108 FXUS63 KIND 011702 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 102 PM EDT Mon Nov 1 2021 ...Updated Aviation Discussion... .Forecast Update... Issued at 1017 AM EDT Mon Nov 1 2021 Going forecast appears to be mostly in good shape, although with temps running a few degrees below forecast across the northwest and a good midlevel cloud deck on its way in per satellite imagery, did lower max temps a bit across that portion of the forecast area. Also nudged up wind gusts this afternoon slightly per BUFKIT soundings. Remainder of forecast is largely left alone. Models, including CAMs, continue to advertise potential for a few showers, primarily late in the day into this evening across the south with a broad upper level disturbance. && .Short Term...(Today through Tuesday) Issued at 255 AM EDT Mon Nov 1 2021 Surface analysis early this morning shows strong high pressure over the northern plains states. A deep low was found over NE Quebec. This was resulting in cool NW flow across Indiana. GOES16 shows clear skies across the state and dew point temps were in the 30s. Water vapor imagery aloft shows a deep and broad low over northern Ontario...resulting in mainly zonal flow across the United States. Within this flow...some upper level moisture was streaming out of the Rockies as a weak short wave over dropping out of the Canadian plains. Today...models suggest increasing moisture within the column. This appears to be due to the arrival of the moisture aloft over the western plains combining with the arrival of the short wave and associated forcing dropping toward Indiana from the upper midwest. Forecast soundings show a top down saturation today that never really reaches the surface...as dry air remains in place there. Given the cool and dry NW flow in place across the region at the surface...will just trend toward increasing cloudiness today. Ongoing cold air advection is also expected as 850mb temps look to fall to near -2C by 00Z. Thus will trend highs at or below the NBM. Tonight...The passing short wave looks to depart the region. This leads to subsidence aloft as forecast soundings dry out through the overnight hours. Meanwhile at the surface the strong area of high pressure over the plains begins to expand to the east...along with the west to east surface ridging nosing into the Ohio Valley. Thus will trend toward decreasing cloudiness overnight. With dew points near 30 along with clear skies and calm winds...a freeze will be expected in many locations. Tuesday...Broad cyclonic flow remains in place across the Quebec and the northeastern parts of the United States as a short wave within this flow pushes through the Great Lakes. Indiana looks to remain far enough away from this forcing to remain rather non- impacted...with W-NW flow in place aloft. Meanwhile at the surface strong high pressure remains in place along with dew points in the 20s. Forecast soundings remain dry. Thus will trend toward just some partly cloudy skies along with highs at or below the NBM as a cold air mass remains in place with 850mb temps near -5C suggested. && .Long Term...(Tuesday night through Sunday) Issued at 255 AM EDT Mon Nov 1 2021 A broad upper trough will encompass much of the Great Lakes, Ohio Valley, and northeast U.S. for the duration of the extended period as a low pressure system continues its track through the Hudson Bay. Initially, forecast ensembles were trending toward some low precipitation chances around midweek and even next weekend. Any, rain chances will now be well south of Indiana as the trough deepens on Wednesday. And, the weekend Plains system is also trending farther north, keeping rain and the first chance for snowflakes out of the area. Any southward shift in the track of that system though could easily put precipitation chances back in the forecast late in the weekend, will continue to closely monitor those model trends. So, with no rain from the first trough and ridging both aloft and at the surface for the second half of the week, the forecast will be dry throughout the extended period at this time. The main focus instead will be the below normal temperatures in the northerly flow, especially through Friday. Daytime highs are progged to top off only in the 40s from Wednesday through Friday with overnight lows plummeting into the low 20s, which is about 10 to 12 degrees below normal for this time of year. As surface flow shifts to the southwest late in the period, temperatures will increase by the weekend, but still only 50s for highs and low to mid 30s for lows. && .Aviation...(18Z TAF Issuance) Issued at 102 PM EDT Mon Nov 1 2021 IMPACTS: * VFR with no significant impacts anticipated. DISCUSSION: Broken to overcast mid and high clouds are moving in and will persist much of the period. A weak upper level disturbance may produce a few showers, primarily south, but low level dry air may produce virga and chances of impact at any one site are far too low for mention. Winds will be primarily 290-320 less than 10KT, although may be a bit more variable at times. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ Update...Nield Short Term...Puma Long Term...TDUD Aviation...Nield