Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 181130

Area Forecast Discussion
National Weather Service Northern Indiana
630 AM EST Sun Feb 18 2018

Issued at 320 AM EST Sun Feb 18 2018

A very wet week is ahead with warm temperatures just down the
road. Highs will climb to near 60 Monday, and then even warmer
Tuesday with highs near 70. A rainy period from Monday into
Wednesday will cause rises on rivers with flooding on many. In
addition to river flooding, areal flooding is also likely
particularly over low lying and other flood prone areas.


.SHORT TERM...(Today and Tonight)
Issued at 312 AM EST Sun Feb 18 2018

Moisture will begin to surge northeast tonight as large scale
lift increases. Rain will develop by late tonight and spread
northeast late. Temperatures will begin to rise overnight in
response to very strong warm air advection.


.LONG TERM...(Monday through Saturday)
Issued at 312 AM EST Sun Feb 18 2018

Rounds of rain are ahead this week which will cause hydrologic
issues. Rainfall amounts of 3 to 5 inches are likely by the end of
the week as moisture continues to surge northeast. Several factors
continue to be very supportive for moderate to occasionally heavy
rain for an extended period. Precipitable water values will rise
above 1.3 inches at times which would top the climatological
values for this time of year. NAEFS/ensemble mean precip water
forecast values exceed the 99.5% percentile/climate for close to
48 hours from Monday afternoon into Wednesday, indicative of the
potential for an extreme event. An analog from Feb 29 to March 5
of 1976 produced 5.45 inches of rain at South Bend. WPC is
supportive of of heavy rainfall with widespread amounts this
upcoming week of 2.5 to 5 inches. After coordination with
surrounding offices, have updated the Hydrologic Outlook that was
initially issued yesterday morning to highlight flooding concerns
from these rainfall amounts. Highs Tuesday may set records and
have the potential to top the highest temperature so early in the


.AVIATION...(For the 12Z TAFS through 12Z Monday Morning)
Issued at 624 AM EST Sun Feb 18 2018

Difficult aviation forecast continues. Satellite shows back edge
of clouds right on top of KSBN. However, areas that have cleared
across IL and NW IN are seeing rapid drops in VIS with light winds
and saturated lower levels along with rapid radiational cooling.
This problematic at KSBN with clouds not moving much. Expect
partial stratus and fog development along this edge so KSBN should
fill back in with MVFR and likely IFR given persistent hires
guidance trends. LIFR not out of question as upstream dense fog
begins to advect northward as low level flow backs this morning,
per HRRR trends. KFWA remains in middle of stratus deck and not
much improvement indicated until this afternoon when low level
winds become more southerly. Clearing and VFR short lived tonight
as next wave and warm front rapidly advance toward the region.
MVFR conditions late in period with rain and lowering cigs.




SHORT TERM...Skipper
LONG TERM...Skipper

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