Area Forecast Discussion
Issued by NWS Hastings, NE
Issued by NWS Hastings, NE
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
41
42
43
44
45
543 FXUS63 KGID 212146 AFDGID Area Forecast Discussion National Weather Service Hastings NE 446 PM CDT Tue May 21 2024 .KEY MESSAGES... - Can`t rule out additional showers and a few non-severe thunderstorms across mainly the southwestern half of the area late this evening/tonight...but chances for most areas are low (20-30 percent). - Wednesday looking to be a pleasant day, with winds of 10-15 MPH, mostly sunny to partly cloudy skies, and highs in the mid 70s. Much of the overnight hours look to be dry, but a few showers/non-severe storms may clip far western areas. Confidence in these chances is not high (20 percent). - Our next shot at potentially more widespread (and unfortunately potentially severe) thunderstorms returns Thursday evening- overnight, and our entire coverage area (CWA) is currently under an SPC Marginal Risk (level 1 of 5). - Compared to the previous forecast, there are a few more dry periods beyond Thursday night (including Friday daytime- night), and although there are still intermittent thunderstorm chances over the weekend, at least for now any severe threat appears to remain relatively low. - Peeking ahead to Memorial Day (Monday), current indications point toward a somewhat cooler (highs only upper 60s-low 70s most places) and mainly dry holiday. That being said, we are carrying small chances for rain showers...but NOT thunderstorms...as the airmass looks to be seasonably-dry and stable. && .DISCUSSION... Issued at 445 PM CDT Tue May 21 2024 -- CURRENTLY... After a hectic overnight period, a brief early morning lull, then yet another round of thunderstorms mid morning to midday...things have been relatively quiet this afternoon. Aloft, upper air and satellite data show the region under north- northwesterly flow, set up on the backside of a low pressure system/trough axis moving from NE/SD into IA/MN. Satellite imagery also showing another shortwave disturbance sliding east along the WY/CO border this afternoon. Activity last night had pushed the brunt of instability east- southeast of the forecast area, but as the last round that developed over central portions of the area pushed further east, enough lingered (and deeper layer shear was sufficient) that a few storms became strong to severe...but fortunately didn`t take too long to push off to our east. At the surface, we sit on the backside of the main surface low over IA and southward extending cold front into OK. Gusty northwest winds continue area-wide this afternoon, with gusts at times near 40 MPH. While temps for most locations looking to fall just a little short of expectations, the fact we are getting a little bit more sun will help readings recover...at 3PM most of the area are in the low-mid 60s, with upper 60s further south. Expecting the rest of this afternoon to remain dry. -- THIS EVENING ON THROUGH WED NIGHT... Overall no notable changes were made to the forecast through tonight. Expecting dry conditions to continue on into this evening, but do have some small chance precipitation chances (mostly 20-30 percent) returning later this evening/overnight. That above mentioned upper level shortwave disturbance currently over WY/CO is expected to continue pushing east with time, with models in generally good agreement showing roughly the southwest half of the forecast area having those better chances of precipitation. Can`t rule out a few thunderstorms, but models showing little instability overall. Winds are expected to taper off with time tonight and turning more westerly, as the pressure gradient weakens with higher pressure building in. Cloud cover also gradually diminishes...and overnight lows tonight are forecast to drop into the mid 40s to low 50s. Wednesday looking to not be too bad of a day across the area, with the forecast currently dry until late Wednesday night when another weak disturbance may bring another round of precipitation to mainly western locations. If anything models have trended back with that potential, so forecast chances are low (20 percent). Expecting partly cloudy to mostly clear skies...and winds remain on the lighter side (10-15 MPH) as the surface pattern across the area remains on the weaker side...westerly for much of the day but turning more southerly by evening. No notable changes were made to forecast highs, which are in the mid 70s. -- THURSDAY DAYTIME-NIGHT: Although the primary daytime hours (before 7 PM) are not guaranteed dry, it should be a mostly dry day, with only some spotty (probably non-severe) thunderstorm potential during the afternoon. The main daytime story will be stronger south winds (sustained 15-20 MPH/gusts around 30 MPH) drawing in increasing low-level moisture (dewpoints back well into the 50s to around 60). High temps will also climb roughly 5-7 degrees warmer than Wed, with most areas aimed a few degrees either side of 80. Things look to turn more active during the evening-overnight (particularly post-sunset), as a vigorous shortwave trough drives out of the Northern Rockies into the Dakotas/northern Nebraska, in turn driving a fairly strong cold front southeastward across our CWA. Although still a few days away, we are already under a Marginal Risk of severe from SPC...which looks reasonable given current NAM/GFS expectations of 1000-2000 J/KG CAPE and 40KT of deep layer-shear. Given the fairly strong frontal/low level forcing, and as supported by the far end hours of latest 18Z NAMNest, we are probably looking more at a complex or line of storms tracking through, as opposed to more discrete supercells, but again, we have a few more days to pin down details. -- FRIDAY DAYTIME-NIGHT: This entire 24-hour period is now a dry forecast, as we experience weak shortwave ridging in between upper waves. It does however looks like a cooler and breezy day (out of the northwest), with highs only mid 60s to low 70s. -- SATURDAY-SUNDAY NIGHT (the weekend): Intermittent thunderstorm chances return to our forecast, as at least a few separate upper disturbances look to track through our region in renewed active flow aloft. While at least a low- end severe storm threat cannot be ruled out at this time range, current model instability progs and CSU Machine Learning severe forecasts suggest only a lower end severe threat at worst (at least for now). High temps mainly 70s. - MONDAY-TUESDAY (including Memorial Day): Overall, this looks like a mainly dry period (especially Tuesday as upper ridging takes hold), but our forecast for the Memorial day holiday does currently contain some low-end rain shower chances. At this time, instability appears very meager, and thus have pulled any thunderstorm mention at this time. Plenty of time for adjustments, but for now this Memorial Day looks to be on the cooler side of "normal" (highs a few degrees either side of 70), with breeze north-northwest winds. Temps then trend up a bit for Tuesday (mainly mid 70s). && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1133 AM CDT Tue May 21 2024 The EAR AWOS is OTS as of this TAF writing, so will carry AMD NOT SKED for the EAR TAF. Over the next few hours expect -SHRA, I am thinking the -TSRA chances are diminishing, so will drop VCTS mention at this time. The winds will be gusty this afternoon with gusts into the upper 20s to the low 30s. The winds will taper off this evening and become more westerly. Clouds are expected to move off by mid-morning tomorrow. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ DISCUSSION...ADP/Pfannkuch AVIATION...Beda