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Hurricane Michael's strengthening trend paused Mon. night but resumed Tue. as very strong convection continues to explode near the center & wrap around an eye that's now readily visible on infra-red satellite data. This rapid intensification cycle took Michael to a high end Cat. 3 Tue. evening then a Cat. 4 shortly after midnight & is forecast to hammer the Panhandle Wed. afternoon & evening. This could surpass hurricane Ivan in 2004 as the most severe Panhandle hurricane since at least hurricane Opal in Oct., 1995.
Michael will hit the Fl. Panhandle as a "major" hurricane Wed. afternoon. There is a possibility that there could be an eyewall replacement cycle prior to landfall which is just about the only factor that could at all weaken Michael prior to landfall but even then, Michael would still likely be at least a Cat. 3 hurricane moving quickly inland.
Given current forecast path - SUBJECT TO MOSTLY MODEST CHANGES - centered on the Central Panhandle - local impacts for Jacksonville, NE Fl. & SE Ga. remain as follows (primarily fringe for Jax/NE Fl. but more impactful for SE Ga.):
* heavy rain in multiple bands through Thu. with the potential for 1-3" of rain (not all due to Michael), more in some spots. Far more rain just offshore to the east & over NW Fl. & Panhandle into Ga. closer to what should be the center of Michael. Looks like a relative lull in the rain Wed. due to dry slot pivoting north around the eastern side of Michael's circulation. However, this dry mid & upper level air could also lead to a band or two of strong to severe t'storms late in the day into the evening that could produce strong winds & isolated tornadoes.
* breezy winds - combination of "Michael" to the west & moderately strong high pressure to the north will result in brisk winds out of the SE increasing each day through Thu. averaging 15-25 mph with gusts 30+ mph becoming southerly Wed. night/Thu. morning.... out of the SW Thu. afternoon & evening.... out of the west by Friday while diminishing. Strongest winds will be at the beaches - gusts up to 40 mph.... & from near Lake City to Waycross to Brunswick, Ga. closer to Michael's center where gusts of 50-60 mph or more will be possible Wed. night into Thu. The offshore winds - out of the west - late Thu. into Fri. - will be a surfer's delight but be careful!
* isolated waterspouts &/or tornadoes, especially Wed. afternoon through Thu. morning.
* high rip current risk at area beaches
* minor to possibly moderate flooding - especially at times of high tide - along the coast, intracoastal & St. Johns River & its tributaries due to a combination of strong/persistent onshore flow, occasional heavy rain & an astronomical boost due to the new moon phase. No significant storm surge is expected for NE Fl. & Jacksonville & SE Ga. with this track/intensity scenario.
* I would expect highways, airports & every day businesses to not be harshly impacted by Michael in Jacksonville/NE Fl. & most of SE Ga. Power outages should only be sporadic & not terribly long lasting. Of course, a much different story for parts of the Carolina's, Georgia & the Fl. Panhandle & Big Bend where travel will be severely hampered & power may be out for days if not weeks.
*** Hurricane WARNING/Storm Surge WARNING Fl. Panhandle & Big Bend... Hurricane WATCH coastal Alabama & Tropical Storm WATCH as far south as Tampa Bay & on the EAST COAST from the Fl./Ga. border to Southern S. Carolina coast ***
Experience tells me to be wary of a possible right or east wobble, even turn for a while Wed. afternoon upon Michael's approach to the coast - a combination of friction from land, the approaching upper level trough & very warm water over the NE Gulf. Then Michael's heading should straighten out or become more NE again after landfall, but it's something to consider & something to carefully monitor. While virtually all weather is complicated & difficult to forecast, a tropical cyclone's decay over land is even more problematic. But at this point, the fast moving powerful & large hurricane will likely maintain hurricane status past I-75 in Ga.... & tropical storm status all the way to the coast of Carolina's before exiting back over the water of the W. Atlantic. Pretty remarkable & the result will be life threatening dangers & damage far inland.
REMEMBER: the "cone of uncertainty" is simply & only forecast error & has nothing to do with potential amount of damage or damage swath. Do not get too caught up in exactly where the center might be going. Keep in mind that a more narrow cone simply means a higher confidence forecast.
History - going back to about the mid 1990s - shows we should be wary of Oct. hurricanes given certain conditions which are in place right now - see "Buresh Blog" - Matthew (Fl.) 2 years ago (Sun., 10/07!)... Joaquin (Bahamas & El Faro) in 2015... Sandy (NY, NJ) in 2012.... Wilma (Yucatan &Fl.) in 2005... Mitch (Central America & Fl.) in 1998... Opal (Fl.) in 1995.
Michael has rapidly organized & strengthened over Gulf of Mexico as shear as relaxed, upper level ventilation & therefore outflow has improved over very warm water. The eye has become centered underneath the stronger, more persistent convection that was being sheared to the east.
Global forecast models have come into very good agreement on Michael's intensity - a hurricane - & have come into much better agreement on track - Fl. Panhandle .... & timing differences have narrowed. The GFS is just west of Panama City, a bit slower than previously - Wed. afternoon.... the European is a little east of this track & only a few hours later now, & the UKMET is now pretty much right in step with the two models leaning toward the slightly faster solution.
So it looks like the stubborn upper level high pressure that's been a mainstay the last 6 weeks or so near Jacksonville will indeed essentially protect Jacksonville/NE Fl. & most of SE Ga. from a potentially major hurricane .... BUT stay up to date!!..... AND there will still be potentially significant fringe effects for the local area.
In any case... Michael looks to be a swift moving tropical cyclone which means dangerous impacts will extend well inland. Everyone from Florida to Pascagoula should "hurricane prepare"..... flooding, high winds & tornadoes will occur far inland over parts of Alabama & especially Ga., NW Fl. & the Carolina's (potentially bad news for Florence - wary Carolina residents).
Radar imagery below courtesy South Fl. Water Management District (magenta line indicates NHC Michael forecast track):
Gulf of Mexico:
Yellow is potential tropical storm force winds:
Spaghetti plots for Michael show nice clustering giving increased forecast confidence (it's one of the reasons the cone is so narrow!):
Ensemble spaghetti model plots give us a good idea of the uncertainty & the array of possible outcomes in the coming days:
"Bath water" over parts of the Gulf:
So for movement - to recap..... the long lasting Bermuda high summer-style system over or near the Southeast U.S. - that has brought an extended summertime weather pattern of heat & dry weather to Jacksonville - will be a major player regarding the ultimate track of Michael. At the same time, a deep upper level trough will dig into the Western U.S. Given additional upstream "energy" that has yet to become a part of this trough + the stubbornness of the eastern ridge the last 6-7 weeks, I have a tendency to favor a more western track. Forecast models have generally come around to the solution of bringing Michael to the Panhandle then turning NE & accelerating as the upper level trough becomes more dominant & the ridge breaks down some as Michael becomes absorbed by the westerlies & upper level trough so as to not hang around any one location for too long while moving northeast. That's a two-edged sword: the tornado & wind threat will extend well inland but rainfall - while heavy - will not be as extreme as would be the case with a slow moving tropical cyclone.
Rainfall will be heavy but not necessarily excessive as Michael will be fast moving:
Map below is upper levels (500mb) - European model, 9am Thu. showing the stubborn & important high pressure just off the east coast vs. the deep trough over the Western/Central U.S:
The overall pattern through the first 2+ weeks of Oct. has favored tropical development over the Atlantic Basin. The velocity potential anomaly map below indicates expansive green lines - upward motion - spreading from the E. Pacific into the Atlantic Basin, part of a MJO (Madden-Julian Oscillation) pulse.
Note the secondary peak of the hurricane season in mid Oct.:
Meanwhile... Long-lived Leslie continues to crawl over the Central Atlantic & has again become a hurricane(!). Leslie will stay far away from any land areas as the tropical cyclone turns sharply eastward moving into the Eastern Atlantic where the storm could have some impact on the Azores late in the week/weekend as Leslie finally becomes post-tropical.
AND(!).... tropical depression #15 has become tropical storm "Nadine" over the far E. Atlantic courtesy a strong tropical wave that's moved off the coast of Africa. Dr. Phil Klotzbach says this is the farthest east that a tropical storm has formed so late in the season. This system has virtually no chance to make it across the Atlantic & will soon encounter strong shear causing pretty fast weakening while peeling off to the west over the Central Atlantic steered then by the more shallow trade winds.
Atlantic Basin "tri-fecta": Michael, Leslie & Nadine. In addition... a tropical wave is forecast to develop into an area of low pressure over the W. Caribbean late in the week/weekend with some tropical development possible as the low moves west eventually into Central America. Looks like this system would stay far south of the U.S.
Mid & upper level wind shear (enemy of tropical cyclones) analysis (CIMMS). The red lines indicate strong shear:
The Atlantic Basin.....
Water vapor imagery (dark blue indicates dry air):
Deep oceanic heat content is seasonably high over the Caribbean, Gulf of Mexico & SW Atlantic as one would expect early in the fall....
Sea surface temp. anomalies:
SE U.S. surface map:
Surface analysis centered on the tropical Atlantic:
Surface analysis of the Gulf:
The E. Pacific remains active....
After becoming annular, hurricane Sergio - still with a broad eye - is gradually giving in to increasing shear & cooler sea surface temps. Having put on the brakes, Sergio has turned sharply northeast & will accelerate. Eventually the tropical cyclone - or its remnants - may affect parts of Mexico, the Baja & Southwest U.S. late in the week/weekend when a deep upper level trough sets up shop over the Western U.S. & shoots Sergio to the northeast.