Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 260206
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1006 PM EDT MON MAY 25 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 225 PM EDT MON MAY 25 2015

UNSETTLED CONDITIONS EXPECTED INTO THUS UPCOMING WEEKEND AS
OCCASIONAL UPPER DISTURBANCES MOVE OVER THE AREA...RESULTING IN
PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 920 PM EDT MON MAY 25 2015

ADDED A BIT MORE SKY COVER OVERNIGHT AS MOS AND SREF LOW CEILING
PROBABILITIES SUGGEST LINGERING LOW LEVEL MOISTURE WILL EVOLVE INTO
A LOW STRATUS DECK. TEMPERATURES SHOULD NOT DROP MUCH MORE THAN 5 TO
10 DEGREES OVERNIGHT WHICH MATCHES UP WITH CURRENT OVERNIGHT LOWS IN
THE MID 60S.

PREVIOUS DISCUSSION FOLLOWS...

ISSUED AT 626 PM EDT MON MAY 25 2015

PULLED EVENING THUNDERSTORM CHANCES SOUTHEAST PER RADAR TRENDS.

PREVIOUS DISCUSSION FOLLOWS...

ISSUED AT 225 PM EDT MON MAY 25 2015

TAIL END OF VORTICITY CENTER CURRENTLY OVER SOUTHERN LAKE MICHIGAN
EXPECTED TO BRUSH THROUGH THE NORTHERN ZONES DURING THE REST OF THE
AFTERNOON HOURS. WIDELY SCATTERED SHOWER/THUNDERSTORM ACTIVITY IS
POSSIBLE WITH THIS FEATURE. THE TAIL END OF ANOTHER WAVE WHICH
PASSED EARLIER THIS MORNING MAY LINGER IN THE VICINITY OF THE FAR
SOUTHEAST ZONES THROUGH THIS EVENING. MAY NEED TO KEEP A POP OVER
THE SOUTHEAST ZONES FOR A COUPLE OF HOURS AFTER SUNSET...OTHERWISE
ANY OTHER ACTIVITY SHOULD DIMINISH BY SUNSET AS UPPER SUPPORT ENDS.

OTHERWISE...NEXT UPPER WAVE CURRENTLY OVER TEXAS IS EXPECTED TO
EJECT NORTHEAST TONIGHT. LOW LEVEL JET BEGINS TO INCREASE AGAIN
TOWARDS DAWN ON TUESDAY IN RESPONSE TO THE APPROACH OF THIS FEATURE.
WILL BRING IN CHANCE POPS TOWARDS DAWN ON TUESDAY...WITH THE HIGHEST
POPS SOUTHWEST.

THE GFS MOS LOWS TONIGHT LOOK REASONABLE BASED ON LOW LEVEL
THICKNESSES.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 225 PM EDT MON MAY 25 2015

MODELS INDICATE TEXAS UPPER WAVE WILL MOVE ACROSS THE AREA ON
TUESDAY. THERE ARE SOME TIMING DIFFERENCES WITH RESPECT TO THIS
WAVE...WITH THE NAM SUGGESTING MIDDAY INTO THE AFTERNOON WHILE THE
GFS IS A LITTLE EARLIER. WILL GO LIKELY POPS ALL AREAS ON TUESDAY.
LAPSE RATES/DEEP SHEAR LOOK RATHER MARGINAL FOR SEVERE CONVECTION AT
THIS TIME ON TUESDAY...ALTHOUGH MODELS SUGGEST LAPSE RATES MAY
STEEPEN SOME DURING THE AFTERNOON.

APPEARS A PERIODIC THREAT FOR SHOWERS AND THUNDERSTORMS WILL
CONTINUE INTO THE MIDDLE OF WEEK AS UPPER LEVEL DISTURBANCES RIPPLE
THROUGH THE FLOW. MODELS SUGGEST LAPSE RATES MAY BE QUITE A BIT
STEEPER BY WEDNESDAY AND THURSDAY...SUGGESTING BETTER INSTABILITY BY
THEN. HOWEVER...DEEP LAYER SHEAR REMAINS WEAK. WILL CONTINUE WITH
CHANCE POPS FOR WEDNESDAY AND THURSDAY. CONVECTIVE THREAT MAY GET
MORE SUPPRESSED BY THURSDAY AS HEIGHTS START TO RISE AGAIN...BUT FOR
NOW WILL KEEP POPS IN THE FORECAST AT THAT TIME.

BASED ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE
GUIDANCE IN THE LATER PERIODS LOOK OK FOR THE MOST PART. THE LOWS BY
WEDNESDAY NIGHT MAY BE A LITTLE COOL...SO WILL NUDGE UP THE NUMBERS
A BIT IN THAT PERIOD.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...

ISSUED AT 211 PM EDT MON MAY 25 2015

ACTIVE...CHANGEABLE WEATHER PATTERN IS EXPECTED DURING THE PERIOD.

GFS DEPICTS WARM AND HUMID SW FLOW IN PLACE ACROSS INDIANA ON
THURSDAY NIGHT THROUGH EARLY SATURDAY. MINIMAL SUPPORT IS IN PLACE
ALOFT AS WEAK RIDGING PRIMARILY REMAINS IN PLACE. HOWEVER
SUPERBLEND CONTINUES TO INSIST ON POPS AND GIVEN THE WARM AND
HUMID AIR MASS A DIURNAL SHOWER CANNOT BE RULED OUT.

ON SATURDAY A COLD FRONT IS EXPECTED TO SAG SOUTHWARD OUT OF THE
UPPER MIDWEST AND GREAT LAKES. THIS WILL PROVIDE AN IDEAL
CONVERGENCE AREA FOR CLOUDS AND MOISTURE. BETTER CHANCES FOR MORE
ORGANIZED PRECIPITATION AT THAT TIME.

BY MONDAY AN UPPER LOW OVER THE CENTRAL PLAINS LOOKS TO PUSH EAST
IN TO THE OHIO VALLEY...PROVIDING MORE CHANCES FOR PRECIPITATION.

&&

.AVIATION /DISCUSSION FOR 260300Z TAF ISSUANCE/...

ISSUED AT 1006 PM EDT MON MAY 25 2015

TWEAKED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...

VFR CONDITIONS AT THE SITES ARE EXPECTED TO DETERIORATE TONIGHT.
FORECAST SOUNDINGS AND SREF PROBABILITIES INDICATE POTENTIAL FOR MVFR
CEILINGS AFTER AROUND 5Z AND THEN IFR CEILINGS STARTING IN THE 7-9Z
TIMEFRAME. GIVEN THE AMOUNT OF LOW LEVEL SATURATION AND INVERSION IN
THE SOUNDINGS ALSO EXPECT TO SEE SOME MVFR VISIBILITIES...AND COULD
SEE SOME DRIZZLE DURING THE OVERNIGHT HOURS. CONFIDENCE IN IFR
CONDITIONS IS ONLY MODERATE AS GFS MODEL IS NOT AS PESSIMISTIC. BY
AROUND 15Z TUESDAY GUIDANCE INDICATES SOME IMPROVEMENT CAN BE
EXPECTED AND THUS BROUGHT CEILINGS UP TO MVFR. WIND GUSTS SHOULD
RETURN OUT OF THE SOUTH...WITH WINDS 8-14 KTS AND GUSTS OF 18-25 KTS
EXPECTED TO LAST THROUGH THE DAY. ANOTHER WAVE WILL MOVE THROUGH
THAT COULD BRING RAIN AND THUNDERSTORMS TO THE SITES...BUT WITH
UNCERTAINTY HIGH REGARDING TIMING AND PLACEMENT HAVE JUST INCLUDED
VCSH FOR NOW.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JAS
NEAR TERM...JAS/MK
SHORT TERM...JAS
LONG TERM....TDUD
AVIATION...CP

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