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
FXUS63 KIWX 261813

Area Forecast Discussion
National Weather Service Northern Indiana
213 PM EDT Thu Apr 26 2018

Issued at 1254 PM EDT Thu Apr 26 2018

High pressure will provide mostly sunny skies, light winds, and
highs in the low to mid 60s this afternoon. A frontal system will
bring a low chance of rain later tonight through Friday night.
Decreasing clouds can be expected Saturday, but highs will only be
around 50. Temperatures will then warm early next week with highs
into the 70s Monday through Wednesday.


.SHORT TERM...(This Evening through Friday night)
Issued at 206 PM EDT Thu Apr 26 2018

Water vapor imagery depicting longwave northern stream trof axis
extending down into the western great lakes this afternoon with
12Z upper air obs indicating impressive 110kt upper jet speed max
rounding the backside. Two short waves rounding the base of the
trof as it slides across the great lakes region will bring a
couple of rain chances to the area late tonight/Friday morning and
again Friday night. First wave remains rather broad with weak
forcing and limited moisture so only a slight chance in northern
CWA. Second wave more impressive as it digs further south into
northern lower Michigan and closes off as 70-80kt mid level speed
max rotates around on the backside. Even with this better forcing
still appears best chances for precip again will be focused over
northern half of CWA Friday night with higher chance POPs but
still a low QPF event with only 0.10-0.15 expected. Increasing
cloud cover in advance of lead short wave will limit cooling
tonight and keep lows around 40F. Break between systems during the
day Friday will allow for some sun and get highs generally
55-60F...but with NW flow will be cooler near the lake. CAA behind
the front Friday night will be offset somewhat by cloud cover and
keep lows 35-40F.


.LONG TERM...(Saturday through Thursday)
Issued at 206 PM EDT Thu Apr 26 2018

A chilly start to the weekend as high pressure over the western
great lakes has our area in CAA on a breezy NW flow with low level
thermal trof bringing 850mb temps down to -6C. Adiabatic
temperature profile to 850mb and low level moisture in 900-850mb
layer will be supportive of an extensive cu field over much of
the area. Highs will only reach around 50F and with wind and
clouds it will feel closer to 40F. Even colder near the
lake...expect a pronounced lake shadow on temps with highs only in
the mid 40s near the lake and extending inland to the SBN area.
Another cold night in store for Saturday night as ridge axis
shifts eastward over our area. Lows will dip into the upper 20s
northeast and near freezing southern CWA. Closed upper low moving
onshore this weekend will establish western US trough and building
ridge over the Rockies and plains. Warmup for our area to follow
as ridging and subsequent height rises spread eastward over our
area and surface high pressure building into the OH/TN valley will
have less windy conditions and bring a pleasant day for Sunday.
Warming continues next week as 850mb temps rising to around 12C
suggests 80F highs within reach. Short wave energy ejecting out of
western US trof will send surface low pressure into the upper MS
valley and southern Ontario Tuesday/Wednesday. Trailing frontal
boundary will be focus for next chances for rain by mid week.
Surface high pressure anchored just off the SE US coast will allow
multiple waves to ride up along frontal boundary mid-late week
and continue rain chances through the end of the forecast period.


.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1254 PM EDT Thu Apr 26 2018

VFR with light winds and a gradual increase in high clouds can be
expected this afternoon into this evening. A cold front is progged
to progress through northern IN tomorrow morning. There could be a
few showers with this feature, though chances are too low for a
mention in the TAF at this time. Winds will pick up out of the wnw
to near 10 knots in wake of the cold front Friday morning.





Visit us at

Follow us on Facebook...Twitter...and YouTube at: is the U.S. government's official web portal to all federal, state and local government web resources and services.