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
000
FXUS63 KIWX 272349
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
749 PM EDT WED APR 27 2016

.SYNOPSIS...
ISSUED AT 335 PM EDT WED APR 27 2016

RAIN AND A FEW THUNDERSTORMS WILL SPREAD ACROSS THE AREA
TONIGHT...THEN DRYING OUT ON THURSDAY. LOWS THURSDAY MORNING WILL
BE IN THE 40S...AND HIGHS ON THURSDAY WILL RANGE FROM THE UPPER
40S IN SOUTH CENTRAL MICHIGAN TO THE MIDDLE 60S IN WEST CENTRAL
INDIANA.

&&

.UPDATE...
ISSUED AT 748 PM EDT WED APR 27 2016

RAW NIGHT COMING UP AS INTERESTING NR TERM TAKING SHAPE
DOWNSTREAM OF INTENSE DEEP CYCLONE OVR ERN NE. WHILE SFC OCCLUSION
RELEGATED WELL SOUTH FM NE MO SEWD INTO NRN KY...SIG LL THETA-E
BULDGE NOTED UP THROUGH H7 OVERNIGHT INADV OF THIS SYS OPENING EWD
THROUGH THE UPR MIDWEST. ROBUST MSTR CVRG CNTRD NR 850MB WOULD
SUGGEST THUNDER PROBABLE PARTICULARLY WRN PORTIONS OF CWA ALG NOSE
OF 30KT LLJ TWD MIDNIGHT. ADDNLY WK FLW ALOFT SUGGESTS SOME
APPRECIABLE RAINFALL AMTS LIKELY SW HALF ESP WITHIN CONV CORES. ERLY
SFC GRADIENT ALREADY ON THE UPSWING AND WILL CONT TO INTENSIFY AS
UPSTREAM SYS APCHS W/GUSTY EAST WINDS XPCD AFT MIDNIGHT. GENERAL POP
TRANSITION/EVOLUTION OVERNIGHT LOOKS GOOD FOR THE MOST PART BUT WILL
EXPAND CAT MENTION TO ENCOMPASS THE ENTIRETY OF WRN ZONES.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 PM EDT WED APR 27 2016

WIDE BREADTH OF MOISTURE LAID OUT ALONG/S OF I70 CORRIDOR WITH
8-10 G/KG MIXING RATIOS TAPPED BY WARM CONVEYOR BELT OF NEGATIVELY
TILTED CENTRAL PLAINS VORTEX. NARROWING WARM SECTOR PINCHED OFF
SOUTH OF CWA AS SURFACE OCCLUSAL PROCESS CONTINUES OVERNIGHT.
STILL 200-400 J/KG MUCAPE SUFFICIENT FOR TOKEN SLIGHT CHC TSRA AS
BANDED SHRA LIFTS/FILLS ACROSS CWA OVERNIGHT. UPPER LEVEL SYSTEM
CONTS TO FILL ON THU AS IT LIFTS NEWD THEN EWD TO UPR MS VLY/INTO
WRN UPPER GREAT LAKES. SUSPECT ORPHANED LOW LEVEL MOISTURE /AFTER
MID LVL DRY SLOT WRAPS INTO IN/IL THU AM/ TO MAINTAIN SIGNIFICANT
LOW LEVEL CLOUD COVER AND NOMINAL SHRA CHCS THROUGH MUCH OF THE
DAY. HAVE LOWERED TEMPS ESPCLY NORTHERN CWA ON THU ANTICIPATING
THICK CLOUD COVER/E-NERLY LOW LEVEL FLOW.

&&

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 PM EDT WED APR 27 2016

PARADE OF SHORT WAVE ENERGY TO CONTINUE IN THE LONG TERM PERIOD
WITH SEVERAL CHANCES FOR RAINFALL ALONG WITH SEASONABLE
TEMPERATURES. REX BLOCK WILL BE SET UP TO OUR WEST WITH UPPER
RIDGE OVER SOUTH CENTRAL PROVINCES OF CANADA WHILE PARADE OF UPPER
LOWS MIGRATE OUT OF SOUTHWEST CONUS UNDERCUTTING THIS RIDGING.

FIRST WAVE WILL BE WEAKENING AND OPENING AS IT MOVES ACROSS THE
LOWER LAKES THURSDAY NIGHT. LOW CHANCE POPS WITH THIS WAVE AND
RESIDUAL MOISTURE AS A FEW HUNDREDTHS COULD BE SQUEEZED OUT
OVERNIGHT. SUBSIDENCE AND SHORT WAVE RIDGE IN ITS WAKE SHOULD
ALLOW FOR A DRY FRIDAY AND FRIDAY NIGHT. CLOUDS MAY BE SLOW TO
CLEAR FRIDAY AND WILL STICK WITH TRANSITION FROM CLOUDY TO PARTLY
CLOUDY. STILL A RELATIVELY COOL DAY WITH TEMPS A BIT BELOW NORMAL
IN THE UPPER 50S TO LOWER 60S.

OUR NEXT WEATHER SYSTEM WILL APPROACH SATURDAY AS SECOND UPPER
LOW IN SOUTHWEST CONUS GETS EJECTED AND REPLACED BY ANOTHER LOW
UNDER BLOCKING RIDGE. IN THIS OFTEN REPEATED PATTERN A THETA E
SURGE IS EXPECTED WITH LEAD SHORT WAVE AND INCREASING LOW LEVEL
JET WHICH SHOULD SPREAD SHOWERS NORTHEAST ACROSS THE AREA SATURDAY
AFTERNOON AND ESPECIALLY SATURDAY NIGHT. DRY EASTERLY FLOW
SATURDAY TO INITIALLY EAT AWAY AT PCPN SHIELD BUT STRONGER SURGE
LATER IN THE DAY SHOULD OVERCOME THE DRY LOWER LEVELS. REMNANT
WEAKENING UPPER LOW TO THEN CROSS THE REGION SUNDAY KEEPING LOW
CHANCE POPS IN FORECAST WITH RESIDUAL MOISTURE ONCE AGAIN.

MODEL UNCERTAINTY THEN INCREASES NEXT WEEK WITH ECMWF DROPPING A
STRONG SHORT WAVE STRAIGHT OUT OF NORTHERN CANADA INTO THE GREAT
LAKES ON EASTERN SIDE OF LARGE RIDGE. THIS CLOSES OFF OVER WESTERN
LAKES LEADING TO COOL AND WET PATTERN. GFS HAS LESS ENERGY COMING
SOUTH AND BRINGS A WEAKER LOW OUT OF THE WEST INTO THE REGION. FOR
NOW WILL STAY WITH SUPERBLEND ENSEMBLE APPROACH UNTIL BETTER
AGREEMENT IS SEEN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 748 PM EDT WED APR 27 2016

VFR CONDS TO START WILL DETERIORATE RAPIDLY AFT MID
EVENING IN CONJUNCTION W/NWD SPREAD/DVLPMNT OF SHRA/ISOLD THUNDER
OUT OF THE MID MS VALLEY. XPC MVFR CONDS DVLPG TWD MIDNIGHT AND
PERSISTING THEREAFTER AS PCPN SHIELD EXPANDS ACRS THE TERMINALS.
RAMPING ERLY GRADIENT WILL YIELD GUSTS AOA 20KTS AFT MIDNIGHT
THROUGH LT THU AM.

&&

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

$$

UPDATE...T
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...LASHLEY
AVIATION...T


VISIT US AT WWW.WEATHER.GOV/IWX

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.