Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 KIWX 201027
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
527 AM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO SENSIBLE WEATHER CONCERNS THIS PERIOD AS LOW LEVEL RIDGE REMAINS
ANCHORED ACROSS THE REGION. UNFORTUNATELY RIDGE LOOKS TO REMAIN
DIRTY WITH LITTLE IN THE WAY OF FLOW/ADVECTION AND LOW SUN ANGLE
HELPING TO KEEP RESIDUAL BOUNDARY LAYER MOISTURE TRAPPED UNDER
INVERSION. THIS AND MID LEVEL CLOUD COVER/ASCENT ASSOCIATED WITH A
LOWER AMPLITUDE SHORTWAVE DROPPING SOUTHEAST FROM IA/NRN MO TODAY
SHOULD SUPPORT A MAINLY CLOUDY PERIOD (POSSIBLY A FEW FLURRIES)
AND A LIMITED DIURNAL TEMP RANGE.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO REAL CHANGES IN LONG TERM ONCE AGAIN AS FOCUS REMAINS ON MID
WEEK WINTER STORM. MODELS CONTINUE TO ADVERTISE SAME LARGE SCALE
SYNOPTIC DEVELOPMENT OF A MAJOR STORM SYSTEM IN THE UPPER MIDWEST
AND GREAT LAKES REGION. DIFFERENCES CONTINUE IN THE DETAILS AND
EVOLUTION OF SYSTEM WITH CRITICAL STORM TRACK AND THERMAL DETAILS
STILL YET TO BE SORTED OUT.

POWERFUL 180+ KT JET OVER NORTHERN PACIFIC NEARING WEST COAST TODAY.
RAOB NETWORK TO LIKELY GET A BETTER SAMPLING OVER THE NEXT 24 TO 36
HOURS WHICH MAY HELP RESOLVE SOME OF THE DETAIL DISCREPANCIES. STILL
EXPECT INITIAL LOW TO DEVELOP MONDAY OVER THE MIDWEST WITH
INCREASING SOUTHERLY LOW LEVEL JET AND MOISTURE TRANSPORT INTO OUR
AREA. THERMAL PROFILES STILL WARM SUFFICIENTLY AND SHOULD SEE ALL
RAIN INTO TUESDAY EVENING. JET ENERGY EXPECTED TO AID IN DEVELOPMENT
OF SECOND LOW WITHIN BASE OF LONGWAVE TROUGH TUESDAY NIGHT. MODEL
DISPARITY CONTINUES WITH TRACK OF THIS DEEPENING LOW PRESSURE WHICH
APPROACHES BOMB STATUS WITH MODELS SHOWING 20 TO 25MB OF DEEPENING
BETWEEN 00Z WED AND 00Z THU. TRACK OF THIS NORTHWARD MOVING SURFACE
LOW VARIES FROM EASTERN OHIO TO WESTERN INDIANA. FURTHER EAST TRACK
WILL ALLOW COLDER AIR TO MOVE IN FASTER AND CHANGE PCPN OVER TO SNOW
FOR GREATER ACCUMS WHILE WESTERN TRACK DELAYS COLD AIR AND LIMITS
SNOW ACCUMS. AS MENTIONED BEFORE WITH THESE STRONG DYNAMIC SYSTEMS
TAKING ON A NEGATIVE TILT...WEST IS BEST APPROACH OFTEN WORKS WITH
REGARDS TO SURFACE LOW MOVEMENT. WILL CONTINUE TO RELY ON CONTINUITY
AND FEW CHANGES TO FORECAST WHICH STILL FITS WELL WITH MODEL
CONSENSUS AND ENSEMBLE APPROACH. WILL KEEP PCPN TYPE AS ALL RAIN
THROUGH 06Z WED FOLLOWED BY TRANSITION TO RAIN OR SNOW BY DAYBREAK
WED THEN ALL SNOW WEST ON WED. DID KEEP RAIN OR SNOW MENTION EAST ON
WED GIVEN THERMAL DIFFERENCES AMONG MODELS. AS LOW DEEPENS AND
GRADIENT TIGHTENS...WINDY CONDITIONS WILL DEVELOP LATER WEDNESDAY
AND WED NIGHT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 524 AM EST SAT DEC 20 2014

HIGH MVFR TO LOW VFR MVFR CIGS ARE EXPECTED TO PERSIST THROUGH THE
TAF CYCLE AS MOISTURE REMAINS TRAPPED UNDER INVERSION/DIRTY HIGH.
DRY/LIGHT WINDS OTHERWISE WITH LOW LEVEL RIDGE IN PLACE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

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





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