Hurricane Center goes code red on two Atlantic systems


UPDATE: Early forecast models for the Caribbean low pressure system, which was designated Invest 93L by the National Hurricane Center Saturday afternoon. (Credit: NHC)

Forecast development areas for Invests 92L (right) and 93L. (Credit: NHC)

National Hurricane Center forecasters got out their red markers on Saturday to announce a high chance of tropical development for each of the two areas of disturbed weather in the Atlantic.

Model wars continued between the European (ECMWF) and NOAA’s GFS, the latter of which has changed its forecast track for the low in the western Caribbean from Texas/ Mexico to the Florida panhandle. This is echoed by the Canadian (CMC) — the Rodney Dangerfield of tropical forecast models, which doesn’t seem to get much respect among weather professionals and amateurs alike.

But it’s interesting that the CMC has been the most consistent with the Caribbean low in keeping it in the Eastern/ Central Gulf of Mexico and spinning it into the northern Gulf Coast.

On the other hand, the gold-standard ECMWF still projects that the Caribbean low will slide across the Yucatan Peninsula, into the southwest Gulf and eventually make its way into Mexico or Texas.

The question is whether the ECMWF will begin trending east to catch up with the rest of the pack or if the others will see the errors of their ways and join the European in supporting the system’s western march.

On Saturday morning, you could be forgiven for thinking that it was much ado about nothing, since the showers and storms in the western Caribbean seemed to lack any organization at all. In fact, the heaviest rainfall was occurring south of eastern Cuba and near Jamaica, with very little activity near the coast of Central America.

Nevertheless, NHC forecasters give this area a 70 percent chance of becoming a depression or tropical storm by around mid-week. In their Saturday morning Tropical Weather Outlook, they did expand their red cone of development area a bit to the northeast, probably in deference to the GFS.

As for Invest 92L in the Central Atlantic, this system also earned an upgrade to a high chance of development — 70 percent — although some of the tropical waves behind it looked more robust.  (Development chances were downgraded to 60 percent Saturday afternoon). Most forecast models show 92L eventually rolling across the Caribbean and approaching the Yucatan, although a couple of outliers take it over Cuba or Hispaniola.

At this point, nothing suggests a threat to Florida from 92L.

If the western Caribbean low can manage to get its act together sufficiently this weekend, it will be tagged Invest 93L and then we’ll get the benefit of some of the more specific hurricane models, such as the HWRF.

The National Weather Service in Key West sums it up: “Still a tale of two camps between the 00Z ECMWF & GFS, which present different impacts given the associated track of low pressure yet to develop. In the case of the ECMWF, the model subsequent model runs continue to develop low pressure near the Yucatan and then move it more northwestward across the Yucatan Peninsula into either the Southwestern or South-central Gulf of Mexico.

“In this case, the best confluent bands of heavy showers and scattered thunderstorms could only graze the Lower Keys with heavy rainfall, with most of the heavy rainfall moving by to our west. In the case of the GFS solutions, the lower pressure that eventually develops, does move more north northwestward towards the Yucatan Channel and into the Southern Gulf. This scenario allows deep moisture and good confluence bands to move across Central and Western Cuba and to across all of the Keys. So we would include potential for locally heavy rainfall.”

Eastern Atlantic waves

Is this June — or August? Strong tropical waves keep emerging off the coast of Africa, more typical of late summer. (Credit: NOAA)


LONG-RANGE: Will the Florida peninsula start to dry out over the next week or so? That’s still the picture painted by National Weather Service forecasters in Miami, who say a strengthening Bermuda high and an intrusion of Saharan air will hit the shut-off valve on nature’s rainfall faucet — at least for the East Coast — by late next week.

In the meantime, rain chances remain in the 50-70 percent range through mid-week, before falling to around 30 percent by Friday night.

The last week of the month may kick off a pattern change to drier July weather — if there are no tropical surprises.

Friday’s storms brought up to 2 inches of rain along parts of the East Coast from Broward County all the way up to Volusia County. The Tampa area received about an inch, according to the Community Collaborative Rain, Hail & Snow Network.



Author: jnelander

Freelance writer and editor

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