textproduct: Raleigh

WHAT HAS CHANGED

As of 155 PM Thursday...

* No major changes to the forecast with the afternoon update.

KEY MESSAGES

As of 155 PM Thursday...

1) Areas of fog and very low overcast along and just offshore the South Atlantic coast will develop/advect inland and across the ern Carolinas and portions of the cntl Carolinas each morning through the weekend.

2) Very warm to near record breaking temperatures will prevail through at least the middle of next week, with highs around 15-20 degrees above normal and lows around 20-25 degrees above normal.

3) Unsettled weather returns this weekend into next week as a few weak fronts progress into the Mid-Atlantic and Carolinas. The best chance for rain will be Sunday into Monday and again Wednesday into Thursday.

DISCUSSION

As of 155 PM Thursday...

KEY MESSAGE 1... Areas of fog and very low overcast along and just offshore the South Atlantic coast will develop/advect inland and across the ern Carolinas and portions of the cntl Carolinas each morning through the weekend.

Onshore flow, around a persistent sub-tropical high that will extend from near Bermuda to the South Atlantic states, will transport an increasingly-moist airmass inland, such that surface dewpoints mostly in the low-mid 50s F over cntl NC this morning will increase to upr 50s to low-mid 60s by this weekend. This pattern will favor the inland development/advection of fog and low overcast into the NC Coastal Plain and ern Sandhills each morning, with SREF and HREF probabilities that favor greatest coverage Fri through Sun morning, as the aforementioned surface dewpoints maximize. Steady south- southwesterly flow at the surface should mitigate widespread and persistent dense fog, but locally dense fog of less than 1/2 mile will be possible, especially in sheltered locations.

KEY MESSAGE 2... Very warm to near record breaking temperatures will prevail through at least the middle of next week, with highs around 15-20 degrees above normal and lows around 20-25 degrees above normal.

Mid-level ridging atop a surface high centered near Bermuda will extend from the western Atlantic into the Southeast US from today through Saturday, as deep troughing sets up over the Western US. Thus, it will be very warm, with highs in the upper-70s to lower-80s and lows in the upper-50s to lower-60s today through Saturday. A weak cold front looks to cool temperatures very slightly Sunday and Monday, with highs still expected to reach the mid-70s to around 80 and lows in the mid-50s to around 60. Temperatures will then rise back into the upper-70s to low/mid-80s on Tuesday and Wednesday.

KEY MESSAGE 3... Unsettled weather returns this weekend into next week as a few weak fronts progress into the Mid-Atlantic and Carolinas. The best chance for rain will be Sunday into Monday and again Wednesday into Thursday.

There could be enough moisture and upslope flow on the periphery of the aforementioned ridge to produce some isolated showers and storms over the Foothills that trickle into our western Piedmont on Friday and Saturday. A greater chance of rain will come Sunday into Monday ahead of a cold front which appears to weaken as it approaches central NC. As temperatures and dewpoints will be above normal for this time of year, showers and storms will be possible Sunday afternoon into Monday. A few stronger storms cannot be ruled out Sunday afternoon as there appears to be a marginal amount of instability and shear over the region. However, model trends will continue to be monitored as we get closer.

As a few rounds of shortwave energy look to move over the region on Monday and Tuesday, showers with a few embedded thunderstorms will continue to be possible both afternoons. The potential for additional showers and storms will increase again Wednesday into Thursday as another cold front looks to approach the region. However, ensemble guidance is still suggesting a wide range in the timing and strength of the frontal passage and the associated mid- level low, so details remain unclear at this time.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

As of 100 PM Thursday...

Flight categories have improved to VFR at all terminals with only localized areas of MVFR cigs, which should continue to lift to VFR over the next couple hours. SCT to BKN 3-6k ft cumulus and light gusty southwesterly winds will prevail until around sunset. Development/advection of VLIFR/LIFR stratus is once again expected tonight into Fri morning and most probable at FAY and RWI where local enhancement from marine layer advecting inland. Less confidence exists at INT, GSO, and RDU; more aggressive guidance suggests the regime of radiation/advection fog that developed over GA and central/western SC this past morning may develop farther north and affect the Triad terminals after midnight. Confidence is too low to include in 18z package at this time. Where sub-VFR conditions develop should be slow to lift, but scatter by 15/16z.

Outlook: Areas of fog and/or stratus will likely develop over the ern Carolinas and portions of the cntl Carolinas each morning through the weekend. Additionally, a weakening frontal system will settle into cntl NC, with an associated likely probability of convection and flight restrictions, on Sunday.

CLIMATE

Record High Temperatures:

March 5: KGSO: 81/1967 KRDU: 83/1967 KFAY: 87/1976 March 6: KGSO: 78/2022 KRDU: 82/1967 KFAY: 86/1918 March 7: KGSO: 81/1974 KRDU: 85/1974 KFAY: 84/1961 March 8: KGSO: 83/2000 KRDU: 87/1974 KFAY: 87/1974 March 9: KGSO: 81/1974 KRDU: 84/2009 KFAY: 87/1974 March 10: KGSO: 78/2016 KRDU: 81/1974 KFAY: 84/1974 March 11: KGSO: 86/1967 KRDU: 85/1925 KFAY: 87/1925

Record High Minimum Temperatures:

March 5: KGSO: 61/1976 KRDU: 65/1976 KFAY: 63/1976 March 6: KGSO: 64/1967 KRDU: 64/1967 KFAY: 65/1961 March 7: KGSO: 63/1956 KRDU: 64/1956 KFAY: 65/1961 March 8: KGSO: 57/1946 KRDU: 60/1946 KFAY: 63/1961 March 9: KGSO: 61/1921 KRDU: 61/1921 KFAY: 62/1980 March 10: KGSO: 58/2016 KRDU: 57/2020 KFAY: 65/1964 March 11: KGSO: 62/2016 KRDU: 63/2016 KFAY: 63/2016

RAH WATCHES/WARNINGS/ADVISORIES

None.