Area Forecast Discussion
Issued by NWS Indianapolis, IN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KIND 310220
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
918 PM EST FRI JAN 30 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310300Z KIND TAF UPDATE/...
ISSUED AT 918 PM EST FRI JAN 30 2015

NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS












USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.