While it has been rather calm hurricane season so far but with the Hurricane season now underway it is a good time to look at the Hurricane Saffir- Simpson scale.
History
The scale was developed in 1971 by civil engineer Herbert Saffir and meteorologist Robert Simpson, who at the time was director of the U.S. National Hurricane Center. The scale was introduced to the general public in 1973, and saw widespread use after Neil Frank replaced Simpson at the helm of the NHC in 1974.
The initial scale was developed by Herbert Saffir, who in 1969 went on commission for the United Nations to study low-cost housing in hurricane-prone areas. While conducting the study, Saffir realized there was no simple scale for describing the likely effects of a hurricane. Mirroring the utility of the Richter Magnitude Scale for describing earthquakes, he devised a 1–5 scale based on wind speed that showed expected damage to structures. Saffir gave the scale to the NHC, and Simpson added the effects of storm surge and flooding. The five categories are described in the following subsections, in order of increasing intensity but before and after a storm becomes a hurricane there are 1. A tropical depression winds under 38 MPH (note we get storms like that many times in Michigan in the late fall) 2. Tropical storm winds of 39 to 73 MPH. Some of our fall storms can reach winds of this force as well. And in summer thunderstorms there can be winds of more then 75 MPH even here in Michigan.
Category 1
Category 1 winds of 74 to 95 MPH. Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days
Category 2
Category 2 winds of 96 to 110 MPH Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks
Category 3
Category 3 winds of 111 to 129 MPH are described as major hurricanes. Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
Category 4
Category 4 Winds of 130 to 156. Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
Category 5
Category 5 winds of 157 and higher. A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
It is nice to know that we do not have to deal with Hurricanes here in Michigan for the most part. There have been some storms that have brought rain and even some wind this far north but it is not real common.
Yesterday was our first taste of fall here in Grand Rapids with the official H/L of 67/52. That 67 was the coldest high since May 27th and was only the 2nd time the high did not reach 70 or better since May 14th There was a trace of rainfall yesterday the sun was out 26% of the time. For today the average H/L is 77/56 the record high of 96 was set in 1960 the coldest high of 55 was set in 1917 the record low of 38 was set in 1986 the warmest low of 74 was set in 1985 and 1939. The most rainfall of 1.64” fell in 1983.
The overnight low so far here in MBY has been 45.
AREA
The overnight low so far here in MBY has been 45.
FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
241 AM EDT SAT SEP 7 2024
KEY MESSAGES
– COOL WITH LAKE EFFECT SHOWERS TODAY, WARMER SUNDAY
– HIGH CONFIDENCE FOR UPPER RIDGING NEXT WEEK
DISCUSSION
ISSUED AT 240 AM EDT SAT SEP 7 2024
– COOL WITH LAKE EFFECT SHOWERS TODAY, WARMER SUNDAY
IT FEELS LIKE FALL OUT THERE WITH THE 500MB TROUGH AND 850MB THERMAL
TROUGH DIRECTLY OVERHEAD. THE COLD AIR ALOFT COMBINED WITH WATER
TEMPS IN THE LOW 20S C IS GENERATING ENOUGH INSTABILITY FOR A FEW
LAKE EFFECT RAIN SHOWERS. SHOWERS WILL INCREASE IN COVERAGE OVER THE
NEXT FEW HOURS THROUGH MID MORNING AS A LAKE BREEZE DEVELOPS AND
INCREASES LOW LEVEL CONVERGENCE. SHOWERS THEN DIMINISH LATER TODAY
AS THE TROUGH AND ASSOCIATED COLD AIR EXIT AND WARM AIR ADVECTION
BEGINS. HIGHS WILL BE IN THE 60S TODAY AND CLIMB TO NEAR 70 SUNDAY.
LAKE EFFECT CLOUDS WILL DIMINISH TONIGHT AS INSTABILITY DECREASES,
WITH LOW-LEVEL MOISTURE ADVECTED FROM THE NORTHWEST BRINGING MOSTLY
TO PARTLY SUNNY SKIES SUNDAY.
– HIGH CONFIDENCE FOR UPPER RIDGING NEXT WEEK
THERE IS GOOD MODEL AGREEMENT IN THE EVOLUTION OF THE FLOW REGIME
NEXT WEEK, WITH THE UPPER LOW LIFTING OUT AND BEING REPLACED BY
ZONAL FLOW EARLY IN THE WEEK. THIS IS FOLLOWED BY RIDGING ALOFT BY
THURSDAY IN RESPONSE TO AN UPPER LOW DIGGING INTO THE NW CONUS.
SENSIBLE WEATHER WILL FEATURE A LONG PERIOD OF DRY WEATHER WITH
TEMPERATURES MODERATING TO ABOVE NORMAL DURING THE MIDDLE OF THE
WEEK.
Nice post, Slim. I recently read an article about the lack of Atlantic storms this season. It appears that the experts were horribly wrong in their predictions and they just don’t really know why.