National Weather Service Raw Text Product
Displaying AFOS PIL: AFDIWX Received: 2018-02-14 01:57 UTC
Previous in Time Latest Product Next in Time
View All KIWX Products for 14 Feb 2018 View All AFD Products for 14 Feb 2018 View As Image Download As Text
126 FXUS63 KIWX 140157 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 857 PM EST Tue Feb 13 2018 .SYNOPSIS... Issued at 302 PM EST Tue Feb 13 2018 Much warmer air will continue to overspread the region into Thursday, along with increasing chances for rain, drizzle and fog. This will be followed by a briefly cooler but dry weather period for Friday and Saturday. && .UPDATE... Issued at 845 PM EST Tue Feb 13 2018 Some light precip in the form of some very light sleet/sprinkles has been observed across along and east of I-69 this evening. This precip was in association with axis of strong isentropic lift. Highly sheared upper wave tracking across the Great Lakes add accompanying proximity to right entrance region of 120 knot upper jet have also aided in forcing this evening. Eastward translation of this upper wave will allow axis of stronger warm advection to also shift eastward across OH/western PA late this evening. This will bring an end to light precip (trace amounts) after 03Z across the far southeast. Primarily westerly low level flow remainder of night should keep bulk of low clouds south across the Lower Ohio Valley. Some patchy fog not completely out of the question across far north/northwest where some melting of snowpack has occurred today, but as mentioned in previous discussion, dry nature of low level airmass should largely limit significant fog potential tonight. && .SHORT TERM...(This Evening through Wednesday) Issued at 346 PM EST Tue Feb 13 2018 Plenty of sunshine was allowing temperatures to climb into the upper 20s to middle 30s, warmest where snowpack is non existent (generally along/south of a Monticello to Peru to Lima line. Area of stratus was working north through central Indiana and Ohio and will likely move into southern areas towards evening. Mid clouds also streaming in from the west. The cloud cover and increasing humidity raises challenges in potential of more widespread stratus and fog, especially on Weds into Weds eve as dewpoints climb above freezing and pace of melting increases somewhat. Some drizzle/light rain could materialize as limited lift begins to arrive ahead of the first rain maker arriving for the start of the long term. In terms of temperatures, lows will fall back into the middle to upper 20s, with highs Wednesday climbing above freezing and likely well into the 40s in most areas outside of the deeper snow pack. Guidance would suggest gridded highs are too high (by a few degrees) over the snowpack, but despite the cloud cover do think we will end up somewhat warmer and will leave previous forecast untouched. Hydro concerns will be handled in a separate portion of the discussion. && .LONG TERM...(Wednesday Night through Tuesday) Issued at 346 PM EST Tue Feb 13 2018 Depth of warm air and moisture will increase into Thursday night with subsequent ramp up in pops as moderate amplitude trough moves quickly out of Kansas Thursday morning and into the Ohio Valley Thurs ngt and Friday. Most significant QPF would still appear to well southeast of the area, but everyone should still see between a tenth to nearly a half inch with highest amounts SE. Impacts hydro wise discussed below. High pressure will build in across the area by Friday night, persisting into early Sunday bringing dry conditions. Much more significant trough will dig into the Four Corners region to allow for a rapid return flow out of the Gulf that will set the stage for much warmer temperatures and an extended period of precipitation, mainly in the form of rain. Challenge will be how how long Bermuda high will be able to hold back the main trough ejection. Luckily, greatest precip chances are outside the forecast period, but precip chances exist starting late Saturday night and especially Monday and Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 632 PM EST Tue Feb 13 2018 With high pressure to the east, southerly winds continue to push warm, moist air into the region. High clouds will continue into the first portion of the overnight and low level moisture will be able to overtake the low level dryness especially as we head towards daybreak at both TAF sites so look for MVFR CIGs to begin after midnight and continue into Wednesday. The other thing that bears watching will be if we start to see any fog form towards the end of the period as low level moisture comes in. && .HYDROLOGY... Issued at 346 PM EST Tue Feb 13 2018 Moisture content of the snowpack across the area varies greatly with even lower snow depths holding a fair amount of water (5 inch snow depth here with just over 9 tenths liquid). Getting a few water eq readings in the deeper snow pack of 1.5 to possibly as much as 2 inches of water. Expecting significant loss/elimination of snowpack in areas currently under 6 inches of snow by Thursday and likely at least further compaction of snowpack further northwest. Always tricky as to exactly how much water will release and expected QPF from Thurs ngt rainfall of tenth to quarter inch will just add to the content. In the SE QPF will approach a half inch and maybe a touch more by Friday. At this point, expecting any river response to be limited to action stage with "flashier" sites possibly reaching minor flood stage for a period. With colder temps moving back in for a few days, think any release will be slowed. Return to warmer conditions will get rid of any further snow pack late in the weekend into next week. To further complicate things, extended period of rainfall is in store with PWATS increasing to well over an inch across the area with each round of rain in the later part of the forecast period and beyond likely to become heavier to set the stage for more significant flooding concerns. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...Marsili SYNOPSIS...Fisher SHORT TERM...Fisher LONG TERM...Fisher AVIATION...Roller HYDROLOGY...Fisher 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