754 FXUS63 KGID 080005 AFDGID AREA FORECAST DISCUSSION National Weather Service Hastings NE 705 PM CDT Tue Jun 7 2022 ...Aviation Update... .DISCUSSION...(This evening through Tuesday) Issued at 400 PM CDT Tue Jun 7 2022 The main concern in the near term forecast is the probability of strong to severe thunderstorms impacting the forecast area this afternoon and evening. Visible satellite imagery shows cumulus across the area and a boundary moving from north to south toward the Kansas-Nebraska border. As a note, cloud cover has limited our ability to warm up today in many areas which may put a dent in a bit of the severe weather potential. Environment is fairly unstable right now and mid-level lapse rates are expected to be around 8+ C/km through the evening. Additionally, 0-6km bulk shear values of around 45-55kts, and 0-3km bulk shear values around 30-40kts will support supercell development with the potential for some bowing segments or a semi-disorganized line of storms forming. Large hail up to at least two inches in diameter and wind gusts up to 75 mph will be possible. Additionally, an isolated tornado cannot be entirely ruled out. Another topic of concern is the potential for heavy rain and flash flooding. Soil saturation is a concern in several locations due to heavy rainfall over the past few days. Precipitable water values are expected to range from 1.00-1.50 inches through the course of this event. Additionally, moisture is being advected into the region. One to two rounds of storms may move through a few areas, bringing heavy rainfall areas that have received a decent amount of rain. Any additional heavy rainfall raises the concern for flash flooding. A Flood Watch will be in effect beginning this evening and continuing through Wednesday morning for Furnas, Harlan, Phillips, Rooks, and Osborne counties. Light winds, moisture in the area and cooling temperatures may result in the development of some patchy fog overnight. Expect some reductions to visibility in areas where fog does occur. Wednesday brings a welcome break from the rain for those who have experienced flooding. A mid-level ridge moves across the Rockies and Bighorns into the region. High temperatures will be fairly pleasant, ranging from the mid to upper 70s. Lows will be in the mid to upper 50s. Thursday brings our next chance for showers and storms as a mid- level wave moves across the area. A few storms may become strong to severe. Temperatures will be in the mid-70s to low 80s for highs and the mid-50s to low 60s for lows. Friday and Saturday have trended drier as a ridge moves in from the west and high pressure sets up over the south. Through the weekend, temperatures will be on a gradual warming trend with highs returning to the upper 80s to low 90s in the afternoon. Uncertainty grows in the extended forecast over the potential for a few isolated thunderstorms. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday) Issued at 705 PM CDT Tue Jun 7 2022 General overview: For the majority of the period, high confidence VFR ceiling/visibility and dry conditions. The BIG exception will be right away this evening, as particularly sometime during the 01-04Z time frame features a decent chance of thunderstorms (possibly severe). Aside from any thunderstorm-related influences/outflow, winds should not be a major issue, with sustained speeds largely near/below 12KT throughout, initially out of the east-northeast this evening, and then prevailing north- northwesterly through most of the period (especially Wed daytime). Thunderstorm potential/timing: By far the main concern of the period is a decent chance for thunderstorms this evening, possibly severe. Have a generic "vicinity" (VCTS) going through 06Z, but have confined a TEMPO 01-04Z to account for the MAIN window of opportunity for storms. Should any storms be severe, hail to 1+" diameter and/or 50+KT gusts cannot be ruled out, but actually realizing either of these conditions at KGRI/KEAR is still a fairly low probability scenario at this point. Ceiling/visibility: Although ceiling and/or visibility could at least briefly become sub- VFR during thunderstorms this evening, confidence is reasonably-high that at least the vast majority of the latter 18 hours of the period should prevail VFR. There are various "hints" that at least brief MVFR ceiling could develop especially within a few hours either side of sunrise Wednesday, but with confidence only medium at-best have gone with only a scattered low cloud group. There is probably also a non-zero chance for light fog/sub- VFR visibility late tonight/early Wed, but believe there should be just enough of a northerly breeze to hold sub-VFR at bay. && .GID WATCHES/WARNINGS/ADVISORIES... NE...Flood Watch through Wednesday morning for NEZ082-083. KS...Flood Watch through Wednesday morning for KSZ005-017-018. && $$ DISCUSSION...Wekesser AVIATION...Pfannkuch