHEAR VALUES SUGGEST SUB-SEVERE ACTIVITY.
THE UPPER RIDGE OFF THE EAST COAST WILL THEN REBUILD OVER THE
SOUTHEAST COASTAL REGION FRIDAY THROUGH THE WEEKEND...AND SHOULD
HELP LIMIT THE COVERAGE OF SHOWER/TSTM ACTIVITY OVER OUR AREA FRIDAY
AND SATURDAY.
A COLD FRONT CROSSING THE MIDWEST ON FRIDAY IS PROGGED BY THE LATEST
GFS TO DROP SOUTH ACROSS OUR AREA BY SUNDAY AND DISSIPATE OVER US BY
MONDAY. DESPITE THE LIFT PROVIDED BY THIS FRONT...MODELS SUGGEST THE
AFOREMENTIONED RIDGE OVER THE SOUTHEAST WILL KEEP THE BULK OF THE
MOISTURE JUST TO OUR NORTH. NEVERTHELESS...THERE`S ENOUGH FORCING
AND MOISTURE TO WARRANT A DECENT CHANCE POP ACROSS OUR AREA LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.
AS FOR TEMPS...PERSISTENCE IS THE BEST FORECAST AT THIS POINT WITH
LITTLE CHANGE IN THE AIRMASS. HIGHS IN THE MID TO UPPER 80S AND
LOWS IN THE MID 60S EACH DAY DURING THE PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 200 PM TUESDAY...
FOR THE 18Z VALID TAF PERIOD...VFR CONDITIONS OUTSIDE OF ANY MOSTLY
ISOLATED...DEEP CONVECTION SHOULD PERSIST THROUGH MUCH OF TONIGHT.
AS OF THIS WRITING...ISOLATED TO SCATTERED SHOWERS WERE NOTED TOWARD
KCTZ...AND DURING THIS EVENING WITH A WEAK SHORTWAVE MOVING NORTH
OVER THE WESTERN CAROLINAS...ISOLATED TO SCATTERED SHOWERS MAY OCCUR
MORE TOWARD THE TRIAD. THERE EXISTS A MODEST PROBABILITY OF IFR
CONDITIONS IN LOW CLOUDS OVERNIGHT. SREF MODEL PROBABILITIES OF SUCH
ARE HIGH ESPECIALLY WEST OF INTERSTATE 95...HOWEVER...THE
STATISTICAL GUIDANCE IS NOT AS BULLISH AND MODEL SOUNDINGS FROM THE
GFS AND NAM DIFFER AS TO THE POTENTIAL OF LOW CLOUDS LATE. SINCE LOW
CLOUDS OCCURRED MAINLY TOWARD THE YADKIN RIVER AND THE TRIAD EARLY
THIS MORNING...THE OVERALL AIR MASS HAS MOISTENED...AND 925MB WINDS
SHOULD BE FAVORABLE OVERNIGHT...HAVE FORECAST IFR CONDITIONS BY 10Z
IN THE TRIAD AND AT KRDU...WITH TEMPORARY CONDITIONS OF SUCH AT KFAY
AND KRWI WHERE CONFIDENCE CURRENTLY IS NOT AS HIGH WITH LIGHTER
925MB WINDS AND LESSER PROBABILITIES EVEN ON THE AGGRESSIVE SREF.
DURING WEDNESDAY MORNING...ANY IFR CONDITIONS SHOULD LIFT AT LEAST
INTO MVFR...WITH SCATTERED SHOWERS BEGINNING TO DEVELOP TOWARD THE
END OF THE TAF PERIOD. ANY SOUTHWEST WIND GUSTS SHOULD BE LIMITED TO
THE LOWER TO MID TEENS KNOTS WITH MIXING WEDNESDAY AND BE BRIEF.
BEYOND THE 18Z VALID TAF PERIOD...THE LATEST MODEL SOUNDINGS SUGGEST
THAT LOW CLOUDS ARE POSSIBLE AGAIN THURSDAY MORNING...THOUGH WITH A
BETTER PROBABILITY TOWARD KFAY AND KRWI RELATIVE TO THE REST OF
CENTRAL NORTH CAROLINA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS ARE ALSO POSSIBLE. LOWEST CHANCES OF THOSE
APPEAR TO BE SATURDAY WHEN THE AIR MASS IS RELATIVELY MORE STABLE
COMPARED TO OTHER DAYS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...RAH
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
210 PM EDT TUE MAY 26 2015
.SYNOPSIS...THE WESTERN EXTENT OF BROAD SURFACE HIGH PRESSURE...AND
A SEASONABLY MOIST AIR MASS...WILL PREVAIL OVER THE REGION FOR THE
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...
THE LATEST UPPER-AIR ANALYSIS SHOWED THE WEST PART OF RIDGING
SURFACE AND ALOFT OVER THE CAROLINAS...AND THE LATEST SATELLITE
WATER VAPOR IMAGES SHOWS AMPLE MID-LEVEL DRY AIR ALONG THE CAROLINA
COAST. DURING THE MORNING...THE SPC MESOANALYSIS HAS SHOWN A GRADUAL
INCREASE IN PRECIPITABLE WATER VALUES OVER AND EAST OF THE COASTAL
PLAIN...IN CONCERT WITH THE RAP WHICH FORECASTS OVERALL PRECIPITABLE
WATER VALUES OF AROUND 1.5 INCHES OVER CENTRAL NORTH CAROLINA BY
00Z. WHILE FORECAST SOUNDINGS ARE FAIRLY STABLE...THE RAP DOES
FORECAST AFTERNOON MLCAPE IN THE LOWEST 3KM TO 500J/KG OR LESS.
850MB LIFT IS GREATEST TOWARD KFAY AND KCTZ EARLY THIS AFTERNOON...
WHERE THE LATEST REGIONAL RADAR IMAGES SHOW ISOLATED TO SCATTERED
SHOWERS NEAR AND JUST NORTH OF KILM. THE HRRR WRF GUIDANCE IS DOING
WELL WITH THIS MODEST CONVECTION...AND DESPITE ONLY MODEST
INSTABILITY...IN THE MOISTURE ADVECTION THE HRRR WRF DOES SHOW
MOSTLY ISOLATED SHOWERS SLOWLY MOVING NORTH ACROSS THE KFAY AND KCTZ
AREAS TO NEAR KRDU AND KRWI BY LATE IN THE DAY. FARTHER WEST...RAP
SOUNDINGS SHOW DECENT CIN THROUGH MUCH OF THE DAY...AND ANY ISOLATED
SHOWER OR STORM MAY HOLD OFF AS WELL UNTIL VERY LATE IN THE DAY
GIVEN THE WEAK LIFT AND LIMITED FORCING. HIGH TEMPERATURES IN THE
MID TO UPPER 80S WITH A FEW WIND GUSTS IN THE TEENS KNOTS WITH
MIXING DURING THE DAY...925MB AND 850MB WINDS TO 15KT.
CONVECTION SHOULD BE LARGELY DIURNALLY DRIVEN...BUT WILL KEEP A
SLIGHT CHANCE ACROSS THE WESTERN PIEDMONT OVERNIGHT WHERE THE
POTENTIAL FOR GLANCING SHOT DPVA ATTENDANT TO UPPER DISTURBANCES IS
HIGHEST. LOWS IN THE MID TO UPPER 60S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 300 AM TUESDAY...
MODELS GENERALLY AGREE THAT THE MID/UPPER LEVEL RIDGE MAY WEAKEN A
BIT WHILE DRIFTING EVER SO SLIGHTLY EASTWARD OVER THE WESTERN
ATLANTIC. FACTORS CONTRIBUTING TO RAIN CHANCES TODAY(DAYTIME HEATING
AND RESULTANT DESTABILIZATION...POTENTIAL FOR SHORTWAVE DISTURBANCES
ALOFT...AND SEABREEZE BOUNDARY) WILL ESSENTIALLY GOVERN RAIN CHANCES
AGAIN ON WEDNESDAY...BUT PERHAPS WITH MORE EQUITABLE RAIN CHANCES
EASTWARD INTO CENTRAL PIEDMONT.
HIGHER RAIN CHANCES AND CLOUD COVER MAY KNOCK A DEGREE OR TWO OFF OF
DAYTIME HIGHS. HIGHS IN THE LOWER/80S NORTHWEST TO MID/UPPER 80S
SOUTHEAST. LOWS IN THE MID/UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 210 PM TUESDAY...
THE REMNANT MOISTURE AND SHEAR AXIS FROM THE SYSTEM CURRENTLY OVER
THE MISS RIVER VALLEY WILL MOVE EAST AND BECOME CENTERED OVER
CENTRAL NC BY THURSDAY. WHILE THE BEST MID/UPR ENERGY WILL HAVE
LIFTED WELL TO OUR NORTH...THERE SHOULD BE ENOUGH MOISTURE AND
FORCING FOR AT LEAST SCATTERED AFTERNOON/EVENING SHOWERS/TSTMS.
INSTABILITY AND SHEAR VALUES SUGGEST SUB-SEVERE ACTIVITY.
THE UPPER RIDGE OFF THE EAST COAST WILL THEN REBUILD OVER THE
SOUTHEAST COASTAL REGION FRIDAY THROUGH THE WEEKEND...AND SHOULD
HELP LIMIT THE COVERAGE OF SHOWER/TSTM ACTIVITY OVER OUR AREA FRIDAY
AND SATURDAY.
A COLD FRONT CROSSING THE MIDWEST ON FRIDAY IS PROGGED BY THE LATEST
GFS TO DROP SOUTH ACROSS OUR AREA BY SUNDAY AND DISSIPATE OVER US BY
MONDAY. DESPITE THE LIFT PROVIDED BY THIS FRONT...MODELS SUGGEST THE
AFOREMENTIONED RIDGE OVER THE SOUTHEAST WILL KEEP THE BULK OF THE
MOISTURE JUST TO OUR NORTH. NEVERTHELESS...THERE`S ENOUGH FORCING
AND MOISTURE TO WARRANT A DECENT CHANCE POP ACROSS OUR AREA LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.
AS FOR TEMPS...PERSISTENCE IS THE BEST FORECAST AT THIS POINT WITH
LITTLE CHANGE IN THE AIRMASS. HIGHS IN THE MID TO UPPER 80S AND
LOWS IN THE MID 60S EACH DAY DURING THE PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 200 PM TUESDAY...
FOR THE 18Z VALID TAF PERIOD...VFR CONDITIONS OUTSIDE OF ANY MOSTLY
ISOLATED...DEEP CONVECTION SHOULD PERSIST THROUGH MUCH OF TONIGHT.
AS OF THIS WRITING...ISOLATED TO SCATTERED SHOWERS WERE NOTED TOWARD
KCTZ...AND DURING THIS EVENING WITH A WEAK SHORTWAVE MOVING NORTH
OVER THE WESTERN CAROLINAS...ISOLATED TO SCATTERED SHOWERS MAY OCCUR
MORE TOWARD THE TRIAD. THERE EXISTS A MODEST PROBABILITY OF IFR
CONDITIONS IN LOW CLOUDS OVERNIGHT. SREF MODEL PROBABILITIES OF SUCH
ARE HIGH ESPECIALLY WEST OF INTERSTATE 95...HOWEVER...THE
STATISTICAL GUIDANCE IS NOT AS BULLISH AND MODEL SOUNDINGS FROM THE
GFS AND NAM DIFFER AS TO THE POTENTIAL OF LOW CLOUDS LATE. SINCE LOW
CLOUDS OCCURRED MAINLY TOWARD THE YADKIN RIVER AND THE TRIAD EARLY
THIS MORNING...THE OVERALL AIR MASS HAS MOISTENED...AND 925MB WINDS
SHOULD BE FAVORABLE OVERNIGHT...HAVE FORECAST IFR CONDITIONS BY 10Z
IN THE TRIAD AND AT KRDU...WITH TEMPORARY CONDITIONS OF SUCH AT KFAY
AND KRWI WHERE CONFIDENCE CURRENTLY IS NOT AS HIGH WITH LIGHTER
925MB WINDS AND LESSER PROBABILITIES EVEN ON THE AGGRESSIVE SREF.
DURING WEDNESDAY MORNING...ANY IFR CONDITIONS SHOULD LIFT AT LEAST
INTO MVFR...WITH SCATTERED SHOWERS BEGINNING TO DEVELOP TOWARD THE
END OF THE TAF PERIOD. ANY SOUTHWEST WIND GUSTS SHOULD BE LIMITED TO
THE LOWER TO MID TEENS KNOTS WITH MIXING WEDNESDAY AND BE BRIEF.
BEYOND THE 18Z VALID TAF PERIOD...THE LATEST MODEL SOUNDINGS SUGGEST
THAT LOW CLOUDS ARE POSSIBLE AGAIN THURSDAY MORNING...THOUGH WITH A
BETTER PROBABILITY TOWARD KFAY AND KRWI RELATIVE TO THE REST OF
CENTRAL NORTH CAROLINA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS ARE ALSO POSSIBLE. LOWEST CHANCES OF THOSE
APPEAR TO BE SATURDAY WHEN THE AIR MASS IS RELATIVELY MORE STABLE
COMPARED TO OTHER DAYS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/CBL
SHORT TERM...CBL
LONG TERM...RAH
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
201 PM EDT TUE MAY 26 2015
.SYNOPSIS...THE WESTERN EXTENT OF BROAD SURFACE HIGH PRESSURE...AND
A SEASONABLY MOIST AIR MASS...WILL PREVAIL OVER THE REGION FOR THE
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...
THE LATEST UPPER-AIR ANALYSIS SHOWED THE WEST PART OF RIDGING
SURFACE AND ALOFT OVER THE CAROLINAS...AND THE LATEST SATELLITE
WATER VAPOR IMAGES SHOWS AMPLE MID-LEVEL DRY AIR ALONG THE CAROLINA
COAST. DURING THE MORNING...THE SPC MESOANALYSIS HAS SHOWN A GRADUAL
INCREASE IN PRECIPITABLE WATER VALUES OVER AND EAST OF THE COASTAL
PLAIN...IN CONCERT WITH THE RAP WHICH FORECASTS OVERALL PRECIPITABLE
WATER VALUES OF AROUND 1.5 INCHES OVER CENTRAL NORTH CAROLINA BY
00Z. WHILE FORECAST SOUNDINGS ARE FAIRLY STABLE...THE RAP DOES
FORECAST AFTERNOON MLCAPE IN THE LOWEST 3KM TO 500J/KG OR LESS.
850MB LIFT IS GREATEST TOWARD KFAY AND KCTZ EARLY THIS AFTERNOON...
WHERE THE LATEST REGIONAL RADAR IMAGES SHOW ISOLATED TO SCATTERED
SHOWERS NEAR AND JUST NORTH OF KILM. THE HRRR WRF GUIDANCE IS DOING
WELL WITH THIS MODEST CONVECTION...AND DESPITE ONLY MODEST
INSTABILITY...IN THE MOISTURE ADVECTION THE HRRR WRF DOES SHOW
MOSTLY ISOLATED SHOWERS SLOWLY MOVING NORTH ACROSS THE KFAY AND KCTZ
AREAS TO NEAR KRDU AND KRWI BY LATE IN THE DAY. FARTHER WEST...RAP
SOUNDINGS SHOW DECENT CIN THROUGH MUCH OF THE DAY...AND ANY ISOLATED
SHOWER OR STORM MAY HOLD OFF AS WELL UNTIL VERY LATE IN THE DAY
GIVEN THE WEAK LIFT AND LIMITED FORCING. HIGH TEMPERATURES IN THE
MID TO UPPER 80S WITH A FEW WIND GUSTS IN THE TEENS KNOTS WITH
MIXING DURING THE DAY...925MB AND 850MB WINDS TO 15KT.
CONVECTION SHOULD BE LARGELY DIURNALLY DRIVEN...BUT WILL KEEP A
SLIGHT CHANCE ACROSS THE WESTERN PIEDMONT OVERNIGHT WHERE THE
POTENTIAL FOR GLANCING SHOT DPVA ATTENDANT TO UPPER DISTURBANCES IS
HIGHEST. LOWS IN THE MID TO UPPER 60S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 300 AM TUESDAY...
MODELS GENERALLY AGREE THAT THE MID/UPPER LEVEL RIDGE MAY WEAKEN A
BIT WHILE DRIFTING EVER SO SLIGHTLY EASTWARD OVER THE WESTERN
ATLANTIC. FACTORS CONTRIBUTING TO RAIN CHANCES TODAY(DAYTIME HEATING
AND RESULTANT DESTABILIZATION...POTENTIAL FOR SHORTWAVE DISTURBANCES
ALOFT...AND SEABREEZE BOUNDARY) WILL ESSENTIALLY GOVERN RAIN CHANCES
AGAIN ON WEDNESDAY...BUT PERHAPS WITH MORE EQUITABLE RAIN CHANCES
EASTWARD INTO CENTRAL PIEDMONT.
HIGHER RAIN CHANCES AND CLOUD COVER MAY KNOCK A DEGREE OR TWO OFF OF
DAYTIME HIGHS. HIGHS IN THE LOWER/80S NORTHWEST TO MID/UPPER 80S
SOUTHEAST. LOWS IN THE MID/UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 320 AM TUESDAY...
STRONG UPPER LEVEL RIDGING ALONG THE SOUTHEAST COAST SHOWS SOME
SIGNS OF WEAKENING BY THURSDAY BUT IS STILL STRONG ENOUGH TO DEFLECT
THE SHORTWAVE CURRENTLY OVER THE CENTRAL PLAINS NORTH TOWARD THE
GREAT LAKES AND KEEP THE ASSOCIATED FRONTAL ZONE TO OUR NORTHWEST.
THOUGH FORCING OVER CENTRAL NC WILL BE WEAK ON THURSDAY...A WEAK
REMNANT SHEAR AXIS AMIDST PW OVER 1.5 INCHES AND 600 TO 1200 J/KG OF
MLCAPE...HIGHEST OVER THE WESTERN PIEDMONT...SHOULD LEAD TO
INCREASED...THOUGH STILL SCATTERED COVERAGE OF AFTERNOON
SHOWERS/STORMS. SHEAR WILL BE WEAK WITH THE UPPER TROUGH AND
STRONGEST WESTERLIES WELL WEST OF THE MOUNTAINS...SO SEVERE STORMS
WILL BE LIMITED.
THE UPPER RIDGE THEN LOOKS TO BUILD BACK SLIGHTLY FRIDAY INTO THE
WEEKEND WITH A LITTLE DRIER AIR ACTUALLY FORECAST TO FILTER IN FROM
THE EAST ON FRIDAY. THUS EXPECT MAINLY ISOLATED SHOWERS AND STORMS
FRIDAY AND SATURDAY AS THE AIRMASS SLOWLY RE-MOISTENS THROUGH THE
WEEKEND. ANOTHER SHORTWAVE AND COLD FRONT ARE FORECAST TO MOVE INTO
THE MIDWEST STATES EARLY NEXT WEEK...AND WHILE IT IS UNCERTAIN
WHETHER THAT FRONT WILL MAKE IT ALL THE WAY INTO NC AS WELL...THE
CHANCES OF CONVECTION WILL INCREASE FROM NORTH TO SOUTH SUNDAY
THROUGH TUESDAY.
THICKNESSES ARE PROJECTED TO BE NEARLY UNCHANGED THROUGH THE
PERIOD...WITH HIGHS MOSTLY IN THE MID TO UPPER 80S NEARLY
EVERYDAY...WITH SOME AREAS IN THE SOUTH REACHING 90 ON SATURDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 200 PM TUESDAY...
FOR THE 18Z VALID TAF PERIOD...VFR CONDITIONS OUTSIDE OF ANY MOSTLY
ISOLATED...DEEP CONVECTION SHOULD PERSIST THROUGH MUCH OF TONIGHT.
AS OF THIS WRITING...ISOLATED TO SCATTERED SHOWERS WERE NOTED TOWARD
KCTZ...AND DURING THIS EVENING WITH A WEAK SHORTWAVE MOVING NORTH
OVER THE WESTERN CAROLINAS...ISOLATED TO SCATTERED SHOWERS MAY OCCUR
MORE TOWARD THE TRIAD. THERE EXISTS A MODEST PROBABILITY OF IFR
CONDITIONS IN LOW CLOUDS OVERNIGHT. SREF MODEL PROBABILITIES OF SUCH
ARE HIGH ESPECIALLY WEST OF INTERSTATE 95...HOWEVER...THE
STATISTICAL GUIDANCE IS NOT AS BULLISH AND MODEL SOUNDINGS FROM THE
GFS AND NAM DIFFER AS TO THE POTENTIAL OF LOW CLOUDS LATE. SINCE LOW
CLOUDS OCCURRED MAINLY TOWARD THE YADKIN RIVER AND THE TRIAD EARLY
THIS MORNING...THE OVERALL AIR MASS HAS MOISTENED...AND 925MB WINDS
SHOULD BE FAVORABLE OVERNIGHT...HAVE FORECAST IFR CONDITIONS BY 10Z
IN THE TRIAD AND AT KRDU...WITH TEMPORARY CONDITIONS OF SUCH AT KFAY
AND KRWI WHERE CONFIDENCE CURRENTLY IS NOT AS HIGH WITH LIGHTER
925MB WINDS AND LESSER PROBABILITIES EVEN ON THE AGGRESSIVE SREF.
DURING WEDNESDAY MORNING...ANY IFR CONDITIONS SHOULD LIFT AT LEAST
INTO MVFR...WITH SCATTERED SHOWERS BEGINNING TO DEVELOP TOWARD THE
END OF THE TAF PERIOD. ANY SOUTHWEST WIND GUSTS SHOULD BE LIMITED TO
THE LOWER TO MID TEENS KNOTS WITH MIXING WEDNESDAY AND BE BRIEF.
BEYOND THE 18Z VALID TAF PERIOD...THE LATEST MODEL SOUNDINGS SUGGEST
THAT LOW CLOUDS ARE POSSIBLE AGAIN THURSDAY MORNING...THOUGH WITH A
BETTER PROBABILITY TOWARD KFAY AND KRWI RELATIVE TO THE REST OF
CENTRAL NORTH CAROLINA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS ARE ALSO POSSIBLE. LOWEST CHANCES OF THOSE
APPEAR TO BE SATURDAY WHEN THE AIR MASS IS RELATIVELY MORE STABLE
COMPARED TO OTHER DAYS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/CBL
SHORT TERM...CBL
LONG TERM...BLS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
125 PM CDT TUE MAY 26 2015
.UPDATE...
ISSUED AT 121 PM CDT TUE MAY 26 2015
NO SIGNIFICANT CHANGE WITH THIS FORECAST UPDATE AS CUMULUS FIELDS
ARE JUST BEGINNING TO FORM ACROSS THE AREA AS OF 18 UTC. THE
15-17 UTC HRRR RUNS CONTINUE TO DEPICT SCATTERED CONVECTIVE
DEVELOPMEMT WITH FURTHER HEATING...ESPECIALLY ALONG AND EAST OF
HIGHWAY 83 AFTER 19-20 UTC.
UPDATE ISSUED AT 952 AM CDT TUE MAY 26 2015
GIVEN TRENDS IN THE 11-13 HRRR ITERATIONS...AND 00 UTC WRF-
ARW/NMM...ALL OF WHICH PERFORMED WELL YESTERDAY...INCREASED POPS
ALONG AND EAST OF THE MISSOURI RIVER FOR THIS AFTERNOON AND EARLY
EVENING WITH SLIGHTLY HIGHER DEWPOINTS IN PLACE AND A TAD STRONGER
OVERALL FORCING. ACROSS THE WEST...CLOSER TO THE SURFACE RIDGE
AXIS...TRENDED POPS DOWN...WHICH IS IN AGREEMENT WITH THE 06 AND
INCOMING 12 UTC GLOBAL SUITES.
UPDATE
ISSUED AT 635 AM CDT TUE MAY 26 2015
ONLY UPDATE WAS TO EXPAND FOG WORDING SOUTHWEST. WILL ALSO ISSUE A
SPECIAL WEATHER STATEMENT FOR THIS AREA WITH WEB CAMS INDICATING
SOME AREAS OF DENSE FOG. AT THIS TIME DOES NOT APPEAR WIDESPREAD
ENOUGH FOR A DENSE FOG ADVISORY WITH VISIBILITIES FLUCTUATING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM CDT TUE MAY 26 2015
A NICE DAY WITH TEMPERATURES IN THE 70S AND 80S IS ON TAP FOR
WESTERN AND CENTRAL NORTH DAKOTA.
SOME ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AS DIURNAL
HEATING PROVIDES SOME INSTABILITY AND DIFFERENTIAL DIVERGENCE
PROVIDES ENOUGH LIFT ENHANCEMENT. THE 00 UTC WRFS AND THE LATEST
RAP RUN SHOWS ISOLATED CONVECTION DEVELOPING MAINLY OVER CENTRAL
NORTH DAKOTA THIS AFTERNOON AND DIEING OUT AROUND SUNSET.
HOWEVER...DUE TO THE BROAD AREA OF INSTABILITY AND DIVERGENCE
ALOFT...AND LOW CONFIDENCE IN ANY ONE PARTICULAR MODEL...WENT
AHEAD AND PUT IN POSSIBLE ISOLATED THUNDERSTORMS ACROSS ALL
WESTERN AND CENTRAL NORTH DAKOTA.
LATE TONIGHT A COLD FRONT WILL ENTER NORTHERN NORTH DAKOTA. SOME
ISOLATED SHOWERS ARE POSSIBLE EARLY TOMORROW MORNING NORTH. LEE
CYCLOGENESIS WILL ALSO OCCUR LATE TONIGHT INTO TOMORROW. A SURFACE
LOW IS PROGGED TO ENTER THE WESTERN DAKOTAS BY TOMORROW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 403 AM CDT TUE MAY 26 2015
TWO ACTIVE PERIODS...WITH A DRY AND COOL COUPLE OF DAYS IN THE
MIDDLE...WILL HIGHLIGHT THE LONG TERM PERIOD.
UPPER LEVEL LOW/SHORT WAVE TROUGH OVER THE PACIFIC NORTHWEST WILL
EJECT LEAD WAVES ACROSS THE DAKOTAS EACH BRINGING CHANCES FOR
PRECIPITATION WEDNESDAY-THURSDAY. BEST CHANCE FOR WIDESPREAD
RAINFALL AND SCATTERED THUNDERSTORMS LOOKS TO BE THE WEDNESDAY
AFTERNOON-EVENING PERIOD WHEN ONE OF THE MORE DEFINED S/WV
IMPULSES MOVES EAST ACROSS NORTH DAKOTA ALONG WITH AN AREA OF SFC
LOW PRESSURE. PARENT UPPER LOW IS PROJECTED TO REMAIN OFF TO OUR
SOUTH AS IT MOVES EAST INTO THE CENTRAL PLAINS TOWARDS THE END OF
THE WEEK. A STABLE AIRMASS ASSOCIATED WITH SURFACE HIGH PRESSURE
WILL DEVELOP FROM NORTH TO SOUTH LATE THURSDAY NIGHT INTO FRIDAY
ACROSS THE NORTHERN PLAINS...AND REMAINS IN PLACE THROUGH
SATURDAY. HIGHS FRI-SAT COMFORTABLE AT 55-65.
ROBUST RETURN FLOW SUNDAY INTO EARLY NEXT WEEK AS HIGH PRESSURE
MOVES OFF TO OUR EAST. STRONG MOISTURE ADVECTION ALONG WITH
HIGH TEMPERATURES WARMING INTO THE 70S TO LOWER 80S WILL RESULT
IN INCREASING INSTABILITY MONDAY INTO TUESDAY. 12Z GFS/EC PROJECT
ANYWHERE FROM 1500-3500 J/KG OF MUCAPE. BECOMES MORE INTERESTING
TUESDAY-WEDNESDAY WHEN FLOW ALOFT TRANSITIONS TO SOUTHWESTERLY.
LOTS OF UNCERTAINTY YET BUT SOMETHING WORTH KEEPING AN EYE ON OVER
THE NEXT SEVERAL DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 121 PM CDT TUE MAY 26 2015
VFR CONDITIONS EXPECTED AREA WIDE FOR TODAY OUTSIDE OF SCATTERED
SHOWERS AND THUNDERSTORMS THAT ARE EXPECTED TO DEVELOP THIS
AFTERNOON AND INTO THE EVENING...MAINLY ACROSS CENTRAL NORTH
DAKOTA. KMOT AND KJMS ARE THE MOST LIKELY TERMINALS TO BE
IMPACTED. ISOLATED SHOWERS AND THUNDERSTORMS MAY IMPACT THE KISN
TERMINAL TONIGHT AROUND 04-08 UTC. WILL ALSO MONITOR THE POTENTIAL
FOR PATCHY FOG DEVELOPMENT ACROSS THE AREA. HOWEVER...UNCERTAINTY
IS HIGH REGARDING FORMATION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
205 PM EDT TUE MAY 26 2015
.SYNOPSIS...
WARM AND HUMID AIR WILL REMAIN IN PLACE OVER THE MIDDLE OHIO VALLEY
THROUGH THE REST OF THE WEEK. AS UPPER LEVEL DISTURBANCES MOVE
THROUGH THE AREA...THERE WILL BE OCCASIONAL CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND WEDNESDAY...AND THEN AGAIN OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONVECTION HAS DEVELOPED SOUTH AND WEST OF THE FORECAST AREA AND
HAS ALREADY SPREAD INTO SOUTHERN COUNTIES. WITH HRRR AND RAP RUNS
BEING FAIRLY CONSISTENT AND RELIABLE IN THIS REGARD TODAY...THERE
IS ABOVE AVERAGE CONFIDENCE IN FORECAST. SHOWERS AND STORMS SHOULD
CONTINUE TO SPREAD EAST NORTHEAST THROUGH THE FORECAST AREA IN A
COUPLE OF BANDS/CLUSTERS AND PASS OFF TO THE EAST BY EARLY
EVENING. BULK SHEAR WILL BE 25 TO 30 KT. MID LEVEL LAPSE RATE MAY
IMPROVE SLIGHTLY BUT DO NOT EXPECT SUBSTANTIAL CHANGE. MAXIMUM IN
DCAPE SHOULD CONTINUE TO TRANSLATE EAST OUT AHEAD OF ACTIVITY.
STILL MONITORING FOR STRONG STORMS OVER THE NEXT SEVERAL HOURS
WITH A FEW SEVERE CELLS NOT OUT OF THE QUESTION. DAMAGING STRAIGHT
LINE WINDS REMAINS THE PRIMARY THREAT.
AFTER THIS PASSES THROUGH THE REGION THERE IS STILL SOME POTENTIAL
FOR ADDITIONAL SHOWERS AND THUNDERSTORMS OVERNIGHT. BUT IF THIS
DOES DEVELOP IT SHOULD BE WEAKER AND WITH LESS COVERAGE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ON WEDNESDAY...AN UPPER TROUGH WILL BE MOVING EAST INTO THE GREAT
LAKES REGION. INITIALLY FAIRLY WELL-DEFINED OVER THE UPPER
MISSISSIPPI VALLEY (AND HELPING TO DRIVE THE MORE ACTIVE WEATHER
ON TUESDAY)...THIS TROUGH WILL BE WASHING OUT AS IT PROGRESSES
AHEAD. STILL...IT WILL LEAVE THE MIDDLE OHIO VALLEY IN A FAVORABLE
AREA OF LIFT...THOUGH SURFACE FEATURES WILL BE LACKING AND THUS
FORCING MAY NOT BE PARTICULARLY WELL FOCUSED. WHILE SHEAR WILL
CONTINUE TO BE MODEST...INSTABILITY SHOULD ACTUALLY INCREASE
SLIGHTLY FROM TUESDAY...WITH MLCAPE VALUES PERHAPS APPROACHING
2000 J/KG IN THE SOUTHWESTERN SECTIONS OF THE CWA (AND UP TO 1500
J/KG ELSEWHERE). THUS...AMONG THE SCATTERED THUNDERSTORMS THAT
DEVELOP...A FEW STRONG TO POSSIBLY SEVERE STORMS MAY OCCUR.
AS THE AFOREMENTIONED TROUGH CONTINUES TO WEAKEN AND MOVE
EAST...THE ILN FORECAST AREA WILL END UP IN A REGIME OF BUILDING
RIDGING ALOFT...AND A WEAK/NEBULOUS AREA OF HIGH PRESSURE AT THE
SURFACE. BY THURSDAY...THIS WILL BEGIN TO LIMIT THE CHANCES FOR
CONVECTION...WITH DIURNAL DEVELOPMENT ONLY APPEARING TO BE A
POSSIBILITY IN THE SOUTHERN HALF OF THE FORECAST AREA. FRIDAY WILL
LIKELY BEGIN DRY AS WELL...THOUGH THE FLOW WILL BE SWITCHING BACK
TO THE SOUTH IN THE SECOND HALF OF THE DAY...LEAVING A POSSIBILITY
FOR SOME DEVELOPMENT (ESPECIALLY FOR THE SOUTHWESTERN HALF OF THE
FORECAST AREA) BY LATE AFTERNOON AND EVENING. TO NOTE...THE GFS
HAS BEEN A LITTLE MORE AGGRESSIVE THAN OTHER MODELS WITH THE
SOUTHWARD PUSH OF THE AREA OF HIGH PRESSURE INTO THE OHIO
VALLEY...AND WOULD SUPPORT AN EVEN DRIER FORECAST FOR THURSDAY AND
THE FIRST HALF OF FRIDAY.
TEMPERATURES AND DEWPOINTS ARE EXPECTED TO CHANGE VERY LITTLE OVER
THE COURSE OF THE WEEK. A VERY SLIGHTLY DRIER AIR MASS WILL BE
SETTLING IN ON THURSDAY AND INTO FRIDAY...WHICH MAY ALLOW SOME
SLIGHTLY COOLER MIN TEMPS ON FRIDAY MORNING. OTHERWISE...MIN TEMPS
WILL LIKELY NOT DROP BELOW THE MID 60S. MAX TEMPS SHOULD REMAIN
AROUND 80 DEGREES...BUT CONVECTION AND CLOUDS (OR A LACK THEREOF)
COULD HAVE AN IMPACT IN EITHER DIRECTION...ESPECIALLY TODAY
(TUESDAY) AND WEDNESDAY. FRIDAY MAY BE THE WARMEST DAY OF THE
WEEK...WITH DRY AND SUNNY CONDITIONS TO BEGIN THE DAY...WITH WARM
ADVECTION KICKING IN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MID/UPPER LEVEL FLOW WILL BECOME MORE AMPLIFIED THROUGH THE
WEEKEND AS SHORT WAVE ENERGY MOVES OUT OF THE ROCKIES AND INTO THE
CENTRAL PLAINS. THIS WILL EVENTUALLY LEAD TO A FRONTAL BOUNDARY
PUSHING DOWN TOWARD AND POSSIBLY THROUGH OUR FA THROUGH EARLY NEXT
WEEK. HOWEVER...THERE REMAINS QUITE A BIT OF DIFFERENCE BETWEEN
THE ECMWF/GFS/CMC WITH HOW FAST AND HOW FAR SOUTH TO PUSH THE
FRONT AND WHETHER OR NOT TO STALL IT OUT ACROSS OUR AREA TOWARD
THE END OF THE PERIOD. THIS WILL LEAD TO THE POTENTIAL FOR A
FAIRLY WET/MORE ACTIVE PERIOD THROUGH THE END OF THE LONG TERM BUT
DUE TO THE TIMING UNCERTAINTIES...WILL JUST KEEP POPS IN THE HIGH
CHANCE CATEGORY.
FRIDAY WILL BE SEASONABLY WARM WITH HIGHS IN THE MID 80S. MORE
SEASONABLE TEMPERATURES WILL THEN BEGIN TO PUSH DOWN FROM THE NORTH
OVER THE WEEKEND...BUT THEY WILL ULTIMATELY BE DICTATED BY THE
PLACEMENT/TIMING OF THE FRONTAL BOUNDARY. FOR THAT REASON...HAVE
GENERALLY GONE WITH A MODEL BLEND FOR TEMPERATURES SATURDAY THROUGH
MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
CONVECTION DEVELOPING ACROSS THE REGION WILL POTENTIALLY AFFECT
ALL TERMINALS DURING THE EARLY PART OF THE TAF PERIOD. HEAVIEST
DOWNPOURS COULD BRIEFLY REDUCE VISIBILITY TO IFR. BUT FELT THAT
MVFR CONDITIONS WITH THE STORMS WAS MORE LIKELY. SOME SHOWERS OR
POSSIBLY THUNDERSTORMS COULD LINGER AFTER 00Z. BUT AT THIS POINT
THE POTENTIAL WAS LOW ENOUGH TO NOT HAVE FURTHER MENTION WITHIN
THE TAFS.
GUIDANCE IS SUGGESTING THAT LOW LEVEL MOISTURE WILL INCREASE LATE
TONIGHT. SIGNALS ARE MIXED ON WHETHER THAT WILL MANIFEST ITSELF
AS CLOUDS OR MIST OR BOTH. FORECAST CONTINUES WITH STRATUS AROUND
MVFR/IFR THRESHOLD. EXCEPTION IS FOR CINCINNATI TERMINALS WHERE
MIST/FOG MAY BE A BETTER POSSIBILITY.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY AFTERNOON AND EVENING
AND AGAIN SATURDAY INTO SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...JGL
AVIATION...
AREA FORECAST DISCUSSION
NWS MEDFORD OR
232 PM PDT TUE MAY 26 2015
.SHORT TERM...AN UPPER LOW IS CENTERED OVER WESTERN WASHINGTON
AND EXTREME NORTHEAST OREGON. THIS LOW WILL BRING WEAK SHORTWAVES
AND WESTERLY MOISTURE INTO SOUTHEAST PORTIONS OF THE AREA THIS
AFTERNOON AND EVENING AND MAY ALLOW SOME SHOWERS AND
THUNDERSTORMS TO DEVELOP, MAINLY IN SOUTHEAST SISKIYOU AND MODOC
COUNTIES. MODELS CONTINUE TO INDICATE THAT THE THERMODYNAMICS,
ALTHOUGH SLIGHTLY WEAKER THAN YESTERDAY, WOULD SUPPORT SOME
SHOWERS AND THUNDERSTORMS OVER THESE AREAS IN NORTHERN CALIFORNIA
THIS AFTERNOON AND EVENING. HOWEVER, LIGHTNING GUIDANCE AND HIGH
RESOLUTION HRRR MODEL OUTPUT INDICATES THAT ACTIVITY MAY REMAIN
ISOLATED OVER THE CWA. SOME ISOLATED STORMS ARE ALSO POSSIBLE IN
THE SOUTHEAST LAKE COUNTY BUT ELSEWHERE IN SOUTHERN OREGON EXPECT
DRY WEATHER THIS EVENING. SHOWERS AND THUNDERSTORMS WILL DIMINISH
BY LATE EVENING.
THEN AS THE UPPER LOW GRADUALLY SHIFTS EASTWARD AND BECOMES
CENTERED OVER IDAHO ON WEDNESDAY, EXPECT MAINLY DRY CONDITIONS
WITH ONLY A SLIGHT CHANCE FOR SOME ISOLATED SHOWER OR
THUNDERSTORM ACTIVITY IN THE AREA ON WEDNESDAY. THE POTENTIAL FOR
ACTIVITY IS MAINLY LIMITED TO NORTHERN CALIFORNIA AND INTO THE
CASCADES AND NORTHERN KLAMATH COUNTY ON WEDNESDAY AFTERNOON AND
EVENING. LATE WEDNESDAY INTO THURSDAY AN UPPER RIDGE WILL MOVE
INTO THE AREA. THIS WILL BRING WARMING TEMPERATURES ACROSS INLAND
AREAS. A SLIGHT CHANCE FOR SHOWER AND THUNDERSTORM ACTIVITY
CONTINUES THOUGH ON THURSDAY AS A SHORTWAVE MOVES INTO THE AREA
AND WEAK DAYTIME INSTABILITY IS FORECAST OVER THE AREA. THIS
SLIGHT CHANCE FOR THUNDERSTORMS IS MAINLY OVER THE CASCADES AND
OVER SOME OF THE HIGHER TERRAIN EAST OF THE CASCADES.
THEN FRIDAY THROUGH SATURDAY...A PACIFIC LOW WILL APPROACH FROM
THE WEST...REACHING THE COAST ON SUNDAY. AHEAD OF THIS LOW EXPECT
A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS FRIDAY AND SATURDAY
ACROSS MUCH OF THE AREA AS SHORTWAVES MOVE INTO THE AREA WITH
MOIST SOUTHERLY FLOW. CURRENT MODEL RUNS INDICATE THE AREA FOR
POTENTIAL SHOWERS AND THUNDERSTORMS ON FRIDAY AND SATURDAY WILL
BE MAINLY OVER WESTERN AND CENTRAL SISKIYOU COUNTY...NORTHWARD
INTO JACKSON COUNTY...AND INTO THE SOUTHERN OREGON CASCADES AND
EASTWARD INTO NORTHERN KLAMATH COUNTY. HOWEVER CONFIDENCE IN THE
EXACT AREA FOR SHOWER AND THUNDERSTORM DEVELOPMENT IS RELATIVELY
LOW SINCE THE TIMING AND TRACK OF ANY SHORTWAVES MAY ALTER.
CONFIDENCE IS SOMEWHAT HIGHER FOR SHOWERS AND THUNDERSTORMS TO
DEVELOP ON SATURDAY, DUE TO THE LOW MOVING CLOSER TO THE COAST AND
INCREASING MOISTURE AND SHORTWAVES EXPECTED AT THIS TIME.
OVERNIGHT SATURDAY, MODELS SHOW SOME WEAK INSTABILITY...EMBEDDED
SHORTWAVES...AND INCREASED SOUTHERLY MOISTURE OVER THE AREA WITH A
POTENTIAL SHOWERS OR THUNDERSTORMS IN CENTRAL PORTIONS OF THE
AREA, MAINLY NEAR THE SOUTHERN OREGON CASCADES AND THE SISKIYOUS.
SO HAVE KEPT A SLIGHT CHANCE OF SHOWER AND THUNDERSTORMS IN PLACE
SATURDAY NIGHT.
.LONG TERM...THE UPPER LOW WILL APPROACH THE COAST OF SOUTHERN
OREGON AND NORTHERN CALIFORNIA SUNDAY AFTERNOON AND MOISTURE AND
DYNAMIC FORCING WILL INCREASE OVER THE AREA. THE PROBABILITY OF
THUNDERSTORMS IS EXPECTED TO REACH A PEAK SUNDAY AFTERNOON AND
EVENING AND HAS BEEN INCREASED OVER THE PREVIOUS FORECAST. A
RELATIVE BROAD BRUSH OF A SLIGHT CHANCE TO A CHANCE OF
THUNDERSTORMS WAS UTILIZED AS MODEL DIFFERENCES INCREASE REGARDING
THE SPEED/POSITIONING OF THE UPPER TROUGH AS IT MOVES INLAND
SUNDAY EVENING. AS ITS TYPICAL BIAS, THE GFS IS MORE PROGRESSIVE
AND WOULD FOCUS ACTIVITY OVER CENTRAL PORTIONS OF THE AREA,
INITIALLY WEST OF THE CASCADES THEN INTO EASTERN AREA BY SUNDAY
EVENING. MEANWHILE, THE SLOWER ECMWF HAS A FOCUS ON THE WEST
SIDE THROUGH SUNDAY EVENING. GIVEN THE ANTECEDENT SPELL OF HOT
TEMPERATURES, THIS IS A LARGE ENOUGH TROUGH WITH A LIKELY
SUBSTANTIAL ENOUGH INCREASE OF MOISTURE THAT THUNDERSTORM ACTIVITY
MAY END UP AS SCATTERED ACROSS ALL OF OUR AREA INLAND FROM THE
COOLER/LESS UNSTABLE COAST. OVERNIGHT SUNDAY...HAVE KEPT SHOWERS
AND THUNDERSTORMS IN THE FORECAST AS THE LOW IS EXPECTED TO BE
CENTERED NEAR OR OVER THE AREA.
WITH BOTH THE GFS AND ECMWF SHOWING EASTWARD PROGRESSION OF THE
TROUGH SUNDAY NIGHT INTO MONDAY, THERE IS AN INCREASED
PROBABILITY THAT THE FOCUS OF THUNDERSTORMS WILL SHIFT TO THE
CASCADES AND EAST SIDE. WITH AT LEAST A PORTION OF THE LOW LIKELY
TO BE OVER THE AREA, THIS WILL BRING COOLING, INCREASED CLOUD
COVER, AND A MORE FREQUENT OCCURRENCE OF SHOWERS.
BY DAY 7, TUESDAY, UNCERTAINTY IS HIGH AS THE GFS SOLUTION SENDS THE
UPPER LOW EAST OF OUR REGION WHILE THE ECMWF SUGGESTS IT WILL LINGER
OVER THE REGION. THUS, A SLIGHT CHANCE OF AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS WAS MAINTAINED WITH A FOCUS ON THE EAST
SIDE. -DW/CC
&&
.AVIATION...ALONG THE COAST...VFR CONDITIONS WILL PERSIST INTO
EARLY THIS EVENING. THEN EXPECT MVFR/IFR CIGS TO REDEVELOP ALONG
THE COAST AROUND 02-03Z AND BECOME WIDESPREAD LATE IN THE EVENING
THROUGH WEDENSDAY MORNING. INLAND...CONDITIONS WILL REMAIN VFR
THROUGH THIS EVENING, EXCEPT FOR SOME ISOLATED MFR CIGS IN
NORTHERN DOUGLAS COUNTY THROUGH AROUND 23Z. SOME ISOLATED
THUNDERSTORMS ARE EXPECTED OVER SISKIYOU AND MODOC COUNTIES THIS
AFTERNOON AND EARLY THIS EVENING. THEN EXPECT MVFR WITH LOCAL IFR
CIGS TO REDEVELOP IN THE COQUILLE VALLEY TO THE UMPQUA BASIN LATE
TONIGHT AND WEDNESDAY MORNING WITH VFR CONTINUING ELSEWHERE. /CC
&&
.MARINE...UPDATED 130 PM PDT TUESDAY 26 MAY 2015...SURFACE HIGH
PRESSURE WILL REMAIN ANCHORED BETWEEN 130W AND 140W THROUGH THE
REMAINDER OF THE WEEK. LOW PRESSURE JUST INLAND THIS AFTERNOON WILL
KEEP MODERATE NORTH WINDS AND STEEP, WIND DRIVEN SEAS GOING OVER THE
WATERS SOUTH OF CAPE BLANCO THROUGH THIS EVENING. LOW PRESSURE MOVES
FURTHER INLAND TONIGHT ALLOWING WINDS TO WEAKEN, BUT SEAS WILL
REMAIN STEEP AND CHOPPY THROUGH THURSDAY. NORTH WINDS AND CHOPPY
SEAS WILL CONTINUE THROUGH THE UPCOMING WEEKEND, HOWEVER CONDITIONS
ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS. -WRIGHT
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT WEDNESDAY FOR
PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THURSDAY
FOR PZZ356-376.
$$
CC/DW/WRIGHT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
354 PM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE AT THE SFC AND ALOFT WILL REMAIN ANCHORED JUST OFF
THE EAST COAST THROUGH THE END OF THIS WEEK. A COLD FRONT WILL
LIKELY PUSH ACROSS THE REGION SATURDAY NIGHT...THEN STALL JUST
SOUTH OF THE STATE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
DEEP SOUTH-SOUTHWESTERLY FLOW ON THE WESTERN PERIPHERY OF THE
DOMINANT COAST RIDGE WILL CONTINUE TO TRANSPORT GULF OF MEX
MOISTURE NORTHWARD INTO CENTRAL PA.
WATER VAPOR LOOP AND RAP 300-400 MB WIND PROGS INDICATE THAT A
WELL-DEFINED...ALBEIT COMPACT SHORT WAVE WILL BE MOVING NE ACROSS
LAKE ERIE LATE THIS AFTERNOON...WHILE AN ASSOCIATED 45-50 KT
JETLET CROSSES NRN AND WRN PENN.
ENHANCED MESOSCALE LIFT FROM THIS FEATURE WILL TEAM UP WITH THE
GROWING CAPE VALUES /LOCALLY AS HIGH AS 1000-1500 J/KG/ ACROSS
THE ALLEGHENY PLATEAU TO PRODUCE INCREASINGLY NUMEROUS
SHOWERS...AND A FEW TSRA LATE THIS AFTERNOON AND EARLY THIS
EVENING.
BLEND OF THE LATEST NAM/SREF AND HRRR CONTINUE TO FAVOR THE NRN
MTNS...AND PORTIONS OF THE LAUREL HIGHLANDS FOR THE GREATEST CHC
OF SHOWERS/SCTD TSRA.
FOR AREAS SOUTH AND EAST OF KCBE TO KSEG AND KAVP LINE...THE
PERIOD THROUGH 21Z SHOULD REMAIN DRY. HOWEVER...DIFFERENTIAL
HEATING AT THE SE EDGE OF THE MID LEVEL CLOUD SHIELD...AND A
RIBBON OF HIGHEST 850 MB THETA-E AIR ADVECTING EAST INTO THE
MIDDLE SUSQ VALLEY SHOULD HELP TO FOCUS AND ENHANCE ANOTHER AREA
OF SHOWERS THERE LATE TODAY.
SPC PAINTS THEIR MARGINAL RISK OF SVR TSRA ACRS ROUGHLY THE WRN
HALF OF PENN THIS AFTERNOON AND EVENING.
BASIN AVG RAINFALL WILL BE GENERALLY AROUND 0.10 OF AN INCH IN
MOST PLACES THROUGH MIDNIGHT...WITH SOME SPOTTY 0.25-0.50 INCH
AMOUNTS IN TSRA.
TEMPS ARE NEARING THEIR HIGHS FOR THE DAY RANGING FROM THE MID-
UPR 70S OVR THE ALLEGHENY PLATEAU...TO THE M80S ACROSS THE LOWER
SUSQ VALLEY.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
DIURNALLY-DRIVEN CONVECTION WILL DIE OFF AFTER SUNSET THIS
EVENING. THE REST OF THE NIGHT WILL LIKELY FEATURE WARM AND
TRANQUIL CONDS WITH VARIABLE AMOUNTS OF MAINLY ALTO CU CLOUDS.
SOME LOWER OROGRAPHICALLY GENERATED CLOUDS AND HAZE ARE POSSIBLE
BEFORE DAYBREAK...ESPECIALLY ACROSS THE WEST FACING SLOPES OF THE
LAURELS AND NW MTNS WHERE LLVL WINDS WILL VEER AROUND TO THE WSW
AROUND 10Z.
HIGH PWAT AIR MASS WILL RESULT IN MID SUMMER MIN TEMPS...WITH
LOWS IN THE M/U60S MOST PLACES.
A FEW ILL-DEFINED/VERY WEAK AND SMALL SCALE SHORT WAVES LIFTING
NORTH ACROSS THE CENTRAL APPALACHIANS IN THE HEAT OF THIS SOUPY
AIRMASS COULD SPARK SOME ISOLATED SHOWERS...BUT POPS AFTER
MIDNIGHT TONIGHT WILL BE GENERALLY BELOW 20 PERCENT.
A MORE POTENT SHORTWAVE LIFTING THRU THE GRT LKS WILL INTRODUCE A
BETTER CHC OF SHRA/TSRA ON WEDNESDAY. MDL TIMING OF THIS FEATURE
SUGGESTS SHOWERS COULD ARRIVE EARLY IN THE DAY ACROSS THE W
COUNTIES...WITH A GREATER RISK OF PM TSRA ACROSS EASTERN PA.
GEFS MEAN CAPES PEAK ARND 1200 J/KG ACROSS THE SE COUNTIES WED
AFTN. HOWEVER...MID LVL WINDS AND ASSOCIATED DEEP-LYR SHEAR ARE
NOT PARTICULARLY STRONG IN THE LATEST MDL DATA...SO THE SVR WX
THREAT JUST MRGL...AND THAT`S WHAT SPC COVERS PRACTICALLY ALL OF
THE CWA WITH IN THEIR DAY 2 CONVECTIVE OUTLOOK.
MCLDY SKIES WILL HOLD TEMPS DOWN A BIT...BUT CONSALL STILL
SUGGESTS HIGH TEMPS BTWN THE M70S- L80S...SEVERAL DEG ABV NORMAL
FOR LATE MAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
UPPER LEVEL TROUGH WILL DEEPEN AS IT PROPAGATES EASTWARD. EXPECT
COLD FRONT TO MOVE THROUGH PA...WEDNESDAY NIGHT INTO THURSDAY
MORNING. THIS WILL BRING NORTHWESTERLY FLOW AND COOLER AND DRIER
AIR. HIGH PRESSURE AT THE SURFACE AND ALOFT WILL BUILD OVER THE
REGION THROUGH FRIDAY...REDUCING ANY PRECIPITATION CHANCES THROUGH
THE LATTER HALF OF THE WEEK AS THE BULK OF MED RANGE GUIDANCE
IMPLIES DRIER WX AS LOWER PWAT AIR MASS WORKS INTO CENTRAL PA.
A COLD FRONT WILL LIKELY BRING AN END TO THE SUMMER-LIKE
WARMTH/HUMIDITY NEXT WEEKEND. A FAIR AMT OF AGREEMENT AMONG MED
RANGE GUIDANCE FOR RAINY WX SATURDAY NIGHT INTO SUNDAY ALONG AN
INCOMING FRONTAL BOUNDARY. SCATTERED SHOWERS COULD FOLLOW SUNDAY/MONDAY
AS WAVE OF LOW PRES RIDES EASTWARD ALONG STALLED FRONTAL BNDRY
SOUTH OF PA.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
VFR SHOULD CONTINUE FOR THE BULK OF THE TIME AT MOST SITES OVER
THE NEXT 24 HOURS. HIGHEST CONFIDENCE IN BRIEF 1-3HR PERIOD OF
3-6SM VISIBILITY RESTRICTIONS IN BR/HZ IS AT MDT/LNS AROUND
DAYBREAK TUESDAY. A SLIGHTLY LONGER...SEVERAL HOUR PERIOD OF MVFR
CIGS AND BORDERLINE VSBYS IS FCST INVOF KJST AND KBFD BETWEEN
08-15Z AS SFC WINDS VEER MORE TO A FAVORABLE WSW UPSLOPE COMPONENT.
BRIEF...15-30 MINUTE MVFR TO IFR CIGS AND SIMILAR VSBYS WILL
ACCOMPANY THE HEAVIER SHRA AND SCTD TSRA LATE THIS AFTERNOON AND
EARLY THIS EVENING. THESE REDUCTIONS IN CIGS AND VSBYS WILL BE
POSSIBLE AT ANY GIVEN AIRFIELD...BUT MAINLY IMPACTING AIRFIELDS
ACROSS THE NW HALF OF PENN.
BASED ON THE FAIRLY LOW COVERAGE OF THE TSRA EMBEDDED IN THE
FIELD OF MORE NUMEROUS SHOWERS...DECIDED NOT TO EXPLICITLY MENTION
TSTMS IN MOST OF TERMINALS AT THIS TIME...BUT DID INCLUDE VCTS AT
KUNV AND KIPT WHERE THE LATEST RUNS OF HIGH RESOLUTION MODELS
INDICATE THE BEST CHC OF THUNDER AND GREATEST DEG OF INSTABILITY.
A SUMMER-TIME PATTERN WILL PERSIST THROUGH THE WEEK WITH REPLAY
OF PATCHY MORNING FOG GIVING WAY TO VFR AND AFTN ISOLD-SCT TSTMS.
IT APPEARS THAT THE MORE DEFINED TSTM RISKS THIS WEEK WILL BE
WEDNESDAY AFTERNOON AND EVENING...AND AGAIN SATURDAY AFTERNOON AND
EVENING...ALONG AND AHEAD OF A RATHER STRONG COLD FRONT PRESSING
SE FROM THE GREAT LAKES.
OUTLOOK...
WED-FRI...PATCHY A.M. MVFR FOG/BR. ISOLD-SCT P.M. TSTMS.
SAT-SUN...PATCHY A.M. MVFR FOG/BR. SCT-NMRS P.M TSTMS W/COLD
FROPA...MAINLY 19Z SAT-01Z SUNDAY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...FITZGERALD/CERU
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
252 PM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE AT THE SFC AND ALOFT WILL REMAIN ANCHORED JUST OFF
THE EAST COAST THROUGH THE END OF THIS WEEK. A COLD FRONT WILL
LIKELY PUSH ACROSS THE REGION SATURDAY NIGHT...THEN STALL JUST
SOUTH OF THE STATE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
DEEP SOUTH-SOUTHWESTERLY FLOW ON THE WESTERN PERIPHERY OF THE
DOMINANT COAST RIDGE WILL CONTINUE TO TRANSPORT GULF OF MEX
MOISTURE NORTHWARD INTO CENTRAL PA.
WATER VAPOR LOOP AND RAP 300-400 MB WIND PROGS INDICATE THAT A
WELL-DEFINED...ALBEIT COMPACT SHORT WAVE WILL BE MOVING NE ACROSS
LAKE ERIE LATE THIS AFTERNOON...WHILE AN ASSOCIATED 45-50 KT
JETLET CROSSES NRN AND WRN PENN.
ENHANCED MESOSCALE LIFT FROM THIS FEATURE WILL TEAM UP WITH THE
GROWING CAPE VALUES /LOCALLY AS HIGH AS 1000-1500 J/KG/ ACROSS
THE ALLEGHENY PLATEAU TO PRODUCE INCREASINGLY NUMEROUS
SHOWERS...AND A FEW TSRA LATE THIS AFTERNOON AND EARLY THIS
EVENING.
BLEND OF THE LATEST NAM/SREF AND HRRR CONTINUE TO FAVOR THE NRN
MTNS...AND PORTIONS OF THE LAUREL HIGHLANDS FOR THE GREATEST CHC
OF SHOWERS/SCTD TSRA.
FOR AREAS SOUTH AND EAST OF KCBE TO KSEG AND KAVP LINE...THE
PERIOD THROUGH 21Z SHOULD REMAIN DRY. HOWEVER...DIFFERENTIAL
HEATING AT THE SE EDGE OF THE MID LEVEL CLOUD SHIELD...AND A
RIBBON OF HIGHEST 850 MB THETA-E AIR ADVECTING EAST INTO THE
MIDDLE SUSQ VALLEY SHOULD HELP TO FOCUS AND ENHANCE ANOTHER AREA
OF SHOWERS THERE LATE TODAY.
SPC PAINTS THEIR MARGINAL RISK OF SVR TSRA ACRS ROUGHLY THE WRN
HALF OF PENN THIS AFTERNOON AND EVENING.
BASIN AVG RAINFALL WILL BE GENERALLY AROUND 0.10 OF AN INCH IN
MOST PLACES THROUGH MIDNIGHT...WITH SOME SPOTTY 0.25-0.50 INCH
AMOUNTS IN TSRA.
TEMPS ARE NEARING THEIR HIGHS FOR THE DAY RANGING FROM THE MID-
UPR 70S OVR THE ALLEGHENY PLATEAU...TO THE M80S ACROSS THE LOWER
SUSQ VALLEY.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
DIURNALLY-DRIVEN CONVECTION WILL DIE OFF AFTER SUNSET THIS
EVENING. THE REST OF THE NIGHT WILL LIKELY FEATURE WARM AND
TRANQUIL CONDS WITH VARIABLE AMOUNTS OF MAINLY ALTO CU CLOUDS.
SOME LOWER OROGRAPHICALLY GENERATED CLOUDS AND HAZE ARE POSSIBLE
BEFORE DAYBREAK...ESPECIALLY ACROSS THE WEST FACING SLOPES OF THE
LAURELS AND NW MTNS WHERE LLVL WINDS WILL VEER AROUND TO THE WSW
AROUND 10Z.
HIGH PWAT AIR MASS WILL RESULT IN MID SUMMER MIN TEMPS...WITH
LOWS IN THE M/U60S MOST PLACES.
A FEW ILL-DEFINED/VERY WEAK AND SMALL SCALE SHORT WAVES LIFTING
NORTH ACROSS THE CENTRAL APPALACHIANS IN THE HEAT OF THIS SOUPY
AIRMASS COULD SPARK SOME ISOLATED SHOWERS...BUT POPS AFTER
MIDNIGHT TONIGHT WILL BE GENERALLY BELOW 20 PERCENT.
A MORE POTENT SHORTWAVE LIFTING THRU THE GRT LKS WILL INTRODUCE A
BETTER CHC OF SHRA/TSRA ON WEDNESDAY. MDL TIMING OF THIS FEATURE
SUGGESTS SHOWERS COULD ARRIVE EARLY IN THE DAY ACROSS THE W
COUNTIES...WITH A GREATER RISK OF PM TSRA ACROSS EASTERN PA.
GEFS MEAN CAPES PEAK ARND 1200 J/KG ACROSS THE SE COUNTIES WED
AFTN. HOWEVER...MID LVL WINDS AND ASSOCIATED DEEP-LYR SHEAR ARE
NOT PARTICULARLY STRONG IN THE LATEST MDL DATA...SO THE SVR WX
THREAT JUST MRGL...AND THAT`S WHAT SPC COVERS PRACTICALLY ALL OF
THE CWA WITH IN THEIR DAY 2 CONVECTIVE OUTLOOK.
MCLDY SKIES WILL HOLD TEMPS DOWN A BIT...BUT CONSALL STILL
SUGGESTS HIGH TEMPS BTWN THE M70S- L80S...SEVERAL DEG ABV NORMAL
FOR LATE MAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
HIGH PRES AT SFC AND ALOFT JUST OFF THE EAST COAST SHOULD KEEP
WARM/HUMID AIR OVR CENTRAL PA THRU THE END OF THE WEEK. PASSAGE
OF MID LVL SHORTWAVE ON THURSDAY SHOULD SUPPORT ADDITIONAL SCT
SHRA/TSRA THURSDAY. BY FRIDAY...BULK OF MED RANGE GUIDANCE IMPLIES
DRIER WX /ESP NORTHERN PA/...AS LOWER PWAT AIR MASS WORKS INTO
CENTRAL PA IN ASSOC WITH HIGH PRES WORKING ACROSS S ONTARIO INTO N
NEW ENG.
A COLD FRONT WILL LIKELY BRING AN END TO THE SUMMER-LIKE
WARMTH/HUMIDITY BY NEXT WEEKEND. A FAIR AMT OF AGREEMENT AMONG
MED RANGE GUIDANCE THAT A PERIOD OF RAINY WX COULD FOLLOW LATE
SUNDAY/MONDAY AS WAVE OF LOW PRES RIDES EASTWARD ALONG STALLED
FRONTAL BNDRY SOUTH OF PA.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
VFR SHOULD CONTINUE FOR THE BULK OF THE TIME AT MOST SITES OVER
THE NEXT 24 HOURS. HIGHEST CONFIDENCE IN BRIEF 1-3HR PERIOD OF
3-6SM VISIBILITY RESTRICTIONS IN BR/HZ IS AT MDT/LNS AROUND
DAYBREAK TUESDAY. A SLIGHTLY LONGER...SEVERAL HOUR PERIOD OF MVFR
CIGS AND BORDERLINE VSBYS IS FCST INVOF KJST AND KBFD BETWEEN
08-15Z AS SFC WINDS VEER MORE TO A FAVORABLE WSW UPSLOPE COMPONENT.
BRIEF...15-30 MINUTE MVFR TO IFR CIGS AND SIMILAR VSBYS WILL
ACCOMPANY THE HEAVIER SHRA AND SCTD TSRA LATE THIS AFTERNOON AND
EARLY THIS EVENING. THESE REDUCTIONS IN CIGS AND VSBYS WILL BE
POSSIBLE AT ANY GIVEN AIRFIELD...BUT MAINLY IMPACTING AIRFIELDS
ACROSS THE NW HALF OF PENN.
BASED ON THE FAIRLY LOW COVERAGE OF THE TSRA EMBEDDED IN THE
FIELD OF MORE NUMEROUS SHOWERS...DECIDED NOT TO EXPLICITLY MENTION
TSTMS IN MOST OF TERMINALS AT THIS TIME...BUT DID INCLUDE VCTS AT
KUNV AND KIPT WHERE THE LATEST RUNS OF HIGH RESOLUTION MODELS
INDICATE THE BEST CHC OF THUNDER AND GREATEST DEG OF INSTABILITY.
A SUMMER-TIME PATTERN WILL PERSIST THROUGH THE WEEK WITH REPLAY
OF PATCHY MORNING FOG GIVING WAY TO VFR AND AFTN ISOLD-SCT TSTMS.
IT APPEARS THAT THE MORE DEFINED TSTM RISKS THIS WEEK WILL BE
WEDNESDAY AFTERNOON AND EVENING...AND AGAIN SATURDAY AFTERNOON AND
EVENING...ALONG AND AHEAD OF A RATHER STRONG COLD FRONT PRESSING
SE FROM THE GREAT LAKES.
OUTLOOK...
WED-FRI...PATCHY A.M. MVFR FOG/BR. ISOLD-SCT P.M. TSTMS.
SAT-SUN...PATCHY A.M. MVFR FOG/BR. SCT-NMRS P.M TSTMS W/COLD
FROPA...MAINLY 19Z SAT-01Z SUNDAY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT/FITZGERALD
LONG TERM...FITZGERALD
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1213 PM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE AT THE SFC AND ALOFT WILL REMAIN JUST OFF THE EAST
COAST THROUGH THE END OF THE WEEK. A COLD FRONT WILL LIKELY PUSH
ACROSS THE REGION NEXT WEEKEND...THEN STALL JUST SOUTH OF THE
STATE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
DEEP SOUTH-SOUTHWESTERLY FLOW ON WESTERN PERIPHERY OF THE
DOMINANT COAST RIDGE WILL TRANSPORT GULF OF MEX MOISTURE
NORTHWARD INTO CENTRAL PA THROUGH TODAY.
WATER VAPOR LOOP AND RAP 300 MB WIND PROGS INDICATE THAT A WELL-
DEFINED...ALBEIT COMPACT SHORT WAVE WILL BE MOVING NE ACROSS LAKE
ERIE THIS AFTERNOON...WHILE THE LEFT EXIT REGION OF A 45-50 KT
JETLET CROSSES NWRN PENN.
ENHANCED MESOSCALE LIFT FROM THIS FEATURE WILL TEAM UP WITH THE
GROWING CAPE VALUES ACROSS THE ALLEGHENY PLATEAU TO PRODUCE
RATHER NUMEROUS SHOWERS...AND A FEW TSRA AFTER 17Z.
BLEND OF THE LATEST NAM/SREF AND HRRR CONTINUE TO FAVOR THE NRN
AND WRN MTNS OF OUR CWA FOR THE GREATEST CHC OF SHOWERS/SCTD
TSRA. FOR AREAS SOUTH AND EAST OF KCBE TO KSEG AND KAVP
LINE...THE PERIOD THROUGH 18Z SHOULD REMAIN DRY.
HOWEVER...DIFFERENTIAL HEATING AT THE SE EDGE OF THE MID LEVEL
CLOUD SHIELD SHOULD HELP TO FOCUS AND ENHANCE ANOTHER AREA OF
SHOWERS WILL SEE TRACKING NE ACROSS WEST VA AND THE BLUE RIDGE
COUNTRY OF VA. EXPECT SCATTERED TSRA TO DEVELOP INVOF FAVORABLE
OROGRAPHIC FORCING AND WITHIN HOLES IN THE MID AND HIGH CLOUD
DECK/.
RAMPED UP POPS FOR THIS AFTERNOON ACROSS THE CENTRAL AND NW ZONES
BY 30-50 PERCENT...BUT NOT NEARLY AS MUCH ACROSS THE SE ZONES
WHERE PWATS ARE STILL UNDER 1.5 INCHES AND WARMER TEMPS ALOFT WERE
PRESENT.
WILL TAKE A LOOK AT NEWEST HIGH RES MODEL DATA AND MONITOR RADAR
TRENDS FOR A POSSIBLE SIGNIFICANT INCREASE IN THE CHC FOR SHOWERS
AND SCATTERED TSRA ACROSS THE LOWER SUSQ VALLEY FOR THIS
AFTERNOON.
MEAN SREF/GEFS CAPES TOP OUT NR OR SLIGHTLY LESS THAN 1000 J/KG
THIS AFTN AND SHEAR NOT PARTICULARLY STRONG. HOWEVER...A FEW
STRONG TSRA ARE EXPECTED TO DEVELOP ACROSS THE CENTRAL AND WRN
MTNS OF PA WHERE A SEVERAL HOUR PERIOD OF MDT...DEEP LAYER SHEAR
WILL ACCOMPANY THE PASSAGE OF THE AFOREMENTIONED UPPER SHORT WAVE
AT THE TIME OF PEAK HEATING. SPC HAS SHIFTED THEIR MARGINAL RISK
OF SVR TSRA BACK ACRS CENTRAL PENN FOR THIS AFTERNOON AND EVENING.
A GOOD DEAL OF CU SHOULD DEVELOP BY MIDDAY BASED ON MDL
SOUNDINGS. TEMPS ARE LIKELY TO BE A BIT COOLER THAN MONDAY DUE TO
MORE CLOUDS...WITH MAXES FROM THE U70S OVR THE ALLEGHENY
PLATEAU...TO THE M80S ACROSS THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
DIURNALLY-DRIVEN CONVECTION SHOULD DIE OFF AFTER SUNSET THIS
EVENING. THE REST OF THE NIGHT WILL LIKELY FEATURE WARM AND
TRANQUIL CONDS. HIGH PWAT AIR MASS WILL RESULT IN MID SUMMER MIN
TEMPS...WITH LOWS IN THE M/U60S MOST PLACES.
A POTENT SHORTWAVE LIFTING THRU THE GRT LKS WILL INTRODUCE A
BETTER CHC OF SHRA/TSRA ON WEDNESDAY. MDL TIMING OF THIS FEATURE
SUGGESTS SHOWERS COULD ARRIVE EARLY IN THE DAY ACROSS THE W
COUNTIES...WITH A GREATER RISK OF PM TSRA ACROSS EASTERN PA. GEFS
MEAN CAPES PEAK ARND 1200 J/KG ACROSS THE SE COUNTIES WED AFTN.
HOWEVER...MID LVL WINDS AND ASSOC DEEP LYR SHEAR NOT PARTICULARLY
STRONG IN MDL DATA...SO SVR WX THREAT JUST MRGL. MCLDY SKIES WILL
HOLD TEMPS DOWN A BIT...BUT CONSALL STILL SUGGESTS HIGH TEMPS BTWN
THE M70S-L80S...SEVERAL DEG ABV NORMAL FOR LATE MAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRES AT SFC AND ALOFT JUST OFF THE EAST COAST SHOULD KEEP
WARM/HUMID AIR OVR CENTRAL PA THRU THE END OF THE WEEK. PASSAGE
OF MID LVL SHORTWAVE ON THURSDAY SHOULD SUPPORT ADDITIONAL SCT
SHRA/TSRA THURSDAY. BY FRIDAY...BULK OF MED RANGE GUIDANCE IMPLIES
DRIER WX /ESP NORTHERN PA/...AS LOWER PWAT AIR MASS WORKS INTO
CENTRAL PA IN ASSOC WITH HIGH PRES WORKING ACROSS S ONTARIO INTO N
NEW ENG.
A COLD FRONT WILL LIKELY BRING AN END TO THE SUMMER-LIKE
WARMTH/HUMIDITY BY NEXT WEEKEND. A FAIR AMT OF AGREEMENT AMONG
MED RANGE GUIDANCE THAT A PERIOD OF RAINY WX COULD FOLLOW LATE
SUNDAY/MONDAY AS WAVE OF LOW PRES RIDES EASTWARD ALONG STALLED
FRONTAL BNDRY SOUTH OF PA.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
VFR SHOULD CONTINUE FOR THE BULK OF THE TIME AT MOST SITES OVER
THE NEXT 24 HOURS. HIGHEST CONFIDENCE IN BRIEF 1-3HR PERIOD OF
3-6SM VISIBILITY RESTRICTIONS IN BR/HZ IS AT MDT/LNS AROUND
DAYBREAK TUESDAY.
BRIEF 15-30 MINUTE MVFR TO IFR CIGS AND SIMILAR VSBYS WILL
ACCOMPANY THE HEAVIER SHRA AND SCTD TSRA THIS AFTERNOON. THESE
REDUCTIONS IN CIGS AND VSBYS WILL BE POSSIBLE AT ANY GIVEN
AIRFIELD. BASED ON THE FAIRLY LOW COVERAGE OF THE TSRA EMBEDDED IN
THE FIELD OF MORE NUMEROUS SHOWERS...DECIDED NOT TO EXPLICITLY
MENTION TSTMS IN TERMINALS AT THIS TIME. UPCOMING 18Z TAF PACKAGE
MAY NEED TO INTRODUCE A VCTS FM GROUP...AS THE AREA OF GREATEST
TSRA DEVELOPMENT/CONCENTRATION CAN BE PINNED DOWN.
A SUMMER-TIME PATTERN WILL PERSIST THROUGH THE WEEK WITH REPLAY OF
PATCHY MORNING FOG GIVING WAY TO VFR AND AFTN ISOLD-SCT TSTMS. A
MORE DEFINED TSTM RISK SHOULD ARRIVE BY NEXT WEEKEND AS A COLD
FRONT PRESSES SEWD FROM THE GREAT LAKES.
OUTLOOK...
TUE-FRI...PATCHY A.M. MVFR FOG/BR. ISOLD-SCT P.M. TSTMS.
SAT-SUN...PATCHY A.M. MVFR FOG/BR. SCT-NMRS P.M TSTMS W/COLD
FROPA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...LAMBERT/GARTNER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
702 PM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A LINE OF SHOWERS/TSTMS STRETCHING FROM EASTERN GEORGIA INTO
NORTHERN FLORIDA CONTINUES TO MOVE SLOWLY EAST. BOTH THE RAP AND
H3R SHOW THIS ACTIVITY STRENGTHENING AFTER SUNSET AS IT INTERSECTS
THE SEA BREEZE LURKING ACROSS FAR INTERIOR SOUTHEAST GEORGIA. THIS
SCENARIO SEEMS PLAUSIBLE GIVEN CURRENT RADAR AND MESOSCALE TRENDS.
THE GRIDDED AND TEXT FORECASTS HAVE BEEN UPDATED TO INCREASE POPS
UP TO 40 PERCENT ACROSS THE FAR SOUTHWESTERN AREAS.
INSTABILITY PARAMETERS ARE RATHER ELEVATED WITH SBCAPES IN
EXCESS OF 2500 J/KG WITH DCAPES NEARING 1200 J/K. AN ISOLATED
STRONG TO SEVERE TSTM CAN NOT BE RULED OUT GIVEN THE LEVEL OF DCAPE
IN PLACE. DAMAGING WINDS, CLOUD TO GROUND LIGHTNING AND LOCALLY
HEAVY RAINFALL WILL BE THE PRIMARY HAZARDS. GIVEN THE WEAK SHEAR
IN PLACE, WELL- ORGANIZED SEVERE TSTMS APPEAR UNLIKELY ATTM,
ALTHOUGH MESOSCALE BOUNDARY INTERACTIONS COULD SUPPORT SHORT-TERM
CONVECTIVE CONGLOMERATIONS.
PATCHY FOG WILL BE POSSIBLE AGAIN INLAND LATE TONIGHT TOWARDS SUNRISE
WHERE TEMPERATURES ARE EXPECTED TO MEET/EXCEED CROSSOVER TEMPS AND
WHERE MORE SIGNIFICANT RAINFALL WILL HAVE FALLEN. TEMPERATURES
OVERNIGHT WILL BE QUITE MILD...WITH LOWS IN THE UPPER 60S/LOW
70S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...PART OF THE DEEP LAYERED MEAN ANTI-CYCLONE CENTERED OFF
THE SE COAST WILL GET NUDGED A BIT FURTHER INTO THE ATLANTIC IN
RESPONSE TO WEAK IMPULSES THAT IMPINGE ON THE WESTERN PERIPHERY OF
THIS LARGE SCALE FEATURE. UNDERNEATH AT THE SURFACE WE STILL FIND
SPRAWLING ATLANTIC HIGH PRESSURE ALIGNED ACROSS THE FORECAST
ZONES...BUT IN RESPONSE TO THE PERTURBATIONS ALOFT AND A SLIGHTLY
WEAKER RIDGE THERE IS ALSO A SUBTLE LEE SIDE TROUGH THAT IS ABLE TO
DEVELOP. OVERALL THERE IS STILL ENOUGH OF A CAP TO LIMIT HOW MUCH
CONVECTION IS ABLE TO DEVELOP...ESPECIALLY ACROSS OUR EASTERN
SECTIONS. BUT FURTHER INLAND THE MOISTURE PROFILES ARE A LITTLE
BETTER AND THE SUBSIDENCE IS LESS PRONOUNCED. WE HAVE OPTED FOR
SLIGHT CHANCE-CHANCE POPS MAINLY NEAR AND INLAND FROM I-95 FOR THE
LATE MORNING/AFTERNOON PERIOD WHERE WE FIND THE HIGHEST THETA-E AIR.
THE LACK OF SHEAR AND ONLY MODEST THERMODYNAMICS AT BEST WILL
SUPPORT LITTLE IF ANY RISK OF STRONG/SEVERE STORMS. WITHIN A SUB-
TROPICAL MARITIME AIR MASS OUR MAX TEMPS WILL PEAK IN THE MID-UPPER
80S AWAY FROM THE IMMEDIATE COAST. CONVECTION FAR INLAND WILL FADE
WITHIN THE NOCTURNAL STABILIZING INFLUENCES WEDNESDAY EVENING. WE/LL
MAINTAIN A WEATHER WATCH FOR POSSIBLE FOG NW TIER WHERE RAINS
OCCURRED EARLIER IN CONJUNCTION WITH LIGHT UPSLOPE FLOW. A LARGE
RANGE OF TEMPS FROM LOWER 60S NORMALLY COOL SPOTS TO 68-72 ON THE
BARRIER ISLANDS.
THURSDAY THROUGH FRIDAY...THE DEEP RIDGING GETS SHUNTED BACK A BIT
FURTHER WEST IN RESPONSE TO A DEEP CYCLONE AND IT/S ASSOCIATED
SURFACE WAVE CENTERED FAR EAST/NE OF THE BAHAMAS. INCREASING
SUBSIDENCE...THE LACK OF FORCING AND DIMINISHING MOISTURE SUGGESTS
THAT DIURNAL RAIN CHANCES WILL ONLY BE 20-30 PERCENT FAR INLAND
THURSDAY AND NO MORE THAN 10 PERCENT FRIDAY. VERY LITTLE
FLUCTUATIONS IN MAX/MIN TEMPS FROM RECENT DAYS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A BROAD UPPER RIDGE WILL EXIST FRIDAY NIGHT THROUGH SUNDAY BEFORE AN
UPPER TROUGH BEGINS TO PUSH INTO THE EASTERN UNITED STATES EARLY
NEXT WEEK. ALTHOUGH WEAK CAPPING WILL EXIST FOR THE BRUNT OF THE
PERIOD...ONSHORE MOISTURE FLUX WITH HIGH TEMPS IN THE UPPER 80S TO
NEAR 90 AND A DAILY SEA BREEZE WILL SUPPORT ISOLATED SHOWERS AND
TSTMS. A MORE PROMINENT UPPER TROUGH APPROACHING ON TUESDAY SHOULD
SUPPORT BETTER COVERAGE OF SHOWERS AND TSTMS.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
VFR THIS EVENING. THERE WILL BE AN INCREASING RISK FOR MVFR CIGS
AFTER MIDNIGHT...MAINLY AT KCHS. WILL INTRODUCE PREVAILING MVFR
CIGS AT KCHS FROM 09-13Z...BUT THIS MAY NEED TO BE ADJUSTED. ATTM
IT APPEARS KSAV WILL REMAIN MOSTLY VFR ALTHOUGH A BRIEF PERIOD OF
MVFR CIGS WILL BE POSSIBLE. WILL LEAVE KSAV VFR FOR NOW.
EXTENDED AVIATION OUTLOOK...MAINLY VFR THROUGH THE PERIOD.
&&
.MARINE...
TONIGHT...MARINE CONDITIONS WILL BE RATHER BENIGN TONIGHT AS
SURFACE HIGH PRESSURE REMAINS EAST OF THE WATERS. SOUTHEAST
ONSHORE FLOW OF 10-15 KT WILL DECREASE TO 5-10 KT LATE. SEAS WILL
BE 2-3 FT...EXCEPT IN THE OUTER GA WATERS WHERE 3-4 FT IS
EXPECTED.
WEDNESDAY THROUGH FRIDAY...A RATHER FLAT BUT ENORMOUS SUB-TROPICAL
RIDGE WILL MAINTAIN IT/S HOLD ACROSS THE COASTAL WATERS...GENERATING
A CONTINUOUS ONSHORE FLOW THROUGH THE PERIOD. EVEN WITH MINOR SEA
BREEZE INFLUENCES WINDS WILL HOLD UNDER 10 OR 15 KT. SEAS WILL BE A
MIX OF WIND-DRIVEN WAVES AND EVENTUALLY MORE SWELL ENERGY ARRIVING
DUE TO THE PERSISTENT EAST-SE FLOW. COMBINED SEAS WILL HOLD AT LESS
THAN OR EQUAL TO 3 OR 4 FT.
SATURDAY THROUGH MONDAY...SPRAWLING ATLANTIC HIGH PRESSURE WILL
CONTINUE TO CONTROL CONDITIONS LOCALLY AS IT LIES OVERHEAD INTO
EARLY NEXT WEEK. ONSHORE TRAJECTORIES WON/T OBTAIN ANYTHING MORE
THAN 10 OR 15 KT...AND WHILE SWELL ENERGY WILL BECOME MORE THE
DOMINANT FEATURE...SEAS ARE STILL MAINLY 4 FT OR LESS.
RIP CURRENTS...MARGINAL SWELLS AND ELEVATED ONSHORE WINDS WILL
CONTINUE TODAY SO WE MAINTAIN A MODERATE RISK ACROSS CHARLESTON
COUNTY BEACHES FOR THE REST OF THE DAYTIME.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
451 PM EDT TUE MAY 26 2015
.SYNOPSIS...
A BERMUDA HIGH PATTERN WILL PERSIST ACROSS THE SOUTHEAST STATES
THROUGH THE END OF THE WEEK. THIS WILL PRODUCE A MOIST SOUTHERLY
FLOW WITH INCREASED CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS
EACH DAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
430 PM UPDATE...THE NORTH END OF THE CONVECTIVE LINE OVER GEORGIA
HAS BEGUN TO WEAKEN LIKELY AS IT ENCOUNTERS MORE STABLE AIR OVER
THE NE GA PIEDMONT. HOWEVER THE SOUTH END OF THAT LINE IS
REORGANIZING ALONG A GUST FRONT OR POSSIBLY SEA BREEZE FRONT.
WHILE THE VORT MAXES ASSOC WITH THE SYNOPTIC SCALE SHORTWAVE
APPEAR TO BE ON TRACK TO PASS WEST OF THE MTNS THIS EVENING...MCVS
FROM THESE LINES WILL SWING OVER OUR CWFA. LATEST PROGS STILL
FEATURE INCREASING CAPE VALUES THRU THE EVENING WITH WEAK
ISENTROPIC LIFT AS WELL AS THE DYNAMIC LIFT HIGHER ALOFT. REVISED
POPS TO BRING THE NRN LINE IN OVER THE NEXT COUPLE HRS...AS WELL
AS TO REFLECT BETTER CHANCES OVER THE WRN UPSTATE WITH THIS NEW
SEGMENT ORGANIZING. SOME DISCRETE ACTIVITY WILL ALSO CONTINUE
PRIOR TO THE ARRIVAL OF THE LINES...BUT FROM THE LOOK OF THE CU
FIELD ON VIS SAT...WHICH DOES NOT LOOK CONGESTED OVER MUCH OF THE
AREA...THIS WILL MAINLY AFFECT JUST THE UPSTATE AS CELLS DEVELOP
OVER THE CSRA AND MIDLANDS AND MOVE N.
AS OF 230 PM EDT...DEEP SOUTHWEST FLOW HAS SET UP OVER THE FORECAST
AREA BETWEEN OFFSHORE HIGH PRESSURE AND A LOW PRESSURE SYSTEM
LIFTING NE FROM THE PLAINS. PRECIPITABLE WATER VALUES CONTINUE TO
INCREASE AND WILL MAXIMIZE AT NEARLY 1.75 INCHES OVER THE HEART OF
THE AREA TONIGHT. MEANWHILE...SEVERAL CONSECUTIVE RUNS OF THE HRRR
HAVE BEEN QUITE ACCURATE IN HANDLING THE WIDESPREAD CONVECTION
DEVELOPING OVER WRN GA THIS AFTN AS AN OUTFLOW BOUNDARY FROM EARLIER
DEEP SOUTH CONVECTION WORKS EAST. THE HRRR SHOWS THIS ACTIVITY
MOVING TOWARD THE UPPER SAVANNAH RIVER REGION AROUND 22Z AND THEN
ACROSS THE UPSTATE AND WRN NC THROUGH THE EVENING HOURS AND EARLY
OVERNIGHT. THIS IS CONSISTENT WITH THE EXPECTED ARRIVAL OF UPPER
DIVERGENCE OVER THE SOUTHERN APPALACHIANS THIS EVENING...ALONG WITH
A WEAK H5 VORITICITY LOBE. INSTABILITY WILL BE MARGINAL IN MOST
AREAS...BUT A LOBE OF BRIEFLY ENHANCED LOW LEVEL BULK SHEAR...AND
ANY OUTFLOW PUSH WITH THE ARRIVAL OF THE CONVECTION...COULD PRODUCE
MARGINALLY SEVERE WINDS INTO FAR SW SECTIONS THIS EVENING WITH ANY
STRONG TSRA. THE ACTIVITY SHOULD WANE OVERNIGHT WITH JUST LINGERING
SCATTERED SHOWERS EXPECTED. ANTICIPATE ANOTHER NIGHT OF VERY WARM
MIN TEMPS AS A BLANKET OF LOW CLOUDS FORMS IN THE MOIST BOUNDARY
LAYER.
ALTHOUGH THE H5 PATTERN WILL FLATTEN OUT SOMEWHAT THROUGH
WED...ADDITIONAL WEAK SHORTWAVES WILL MOVE OVER THE AREA IN THE
BROAD SW FLOW ALOFT...WITH DEEP MOISTURE PERSISTING. HEATING WILL
GET OFF TO A SLOW START AGAIN ON WED WITH THE ABUNDANT MORNING
CLOUDS...BUT SBCAPE VALUES SHOULD RISE TO 1500 J/KG OR BETTER BY WED
AFTN WITH ANY BREAKS GIVEN THE ELEVATED DEWPOINTS. ANTICIPATE HIGH
SCATTERED TO LOW LIKELY SHRA/TSRA COVERAGE IN THE MOIST AIRMASS ON
WED AFTN...BUT LOW LEVEL CONVERGENCE WILL LEAD TO THE BEST COVERAGE
OVER THE NC MTNS. TEMPS WILL STRUGGLE THROUGH THE 70S AGAIN TO MAX
OUT NEAR 80 EAST OF THE MTNS...LOWER 80S IN THE PIEDMONT.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AT 200 PM EDT TUESDAY...ON WEDNESDAY EVENING HIGH PRESSURE WILL BE
CENTERED OFF THE EAST COAST...WHILE WEAK UPPER TROUGHING WILL BE
OVER THE WESTERN USA...AND A SHORTWAVE MOVES ACROSS THE GREAT LAKES
AND OH RIVER VALLEY. THE SHORTWAVE MOVES OFF THE NEW ENGLAND COAST
ON THURSDAY...FOLLOWED BY RISING HEIGHTS ALOFT INTO FRIDAY.
AT THE SURFACE...ATLANTIC HIGH PRESSURE MAINTAINS A FOOTHOLD OVER
THE CAROLINAS AND GA FROM WEDNESDAY EVENING INTO FRIDAY...WHILE LOW
LEVEL MOISTURE REMAINS BANKED UP AGAINST THE SOUTHERN APPALACHIANS.
INSTABILITY IS EXPECTED TO BE SOMEWHAT LIMITED UNDER THE UPPER
RIDGE. WITH A LACK OF ISENTROPIC UPGLIDE...AND ONLY MODEST LOW LEVEL
UPSLOPE FLOW...PRECIPITATION SHOULD BE RATHER MODEST...AND GREATEST
NEAR THE BLUE RIDGE. TEMPERATURES WILL EXHIBIT A REDUCED DIURNAL
TREND DUE TO CLOUD COVER AND MOISTURE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AT 200 PM EDT TUESDAY...ON SATURDAY MORNING...HIGH PRESSURE WILL BE
CENTERED SOUTHEAST OF NEW ENGLAND AND ATLANTIC CANADA...WHILE UPPER
TROUGHING WILL EXTEND FROM HUDSON BAY TO THE SOUTHERN US PLAINS. THE
UPPER HIGH WILL VERY SLOWLY BREAKS DOWN....WHILE THE UPPER TROUGH
SLOWLY PROGRESSES...SUCH THAT BY TUESDAY THE UPPER TROUGH CROSSES
THE MS RIVER VALLEY.
AT THE SURFACE...ON SATURDAY HIGH PRESSURE WILL EXTEND FROM THE
WESTERN ATLANTIC TOT HE SOUTHERN APPALACHIANS....WHILE MODEST GULF
INFLOW EXISTS OVER THE GULF STATES...AND A COLD FRONT CROSSES THE
GREAT LAKES...MID MS RIVER VALLEY...AND SOUTHERN PLAINS. HIGH
PRESSURE STARTS TO WEAKEN OVER THE CAROLINAS AND GA ON SUNDAY...
WHILE THE APPROACHING FRONT STRETCHES FROM NEW ENGLAND TO THE OH
RIVER VALLEY. THE EASTERN PORTION OF THE FRONT STALLS TO OUR N ON
MONDAY...WHILE THE SOUTHERN PORTION MOVES INTO THE LOWER MS RIVER
VALLEY. MOIST INFLOW FROM THE ATLANTIC IMPROVES AHEAD OF THIS FRONT.
ON TUESDAY THE FRONT STALLS TO OUR N AND W.
WITH HEIGHTS FALLING ALOFT...AND INSTABILITY AND MOISTURE
INCREASING...CONVECTIVE CHANCES SHOULD IMPROVE WITH TIME. MOIST
INFLOW NEVER REALLY GETS ROBUST...SO PRECIPITATION IS NOT EXPECTED
TO BE EXCESSIVE ON A GRAND SCALE. TEMPERATURES WILL RUN WITHIN A FEW
DEGREES OF NORMAL.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
AT KCLT...ANTICIPATE MAINLY VFR CIGS THROUGH LATE DAY AS CONVECTIVE
CUMULUS ABOUNDS. THE HRRR SHOWS LINEAR CONVECTION OVER GA THIS AFTN
MAKING A RUN ACROSS THE SC UPSTATE AND THREATENING THE KCLT AIRFIELD
BY 02Z. SHRA ARE MORE LIKELY THAN TSRA WITH DIMINISHING
INSTABILITY...BUT THERE APPEARS ENOUGH UPPER FORCING AND LINGERING
MUCAPE TO EXPECT A COUPLE OF EMBEDDED TSRA WITHIN A RAIN SHIELD AS
THE FEATURES MOVE IN. OTHERWISE...WIDESPREAD MVFR CIGS SHOULD
DEVELOP ONCE AGAIN IN THE MOIST BOUNDARY LAYER...WITH A WINDOW OF
DAYBREAK IFR ONCE AGAIN POSSIBLE. CANNOT RULE OUT A LINGERING SHOWER
IN THE VICINITY AT JUST ABOUT ANY TIME DURING THE TAF PERIOD. EXPECT
STEADY S TO SW FLOW AT 10 KT OR LESS.
ELSEWHERE...LOWER VFR TO SPOTTY MVFR CIGS WILL PERSIST AROUND THE
REGION WITH ABUNDANT CONVECTIVE CUMULUS FORMING AT 3 TO 4 KFT. THE
HRRR SHOWS THE UPSTREAM CONVECTION OVER GA MAKING A RUN ACROSS THE
SW HALF OF THE FORECAST THIS EVENING BEFORE GRADUALLY WEAKENING
ACROSS THE NE PART OVERNIGHT. GIVEN THE TIMING...AND THE RELATIVE
CONSISTENCY OF THE HRRR SOLUTIONS...WILL PUSH THE TSRA INTO A TEMPO
GROUP FOR GENERALLY 00Z TO 04Z...A LITTLE SOONER AT KAND...AND WITH
JUST SHRA AT KHKY. EXPECT A QUICK TRANSITION TO MVFR
OVERNIGHT...ESPECIALLY IF WIDESPREAD RAINFALL DEVELOPS...WITH A
PERIOD OF DAYBREAK IFR EXPECTED. SCATTERED SHOWERS MAY CONTINUE TO
AFFECT THE AIRFIELDS AT JUST ABOUT ANY TIME THROUGHOUT THE TAF
PERIOD GIVEN THE MOIST PROFILES AND SW FLOW..
OUTLOOK...MOIST SW FLOW WILL CONTINUE TO AFFECT THE TERMINAL
FORECAST AREA RIGHT THROUGH THE UPCOMING WEEKEND...AS A COLD FRONT
LAYS OVER TO THE NORTH OF THE AREA. EXPECT MORNING STRATUS TO RESULT
EACH DAY...WITH CONTINUED BETTER THAN CLIMATOLOGICAL CHANCES OF
AFTN/EVENING SHRA/TSRA EACH DAY.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-18Z
KCLT HIGH 100% HIGH 98% MED 73% HIGH 82%
KGSP HIGH 100% HIGH 98% HIGH 88% HIGH 92%
KAVL HIGH 85% HIGH 89% HIGH 86% HIGH 90%
KHKY HIGH 100% HIGH 100% MED 78% HIGH 80%
KGMU HIGH 100% HIGH 100% HIGH 88% HIGH 87%
KAND HIGH 100% HIGH 100% HIGH 84% HIGH 87%
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...JPT
NEAR TERM...HG/WIMBERLEY
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG/WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
232 PM EDT TUE MAY 26 2015
.SYNOPSIS...
A BERMUDA HIGH PATTERN WILL PERSIST ACROSS THE SOUTHEAST STATES
THROUGH THE END OF THE WEEK. THIS WILL PRODUCE A MOIST SOUTHERLY
FLOW WITH INCREASED CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS
EACH DAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 230 PM EDT...DEEP SOUTHWEST FLOW HAS SET UP OVER THE FORECAST
AREA BETWEEN OFFSHORE HIGH PRESSURE AND A LOW PRESSURE SYSTEM
LIFTING NE FROM THE PLAINS. PRECIPITABLE WATER VALUES CONTINUE TO
INCREASE AND WILL MAXIMIZE AT NEARLY 1.75 INCHES OVER THE HEART OF
THE AREA TONIGHT. MEANWHILE...SEVERAL CONSECUTIVE RUNS OF THE HRRR
HAVE BEEN QUITE ACCURATE IN HANDLING THE WIDESPREAD CONVECTION
DEVELOPING OVER WRN GA THIS AFTN AS AN OUTFLOW BOUNDARY FROM EARLIER
DEEP SOUTH CONVECTION WORKS EAST. THE HRRR SHOWS THIS ACTIVITY
MOVING TOWARD THE UPPER SAVANNAH RIVER REGION AROUND 22Z AND THEN
ACROSS THE UPSTATE AND WRN NC THROUGH THE EVENING HOURS AND EARLY
OVERNIGHT. THIS IS CONSISTENT WITH THE EXPECTED ARRIVAL OF UPPER
DIVERGENCE OVER THE SOUTHERN APPALACHIANS THIS EVENING...ALONG WITH
A WEAK H5 VORITICITY LOBE. INSTABILITY WILL BE MARGINAL IN MOST
AREAS...BUT A LOBE OF BRIEFLY ENHANCED LOW LEVEL BULK SHEAR...AND
ANY OUTFLOW PUSH WITH THE ARRIVAL OF THE CONVECTION...COULD PRODUCE
MARGINALLY SEVERE WINDS INTO FAR SW SECTIONS THIS EVENING WITH ANY
STRONG TSRA. THE ACTIVITY SHOULD WANE OVERNIGHT WITH JUST LINGERING
SCATTERED SHOWERS EXPECTED. ANTICIPATE ANOTHER NIGHT OF VERY WARM
MIN TEMPS AS A BLANKET OF LOW CLOUDS FORMS IN THE MOIST BOUNDARY
LAYER.
ALTHOUGH THE H5 PATTERN WILL FLATTEN OUT SOMEWHAT THROUGH
WED...ADDITIONAL WEAK SHORTWAVES WILL MOVE OVER THE AREA IN THE
BROAD SW FLOW ALOFT...WITH DEEP MOISTURE PERSISTING. HEATING WILL
GET OFF TO A SLOW START AGAIN ON WED WITH THE ABUNDANT MORNING
CLOUDS...BUT SBCAPE VALUES SHOULD RISE TO 1500 J/KG OR BETTER BY WED
AFTN WITH ANY BREAKS GIVEN THE ELEVATED DEWPOINTS. ANTICIPATE HIGH
SCATTERED TO LOW LIKELY SHRA/TSRA COVERAGE IN THE MOIST AIRMASS ON
WED AFTN...BUT LOW LEVEL CONVERGENCE WILL LEAD TO THE BEST COVERAGE
OVER THE NC MTNS. TEMPS WILL STRUGGLE THROUGH THE 70S AGAIN TO MAX
OUT NEAR 80 EAST OF THE MTNS...LOWER 80S IN THE PIEDMONT.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AT 200 PM EDT TUESDAY...ON WEDNESDAY EVENING HIGH PRESSURE WILL BE
CENTERED OFF THE EAST COAST...WHILE WEAK UPPER TROUGHING WILL BE
OVER THE WESTERN USA...AND A SHORTWAVE MOVES ACROSS THE GREAT LAKES
AND OH RIVER VALLEY. THE SHORTWAVE MOVES OFF THE NEW ENGLAND COAST
ON THURSDAY...FOLLOWED BY RISING HEIGHTS ALOFT INTO FRIDAY.
AT THE SURFACE...ATLANTIC HIGH PRESSURE MAINTAINS A FOOTHOLD OVER
THE CAROLINAS AND GA FROM WEDNESDAY EVENING INTO FRIDAY...WHILE LOW
LEVEL MOISTURE REMAINS BANKED UP AGAINST THE SOUTHERN APPALACHIANS.
INSTABILITY IS EXPECTED TO BE SOMEWHAT LIMITED UNDER THE UPPER
RIDGE. WITH A LACK OF ISENTROPIC UPGLIDE...AND ONLY MODEST LOW LEVEL
UPSLOPE FLOW...PRECIPITATION SHOULD BE RATHER MODEST...AND GREATEST
NEAR THE BLUE RIDGE. TEMPERATURES WILL EXHIBIT A REDUCED DIURNAL
TREND DUE TO CLOUD COVER AND MOISTURE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AT 200 PM EDT TUESDAY...ON SATURDAY MORNING...HIGH PRESSURE WILL BE
CENTERED SOUTHEAST OF NEW ENGLAND AND ATLANTIC CANADA...WHILE UPPER
TROUGHING WILL EXTEND FROM HUDSON BAY TO THE SOUTHERN US PLAINS. THE
UPPER HIGH WILL VERY SLOWLY BREAKS DOWN....WHILE THE UPPER TROUGH
SLOWLY PROGRESSES...SUCH THAT BY TUESDAY THE UPPER TROUGH CROSSES
THE MS RIVER VALLEY.
AT THE SURFACE...ON SATURDAY HIGH PRESSURE WILL EXTEND FROM THE
WESTERN ATLANTIC TOT HE SOUTHERN APPALACHIANS....WHILE MODEST GULF
INFLOW EXISTS OVER THE GULF STATES...AND A COLD FRONT CROSSES THE
GREAT LAKES...MID MS RIVER VALLEY...AND SOUTHERN PLAINS. HIGH
PRESSURE STARTS TO WEAKEN OVER THE CAROLINAS AND GA ON SUNDAY...
WHILE THE APPROACHING FRONT STRETCHES FROM NEW ENGLAND TO THE OH
RIVER VALLEY. THE EASTERN PORTION OF THE FRONT STALLS TO OUR N ON
MONDAY...WHILE THE SOUTHERN PORTION MOVES INTO THE LOWER MS RIVER
VALLEY. MOIST INFLOW FROM THE ATLANTIC IMPROVES AHEAD OF THIS FRONT.
ON TUESDAY THE FRONT STALLS TO OUR N AND W.
WITH HEIGHTS FALLING ALOFT...AND INSTABILITY AND MOISTURE
INCREASING...CONVECTIVE CHANCES SHOULD IMPROVE WITH TIME. MOIST
INFLOW NEVER REALLY GETS ROBUST...SO PRECIPITATION IS NOT EXPECTED
TO BE EXCESSIVE ON A GRAND SCALE. TEMPERATURES WILL RUN WITHIN A FEW
DEGREES OF NORMAL.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AT KCLT...ANTICIPATE MAINLY VFR CIGS THROUGH LATE DAY AS CONVECTIVE
CUMULUS ABOUNDS. THE HRRR SHOWS CONVECTION OVER GA THIS AFTN MAKING
A RUN ACROSS THE SC UPSTATE AND THREATENING THE KCLT AIRFIELD BY
03Z. THERE IS QUITE A BIT OF UNCERTAINTY OVER INSTABILITY IN THE
IMMEDIATELY UPSTREAM AREAS...BUT A PROB30 FOR TSRA AFTER 03Z STILL
SEEMS REASONABLE. OTHERWISE...WIDESPREAD MVFR CIGS SHOULD DEVELOP
ONCE AGAIN IN THE MOIST BOUNDARY LAYER...WITH A WINDOW OF DAYBREAK
IFR ONCE AGAIN POSSIBLE. CANNOT RULE OUT A LINGERING SHOWER IN THE
VICINITY AT JUST ABOUT ANY TIME DURING THE TAF PERIOD. EXPECT STEADY
S TO SW FLOW AT 10 KT OR LESS.
ELSEWHERE...LOWER VFR TO SPOTTY MVFR CIGS WILL PERSIST AROUND THE
REGION WITH ABUNDANT CONVECTIVE CUMULUS FORMING AT 3 TO 4 KFT. THE
HRRR SHOWS THE UPSTREAM CONVECTION OVER GA MAKING A RUN ACROSS THE
SW HALF OF THE FORECAST THIS EVENING BEFORE GRADUALLY WEAKENING
ACROSS THE NE PART OVERNIGHT. GIVEN THE TIMING...AND THE RELATIVE
CONSISTENCY OF THE HRRR SOLUTIONS...WILL PUSH THE TSRA INTO A TEMPO
GROUP FOR GENERALLY 00Z TO 04Z...A LITTLE SOONER AT KAND...AND WITH
JUST SHRA AT KHKY. EXPECT A QUICK TRANSITION TO MVFR
OVERNIGHT...ESPECIALLY IF WIDESPREAD RAINFALL DEVELOPS...WITH A
PERIOD OF DAYBREAK IFR EXPECTED. SCATTERED SHOWERS MAY CONTINUE TO
AFFECT THE AIRFIELDS AT JUST ABOUT ANY TIME THROUGHOUT THE TAF
PERIOD GIVEN THE MOIST PROFILES AND SW FLOW..
OUTLOOK...MOIST SW FLOW WILL CONTINUE TO AFFECT THE TERMINAL
FORECAST AREA RIGHT THROUGH THE UPCOMING WEEKEND...AS A COLD FRONT
LAYS OVER TO THE NORTH OF THE AREA. EXPECT MORNING STRATUS TO RESULT
EACH DAY...WITH CONTINUED BETTER THAN CLIMATOLOGICAL CHANCES OF
AFTN/EVENING SHRA/TSRA EACH DAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 99% HIGH 81% HIGH 84%
KGSP HIGH 97% HIGH 100% HIGH 85% HIGH 95%
KAVL HIGH 80% HIGH 89% HIGH 85% HIGH 95%
KHKY HIGH 100% HIGH 100% HIGH 85% HIGH 90%
KGMU HIGH 99% HIGH 100% HIGH 84% HIGH 95%
KAND HIGH 93% HIGH 99% MED 76% HIGH 94%
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...JPT
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
343 PM CDT TUE MAY 26 2015
.DISCUSSION...
LINE OF STORMS LOCATED ALONG I-65 CURRENTLY. SO FAR...NO DAMAGE WITH
ANY OF THESE STORMS. LATEST LAPS DATA SHOWS THAT CAPES ARE
INCREASING TOWARD THE PLATEAU. THUS...STRONG STORMS WILL BE POSSIBLE
THROUGH THE LATE AFTERNOON FOR OUR EC AND NE COUNTIES. HRRR DATA
SHOWS SOME INTENSIFICATION ACROSS OUR EASTERN COUNTIES. BEHIND THIS
ADVANCING LINE...LITTLE IF ANY REDEVELOPMENT IS EXPECTED OVERNIGHT.
BUT...WILL GO AHEAD AND INCLUDE LOW SLIGHT CHANCE POPS FOR WESTERN
AREAS PRIOR TO 04Z. WILL KEEP PATCHY FOG OUT OF THE FORECAST FOR NOW
AS SOME DRIER AIR WILL MOVE IN AND KEEP VSBYS ABOVE 1SM.
RELATIVELY DRIER AIR WILL MOVE IN FOR WED AND THU. WE
STILL...HOWEVER...WILL SEE CAP EROSION BY 18Z. THUS...SCATTERED
MAINLY AFT SHOWERS AND TSTMS WILL AGAIN BE POSSIBLE BUT POPS WILL BE
KEPT LOW.
FOR THE SHORT TERM TEMPS...ABOVE NORMAL VALUES EXPECTED. I WILL GO
AHEAD AND UNDERCUT THE GUIDANCE BY 1 DEGREE TONIGHT AS SOME
PARTIAL CLEARING IS EXPECTED LATE.
IN THE EXT FCST...WEAK UPPER TROUGHING WILL GRADUALLY GAIN STRENGTH
OVER THE PLAINS STATES. THIS FEATURE WILL BEGIN TO SLOWLY MOVE
EASTWARD OVER THE WEEKEND. ADDITIONALLY...AN ASSOCIATED FRONTAL
BOUNDARY WILL BEGIN TO WORK OUR WAY AS WELL. THOUGH THIS FRONT IS
NOT EXPECTED TO MOVE THROUGH OUR AREA...IT WILL APPROACH US AND
INCREASE OUR SHOWER AND TSTM CHANCES THIS WEEKEND AND INTO EARLY
NEXT WEEK. RIGHT NOW...THE FRONT WILL WEAKEN TO THE POINT THAT ANY
ORGANIZED SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. THE EXT TEMPS
WILL CONTINUE TO RUN ABOVE NORMAL WITH LOWS IN THE MID TO UPPER
60S...AND HIGHS GENERALLY IN THE 80S.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 65 87 63 88 / 40 30 30 30
CLARKSVILLE 65 87 63 86 / 20 30 30 30
CROSSVILLE 63 79 61 82 / 60 30 30 30
COLUMBIA 64 85 63 87 / 40 30 30 30
LAWRENCEBURG 64 83 63 85 / 20 30 30 30
WAVERLY 66 87 63 86 / 20 30 30 30
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1241 PM CDT TUE MAY 26 2015
.UPDATE...ADDED AVIATION SECTION FOR 18Z TAF`S.
&&
.AVIATION...BNA/CKV/CSV...EXISTING LINE OF SHOWERS MOVING THROUGH
MIDDLE TENNESSEE APPEARS TO REPRESENT THE EXTENT OF OUR ACTIVE
WEATHER THE NEXT 24 HRS, AS THE HRRR SHOWS VERY LITTLE DEVELOPING
IN THE MORE STABLE AIR BEHIND. LOOK FOR SOME MVFR CIGS ALONG AND
AHEAD OF THE SHOWERS, WITH WINDS REMAINING GUSTY UNTIL THE
EVENING. THERE MAY BE SOME LIGHT FOG AROUND DAYBREAK, BUT
OTHERWISE LOOK FOR GOOD FLYING WEATHER ONCE THE LINE OF SHOWERS
MOVES OUT.
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT TUE MAY 26 2015/
UPDATE...FOR 12Z AVIATION FORECAST
AVIATION...
MOISTURE WILL CONTINUE TO STREAM NORTHWARD INTO MIDDLE TENNESSEE
TODAY AS NEGATIVE TILTED SHORT WAVE SWINGS ACROSS OUR AREA. LOOK
FOR SHOWERS AND A FEW THUNDERSTORMS GENERALLY WEST OF INTERSTATE
65 THROUGH 18Z THEN FROM INTERSTATE 65 EASTWARD IN THE AFTERNOON.
ISOLATED MARGINALLY SEVERE STORM OR TWO POSSIBLE IN THE AFTERNOON.
SURFACE PRESSURE GRADIENT TIGHT ENOUGH FOR SOUTHERLY GUSTS TO 25
KNOTS DURING THE DAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
351 PM CDT TUE MAY 26 2015
.DISCUSSION...
ISO/SCT SHOWERS AND TSTMS SHOULD TAPER OFF W/ THE LOSS OF DAYTIME
HEATING. IN THE MEANTIME...GOING TO ALLOW FF WATCH FOR HARRIS AND
FORT BEND COUNTIES TO CONTINUE THRU 6 PM AS THERE ARE COME CELLS
NEARBY. ATTENTION TURNS TO N AND W TX AS CONVECTION FIRES THERE.
VAST MAJORITY OF GUIDANCE SHOWS THIS DISSIPATING BEFORE EVEN
REACHING SE TX. HOWEVER...LATEST COUPLE HRRR RUNS INDICATE
POTENTIAL FOR SOME REMNANTS TO MOVE INTO N & E PARTS OF THE CWA
AFTER MIDNIGHT. SUSPECT CHANCES ARE PRETTY LOW BUT WILL LEAVE SOME
POPS IN THE OVERNIGHT FCST AND LET NEXT SHIFT UPDATE WITH TRENDS.
WX ON WED & THURS WILL CONSIST OF WHAT WOULD TYPICALLY BE NORMAL
EARLY SUMMER CONDITIONS AROUND HERE. ANTICIPATE SCT PRECIP ACTIVITY
TO START DEVELOPING ONCE READINGS APPROACH THE LOW TO MID 80S
DURING LATE MORNING HOURS AND PERSIST UNTIL AROUND SUNSET.
A PORTION OF THE EASTERN H5 RIDGE WILL TRANSITION INTO THE NW
GULF THE NEXT FEW DAYS. IT WILL THEN FLATTEN THEN RETROGRADE BACK
INTO MEXICO GOING INTO THE WEEKEND ALLOWING THE SRN PERIPHERY OF
THE NEXT TROF TO DIG INTO TX. THIS WILL BRING HIGHER RAIN CHANCES
BACK GOING INTO THE WEEKEND. REALLY NOT A BIG FAN OF SEEING THE
AGREEMENT BETWEEN ECMWF/GFS TRYING TO BRING A WEAKENING FRONTAL
BOUNDARY INTO SE TX LATE SAT AND SUN. THE LAST THING WE NEED IS
ANOTHER SLOW MOVING FOCUSING MECHANISM FOR TSTMS. 47
&&
.MARINE...
NOT A LOT OF ACTIVITY OVER THE GULF SO FAR THIS AFTN BUT THE
STRONG TO MODERATE ONSHORE WIND IN PLACE WILL HELP MAINTAIN SMALL
CRAFT EXERCISE CAUTION (SCEC) CONDITIONS THROUGH THIS EVENING.
HOWEVER THIS COULD BE EXTENDED INTO THE OVERNIGHT HOURS AS SEAS
REMAIN ELEVATED.
WITH THE LARGE SCALE WX PATTERN REMAINING IN PLACE...OTHER CONCERNS
THESE SEVERAL DAYS INVOLVE RIP CURRENTS AND SLIGHTLY ABOVE NORMAL
HIGH TIDES. WE COULD STILL SEE SOME MINOR FLOODING DURING HIGH
TIDE NEAR AND ALONG THE GULF FACING BEACHES OF THE BOLIVAR
PENINSULA THE NEXT DAY OR SO. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 88 73 86 73 / 30 40 20 40 20
HOUSTON (IAH) 74 88 74 87 74 / 30 40 20 40 20
GALVESTON (GLS) 78 86 78 85 78 / 20 30 10 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK UNTIL 9 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...
MATAGORDA.
FLASH FLOOD WATCH UNTIL 6 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: FORT BEND...HARRIS.
GM...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
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
121 PM CDT TUE MAY 26 2015
.AVIATION...
MVFR CIGS SHOULD PREVAIL THROUGH 06Z...ALTHOUGH SOME PATCHES OF
VFR MAY OCCUR. SOME OF THE HIGH RESOLUTION MODELS DEVELOP A LINE
OF TSRA/SHRA OVER NORTHWEST TEXAS AND MOVE IT TOWARD THE I-35 TAF
SITES BY 12Z. WE THINK THIS IS UNLIKELY...HENCE NO MENTION IN
THOSE TAFS. TSRA ALREADY DEVELOPING OVER THE MEXICAN MOUNTAINS HAS
THE POTENTIAL TO BE IN THE VCNTY OF KDRT AFTER 20Z...SO INCLUDED
MENTION. 3-5SM BR AND IFR CIGS SHOULD DEVELOP BY 08Z AND CONTINUE
THROUGH 16-17Z WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 1042 AM CDT TUE MAY 26 2015/
UPDATE...
THE MAIN CHANGES MADE TO THE ONGOING FORECAST WERE TO DROP HIGH
TEMPERATURES ACROSS PARTS OF THE AREA DUE TO THE CLOUDS ALONG THE
I-35 CORRIDOR AND TO ADJUST POPS FOR TODAY. HIGH RESOLUTION MODELS
CONTINUE TO SUGGEST THAT WE WILL ONLY SEE A FEW ISOLATED
THUNDERSTORMS THIS AFTERNOON. THE HRRR AND TEXAS TECH WRF BOTH
PICK UP ON THE POSSIBILITY OF A SERRANIAS DEL BURRO SUPERCELL OR
TWO. BOTH MESOSCALE MODELS KEEP THESE STORMS OVER MEXICO...BUT
WITH A FAVORABLE ENVIRONMENT FOR STORMS ACROSS THE RIO GRANDE
PLAINS IT IS WORTH WATCHING. THE MORNING DEL RIO UPPER AIR
SOUNDING WAS UN-CAPPED WITH A GOOD AMOUNT OF SHEAR AND LARGE CAPE
NEAR 4000 J/KG. WHAT SHOULD KEEP ACTIVITY MORE ISOLATED TODAY IS
THAT THE MID AND UPPER LEVELS ARE FAIRLY DRY.
RIVER FLOODING IS STILL A MAJOR CONCERN ACROSS OUR ARE WITH
MODERATE OR MAJOR FLOODING ONGOING ALONG THE
COLORADO...FRIO...GUADALUPE...SAN MARCOS...AND NUECES RIVERS.
THERE ARE TWO SURVEY TEAMS CURRENTLY OUT SURVEYING DAMAGE REPORTS
FROM YESTERDAYS STORMS. ONE WENT OUT TO THE TEXAS HILL COUNTRY
WHILE THE OTHER WILL BE VISITING BASTROP COUNTY AND THE COASTAL
PLAINS COUNTIES. MORE INFORMATION WILL BE PROVIDED THIS AFTERNOON
ONCE THESE TEAMS RETURN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 73 88 72 86 71 / 30 20 20 30 40
AUSTIN BERGSTROM INTL AIRPORT 72 88 72 85 71 / 30 20 20 30 30
NEW BRAUNFELS MUNI AIRPORT 73 89 73 86 72 / 30 20 10 30 30
BURNET MUNI AIRPORT 70 86 71 84 70 / 20 20 20 30 40
DEL RIO INTL AIRPORT 74 89 74 87 71 / 30 20 20 40 50
GEORGETOWN MUNI AIRPORT 72 87 71 85 71 / 30 20 20 30 30
HONDO MUNI AIRPORT 73 88 74 87 72 / 30 20 20 40 40
SAN MARCOS MUNI AIRPORT 73 88 73 85 71 / 30 20 10 30 30
LA GRANGE - FAYETTE REGIONAL 74 88 73 86 73 / 20 30 20 40 20
SAN ANTONIO INTL AIRPORT 73 89 74 86 73 / 30 20 20 30 30
STINSON MUNI AIRPORT 74 89 74 87 73 / 30 20 20 30 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...26
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
620 PM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL MAINTAIN A BROAD
SOUTHERLY FLOW OF DEEP MOISTURE INTO THE REGION THROUGH MUCH OF
THIS WEEK. AN UPPER LEVEL TROUGH OF LOW PRESSURE TO THE NORTHWEST
WILL GRADUALLY SLIDE EAST AND INTERACT WITH THIS MOISTURE ACROSS
THE AREA. THIS WILL RESULT IN PERIODIC ROUNDS OF SHOWERS AND
STORMS OVER THE NEXT FEW DAYS.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 600 PM EDT TUESDAY...
MADE SOME ADJUSTMENTS...MAINLY TO POP/WX GRIDS AT THIS TIME IN
CONCERT WITH LATEST HRRR AND NSSL WRF SIMULATED RADAR
FORECASTS...WHICH SEEM TO BE IN LINE WITH LATEST SYNOPTIC SCALE
MODEL TRENDS AS WELL REGARDING PRECIPITATION. INITIAL AREA...NOW
EXITING THE SOUTHERN SHENANDOAH VALLEY INTO LWX CWA...WILL
CONTINUE TO MOVE NORTHEAST AWAY FROM THE AREA. THE NEXT AREA TO
WATCH IS NOW DOWN IN GEORGIA PACKING QUITE A PUNCH THERE. FEEL
THAT THE REMNANTS OF THIS WILL WORK ITS WAY NORTHEAST INTO OUR CWA
TOWARD MIDNIGHT AND SEVERAL HOURS THEREAFTER...ALBEIT IN A
DIMINISHING STATE. THUS...HAVE DECREASED POPS FOR THE NEXT FEW
HOURS...THEN INCREASED FROM THE SOUTHWEST FROM 06Z ONWARD TOWARD
DAYBREAK WESTERN HALF. USED A BLEND OF SYNOPTIC AND MESOSCALE
MODEL POPS THROUGH 12Z...LEANING HEAVILY TOWARD THE HRRR.
TEMPS WERE A LITTLE TOO WARM IN RAIN COOLED AREAS AND A LITTLE TOO
COOL ACROSS THE PIEDMONT. MADE SOME MINOR ADJUSTMENTS TO BRING
BETTER IN LINE WITH CURRENT OBSERVATIONS. OTHERWISE...REMAINING
GRIDS LOOK GOOD AT THIS TIME AND DID NOT NEED ADJUSTMENT.
AS OF 215 PM EDT TUESDAY...
BANDS OF CONVECTION CONTINUE TO DEVELOP AND PUSH SLOWLY NE MAINLY JUST
WEST OF THE BLUE RIDGE WHERE 1000 J/KG ML CAPE EXISTS AND MOISTURE IS
DEEPER NEAR A FAINT SHORTWAVE LIFTING NE. MOST SHORT TERM GUIDANCE
CONTINUES TO FOLLOW SUIT WITH THE LATEST HRRR AND HIRES MODELS SLIDING
CLUSTERS OF DEEPER CONVECTION NE...PASSING ACROSS THE HIGHLANDS AND SRN
SHENANDOAH VALLEY BY EARLY THIS EVENING. EITHER SIDE OF THIS
AXIS...EXPECTING ONLY ISOLATED COVERAGE MAINLY ALONG THE BLUE RIDGE
WITH LITTLE OVER THE FAR EAST PER RIDGING...AND FAR WEST WHERE IN
BETWEEN LIFT SOURCES. THUS WILL HAVE CONTINUED LIKELY POPS FOR A WHILE
LONGER OVER PARTS OF THE WEST INTO THIS EVENING AND LOW TO SLIGHT
ELSEWHERE BEFORE TRIMMING BACK TOWARD SUNSET.
MAIN CONCERN OVERNIGHT SHIFTS TO ENERGY NOW WELL TO THE SW ALONG THE
LEADING EDGE OF THE NEXT UPSTREAM 5H TROUGH THAT WILL HELP EJECT A
SHORTWAVE NE INTO THE WESTERN PORTIONS AFTER MIDNIGHT. MODELS DISAGREE
ON THE DEGREE OF RESIDUAL DEEP CONVECTION WITH THIS FEATURE WITH SOME
HOLDING IT TOGETHER OVER THE FAR WEST LATE AND OTHERS FIZZLING
COVERAGE INTO LIGHTER SHOWERS BY DAYBREAK. GIVEN SPEED OF MOVEMENT WITH
THIS FEATURE AND PROGGED STRONG 85H THETA-E ALONG WITH GOOD MOISTURE
TRANSPORT OFF MOST GUIDANCE WILL REINTRODUCE LIKELY POPS WEST
AFTER THIS EVENING...AND SLIDE BETTER COVERAGE TOWARD THE BLUE
RIDGE EARLY IN THE MORNING AS CONVECTION WEAKENS. LEFT TEMPS CLOSE
TO THE LATEST MAV MOS WITH LOWS MOSTLY IN THE 60S PER DEEP
MOISTURE AROUND.
WEAK DAMPENING WAVE SLIDES EAST ACROSS THE REGION WEDNESDAY FOLLOWED BY
ANOTHER WEAK SHORTWAVE OVER THE SW LATE IN THE DAY. DESPITE DEEP
MOISTURE AND HIGH PWATS ESPCLY EAST...TIMING OF THIS FEATURE AND DEGREE
OF HEATING/INSTABILITY REMAINS IN QUESTION. LATEST SREF CONSENSUS WOULD
SUGGEST INITIAL BATCH OF SHRA WILL FADE NEAR THE BLUE RIDGE WED
MORNING FOLLOWED BY REDEVELOPMENT ACROSS EASTERN SECTIONS IN THE
AFTERNOON WHERE HEATING AND FORECAST CAPES APPEAR BEST. POTENTIAL
MORE OF A WEST WIND AND DRYING ALOFT PER LATEST SOUNDINGS COULD
LIMIT THINGS IN THE MOUNTAINS WHERE CLOUDS MAY LINGER LONGER.
THEREFORE TRIMMED BACK POPS A BIT BUT UPPED ALONG/JUST EAST OF THE
BLUE RIDGE WHERE CONVERGENCE LOOKS BETTER. HOWEVER OVERALL LIKELY
TO CHANCE POPS WITH SOME HEAVY RAIN POTENTIAL GIVEN EVEN LIGHTER
STEERING THAT TODAY. FOLLOWED CLOSER TO THE COOLER MAV TEMPS GIVEN
MORE CLOUDS AND MOISTURE/SHRA AROUND EARLY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 225 PM EDT TUESDAY...
THE AREA RESETS IN THE SENSE THAT THE EXTRA INFLUENCE OF AN UPPER
TROUGH HEADING THROUGH THE NORTHERN END OF THE UPPER RIDGE ENDS.
WHAT IS LEFT OF THE TROUGH IS ALMOST WASHED OUT AND HEADS THROUGH
SOUTHEAST CANADA WEDNESDAY NIGHT INTO THURSDAY. WHAT REMAINS IS THE
PERSISTENT SOUTHEAST U.S. UPPER RIDGE...AND THERE WILL BE A NEW
UPPER TROUGH DEEPENING IN NORTHERN PLAINS STATES. THIS WILL PLACE
OUR AREA IN A SCENARIO COMPARABLE TO THE CONDITIONS OF TODAY. THERE
WILL BE PLENTY OF MOISTURE IN THE LOW LEVELS WITH GOOD DAYTIME
HEATING. UPPER LEVEL SUPPORT WILL BE AT A MINIMUM...SO SHOWER AND
THUNDERSTORM ACTIVITY DURING THIS PORTION OF THE FORECAST WILL BE
PRIMARILY DIURNAL IN NATURE. A ROUGE BIT OF ENERGY COULD GET EJECTED
EASTWARD OFF THE MAIN UPPER TROUGH TO HELP ENHANCE OR PROLONG
COVERAGE...BUT AT THIS TIME...PROJECTING ACCURATELY WHEN OR IF THAT
HAPPENS WOULD BE CHALLENGING.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 PM EDT TUESDAY...
SATURDAY INTO SUNDAY THE NEXT UPPER TROUGH MAKES HEADWAY INTO THE
RIDGE...JUST LIKE ITS PREDECESSOR A FEW DAYS PRIOR. ANTICIPATE THIS
FEATURE TO GENERATE A GREATER COVERAGE OF SHOWERS AND
STORMS...ESPECIALLY ACROSS THE WESTERN HALF OF THE AREA. THIS
ASSOCIATED SURFACE COLD FRONT IS EXPECTED TO THE AREA SUNDAY
NIGHT....AND STALL OVER OR JUST TO OUR SOUTH ON MONDAY. THE FRONT
WILL BUCKLE BACK NORTH EARLY NEXT WEEK AS SOUTHERLY FLOW AROUND THE
WEST SIDE OF THE HIGH RE-ESTABLISHES ITSELF. THIS WILL KEEP THE
CHANCE OF SHOWERS AND STORMS IN THE FORECAST...AGAIN WITH THE FOCUS
WITH THE GREATEST CONCENTRATION IN THE WEST.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
AS OF 1245 PM EDT TUESDAY...
STARTING TO SEE ISOLATED CONVECTION POP UP ACROSS THE FAR WEST
EARLY THIS AFTERNOON WHERE MOISTURE REMAINS DEEPER AND AIDED BY
DIFFERENTIAL HEATING. EXPECT THIS AREA TO GRADUALLY FILL IN AND
BECOME A BIT MORE ORGANIZED WHICH WILL AFFECT THE KBLF-KLWB
CORRIDOR AND POSSIBLY AROUND KBCB IF SHRA/TSRA SPILL FARTHER EAST.
THUS WILL CARRY A PREVAILING VCTS/VCSH AND TEMPO IN MORE IN THE
WAY OF MVFR TO IFR CONDITIONS PENDING IF A SHOWER OR STORM
DIRECTLY IMPACT ONE OF THESE LOCATIONS. OTRW EXPECTING MAINLY 4-6K
FT VFR CIGS THIS AFTERNOON WITH LITTLE SHOWER COVERAGE AT
KLYH/KDAN WITH ISOLATED POTENTIAL AT KROA. WINDS THIS AFTERNOON
WILL REMAIN OUT OF THE SOUTH 5-10KTS...WITH GUSTS 14-18KTS.
EXPECTING CONVECTION TO FADE WITH LOSS OF HEATING THIS EVENING AND
IN THE WAKE OF A WEAK IMPULSE SLIDING BY TO THE NE. THIS MAY LEAVE
MOST OF THE REGION IN VFR UNDER MID DECK WITH PERHAPS SOME MVFR IN
FOG THIS EVENING WHERE EARLIER RAIN OCCURRED. NEXT SHORTWAVE
TROUGH NOW TO THE SW WILL SLIDE INTO THE AREA LATER TONIGHT WITH
AN ASSOCIATED BAND OF SHRA/ISOLATED TSRA SPREADING IN FROM THE SW
AFTER MIDNIGHT. GUIDANCE HAS MOST OF THIS AFFECTING THE MOUNTAINS
MAINLY KBLF/KLWB LATE AND EAST TO KBCB/KROA AROUND DAYBREAK IF NOT
A BIT SOONER. THUS INCLUDING A PERIOD OF PREVAILING MVFR IN SHRA
EARLY WEDNESDAY MORNING WITH SOME OF THIS PERHAPS SLIDING INTO
KROA/KLYH WEDNESDAY MORNING WITH POSSIBLE MVFR. LOW CLOUDS AHEAD
OF THIS FEATURE MAY ALSO BRING MVFR TO IFR CIGS ALONG AND EAST OF
THE BLUE RIDGE OVERNIGHT BUT IFFY GIVEN MODEL TENDENCY TO BRING IN
STRATUS SO HELD OFF GOING THAT PESSIMISTIC FOR NOW.
EXTENDED AVIATION DISCUSSION...
WEDNESDAY...THE UPPER DISTURBANCE WILL CONTINUE TO SHIFT EAST
ACROSS THE REGION WITH DECREASING ACTIVITY OVER THE WEST BY MIDDAY
LIKELY REDEVELOPING ALONG AND EAST OF THE BLUE RIDGE WEDNESDAY
AFTERNOON. TIMING OF THIS WEAK TROUGH TRICKY AS COULD SEE MORE
DRYING ALOFT OVER THE WEST BY AFTERNOON PER LATEST BUFKIT
SOUNDINGS WITH CONVERGENCE OVER THE EAST. LATEST GUIDANCE EVEN
SUGGESTS A RETURN TO VFR WEST OF THE BLUE RIDGE WEDNESDAY
AFTERNOON WITH PERIODS OF MVFR/IFR OUT EAST PENDING CONVECTIVE
COVERAGE. THIS BOUNDARY DRIFTS INTO EASTERN VA THU BEFORE WASHING
OUT...SO ACTIVITY COULD BE SOMEWHAT MORE FOCUSED ALONG- EAST OF
THE BLUE RIDGE THURSDAY.
FOR THE REMAINDER OF THE PERIOD...A MOIST UNSTABLE AIR MASS
REMAINS ACROSS THE REGION WITH WEAK TRIGGERING MECHANISMS AND
DYNAMICS. A FRONTAL SYSTEM WILL APPROACH FROM THE NORTH BY THE
WEEKEND...BUT WILL LIKELY REMAIN WELL NORTH OF THE CWA. THUS...NO
CHANGE IN AIR MASS OR THE OVERALL SYNOPTIC PATTERN IS EXPECTED
THROUGH THE PERIOD.
EARLY MORNING LOW CLOUDS/FOG AND ASSOCIATED IFR-LIFR CIGS/VSBYS BECOME
INCREASINGLY MORE LIKELY THROUGH THE PERIOD...ESPECIALLY FOLLOWING
ANY LATE DAY RAINFALL. OTHERWISE...EXPECT MOSTLY VFR-MVFR CIGS
OUTSIDE HEAVIER SHOWERS/THUNDERSTORMS. WINDS REMAINING SW 5-10KTS
THROUGH MUCH OF THE PERIOD...EXCEPT VARIABLE AND GUSTY IN/NEAR
THUNDERSTORMS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/RAB
SHORT TERM...DS
LONG TERM...DS
AVIATION...JH/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
313 PM EDT TUE MAY 26 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL MAINTAIN A BROAD
SOUTHERLY FLOW OF DEEP MOISTURE INTO THE REGION THROUGH MUCH OF
THIS WEEK. AN UPPER LEVEL TROUGH OF LOW PRESSURE TO THE NORTHWEST
WILL GRADUALLY SLIDE EAST AND INTERACT WITH THIS MOISTURE ACROSS
THE AREA. THIS WILL RESULT IN PERIODIC ROUNDS OF SHOWERS AND
STORMS OVER THE NEXT FEW DAYS.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 215 PM EDT TUESDAY...
BANDS OF CONVECTION CONTINUE TO DEVELOP AND PUSH SLOWLY NE MAINLY JUST
WEST OF THE BLUE RIDGE WHERE 1000 J/KG ML CAPE EXISTS AND MOISTURE IS
DEEPER NEAR A FAINT SHORTWAVE LIFTING NE. MOST SHORT TERM GUIDANCE
CONTINUES TO FOLLOW SUIT WITH THE LATEST HRRR AND HIRES MODELS SLIDING
CLUSTERS OF DEEPER CONVECTION NE...PASSING ACROSS THE HIGHLANDS AND SRN
SHENANDOAH VALLEY BY EARLY THIS EVENING. EITHER SIDE OF THIS
AXIS...EXPECTING ONLY ISOLATED COVERAGE MAINLY ALONG THE BLUE RIDGE
WITH LITTLE OVER THE FAR EAST PER RIDGING...AND FAR WEST WHERE IN
BETWEEN LIFT SOURCES. THUS WILL HAVE CONTINUED LIKELY POPS FOR A WHILE
LONGER OVER PARTS OF THE WEST INTO THIS EVENING AND LOW TO SLIGHT
ELSEWHERE BEFORE TRIMMING BACK TOWARD SUNSET.
MAIN CONCERN OVERNIGHT SHIFTS TO ENERGY NOW WELL TO THE SW ALONG THE
LEADING EDGE OF THE NEXT UPSTREAM 5H TROUGH THAT WILL HELP EJECT A
SHORTWAVE NE INTO THE WESTERN PORTIONS AFTER MIDNIGHT. MODELS DISAGREE
ON THE DEGREE OF RESIDUAL DEEP CONVECTION WITH THIS FEATURE WITH SOME
HOLDING IT TOGETHER OVER THE FAR WEST LATE AND OTHERS FIZZLING
COVERAGE INTO LIGHTER SHOWERS BY DAYBREAK. GIVEN SPEED OF MOVEMENT WITH
THIS FEATURE AND PROGGED STRONG 85H THETA-E ALONG WITH GOOD MOISTURE
TRANSPORT OFF MOST GUIDANCE WILL REINTRODUCE LIKELY POPS WEST
AFTER THIS EVENING...AND SLIDE BETTER COVERAGE TOWARD THE BLUE
RIDGE EARLY IN THE MORNING AS CONVECTION WEAKENS. LEFT TEMPS CLOSE
TO THE LATEST MAV MOS WITH LOWS MOSTLY IN THE 60S PER DEEP
MOISTURE AROUND.
WEAK DAMPENING WAVE SLIDES EAST ACROSS THE REGION WEDNESDAY FOLLOWED BY
ANOTHER WEAK SHORTWAVE OVER THE SW LATE IN THE DAY. DESPITE DEEP
MOISTURE AND HIGH PWATS ESPCLY EAST...TIMING OF THIS FEATURE AND DEGREE
OF HEATING/INSTABILITY REMAINS IN QUESTION. LATEST SREF CONSENSUS WOULD
SUGGEST INITIAL BATCH OF SHRA WILL FADE NEAR THE BLUE RIDGE WED
MORNING FOLLOWED BY REDEVELOPMENT ACROSS EASTERN SECTIONS IN THE
AFTERNOON WHERE HEATING AND FORECAST CAPES APPEAR BEST. POTENTIAL
MORE OF A WEST WIND AND DRYING ALOFT PER LATEST SOUNDINGS COULD
LIMIT THINGS IN THE MOUNTAINS WHERE CLOUDS MAY LINGER LONGER.
THEREFORE TRIMMED BACK POPS A BIT BUT UPPED ALONG/JUST EAST OF THE
BLUE RIDGE WHERE CONVERGENCE LOOKS BETTER. HOWEVER OVERALL LIKELY
TO CHANCE POPS WITH SOME HEAVY RAIN POTENTIAL GIVEN EVEN LIGHTER
STEERING THAT TODAY. FOLLOWED CLOSER TO THE COOLER MAV TEMPS GIVEN
MORE CLOUDS AND MOISTURE/SHRA AROUND EARLY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 225 PM EDT TUESDAY...
THE AREA RESETS IN THE SENSE THAT THE EXTRA INFLUENCE OF AN UPPER
TROUGH HEADING THROUGH THE NORTHERN END OF THE UPPER RIDGE ENDS.
WHAT IS LEFT OF THE TROUGH IS ALMOST WASHED OUT AND HEADS THROUGH
SOUTHEAST CANADA WEDNESDAY NIGHT INTO THURSDAY. WHAT REMAINS IS THE
PERSISTENT SOUTHEAST U.S. UPPER RIDGE...AND THERE WILL BE A NEW
UPPER TROUGH DEEPENING IN NORTHERN PLAINS STATES. THIS WILL PLACE
OUR AREA IN A SCENARIO COMPARABLE TO THE CONDITIONS OF TODAY. THERE
WILL BE PLENTY OF MOISTURE IN THE LOW LEVELS WITH GOOD DAYTIME
HEATING. UPPER LEVEL SUPPORT WILL BE AT A MINIMUM...SO SHOWER AND
THUNDERSTORM ACTIVITY DURING THIS PORTION OF THE FORECAST WILL BE
PRIMARILY DIURNAL IN NATURE. A ROUGE BIT OF ENERGY COULD GET EJECTED
EASTWARD OFF THE MAIN UPPER TROUGH TO HELP ENHANCE OR PROLONG
COVERAGE...BUT AT THIS TIME...PROJECTING ACCURATELY WHEN OR IF THAT
HAPPENS WOULD BE CHALLENGING.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 PM EDT TUESDAY...
SATURDAY INTO SUNDAY THE NEXT UPPER TROUGH MAKES HEADWAY INTO THE
RIDGE...JUST LIKE ITS PREDECESSOR A FEW DAYS PRIOR. ANTICIPATE THIS
FEATURE TO GENERATE A GREATER COVERAGE OF SHOWERS AND
STORMS...ESPECIALLY ACROSS THE WESTERN HALF OF THE AREA. THIS
ASSOCIATED SURFACE COLD FRONT IS EXPECTED TO THE AREA SUNDAY
NIGHT....AND STALL OVER OR JUST TO OUR SOUTH ON MONDAY. THE FRONT
WILL BUCKLE BACK NORTH EARLY NEXT WEEK AS SOUTHERLY FLOW AROUND THE
WEST SIDE OF THE HIGH RE-ESTABLISHES ITSELF. THIS WILL KEEP THE
CHANCE OF SHOWERS AND STORMS IN THE FORECAST...AGAIN WITH THE FOCUS
WITH THE GREATEST CONCENTRATION IN THE WEST.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 1245 PM EDT TUESDAY...
STARTING TO SEE ISOLATED CONVECTION POP UP ACROSS THE FAR WEST
EARLY THIS AFTERNOON WHERE MOISTURE REMAINS DEEPER AND AIDED BY
DIFFERENTIAL HEATING. EXPECT THIS AREA TO GRADUALLY FILL IN AND
BECOME A BIT MORE ORGANIZED WHICH WILL AFFECT THE KBLF-KLWB
CORRIDOR AND POSSIBLY AROUND KBCB IF SHRA/TSRA SPILL FARTHER EAST.
THUS WILL CARRY A PREVAILING VCTS/VCSH AND TEMPO IN MORE IN THE
WAY OF MVFR TO IFR CONDITIONS PENDING IF A SHOWER OR STORM
DIRECTLY IMPACT ONE OF THESE LOCATIONS. OTRW EXPECTING MAINLY 4-6K
FT VFR CIGS THIS AFTERNOON WITH LITTLE SHOWER COVERAGE AT
KLYH/KDAN WITH ISOLATED POTENTIAL AT KROA. WINDS THIS AFTERNOON
WILL REMAIN OUT OF THE SOUTH 5-10KTS...WITH GUSTS 14-18KTS.
EXPECTING CONVECTION TO FADE WITH LOSS OF HEATING THIS EVENING AND
IN THE WAKE OF A WEAK IMPULSE SLIDING BY TO THE NE. THIS MAY LEAVE
MOST OF THE REGION IN VFR UNDER MID DECK WITH PERHAPS SOME MVFR IN
FOG THIS EVENING WHERE EARLIER RAIN OCCURRED. NEXT SHORTWAVE
TROUGH NOW TO THE SW WILL SLIDE INTO THE AREA LATER TONIGHT WITH
AN ASSOCIATED BAND OF SHRA/ISOLATED TSRA SPREADING IN FROM THE SW
AFTER MIDNIGHT. GUIDANCE HAS MOST OF THIS AFFECTING THE MOUNTAINS
MAINLY KBLF/KLWB LATE AND EAST TO KBCB/KROA AROUND DAYBREAK IF NOT
A BIT SOONER. THUS INCLUDING A PERIOD OF PREVAILING MVFR IN SHRA
EARLY WEDNESDAY MORNING WITH SOME OF THIS PERHAPS SLIDING INTO
KROA/KLYH WEDNESDAY MORNING WITH POSSIBLE MVFR. LOW CLOUDS AHEAD
OF THIS FEATURE MAY ALSO BRING MVFR TO IFR CIGS ALONG AND EAST OF
THE BLUE RIDGE OVERNIGHT BUT IFFY GIVEN MODEL TENDENCY TO BRING IN
STRATUS SO HELD OFF GOING THAT PESSIMISTIC FOR NOW.
EXTENDED AVIATION DISCUSSION...
WEDNESDAY...THE UPPER DISTURBANCE WILL CONTINUE TO SHIFT EAST
ACROSS THE REGION WITH DECREASING ACTIVITY OVER THE WEST BY MIDDAY
LIKELY REDEVELOPING ALONG AND EAST OF THE BLUE RIDGE WEDNESDAY
AFTERNOON. TIMING OF THIS WEAK TROUGH TRICKY AS COULD SEE MORE
DRYING ALOFT OVER THE WEST BY AFTERNOON PER LATEST BUFKIT
SOUNDINGS WITH CONVERGENCE OVER THE EAST. LATEST GUIDANCE EVEN
SUGGESTS A RETURN TO VFR WEST OF THE BLUE RIDGE WEDNESDAY
AFTERNOON WITH PERIODS OF MVFR/IFR OUT EAST PENDING CONVECTIVE
COVERAGE. THIS BOUNDARY DRIFTS INTO EASTERN VA THU BEFORE WASHING
OUT...SO ACTIVITY COULD BE SOMEWHAT MORE FOCUSED ALONG- EAST OF
THE BLUE RIDGE THURSDAY.
FOR THE REMAINDER OF THE PERIOD...A MOIST UNSTABLE AIR MASS
REMAINS ACROSS THE REGION WITH WEAK TRIGGERING MECHANISMS AND
DYNAMICS. A FRONTAL SYSTEM WILL APPROACH FROM THE NORTH BY THE
WEEKEND...BUT WILL LIKELY REMAIN WELL NORTH OF THE CWA. THUS...NO
CHANGE IN AIR MASS OR THE OVERALL SYNOPTIC PATTERN IS EXPECTED
THROUGH THE PERIOD.
EARLY MORNING LOW CLOUDS/FOG AND ASSOCIATED IFR-LIFR CIGS/VSBYS BECOME
INCREASINGLY MORE LIKELY THROUGH THE PERIOD...ESPECIALLY FOLLOWING
ANY LATE DAY RAINFALL. OTHERWISE...EXPECT MOSTLY VFR-MVFR CIGS
OUTSIDE HEAVIER SHOWERS/THUNDERSTORMS. WINDS REMAINING SW 5-10KTS
THROUGH MUCH OF THE PERIOD...EXCEPT VARIABLE AND GUSTY IN/NEAR
THUNDERSTORMS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...DS
LONG TERM...DS
AVIATION...JH/PM