Area Forecast Discussion
Issued by NWS Huntsville, AL
Issued by NWS Huntsville, AL
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
46
47
48
49
50
629 FXUS64 KHUN 240250 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 950 PM CDT Sun Jun 23 2024 ...New NEAR TERM... .NEAR TERM... (Rest of tonight) Issued at 950 PM CDT Sun Jun 23 2024 Scattered showers and thunderstorms in Tennessee/Kentucky continue to develop and move SE along a couple of pre-frontal trough axes ahead of a primary cold front further north. This cold front appears to extend from northeastern Kentucky into northern Arkansas. Very moist air ahead of this front can be seen in observations with dewpoints in the lower 70s to around 80 degrees in a few spots. This is helping to keep a good amount of elevated and surface based CAPE in place this evening (1000-2000 J/KG) near and ahead of this front. Models seem to be a bit light on 0-8 km shear (15 to 20 kts versus 30-40 kts). Luckily mid level lapse rates are not very strong. Low level lapse rates are still decent (6.0 to 6.5 degrees/km), but not great. All this being said, strong storms look like a good possibility as this front pushes through tonight into the early morning hours. We could see a severe storm, likely mainly in southern middle Tennessee. Good DCAPE values near and ahead of the front can be seen in meso- analysis. Thus, the main threat with any severe storm would be strong to damaging winds. It will be a very warm night, based on several models actual movement of the main cold front southward. Many models show this front only moving into southern middle Tennessee by 7 AM. With such high dewpoints already in place ahead of this front, lows will likely only be able to drop into the 71 to 75 degree range in many locations (maybe not even that low since winds may stay between 2 and 6 mph overnight in many locations). Shower and thunderstorm chances were raised due to increased shear seen in upstream soundings. The pooling of such high dewpoints also will help to keep instability in place much of the night. However, given the fairly weak nature of the lift, kept chances only between 30 and 50 percent towards midnight into the 2 to 4 AM period. && .SHORT TERM... (Monday through Tuesday Night) Issued at 236 PM CDT Sun Jun 23 2024 Northwest flow aloft will persist into Monday, but upper ridging will begin to push back into the region for Tuesday. Although, this will be short-lived as an upper shortwave looks to move over the Mississippi Valley and towards the Tennessee Valley Tuesday night. At the surface, the cold front that brought low chances of showers in the near term will move to our south. High pressure will build in behind it and progress southeastward over the Appalachians through Tuesday. Overall, no rain chances are anticipated Monday through Tuesday evening. Very low chances (10-15%) of showers return to northwest Alabama and portions of southern middle Tennessee late Tuesday night into early Wednesday morning ahead of a system slated to move through the area on Wednesday (discussed in the section below). It will be hot early next week as high temperatures are expected to reach the mid to upper 90s. Continued elevated moisture will cause "feels like" temperatures (heat indices) to be in the mid 90s to around 100 degrees on Monday. It`ll be a bit warmer on Tuesday, with heat indices forecast to reach the mid 90s to around 102 degrees east of I-65 and between the upper 90s to around 103-104 degrees on Tuesday (perhaps a few areas around 105 in far northwest Alabama). While these values are below Heat Advisory criteria, we urge caution. Remember heat safety! Wear loose- fitting, light-colored clothing, take frequent breaks in the shade, and stay hydrated! Also, take caution for your pets as well! Be cautious of the hot pavement, make sure they have ample water and shade, and limit their time outdoors. The aforementioned cold front will bring a slight reprieve Monday night, allowing lows to dip into the mid to upper 60s. However, warm conditions return Tuesday night with lows in the lower 70s. && .LONG TERM... (Wednesday through Saturday) Issued at 1255 AM CDT Sun Jun 23 2024 A shortwave and possibly MCS in the central Plains will arrive in the TN valley Tuesday night into Wednesday, which could factor into our temperature forecast which right now says lower to middle 90s. However, PoPs will be increasing to the 30-50% range Wednesday into Wednesday night. Although sustained large scale heavy rain is not foreseen at this point, a few areas of 0.25-0.50 inch totals look obtainable. This will be followed by a weakening frontal passage Wednesday night into Thursday morning. Notice I didn`t even mention the word cold. Southerly low level flow will develop Friday into Saturday, bringing sustained higher dew points in the 70s along with the hot temperatures, thus increasing the potential for excessive heat index values and risk into next weekend. && .AVIATION... (00Z TAFS) Issued at 627 PM CDT Sun Jun 23 2024 VFR conditions will prevail through the TAF period. Showers and storms are currently remaining north of the terminals up in TN, however additional convection development is possible over the next few hours. With low confidence on storms directly impacting the terminals, included them as a TEMPO at this time along with gusts up to 15kts. Lower but still expected to be VFR clouds will slide through with the cold front overnight and winds will become northerly by tomorrow morning. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...KTW SHORT TERM....26 LONG TERM....17 AVIATION...JMS